*See our Hi-Fi Blog page
lots of New Sections since Jan 2017 that add a wide range of Hi-Fi & Tech related subjects plus opinion on Hi-Fi News 1970-1980 as we read through.
CLASSIC HIFI: Revived, Restored, Upgraded & Reviewed.
Over 200 Vintage Amplifiers Reviewed
Covering mostly 1963-1978 but others from 1956 to 2007. Reviews of Vintage Receivers. Reviews of Vintage Amplifiers, Reviews of Vintage Valve Amplifiers, Reviews of Vintage Tube amplifiers. Vintage Amplfier Reviews Ranked against other amplifiers & receivers. What is the Best Pioneer amp? What is the Best Sony amp? What Amplifiers Upgrade Well? What problems do some Hifi amps always get? Which are the Best Looking Stylish Amplifiers. Why do I keep asking questions?
Classic Vintage Hifi deserves your Respect. It Looks Great & Sounds Great. Aged dusty amps can be Revived & shown to Better Anything Modern & with a Retro Style.
Reviews of Amplifiers & Receivers mostly 1963-1978 & a few later. Rated by Direct Comparing with many others based on Aux input only. Vintage & Valve amps interest us, Post 1980 & huge 500w Amps are not our Bag... We are in the UK & our site covers amps mostly sold in the UK or Europe, though some Amps not available in the UK made it to the UK via Army-Navy stores exports.
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ON THIS select45rpm WEBSITE FROM 1950s TO 1980s
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**See the "How We Decide The Top Amps" Page** for Many More Thoughts On Hifi
>>> PAGE INDEX IS BELOW...
This Page Reviews Vintage Amplifiers & receivers that we have had to try out.
THIS PAGE IS ALL OUR RESEARCH! ©2011-2024
For other ones we researched for our needs but haven't tried yet... see the OTHER AMPS page.
We see others rewriting-quoting our unique research as their knowledge in many places, even ebay guides do, it's how the internet is: one good site can spawn a million ideas. Ignore the copycats who pretend they are 'experts' for their egos, read it here & be sure we update our sections regularly. Despite this blatant 'taking us as fact' by Hifi Sheep, there are no false amps or red-herring info deliberately put to show up these that can only copy. Go ask one of these copycats for more info & see what part of our page they plagarise next! Are we bothered? If we were, we'd delete the lot! But read the Copyright notice above...
What Does This "Top Amps" Page Mean? Is Audio Still Important?
As Technology advances with i-everything & everything ultra-portable, Audio Sound Quality has sadly been almost forgotten. Super HD pictures but most TVs still have crappy built-in speakers like they did over 30 years ago. The junk you see on the Gadget Show that they rate as "Excellent Sound" is laughably sad. How many actually connect their TV to the Hifi? It's not so easy now as Phono sockets aren't on most TVs but you can use a Scart to Phono on the TiVo box or a DAC. So today's technology usually ignores Hifi Quality, mumbly TV programmes we have trouble understanding even played loud on Hifi. People actually do understand Vintage Hifi sounds more pleasant to listen to & even some budget 1970s gear of 15w will be a nicer sound than just about anything modern that has a cold emotionless sound. You read on ebay they tried it out, like the sound yet are still selling it. We are entirely self-taught with our ideals of Hifi Sound & it's been many years in the learning, you don't perfect your ideals overnight. This page is us initially randomly getting any amp that appealed to see what it was like & after many hours of comparing, a ranking of Amplifiers can be made. You'll never find any of this in a quick Shop or Home demo & we've been using Headphones only to get the amps sounding right, without the blurring that Loudspeakers in a room adds. Hifi rating is far more critical on Headphones. After that, spealkers get tried as Speaker matching gets another page as not all amps match all speakers, see our Loudspeakers page. The ideal in Hifi is a sound so effortless it seems surreal, no harsh edges, no rough treble or boomy bloated bass. A tranquil Summer afternoon by a Riverside or a brash annoying visit to a big City is the difference. That lazy Summer afternoon isn't tame though, it's fresh & natural with the lowest amount of artifact. You can pick out a fieldmouse rustling through the undergrowth or a jet plane searing through the sky with a sonic boom, all clear to be heard. And yet today's Audio is heavily compressed & simplistic to suit playing through a Mobile Phone tiny speaker. How far from Audio Reality it has gone? The best Hifi can deliver so much more. It can awaken your Weary Soul. Some of the amps in our page can come close to this & even nearer after upgrading. Plenty below we recommend. But upgrading is not for the newbie to jump into without years of Hifi learning. Please don't experiment on collectable & wanted Vintage Amps, go play around with cheap 1980s ones.
There Is No Perfect Ideal Amp.
After having & reviewing over 200 amps, there are a Good Amount of High Quality Ones. The pre 1974 ones we clearly prefer by the amount shown, if Getting Them to be "Excellent" can take a lot of work. Some Cheeky Sellers with a Sony TA-1120(A) or Trio-Kenwood KA-6000 we see misquote us saying they are the Best, if this can clearly be seen as an Expensive Job to get there that puts a cost reality on Vintage Hifi. To use them as original may not be possible now as too aged. Well worth the spend if it's what you can afford. These two are the first higher power Integrated Amplifiers from 1965-67 & 1969, before that the Receiver was generally more powerful. Realising the Rebuild costs have ended the hype as similary we saw with the Yamaha CR-1000, if you'll still see this one very overpriced. The Basic Fact is Vintage Amps pre 1980 are failing now, they are always tired as unserviced even & going faulty, especially after decades ignored, if still being used unaware how far from 'Sounding Good' they are. It's like Running a Car into the ground, rather than Respecting it to get it redone. But as you can see there are a lot of Quality Amps from 13w to 160w. Some still can be useable if hoping for a Daily User from 1969 is a bit optimistic. Many Hifi Fans have several amps, they all sound different even with Upgrades. Depends what sort of Sound or Power you're after. Proper Bass is lacking in nearly all amps, to read some love their Thin & Bass-Weak later 1970s amp shows they've not tried pre 1974 gear. We keep getting Amps & Receivers we've not tried before. Takes good research to find there are more to be worth trying plus hidden gems that need a deeper look to see they're worthy. 1965-1973 is certainly the Best Era for Hifi, if it's the Japanese made ones that lead the way, based on the USA ones from just pre 1965. Some UK brands like Rogers & Leak are still good if much is too budget or Quad's ideas to only suit the ESL speaker. Past 1974 you'll still find ones in the earlier style sounding good as well as those overdesigned ones with too much circuitry that limit the sound. There is Good & Bad design amid ones quite similar. Up to 1978 there are still good amps if by 1979 & into the early 1980s too many generic ordinary amps plus the risk of ICs in power amps. ICs in Phono & Tone seem ok, but the Op-Amp type later ones are too far from our interest. Many worthwhile amps out there. If we don't feature it. maybe we've just not had one yet.
Please Don't Just Read This Page Like It's A Shopping List Without Understanding Why...
We did get messages asking for two amplifiers often in 2017... We only want the Trio-Kenwood KA-6000 & Sony TA-1120(A)... How do you know they are what you want? KA-6000 is from 1969 & is 48 years old, the TA-1120 is from 1965 & is 52 years old and the TA-1120A is from 1967 & is 50 years old. These are very old amps. They need a Full Rebuild to be anywhere near how we rate them. The cost of Rebuilds on these puts many off now, these are not cheap to get into. Buy them raw & aged, they'll not be much good unless you get one of the late run ones from c.1971 before they were ended. From our page hits, the majority of page hits are just looking for The Best Amps. Best according to what criteria? Read our site deeper & find out. We've found ones asking for those 2 amps have barely read a thing on the site & tell us they'd still need to hear it. Have you even heard any amp pre 1979? We don't think many just going for the same few have, you're just picking off the obvious ones unaware of what you are doing even. Stop Looking For Easy Answers. There is no Perfect Amp on this page, though there will be plenty that are right for you. Could be a 1966 18w amp, a 1969 45w amp or a 110w 1978 amp. Do Your Research, read our site more. No other Hifi site gives as much info as we do, it's there For You To Read, so Educate yourself. We do get messages wanting a chat on the phone, they've not read a thing clearly as we've got all the info & more on these pages, have a good read. You Need To Try A Few Amps To Find Your Best. Just like in life looking for a Partner. To go for the obvious ones may not be what you need. Read our Blog page, lots more opinions of the Amps we play ourselves. Yes, we had both the TA-1120 & KA-6000 amps ourselves as Reference Amps. They look very nice with wood cases or side panels & the matching tuner, they are Reference Amps. BUT... they need A LOT of work done to rebuild them to be the Quality we go on about. They are NOT perfect, they are NOT the last word in Vintage Hifi. We play them sometimes but other amps are on the Speakers more often, if mainly as they are ones more recently here. (TA-1120 we've since sold, KA6000 is hugely upgraded, see 2021 blogs). We still upgrade the KA-6000 but keep the TA-1120 'original' beyond recapping & transistors, it could improve more, but it's a good Reference to hear one still as close original-to-the-design as possible. Prices on TA-1120 are currently overpriced & this is getting readers thinking these amps are the best there is. No they aren't really & to get into one isn't cheap. To buy either usually from the USA with shipping & import charges could be a £400-£500 buy. To fully rebuild the KA-6000 or TA-1120A to a high standard by us will cost you in excess of the buy price, not far off double what we put to buy one from the USA. Add up the figures. But you've never heard any amp like this, but do you still want to jump in? We do say for those not aware of Vintage Hifi, buy one of our cheaper recapped-upgraded amps on our Sales Page to see what it's all about. SPEND TIME & read our site more than just the Review pages as you won't have much idea of what Vintage Hifi is about. A rebuilt TA-1120A might sound awful on your speakers, we say one bad match with just that amp on the Loudspeakers page. 50w isn't enough power to drive Low Sensitivity Loudspeakers (86dB or less), you'll be pushing the amp into Distortion. You'll think you've wasted your money by buying a great amp that's not suitable for your needs. We can play 18w amps to a good volume on 95dB sensitivity 15" speakers. How big are yours? 6" or 8" bass drivers with 84dB sensitivity? Then 50w isn't enough power for you. Read the site for more info.
Why Do People Want Old Hifi? Isn't New Better?
We had the VM guy bring a new TiVo as the old one had issues. Takes time to set up so to have a chat. This guy is clearly a technical type & is older than us. "Why do people want old hifi? Isn't New better?" he asked. We were a little surprised at that, if perhaps he is trained in general electronics as in 'Book Smarts' rather than vintage crazy upgrades doing things few try like is how we do it & we certainly get delighted buyers. Why Old is better is for the lack of tight budget constraints, pricing to the penny to be competitive is one. All Hifi is made to a price & usually to be Good Enough, but not too good so you don't buy another one in a few years. We bring out the Best from Amplifiers by Upgrading which is strictly Custom Work. Early Transistor designs like the 1965 Sony TA-1120 & 1966 Akai AA7000 are luxurious price no object designs made from scratch based on Valve Amp designs. Those two amps are certainly a few of the best in vintage, if they need a total rebuild to be their best, they are over 50 years old now. For the mastery of the designer, a pure sound is possible, with huge effortless dynamics. Treble so pure, Midrange so effortless & Deep Bass. The Sony & Akai look great too as money was spent on making them look great, the Akai especially is probably the first "Designer" Hifi & should be heralded as an important Design, but it's been forgotten.
Us & The Recent Growth Of Vintage Hifi
Before we started doing these pages, Vintage Hifi was still sleeping. Initially we just had One Page in 2011 covering Old Record Players but then started getting Old Amplifiers & Receivers. As we've added more and more pages we've seen confidence in Vintage Hifi grow hugely. We take a non-technical view of Hifi making it approachable to a wider audience. This gives potential buyers a Confidence in Hifi they'll consider to buy. Look back at old Forums from 2010 & before & their range is very limited. At the time all that seemed to sell were the big Silver Monster Receivers from 1977-79. 1970s Yamaha especially have grown in popularity because we told the world how good they were & the interest in the 1960s-1975 transistor era was largely unknown until we got these & saw how good many were. We used to look at the TVK site to get ideas of amps to try, if their bias was less on the early stuff we've researched. Forums were difficult as it seems every amp good or average is raved about. Plenty of sites now give data & manuals about Vintage Hifi, the best is HFE, but there aren't many reviewing them. Actually there are None Like Us, this page with it's forever updated opinions on Amplifiers we've had to Service, Repair & Upgrade is Unique, but we do it to Advance The Scene as we like these amps & the sounds they play. Vintage Hifi by it's nature is old, amps we cover are 35-50 years old but can be good for years more use if Serviced. To review them as raw amps, as Serviced & as Upgraded tells much. If we give a confident opinion on an amp & you can read many more pages of our opinion, you'll feel more sure to try it. We heard of a few trying the Sansui 3000A when we first rated it highly & they will only have bought it based on our opinion. We see other sites getting more into the reviewing Vintage, even What Hifi are covering these if Hifi News Ken Kessler was doing his Anachrophile in the Mid 1980s. The prices Vintage Hifi goes for is getting higher if it's still early days, as we used to see with Vintage Vinyl as we helped it grow in the 1990s. If you buy a Vintage Amp based on reading these pages, be sure the amps themselves are grateful you took an interest in them.
Why Do We Like The Pre 1974 Hifi More?
Reading through the Hifi News magazine, it reveals the Marketplace for Hifi exactly as it happened. The HFN mag itself is not really as essential reading as we hoped, not much is reviewed, lots of waffly pointless articles & more beyond Amplifiers. Most of the ads are repeated every month & the LP reviews are 99% Classical which is ridiculously narrow-minded & they are so snobby about Pop. In 1966 the Retail Price Management (RPM) was abolished on Electrical goods, nothing much happened if a growing few Discount Shops were around by late 1968 including Comet who started with just one store. 1969 sees a big increase in Budget package deals & Cheapness is the main virtue, Quality is still there but why buy a £109 Trio KA6000 when you can by an amp of lesser quality & power for £30 or less (1970 prices). These cheap "stereos" are crap we avoid, cheap UK & EU brands & some are Japanese, none are USA, but Japan still makes the Best Stuff. The UK brands are ugly outdated looking 10w or less efforts & you can get amp, speakers & a turntable for £65. a step up from the Radiogram which is losing favour, but for the few of these you see today, they were binned long ago. Pre 1969 the Manufacturers could make quality goods & be sure of getting the prices, but by early 1970 you see 30% discounts even on the Big Brands. The issue of after sales service the shops offered when you paid the full price became difficult, as the public naively expect 30% discount & the same service. By 1970, most bought cheap crap "stereos" and they probably lasted 5 years before they broke & off they went to buy the latest budget junk. This continued into the early 1990s with cheap plastic "systems" until CD changed things. Pre 1970 there still is cheap junk, lots of 10w transistor amps & budget gear, but still a lot of good stuff. The Good Stuff was still around to 1979 & beyond, as there is today, but the mass market cheap disposable junk is the main product. Past 1980 the IC dominates & more cheapness, but as Amstrad & Ratners know, there is a big market for crap as many don't know a taste of better, or can afford it. Today we can cherry pick the past & get amps that would be £2500 in today's money for not much so can taste the Best Of The Past, but to think these 40 year old + items are plug & play is naive, they always need Servicing & Often need a rebuild, if generally people use them raw until they break down. But good amps pre 1974 in general are forever repairable & have far more musical pleasure than even the best 1980s amps. We often think we've found all the good ones, then a surprise good one turns up.
The Hifi We Cover In Our Pages.
We look out for Hifi of a certain quality & age that we can relate to, from knowing it years ago or it being familiar from old Hifi Books, Magazines & having similar amps. There is a huge amount of Budget-Midprice gear plus the UK-EU brands that we have tried a few of, but generally have lost interest fast & tend to avoid it now as it doesn't inspire. To say we are Already Snobby about Hifi perhaps is harsh, but not to say some of these aren't great value, Leak & Goodmans amps are a great start into Vintage, but as with anything, man craves better if he is aware of it being out there, even in theory. As with Records, this is a Vinyl 45s Site after all, the lesser items have faded away, yet the market is still there for them, the rewards are thin for the effort. The amps we cover are Better Midprice to Top Of The Range. This Top Of The Range gear may seem quite low powered compared to later years, but it's the Best Amp of It's Era & it was expensive to buy new & it was rarely cost cut until the mid 1970s. Depending on the Economy, some years got a lot of expensive Hifi sold yet tighter years has people go to the Discount Stores, as they still wanted music of the old one failed. As an example, the busiest years in Hifi in the 1970s seem to be 1977-79, the Disco & John Travolta era so many high priced amps like Yamaha, Pioneer, Trio, Sansui etc sold well. To those who prefer Modern High-End, as in Hifi edging into £10K territory, we don't have much for you here if all that catches your eye is the price. But to forget the Quality of these Vintage Quality Hifi for only being 40w, 75w. Those big 100w+ amps not as sweet sounding as the pure musicality of the Best Ones will generally exceed the Megabucks ones which are designed to be Loud but not exactly Real Hi-Fi. Depends on your attitude really & whether things are beneath you high up your Ivory Tower. Most Hifi Buyers are not willing to spend much more than £200-£500 on Hifi as a look at Amazon shows. The amps we sell best are ones of around 40w-50w with Receivers or Amplifiers both wanted. The better Hifi would be like Pearls Before Swine, but as with anything in life, you need to learn it & experience it to appreciate it's 'betterness' which is difficult as high quality can be at one price, but anything appreciably better can be 5 to 10 times the price. The amps we cover are generally found for under £500 & for ones we Upgrade to Sell, usually done for our own interest, need to be priced right to sell, rather than outprice them as we found selling serviced Leak Delta 70s for over £100 a few years ago, the status of these amps keeps them at a certain level. Some of the Best Vintage as Original or Upgraded, if you heard it & used it at home, you may have been happy paying twice the price for in theory, but you wouldn't have in reality as the market level isn't there yet for there to be the trust to pay £1000+ for anything but those 150w ones. As of typing (2016?), we have two of the same excellent amp, one we spent months fully upgrading just to see how far it could go & how good we are, but the other one to sell we'll recap-upgrade only to a certain level to get a certain price. The reality of what the fully upgraded one should sell for would more than double the price and probably alienate the market as does when ebayers put our Serviced & Upgraded prices on raw amps which ruins the market for months as everyone just copies rather than leads. But the Vintage Hifi market still is very young, not seeing the value translated into their worthy prices just yet, though it has altered a lot since we started these pages. To say we had a big hand in popularising Vintage Hifi in the last few years is fair, with our Pages For The People, rather than the same dry biased 'Book Smart' rhetoric that is usually Hifi writing. Upgrading is very worth the effort, if currently it's still not much understood. Those into spending Big Money on Hifi generally aren't yet interested in Vintage, unaware of just how much more musical some modest amps can be. Where will we go with this next?
OUR CRITERIA OF WHAT IS GOOD SOUND
This site has many pages, if we've put several similar on one page with an Index to keep page counts lower, see the Menu bar as Hifi subjects are wide ranging. Pages we used to have like "The Golden Age Of Hifi" tells about the 1963-77 era, the "What Makes Better Hifi" are sections that used to be on this page explaining what we see as Real Hifi Sound, these are now contained on one page under 'Criteria'. See the "Loudspeakers" & "Advice On Buying" pages. Some of these pages were written a few years ago & we do read through them occasionally to make sure they are still what we preach if so much means some is still 2013-2014 opinion. We read others reviewing Hifi & quickly realise they don't understand the item at all. Your ideas of sound can be way off what others like, some play harsh speakers & love them, some play bass way too loud & thick sounding. Others are hair-shirt wearers & insist on Flat Settings Only, unaware that source Direct is often far from what they think. The best Hifi isn't really "there" as in you don't feel like you are listening to Loudspeakers, in recent comparing of Tannoy Gold 12" & 15" we really could tell a huge difference. Amplifiers can be difficult in comparing as one may be less neutral & leave the most neutral supposedly dull sounding. Then there's speaker matching troubles. Plenty of that on this site, Our Opinions made from Our Research based on the ability to upgrade & redesign as well as know Music very well, this is a Record Sales site after all. We don't bother with flowery language about how some track you don't know sounds, we play some test tracks often on amps & they can sound quite different from amp to amp. Again we favour the Neutral sound, but there is no Sin in using Tone Controls. Knowing good sound takes learning, to see fools selling Brand New Hifi with 5 hours use in the pre 2009 days showed how clueless these people are. You need to live with a Hifi item for a week or two to understand it fully. some amps we keep on our speakers for daily use for just this reason. On high quality big Speakers even a fairly ordinary but Good amp can sound surprisingly good, if it will never have been played with speakers way out of it's league, it shows some modest amps are far better than opinions of ago thought. We do our critical testing, upgrading & redesign on headphones as the finesse once heard on headphones will subtly reveal itself on speakers, if speakers suffer from the effects of the room with reflections smoothing roughness away unless your hifi ears are as tuned to the best quality as we can notice. Smaller speakers with boxy colouration to the sound & gritty treble on cheap tweeters can make even the best amp sound disappointing, as can poor matching. So we only rate 'Original spec' but serviced amps no higher than 'Very Good' for the simple fact many can upgrade to be a superior item. Not just better as superficially more exciting, but of a finer quality. The rest of the write-up will tell you more. The ratings are based on headphone use & to match to a speaker may not be as easy as you want, but our Loudspeakers page explains more.
Comparing to Vintage 'Hifi News' Reviews
Some of these amps get reviewed in the HFN magazine so it's interesting to read the opinions when new compared to us playing them decades later, with the issues of aging often overcome & bettered by upgrading. The trouble with the reviews pre mid 1980s is very little is subjective & there are no comparisons to earlier Hifi which is how the thinner sounding Differential era amplifiers went unnoticed. Here we play 1965-67 hifi to compare with any age of Hifi & as well as upgrading, the later post 1971 just hasn't got that sound that amps pre 1969 have. Many of the amps below aren't reviewed by HFN but other mags will, but we'll only be getting the HFN set. The reviews in any mag pre mid 1980s are generally just descriptive & technical, some technical to the point of wondering who cared or could apply such info to deciding which one to buy. There is no real commenting on how smooth, crisp, natural bass or how wide-deep Stereo soundstage is. This is all subjective & relies on the reviewer understanding music quality for pleasure. Similarly with Vinyl Records, we care about the Music & the Original 45, unless it's important to understand the track, to know who's playing on it or to hear the artist perform it live decades later doesn't interest us.
Ones We've Tried Only Listed Here...
See the OTHER AMPS page for others we looked at 2012-2015 but didn't like or try yet for various reasons, plenty of amps there get a look. We research all amps before trying them, to be sure they are worth a try & to avoid ICs in preamps etc, as you can see below some we had early on were not worth bothering with. There are plenty more on the Other amps page that we look closely at via the circuits if we see one & either dismiss it or try it. We take little interest in accepted opinions that were around on Vintage amps, a few years ago only the Monster Receivers & 100w+ amps got interest, without buyers realising these oversized things don't sound as musical as the earlier ones. Some amps like the Quad 33/303 are often on ebay but we've never liked the amp & have looked deeply into the circuits to prove our opinion right. Others who've not heard the amount of Hifi we have will find items impressive compared to Modern Hifi but not realise how lacking they are. British Hifi we've tried all the main brands but don't rate them as high as the superior Japanese-USA amps & we are a UK based site after all. It's too easy to fill the site with salty comments about how poor much of the overhyped overpriced modern gear, but to highlight the best not the also-rans is the idea. We tried the 2007 Marantz PM6002 to see what it was like, seeing it was mostly transistors. There are many 'sleepers' in the Hifi ranges that we've uncovered & we do have a preference for the 1967-73 era simply as it brings us better amps more readily than later or earlier even. We usually stick to 40w or more but if you are happy with 10w or 20w there may be some early transistor ones that sound as nice too, if in a lower powered way. If an amp stirs your soul & makes you happy listening to it, then it's a good one.
As an idea of where we started with these Top Amps, the first amps we upgraded properly were the Hacker gram, the Leak 2000 & the Realistic receiver. The first amps we sold as Serviced were Bang & Olufsen Beomasters, Leak Deltas & 2000 & Trio-Kenwood 1967-70 era. Then finding these interesting started trying more adventurous ones like Pioneer SX-950, NAD 160, the ill-fated Marantz 1152DC and the Yamaha CR-1000, CR-1020, CA-1000 & CA-1010. The first upgraded amp we sold interestingly was the Leak Delta 75 receiver, the only one of four that survived. These hifi pages only started in 2011 & within a year we'd sold a lot of Serviced amps on ebay, but we avoid ebay now for selling hifi for reasons other sellers do. As some opinions are now getting a few years old, we'll put a year date on the reviews to give an idea of how opinions changed as upgrading got far more intense.
These pages are entirely Our Opinion. We only cover what we are interested in, we have no agenda, no advertisers, no bias & no need to pretend a 700w amp costing £20k is the best when some 'crappy little amp' you all ignored for £30 sounds better than many other transistor amps we've heard. Some people need to show off with overpriced 'status symbol' hifi as with any fool-and-his-money type goods, this site isn't for you therefore, so why reveal your ignorance? We know our pages have helped Vintage Hifi along a lot, together with many other sites listing amp info & manuals. Read the old forums from pre 2010 & see the opinions we've helped alter. Our site is unique as we rate many amps together & upgrade them to be their best, just to see how good they are. We also offer Upgrades & Repairs, see the Menu bar. We don't sell Snake Oil.
Our Amplifier Rankings
These have been rated based on current ideas & can be reassessed, read on... We rate amps as simply "Excellent" "Very Good" and "Recommended" without any reference to out of ten scores now, based as it being Excellent for what it is & amid other similar of the same era,. ie 1967 to 1977. By reading the comments you can see "Excellent" will have ones more Excellent than others, but to avoid the risk of people thinking only a few amps that we know as upgraded are the Best isn't fair to be saying. Our descriptions will reveal the ones of 'higher excellence' than other 'excellent' ones, but once an amp upgraded gets 'excellent' be sure it's a good amp to upgrade & worth the effort of us upgrading. For the fact Amps & Speakers don't all match well, to rate higher than 'excellent' may not be excellent to you if a 1967 amp doesn't match 1992 speakers. Any amp Rated Very Good (previously 'Great' was the same level of quality) or higher is the pick of Vintage Hifi that we've tried. We are based in the UK & so we see UK & EU sold amps, if sadly not enough of the more obscure USA & Japanese ones. Any amp to be featured here must be better than Average. There is no higher rating than Excellent, read the details for more info. When we did give ratings it was based then on the knowledge of only using Transistor amps. If we were to rate them against a perfected Valve Amp it'd be unrealistic as valves are just so much better sounding when done right, but we are now finding the Best Transistor amps are outdoing Valves. Our ratings are taken to be rated against the best Transistor Amps only therefore. A "Recommended" for example, on the rough Pioneer SX-950 is in light of better amps are there for your money, though many buy these big cost-cut amps as they haven't got too deep into Vintage Hifi yet to find better. But even there, we are finding Pioneer were very cost cut & put too many Spoilers in these amps & upgrading them we are finding they are actually respectable amps. With progress in our upgrading we are seeing the levels of Fidelity from Transistor amps get higher, so now the "Excellent" rating is used more sparingly & many are now just Recommended because we do recommend you buy one if it appeals to you. Also 'Average' and 'Hopeless' are used, Average being no better than any £20-50 late 1970s to modern amp. Hopeless are just that awful amps you should avoid.
Japanese & USA Hifi gets the Best Ratings. We are UK based so got to try a lot of UK & imported Amps plus ones that were never sold in the UK but got brought in by other ways. We've been reading the Hifi News magazine from 1956-80 and by 1966 the Imported Hifi of all types, except Loudspeakers are becoming more numerous & the reviewers are liking them, even based on old WW2 ideas, they are seeing the USA & Japanese hifi to be so much better in spec & looks than the UK gear which is being seen as 'Old Fashioned' as brands will not update their drab looks to get Overseas buyers. UK Tuners still only went to 100 or 104 if the EU market wants 88-108 FM range so they limit themselves & it's why many brands vanished between 1965 & 1975. Look at our 'Solds Gallery' the UK amps are not attractive if they are usually no better than Mid Price with Leak & Rogers being the main players. Look at our ratings, UK gear is often 'Recommended' rarely 'Very Good' even when upgraded. We've tried, but the UK & EU stuff is just not as good as Japanese & USA gear. By the late 1980s UK Cottage Industry brands change things as we used to see UK brands like Tube Technology making effort to make attractive valve amps, if their circuits were pretty mediocre & safe sounding, well worth upgrading. We'd Recommend the UK Leak, Rogers, Goodmans & Sugden amps as 'starter amps' but generally the UK gear is pretty average in nlooks & midprice quality. The only UK amp as Upgraded we rated "Excellent" was the Rogers HG88 Mk III, if that's based on our upgrades. For Modern Hifi, the Linn & Naim way of selling ugly limited gear we never liked, a turntable that only plays 33rpm is of no use to us. You could buy upgrades & power supplies & other junk that showed you were being sold lesser gear to need upgrades. Every good amp we get we upgrade to see how good it is. Some we consider the 'higher excellent' were often pretty lousy as original but we see potential in the circuits & go further with upgrading than anyne else would dare. Each amp upgraded is still on a learning curve, to forever learn rathe than think you know it all & be sure we've upgraded amps & found new ideas to think 'wish we had that amp to do that with' and will revisit amps if we find one. The Audio World of today is not really Hifi to us, Hifi being "State Of The Art" and if we can upgrade amps from 1965-66 to get remarkable quality, it shows Hifi design in Transistors was better if they were limited by spec & availability. We only hear the 50 years aged version. Today electrical goods are on the wane, the current 2015-16 'Gadget Show' is full ofg internet & gaming as Tech has been combined so much, what else is there? Audio gear they show is laughable tiny speakers & whether the Linn-Naim way of upgrading is popular in new items probably still is 'yes' as the things still make good prices online. But as with anything, these devoted "i-phone" type blind-followers don't know what "better" sounds like. We hear our upgraded "special" amps that we upgrade for our interest & then sell on are being compared to £20,000+ hifi & be sure the musicality of our creations is always preferred to anything. Comparing 1960s 10w-18w amps to 300w "monsters" the beauty & subtlety of Good Vintage will please the ears more, if "that silly little thing" isn't so silly once upgraded. There are others out there doing upgrades, but we see we are way up the ladder in our research & skills to what else we see. If you want a taste of our "sound" some amps we buy may be sold cheaper as condition issues, if the amps sound great.
We Grade our Hifi across the board with a 1963 amp rated equally against a 1977 one, no going easy on any amp here, but not Daring to go Higher than "Excellent" which is equivalent to "First Class". We aren't bothered by commercial bias or are here to massage egos on ones we don't like, though we hear many happy readers who've taken our word on an amp & been delighted by the amp. This is the intention of this, to get the Hifi Scene realising how many "Sleepers" there are in Hifi. Before we started these pages, we used to see the same High Powered amps making big prices but buyers, not knowing where else to try & not wishing to gamble, generally ignored most other Amps. There are many other Hifi sites out there helping us with Service Manuals & Photos of amps inside & out, but you'll not find another that rates amps against each other. Some we've had a while ago now but generally the opinions on what is liked or not is matched on revisiting ones from ago.
Top Rating Is Excellent. Ratings Do Change.
As not to Narrow things too much, 'Excellent' means High Excellent to Just Scrapes an Excellent, as in Rebuilt Ratings. 'Raw Amps' once Serviced can sometimes edge Higher than 'Very Good' if without our Upgrades, can't really call them Excellent. In Nov 2020 as writing his, we're finding a few amps that are pushing the Standards higher, so it's about time Some Amps got Rated differently. Ones pre 2013 we didn't recap unless they had issues, now in 2020 to see Older Amps are failing more will change opinions & if Revisited we'd update. Some of those 'Excellents' need revising, if Upgrades will have bettered over the years, to Keep It Relevant. Read the Review to see a deeper opinion than just a Rating.
Updated: Now Which Are The Best Ones?
For All Original but Serviced amps, the rating "Very Good" is the best you'll get, to rate higher as all original plus being 30-50 years old isn't really possible. If an Amp can be upgraded to sound Excellent, then it wasn't Excellent before, but Very Good shows it's of a good quality & without narrowing things too much. Be sure buyers just go for the Best Rated without any thought if it would suit their needs. Knowing excellence from some amps that have gone further than others. Upgrading as we do is a very different game & from what we know and see elsewhere, no-one has our upgrade skills so we are pretty much alone in this. But it is done to the better amps to see how good they can be & desite rating them "Excellent" there are grades of Excellence but we'll not grade higher to not limit things. But the thing is as our upgrades go further & the more we play valves, to be fair to these amps to rate them afresh as really no amp ever made can really rate higher than "Very Good" & this is reflected clearer now. Our References are in both Transistor & Valve amps.
Ratings based on Headphone and Loudspeaker use.
We use Headphones to test Amps initially & Headphones to get the amps sounding their best. We then use Loudspeakers to see how well the amp can drive our 1967 Tannoy 15" Golds. Some amps don't match our Tannoys too well & this we note on the Loudspeakers page that reveals how well they sounded to us. We sometimes try reliable serviced but Original amps on the speakers to see how they will have sounded when new with the original design. Both Headphones & Loudspeakers are required to really tell how an amp sounds, speakers alone have too much Room Blurring to tell & some amps can sound better on Speakers way ahead of their class, but on Headphones they reveal the weaknesses. Great Amp on Headphones means Great Amp on Speakers less often as not all match the speakers, Using Headphones is a great leveller of how an amp sounds. To use Headphones lets you hear far more of the Amplifier than on Speakers. Amps that may sound quite similar on Headphones can sound hugely different on Speakers, this is due to how well they match. High quality efficient speakers can actually make a fairly ordinary amp sound great, so to be sure to rate them via headphones. One famous brand sounds ok but unexceptional on headphones, but on speakers they initially sounded great, if longer listening revealed the weaknesses. If it sounds great on Headphones, it'll sound great on Speakers, assuming they match. See the Loudspeakers page for more as matching can be tricky. On Headphones, the Power amp drives the Headphones via a Resistor so direct coupling to Headphones doesn't happen which allows for a Level Playing Field, as a 1967 & 1977 amp may sound very different on Speakers for the Matching, or may sound as good. Loudspeakers Are Important Too. All amps we sell are tested on speakers, 1969 Tannoy Monitor Gold 15" ones, to be sure they can drive a speaker & are stable. But to do the main testing & upgrading is done with Headphones & test speakers, we don't try amps on our speakers until we are confident with them. Some amps we have used a few weeks on the speakers before selling as the sound was interesting to us. As you can see from the Loudspeakers page many amps we have tested on our main Speakers to see how they match, just so we can add it to that page. For ones we rate highly, the idea is they sound great on headphones & on speakers. We've never had one that sounds great on speakers but bad on headphones. Some modest amps can sound surprisingly good on speakers way out of their class. Not all amps match, the Differential era ones don't match earlier speakers so well, if only two we've found were unlistenable, but will suit later speakers far better.
Keep It As Original or Upgrade It?
Since 2016 we only Upgrade Amps & choose ones we think are worth our time to get to work on, plus ones we get from Customers to Upgrade. The 'Collector' scene in having 1960s amps in Original Condition like Museum Pieces will be looking for unopened boxes, not used Hifi, so there is no need not to do our Subtle Upgrades & fit 4mm Speaker Sockets as the buyer wishes, if we'll only fit 4mm Sockets to look good, some of the spring connectors are too narrow spaced to look right. To look Professional & realise a new owner may be in the future & not do jobs we don't see suitable just to do it, we'll say it'd not look right. There are some early amps that are more Collectors' Items than Hifi for Modern use. We've kept a few amps as All Original for Reference for a while, but as with the National-Panasonic SA65 we soon found it needed recapping as the sound was louder on one channel, but to recap-upgrade it but leaving the rest as Original as it's such a strong reference. Another one we like, the Trio-Kenwood KA-6000 we'd never upgraded originally, but did get the receiver equivalent TK-140E and X to see the sound it could bring, but in the end upgraded the KA-6000. In the future will there be a tiny want for 'Survivor' amps as there is with Vintage Cars, the Chasing Classic Cars series has highlighted this, but be sure no Car or Amp from 70 years ago will be fully original as parts perish, capacitors being the issue with Hifi. No 1932 high voltage Electrolytic Capacitor still works but in our Pye G/GR Gram the smaller value ones are still working, if probably off spec, but it's not for Hifi use. To upgrade a Car to bring the best out of it we see a lot on TV, putting a brand new engine in a 1960s Corvette will make a better car but for some it's too modern. But whatever is done to Cars or Hifi, to keep it working & being appreciated by new people is the thing as they'll cherish it when we're dust. We'd not be happy if our 1932 Gram stopped working even being pretty mediocre as it is now, it'd be made to at least work. As an opportune advert for Our Upgrading Service, all we do is done to keep things as original as possible, even if noticeable parts could be bettered, the Charm of Original Parts beyond electrolytics is important. The Sony TA-1120A keeps it's kooky red capacitors is an example. Another one is if the amp had black or grey main capacitors, we'd not put bright blue ones in that show through the grille. In watching Car shows on TV, we like the Restore to Original ones, allowing subtle upgrades like Mike & Edd do, but the Hot Rod-Custom scene is awful as they butcher cars that should be left original looking, if perhaps the market for them is way less than the ugly thing they create thinking it's cool... But with all Vintage Hifi pre 1972, if you want to use it regularly, it needs to be recapped or failures could be expensive to repair. Past 1972 to 1980 you can probably still use the capacitors if the amp has been serviced, but be sure it can be bettered by recapping & upgrading. Some amps are better made than others & some have been used & stored differently to have aged differently. Only once you've heard aged amps rebuilt will you understand how tired & lifeless they can sound.
IMPORTANT: These ratings are based on a Serviced & Adjusted Original Spec Amp
Most vintage amps are raw out of storage & will sound very different to the point you may think they are utter rubbish. Only really the late 1970s Monster Amps were used for longer which may mean they have been used a lot more than an attic find that saw 2-3 years use. But it's like a Car, leave it 30 years in a Garage & then try to drive it, only a fool would expect it to be working it's best after a long sleep. Hifi is no different but many just use the amp unaware of how good it could be. As with a Car, bad faults may appear within minutes of first use. Note some amps are unusable through aging of noted failure of capacitors until you fully recap & rebuild them & are not for home tinkerers to be fiddling with, though many do. Most amateur sellers are cautious with valve amps but will plug any transistor amp in without having it checked even. Some amps sound rough & weak until serviced & adjusted. The difference in a few we list below like Yamaha CR-1000, Luxman L-100 & Trio-Kenwood KA-6000 from before & after was very different. On the other end of it, the Leak Delta 30/70 doesn't sound much different serviced or not if in good condition. We're adding in all amps we can remember from over the years & 15-25 years ago these were still used & working items obviously years younger than today, so to rate them is possible. In 1990 a 1972 B+O amp wasn't that old as well as probably still being used, it had not sat in a damp loft for years yet, but they often look very aged inside now.
WHAT GETS THE RATINGS
This means rating the Sound Quality of the Amp & are now done with "AS-ORIGINAL (Once Serviced)" meaning what an original unaltered amp will sound like After Servicing which in certain amps would include required capacitor replacements to get it to work. Any amp unserviced & left unused for decades can sound truly awful so no point grading anything but the Serviced amp. Most people never service amps & it means way more than a squirt of switch cleaner too. "UPGRADED" means what it sounds like done to the best of our skills or how far we chose to go at the time we had it, bear in mind each amp teaches more & our upgrades now are way ahead of some of the earlier ones. "n/a" means we've never upgraded one to any level so won't guess, but assume the amps in the main table will improve to some degree as these are the better amps we've tried. We've not tried all the amps we'd like to yet, so some brands are absent currently. Current ratings are based on current opinions on Hifi which with deeper improvements are more harsh than before, but any "Recommended" are still worthy amps if there is better. Some amps we rated higher early on, only to find better amps to use as Benchmarks for "Excellent". Some of the amps in the lower table that were more borderline have gone into the main one, to be fairer to them, so the Bad Amps table is now just the stinkers. We've been adding in more notable amps we've had over the years that were still clearly remembered so are valid to be adding in with more recent ones.
BETTER THAN EXCELLENT?
To not create too much elitism, 'Excellent' is our highest rating. On one amp, the 1967 National Panasonic SA-65 it previously rated 'Excellent' as original & upgraded. Not that it didn't improve, but as original it was good enough to be 'Excellent' & upgraded in the higher end of Excellent, but that's not too helpful. A 'Very Good' amp genuinely is Very Good. if having heard the 'Excellent' ones there is a difference, especially on headphones. On speakers however a Very Good or Excellent sounds quite similar, we've tried enough on Speakers to know now. In 1980s Hifi we say elsewhere the Pioneer A-400 is considered by others the apparent best amid the awful mid 1980s hifi. Grading Turds is how we call it & similarly at the Top End grading 'Excellent' is indeed possible. But we aren't going to. We find the 1965-69 era most pleasing to our ears, but you can see over our years doing this, plenty of 1970-80 era ones we liked too & do regrade all amps as we find higher quality as per our upgrading. As we hear more amps once we upgrade them, many are settling on "Excellent" but to downgrade them would be wrong, excellence is there for sure as others will agree. But they can be very different in tonal balance as no two amp designs sound identical. A few amps have certainly exceeded others but again we'll leave Excellent as the highest.
LOWER MODELS IN THE SAME RANGE
By 1976 ranges, the Top Of The Line amp we are finding is a bit overdesigned. With Pioneer SX-939, the SX-838 is a better design to us. So you can assume will have similar ideals to the bigger models, but after having tried some, the 20-35w versions will be a smaller sounding amp to keep the level at which distortion sets in within the design. Therefore the lower amp ranges will exhibit some qualities of the bigger amps, but a much more polite small sound as well as the risks of cost cutting with ICs that became common by the mid 1970s. So a Yamaha CR-400 will not sound much like the CR-1000 but will be more like the CR-800 but again the limited power will keep the spec lower to avoid bad clipping as it reaches it's maximums. Now we've had the CR-400 the sound from an 18w amp was much better than expected. In the pre cost cutting era of the Mid 1970s, different models can sound very different amid a range.
BUY-RAW RATING
This means just that. What it'll be like as-found if in nice but forgotten condition assuming there is otherwise no damage to the circuits or other common safety issues. It'll still need Servicing, but the idea is to show amps with known problems beyond general ones. Some amps we've found badly fiddled with or badly repaired regardless of the status of the amp today, so beware. Also some higher power amps of any era got partied hard as well as ones stored in damp conditions can need a huge amount of work to get back to being safe & reliable & sometimes even we give up if it's not financially viable. The (bracketed date) is the last time we had the amp to put our opinions into a time context, as we are getting some again as the Revisited section notes. Some we'll never try again as they aren't the sort to upgrade or were a nightmare to work on.
THE HIFI-COOL RATING
Because we know what Style is in Hifi & have had enough of these amps, to help the scene realise the Beauty in some of these amps, we'll be hedonistic & give them a Cool Rating, like Mike does on Wheeler Dealers: Trading Up. Our tastes appreciate good furniture, cars, advertising signs & retro style so we can give a good idea how cool your amp looks. Receivers with the tuner stages generally look cooler than plain amplifiers, if some amps have a Bachelor Pad style that adds to the Cool Rating. Go read & see if you agree, many are pictured on the Amps We Sold page & when we get a chance, more will be added. As women like vintage items too, generally the ones that score high in our Cool Rating will have high Woman Appeal too. "Come up & see my Cool Amplifier collection, darling" is the new Etchings for the modern-retro favouring male. We started the Best Looking Amps page a few years ago & this is the basis for this. All amps we have on this page we have photos of so to refer to them to remember them in hand is possible. Ratings are 1 for an ugly beast to 9 for the Best Lookers, as with 'Excellent' being the Highest Hifi rating, we don't want to create too much elitism here, a 7 rated amp is still a good one, but 5 is average.
ABBREVIATIONS
To add more to the listings, the design type of the Power Amp: CC = capacitor coupled, SC = semi complimentary, FC = fully complimentary, DIFF = differentials in power amp early stage, Direct Coupled = No Capacitor Coupling. IC = ICs in the main audio preamp, tone or power amp if not noting Phono or Tuner stages. FET = Field Effect Transistor on power amp. PARA = parallel output transistors, this gives more current capability as used on 100w+ amps usually. Relay = On Speaker Outputs. All are Transistor amps unless "Valves" noted.
BE AWARE SOME OF THESE NEED REBUILDING
By 2023, most are getting too Old to just use. Some of these amplifiers & receivers will work to a degree once serviced. But there are some that will need A Full Rebuild-Recap before you should use them. It's because they are getting too old or have known failures & may trash your speakers. Valve amps usually need recapping first, the Quad IIs we had were like new & were still useable, but many are well used & rough. The 1965 Sony TA-1120 is now 50+ years old & generally capacitors pre 1968 will not be reliable. depending on how much use the amp got. A 1967 Sony TA-1120A had an issue since new & was unused but the capacitors were no good. Many UK brands pre 1980 use TV grade capacitors which are failing & leaking. We've had 1967 amps that still work fine but we always recap amps we sell as the life of the amp still using 30-50 year old capacitors can be unpredictable. Just be aware of the work these need, factor in a professional upgrade or if you think you can do it yourself, look how the amp is inside as some are very awkward to work on as well as others are better. We do Rebuilds, Recaps, Repairs & even subtle Redesign. Look around to see who else offers this in Hifi?
AMP AS UPGRADED RATING
This is the verdict based on us upgrading it to some level, some get much more done than others naturally & we've got deeper into upgrading as time goes on. Every amp we've found is compromised by age, low spec parts, weak cost cuts design or deliberate spoilers to hide a better design. To upgrade can be a nightmare sometimes & a delight in others. We read other's opinions of amps & we can see they only know Original amps, not upgraded ones & the comments we read are a little surprising as they seem to accept Rough Sound, Limited Bass & Soft Treble as just how amps are. With our upgrading we find better in every amp we upgrade we know that Transistor amps are only as good as the designer or company wants you to have. Some of our upgrades are very complex now & can reveal the Holy Grail of 'Perfect Sound', a sound that just sounds 'like it should' with zero grain or artifice to hide the sound, but very few transistor amps are capable of this & they are very early ones. But back on Planet Earth, sadly most Vintage Hifi buyers don't even get the amps serviced, so to reveal our opinons of what they'll sound like upgraded is perhaps a very limited market, but for those that are interested, it'll help pick out those to upgrade. Vintage Hifi is still very young & we can see the effect our pages have on the market.
REBUILD RATING
This is worth putting on some amps as we know our pages get a lot of interest & some of the 1960s ones are getting wanted, but the reality is some of these can be big jobs to bring up to the sort of spec we see as worthwhile. You'll find others who'll just use these amps but pre 1972 is 45 years old in 2017 & these are starting to need recapping by default. Ones 1969-72 you can probably still use but they are past their best & you may think it's been hyped. Bear in mind if an amp has an Upgraded Rating then we've Recapped & Upgraded it to know what it's like. Some are expensive jobs as so much needs doing, some are more straightforward if generally these are the post 1972 ones. Buy into Earlier Vintage, but be aware a rebuild will not be a cheap job & anyone offering cheap recaps is doing it badly with cheap parts. Do it properly or not at all. By doing it properly, the amp will be like New in many ways, anything likely to fail in one wek-one month-one year will have been dealt with. As in Vintage Cars, there are no Cheap Jobs unless you want to be forever 'repairing' it.
LOUDSPEAKERS
These are Important to consider if you fancy trying one of our Top Rated amps below. Not all Speakers match all amps. They all can sound quite similar via Headphones due to a big resistor in the circuit between Headphone & Power Amp stages. But a Speaker is directly connected to the Amplifier & certain characteristics of Match or Mismatch two ways are apparent. If you haven't read our Loudspeakers page, you are missing out on understanding that we don't believe anyone has investigated before. Why doesn't my Amp & Speakers match? we can go a good way to answer. In our research we've found most amplifiers match the 1960s Tannoys well, only a few don't quite do it & Yamaha is the most confusing one with CR-800 & CR-2020 sounding Very Good but the CR-700 & CR-1000 being mismatched, the CR-1000 being the worst mismatch we've heard on the 1960s Tannoys. It doesn't matter if it's valves, capacitor coupled or (semi) complimentary, as long as the ampp has enough power it'll sound good. But again, the 18w 1966 Coral amp sounded great.
AFTER 1977: AMPLIFIERS & RECEIVERS
Very few amps are worth trying in the "Modern" Era of 1978 onwards & especially the Black Fascia era from 1982 onwards. It's just that these Amps sound Boring & Uninvolving: Musically Dead, as well as Rough compared to the Best Of the Golden Era 1965-1977. With any year from 1965 to 1977 there are plenty of Mediocre amps but plenty are Really Very Good Ones as you can see detailed. We've tried quite a few of the 1978 onwards amps & only really two stood out as better with only one rating as good as the early ones. We'd like to tell you of other quality Amps in the later years, but we just aren't finding any. See out OTHER AMPS page to see we aren't just being Narrow Minded with Hifi. For the Fact that Modern Amps sell for Higher Prices usually based on Hifi Magazine "reputations" often where a 5* amp was loved but then another comes along that is "so much better" and gets 5* too does get the idea of Hype.
The Stinkers Parade in Hifi..
We've included the few HOPELESS amps in the main list, we wadted our time & money on them so why not tell the reality that plenty more amps we haven't looked at may just be lousy too? To show not all vintage are worthy to warn readers of bad amps. These were got in our first few years of doing this site, used, some recapped & improved but quickly sold as we didn't appreciate them much & to learn the hard way to know what's best avoided. Seeing these awful amps still sell on ebay shows that people aren't Googling. These we did rate as Mediocre or Poor, but the idea of grading Turds is a bit pointless. The idea is these are amps we didn't like for lousy or boring sound or poor quality construction. There will be plenty more bad or lousy amps out there from early 10w Germanium Transistor Amps to the glut of post 1979 low powered silver & black fronted amplifiers of no real quality made for the mass market & pretty much disposable. The Leak Delta 75 actually sounds good, but is so unreliable we have to help stop wasting money as we've had 4 now & only one survived. Other amps can be poorly made & we do note this, but never one as bad as the Delta 75. Some brands that others like are actually ones we avoid now, Bang & Olufsen are poorly made with cheap components, the money is spent on the styling. We keep looking at UK & EU amps but for our 1963-1980 era there just don't seem to be any we like enough to try, not even Revox please us. Quad we think are overrated, plus more, see the Other amps page for more.
*SEE HI-FI PHOTOS: HI-FI GALLERY
PHOTOS PAGE We've added many pages of photos of the actual amps we had & were taken as they were sold. An unique archive of Serviced, Cleaned & sometimes Upgraded amps with many photos inside & out. Most of those below are pictured. The page gets updated irregularly.
*MORE AMP REVIEWS
OTHER AMPS- More Reviews page for others we looked at but didn't like or try yet for various reasons, plenty of amps there get a look.
*Our CRITERIA for Good Hi-Fi SoundDECIDING TOP AMPS is from when we rated amps in a list, if it covers Our ideas of What Makes Good Hifi, including many sections moved from this page to ease this long page.
*NEW PAGES: Hi-Fi Blog since Jan 2017HI-FI BLOG PAGES is growing every month with new Articles covering what we see in Hi-Fi plus what the 1956-1980 Hifi News/RR magazine brings up of interest. A LOT of sections Indexed covering all Hifi Related Subjects including "Other Amps" that we have looked at. The Main Pages beyond Reviews don't get added to now & the BLOG is a Catch-All.
RECENT ADDITIONS in order added since Jan 2014
1970 Sony STR-6850 receiver, 1975 Teleton TFS-70 receiver, 1972 Pioneer SX-828 receiver, 1975 Pioneer SA-9500 Mk I amplifier, 1969-70, Sansui 5000X receiver (F6013 version), 1967 National Panasonic SA-65 receiver, 1973 Sanyo DCX-8000K receiver, 1974 Pioneer SX-838 receiver. 1970 Pioneer SX-990 receiver. 2007 Marantz PM6002 amplifier, 1969 Trio-Kenwood TK-140X receiver (black label), 1978 Luxman L-1040 receiver. 2004 Prima Luna Prologue 2 (valves), 1969 Sony STR-6050 receiver, 1966 Coral A-550 amplifier, 1969 Teac AG6000 receiver, 1965 Sony TA-1120 amplifier. 1967 JVC Nivico 5010U receiver. 1969 JVC Nivico 5003 receiver. 1974 Heathkit AR-1500 receiver. 1966 JVC Nivico MCA-104E amplifier (germanium). 1979 Technics SU-C01, SE-C01 & SH-C01 pre-power amp set. 1973 Pioneer SA-9100 amplifier. 1984 Sansui AU-G90X amplifier. 1971 Hitachi IA-1000 amplifier. 1972 Harman-Kardon 930 receiver. 1979 Luxman LX33 amplifier (valves). 1984 Sansui AU-G30X amplifier. 1968 Armstrong 521 amplifier. 1971 JVC 5521L receiver. 1965 Fisher 600-T receiver (germanium). 1965-66 Duette SA500W amplifier [germanium]. 1995 Spectral DMA90 power amplifier. 1967 JVC Nivico 5040U receiver. 1963 Trio W41 amplifier (valves). 1978 Luxman R-1050 receiver. 1968 JVC Nivico MCA 104Z amplifier. 1965 KLH 27 receiver (germanium?). 1970 Akai AA-8500 receiver. 1967 HH Scott 334-C receiver. 1966 Akai AA-7000 receiver. 1970 Nikko TRM 1200 amplifier. 1970 KLH Model Fifty Two 52 receiver. 1966 Fisher 440-T receiver. 1968 Dokorder Model 8060 amplifier & 8070 tuner. 1976 Technics SU-8080 (A80) amplifier. 1972 Akai AA-8080 receiver. 1995 Sony TA-FA3ES amplifier. 1974 Realistic SA-1500 amplifier. 1972 Realistic (Hitachi) STA-220 receiver. 1982 Luxman L-410 amplifier. 1979 Sansui G-8700DB receiver. 1974 Yamaha CR-400 receiver. 1970 Sansui AU-666 amplifier. 1972 Realistic (Hitachi) STA-150 receiver. 1973 Sherwood S-7200 receiver. 1972 Rotel RX-800 receiver. 1995 Spectral DMC 30 + DMA 90 power amp. 1978 NAD 3030 amplifier. 1967 Pioneer SX-1000TDF receiver. 1971 Sony TA-2000F preamplifier. 1971 Sony TA-3200F power amplifier. 1972 Rotel RA-810 amplifier. 1968 Toshiba SA-15Y receiver. 1963 Fisher X-100-B valve amplifier. 1979 Luxman L2 amplifier. 1978 Pioneer SX-980 receiver. 1966 Rotel 100AMP amplifier. 1972 Akai AA-5800 amplifier. 1971 Trio-Kenwood KR-6160 receiver. 1973 Marantz 4070 Quadraphonic amplifier. 1976 Marantz 2385 Monster Receiver. 1966 Sansui 3000 receiver. 1977 Rotel RA-1603 Monster Receiver. 1967 Sansui 400 receiver. 1976 JVC JR-S 600 receiver. 2000 EAR Yoshino 8L6 Valve amplifier. 1973 Trio-Kenwood KR-6340 Quadraphonic receiver. 1966 Akai AA-5000 S amplifier. 1966 Sansui TR-707A receiver. 1971 Revox A78 amplifier. 1985 Dual CV 1460 amplifier. 1969-72 Luxman FQ-990 receiver. 1972 National Panasonic (Technics) SA-6400X 4ch receiver. 1974 Yamaha CR-200 receiver. 1973 Trio-Kenwood KR-8340 Quadraphonic receiver. 1974 Yamaha CR-400 receiver. 1977 Marantz 1122DC amplifier. 1966 Pioneer SX-800A (SX-2000) valve receiver. 1970 Sansui 350A receiver. 1971 Hitachi SR-800 receiver. 1965 Pioneer ER-420 valve receiver. 1973 JVC 4VN-990 Quadraphonic amplifier. 1969 Pioneer SX-2500 receiver. 1971 Photax Concertone 333 receiver. 1972 Rotel RX-400A receiver. 1973 JVC VR-5525L receiver. 1971 Trio-Kenwood KR 6170 'Jumbo' receiver. 1971 National Panasonic SA-5800 receiver. 1977 Marantz 1122DC amplifier. 1973 Marantz 4230 Quadraphonic receiver. 1977 Marantz 1090 amplifier. 1972 Trio-Kenwood KR-5200 receiver. 1973 Nikko STA-5050 receiver. 1972 Akai AS-8100S 4ch receiver. 1978 Marantz 1072 amplifier. 1966 Sanyo DC-60E receiver. 1969 Sanyo DC-66 receiver. 1968 Trio-Kenwood TK-140X (Silver Label). 1977 Yamaha CA-610 amplifier. 1971 Sony STR-6065 receiver. 1977 Yamaha CA-610. 1966 Akai AA-5000. 1976 Marantz 2235B. 1973 JVC 4VN-880. 1971 Marantz 2270 receiver. 1968 Fisher 800T receiver. 1972 McIntosh MAC 1900 receiver. 1965 Pioneer SX-600T receiver. 1972 Trio-Kenwood KR-6200 receiver. 1974 Pioneer SX-1010 receiver. 1977 Sansui G-3000 receiver. 1979 Harman-Kardon HK 560 receiver. 1978 Marantz 1050 amplifier. 1962 Lux (Luxman) HQ32 valve receiver. 1966 Trio-Kenwood TK-60BU receiver. 1965 Trio-Kenwood TK-80U receiver. 1968 Trio-Kenwood KA-4000 amplifier. 1966 Nikko TRM-120 amplifier. 1964 Sansui 1000A valve receiver. 1976 Sansui 771 receiver. 1968 Sony STR-6040 receiver. 1969 Pioneer SX-440 receiver. 2016 Yamaha R-S 202 D receiver.
Ones Revisited ... sometimes more than once
1971 Sony TA-1130 amplifier. 1972 Bang & Olufsen Beomaster 4000. 1977 Bang & Olufsen Beomaster 4400. 1969 Trio-Kenwood KA-6000 amplifier. 1973 Yamaha CR-800. 1978 Yamaha CR-2020 receiver. 1971 Leak Delta 75 receiver. 1977 Yamaha CA-1010 amplifier. 1977 Yamaha CR-1020 receiver. 1971 Sony TA-1130 amplifier (again). 1967 Sony TA-1120A amplifier. 1977 Rotel RX-603 receiver. 1974 Leak 2000 receiver. 1974 Pioneer SX-838 receiver. 1971 Sony STR-6055 receiver. 1968-78 Ferrograph F307-20+20 amplifier. 1971 Teac AS-100 amplifier. 1972 Rotel RA 610 amplifier. 1975 NAD 160a receiver. 1970 Philco-Ford M1550 amplifier. 1970 Goodmans Module 80 receiver. 1967 JVC Nivico 5010U receiver. 1968 Trio-Kenwood TK-66 receiver. 1969 Trio-Kenwood TK-140X receiver (black label). 1975 Pioneer SA-9500 amplifier. 1972 Rotel RA-610 amplifier. 1974 Heathkit AR-1500 receiver. 1973 Yamaha CR-1000 receiver. 1978 Yamaha CR-2020 receiver. 1970 Akai AA-8500 receiver. 1968 Sansui 3000A receiver. 1967 Pioneer SX-1000TDF receiver. 1971 Sony STR-6055 receiver. 1973 Yamaha CR-1000 receiver (again). 1971 Teac AS-100 amplifier (again). 1969 Teac AG-6000 receiver. 1971 Sony TA-1140 amplifier. 1966 Akai AA 7000 receiver. 1966 Rogers HG88 Mk III amplifier. 1972 Trio-Kenwood KA-6004 amplifier. 1973 Yamaha CA-1000 amplifier. 1973 Yamaha CR-800 receiver. 1967 National Panasonic SA-65 receiver. 1971 JVC VR-5521 receiver. 1971 Sony STR-6055 (again). 1967 JVC Nivico 5010U receiver (again). 1968 Leak Stereo 70. 1971 Sony TA-1130 (once again). 1972 Akai AA-8080 receiver. 1973 Trio-Kenwood KR-8340 4ch receiver.
AMPLIFIER & RECEIVER INDEX...
click on the item ~~ see the OTHER AMPS page for lots more.
↑ TOP
** Part One, this page, covers 1957-1971.
** Part Two is linked to a new page now & covers 1972-2007
OLD OPINIONS MAY NOT BE CURRENT ONES
The difficulty with a website like this is that it's been written by us since 2011. We've revisited a lot of Amps on these pages to get more updated views, but the trouble in reading a 2014 review is that it was "early on" for us before the level of upgrading & building we do now & having had so many more amps of a much wider range leaves the early opinions a little awkward on re-reading so some Amp reviews have been rewritten from further on down the line. Reviews by 2015 will be more relevant if earlier ones will stay & will show either rare amps that don't turn up but we liked, or lousy ones we didn't like so haven't revisited. For example the Quad II/22 review is based on us having top grade original ones in 2002, this is unlikely to occur as 17 years more aging will make them off spec & the fact we've not fancied trying them again for the issues noted.
**see the OTHER AMPS page for lots more.
1953 Quad II valve power amps + 1958 Quad 22 valve preamp ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 15w Valves.
We had a top grade pair of Quad II, the Quad 22 preamp plus the two tuners in 2002. At the time we got a very high price that it took other sellers over Ten Years to better, as we did very detailed photos at a time few bothered to photo things well. These came with two Garrard 301 white oil turntables & the guy we got it from took them all out of a big cabinet from around 1960-62 that we never saw sadly or the speakers. These must have had very little use & were in excellent grade inside & out. We tried them on the Tannoy Golds and found the preamps quite awful with loud thuds as you switched & oddly Tone didn't give much gain, though it could have been faulty perhaps. The preamp slides about as you press the buttons, only really good for building in a cabinet. The Quad II power amps sounded very sweet but the problem is they need 1.4v for full output whereas most other amps need only 400mV. We got some modern adaptors to plug other amps as a preamp. The sound was always a little soft as the other preamps didn't have the gain. But using with the Quad 22 preamp suffering it's mediocrity actually delivered a very tidy sound but still did lack the quality of later gear. The Quads are just so early & that's the issue. Our Quad IIs were like new inside & out with nothing aged or replaced & the non UK buyer bid hard for such fine items. But as we've stated elsewhere, these top grade ones are Museum Pieces rather than amps to alter & the Quad IIs with the ECL86 inputs actually don't have a proper preamp valve explaining the extra gain the preamp must have. Paired with a high output custom made modern preamp they'd sound much better, but they'd not be ones you'd use daily. Important amps to have known & for their age there are just about no other 1950s amps still bought & being used like these Quad are. Remarkably it's as early as 1953, replacing the 1948 Quad I, says Wikipedia & the Quad II was available until 1970. UPGRADES? The Aug 1970 Hifi News gives ideas for upgrading, losing the EZ32 rectifier valve if making other changes as voltages differ & Nov/Dec 1969 mentions upgrades to valve preamps to get lower noise levels, but suggests adding transistors. Can't say we'd like to lose so much of the originality on these amps, either enjoy it for what it is or sell it to buy something else, rather than start butchering it if it's a high grade all-original one, though if you must alter, get a rough one that needs repainting & has little value beyond parts. BUY-RAW RATING: Many are well used & altered with clumsy connectors added, look out for the high grade original ones to see what the fuss is about. REBUILD RATING: Not one we'd consider to rebuild as so much is more in the Collector rather than User area. With a Valve rectifier your options are limited. COOL RATING: 6 difficult as these are for building in cabinets if the power amps have an appeal, the preamps are awkward. (2002)
1962 Lux (Luxman) HQ32 valve receiver ↑
AS-ORIGINAL (Once Serviced): --. UPGRADED: --. 10w-12w Valves.
100v DC. A very early Stereo Valve Receiver from Sept 1962. This is All Valves with Diodes on the Power Supply not the usual Rectifier Valve, one reason we tried this instead of similar early Pioneer, Trio & Sherwood. The Double Tuner is a very short-lived idea. Ours has FM if only on 76-90MHz, 2x MW tuners to play an experimental MW Stereo that couldn't have been too good as MW top limit is 5kHz or less making Stereo on MW not so good. There are several Lux receivers as one site tells: HQ32, HQ31, HR35, EQ23, HQ33 & HQ34 from Sept 1962 to Sept 1963, some will be like the 1963 Trio WX-400U with a Stereo MPX decoder built in. USA had the GE Zenith MPX FM Stereo since 1961 & this is the one still used today. The Lux saw no UK sales as it was Japan 100v DC only & not for Export. How we get ours is our seller bought it from Japan in 2023. To not get advice from those tiny few who can rebuild Valve Amps & buy such a Rare & Early one isn't what we'd recommend, but that's the joy of bidding online. No Japan bidders & relisted shows little interest in a 1960s Valve receiver as people are aware of the High Rebuild Costs & to get a true 100v step down TX seems tricky, silly ones claiming to be 1kW when they look 100w tops. Why Did We Buy It? We liked the look of it, the photos showed the Circuit Diagram on the base showing it has 'easy' valves & the Diodes to rectify. The front 'Lux' slanted wording seen before so must have seen one of these early Lux before if no info at all, these clearly are very rare. How it survived 'lost' for 61 years until it went online to little interest must just be House Clearing of someone who will have been able to afford the 1962 price of 48,000 yen which by online info says 250,000 yen today which is only £1300 today, if Japan inflation very different to other countries. What's In It? The Output Transformers are a possible 15w version of the 'OY15' ones in the 1979 Luxman LX33 we have, if smaller size in the HQ32, still the same fittings underneath. Power Supply Diodes are the 0.5A ones in the 'Voltage Doubler' style like the WX-400U used. This has a strange "MFB" feature which is 'Motional Feedback' with a circuit defining the NFB circuit via how the Speaker reacts. It seems to Boost Bass as switch on the rear shows. No Headphone socket. Aux Input is via a large resistor as was typical right into 1969 on Sansui. DIN socket Tape records & plays an Open Reel tape machine, with the Tape Play input direct to the Volume Control, after the Tone Control oddly & not switched as in 'Tape Monitor' of today. To think this might not have worked so well if maybe 1962 tape machines were different, as in Recording what you're playing Heedback Howl. Top has three Double Capacitor Cans & one more underneath. Valves are 4x 12AX7 (ECC83) with 6BM8 (200v ECL82) as the Splitter-Main Output Valves "Audio Triode plus Output Pentode" similar to the 250v ECL86 in the Rogers Cadet III & HG88 III. Power Rating unknown, somewhere 10w to 15w, if the 15w HG88 III uses 339v HT, the HQ32 voltage is unknown yet. Has a Mains Choke in the Power Supply. The design of this takes more from the Early USA Receivers than the UK amplifiers. All Japanese components, the front buttons use the same Rogers type ones inside. Going To Plug It In? Our Step Down TX is 110v, this is 100v which means 110v is 10% too high which may not suit the Output Valves as usually Power Output Valves are pushed to their limits & 10% more could soon become unreliable. Finding this one online answering where it came from & to wonder if it's a Wanted Rarity actually shows it workimg on Japan 100v DC with the front lights lit. This means it powers up & won't explode capacitors, as the WX-400U did. To try get a 200w 240v to 100v step down transformer, else it sees no 110v mains & stays an ornament. Needs a good clean up, black dust dirt cleans up well, the cream-white Bakelite front panel could take typical Bakelite techniques to be nicer. What Do You Think Of It Otherwise? It's a Historical Piece, a Collector or Museum piece, if there were any. But there aren't & the rebuild cost will put most off. Looking at the circuits & good Valve Line-up, it certainly would be 'Hi-Fi' & for Japan to make a very sophisticated item as early as 1962 before FM Stereo actually arrived, it's hugely impressive. It uses custom Ceramic square blocks for Resistor & Capacitor use, like the USA McIntosh & Fisher gear does. For so early it'll not quite be what the 1965 Pioneer ER-420 can be, but it certainly could hugely impress to hear what 1962 had to offer. Should You Buy A Valve Amplifier Like This? If you think a 62 valve amp, let alone a 1979 Luxman will be easy to use, then sadly it's not going to happen. It looks well made to have you like it, a good brand name. But we'd not recommend you Buy 1960s Valves without knowing what it'd cost to fully rebuild. Buying 100v Japan gear needs the 100v step down TX. The FM Tuner isn't really much good unless it could be 'slid along' in the Tuning Scake, as in adjust '76-90' range to '88-102' like the UK FM Tuners often were, on Hacker & B+O they never went to '108'. It could be Rebuilt with Upgrades as we did the ER-420, but not a speck of interest on that one on testing the market for it. To get any Valve Amp or Receiver to Use Daily Quality with a decent Tuner on a receiver could really get expensive. Who knows how good it may be even? The ER-420 & it's issues took over 3 years to get right, if we did use it over a week on speakers after 2 years. Valve Amps are lovely when right, but a bumpy & expensive road to get there. Power Rating. Based on the Trio WX-400U & others, to see the HT calculation, as in 145v AC makes 350v DC with the doubler circuit, not quite the x2 & then x 1.404 of theory. 127v AC x (350/145) = 306v HT on the Anode of the ECL82, or the label on the TX says 120v 400mA which is 289v DC HT. The Rogers Cadet III runs on 285v DC & is rated 10w RMS. The HG88 III rated 15w runs on around 330v. ECL82 data sheet says '200v max' but other amps can push the HT by 100v & still be 'Safe'. Finding a 'Brimar' data sheet on the ECL82 shows it can take 600v on the first Trode stage & 900v on the second Pentode stage, but look closer to see 300v & 600v are 'working' voltages, the higher ones allow for Surge voltages on turn on. Therefore HQ32 is a 10w RMS amp with 12w max RMS possible in that old 'Music Power' way. The Rear Panel. This is stamped with the various uses. Phono Sockets are fine for modern Phono cables, not the conical sockets like 1965-66 Sansui used. Inputs are Phono & Aux. Left of these is MPX for FM Stereo use as what would possibly have arrived after Sept 1962. MPX In as L+R with Out as 'S' for Stereo, however that works is unknown without a MPX Decoder. The two badges on the upper half are glued on, the same dried out glue leaves 12 loose rectangular bit from the fascia, here the 'HQ32' label fell off just on cleaning it, this could have been long gone leave an unidentified amp with no serial number. The top 4 screw connectors are Antenna: AM, AM, E & FM, two AM as 2 AM tuners inside. Lower level AC input wire, not marked as 100v as not for sale outside Japan. 2x AC outlets unswitched, Fuse 3A was in it, 4 screw connectors just like the Anenna ones are Speakers. Slide switch for Phase: 'Nor' & 'Rev'. Speaker slider for 8 or 16 ohm. A rotary pot for 'Boost' of Bass in the NFB-MFB circuit. A slider for 'MFB' or 'Nor' means the strange MFB circuit can be bypassed. DIN socket for Tape, Record & Input, this goes direct to the Volume without the later 'Tape Mon' switch. A last slider on the right is FM MPX 'Str' or 'Nor' whatever that does, Strong? What To Do With It. Looking at the Japan sale pictures, the R valve shows as glowing too bright when tried on 100v, photo shows it through the rear grille. There is a fault in the amp, 62 years old after all. To try more therefore.
BUY-RAW RATING: Age will mean the main capacitors are nearly failing as with any 1960s valve amp & there are multi capacitors in two cans to deal with. 100v DC required, REBUILD RATING: Very advanced as redesign needed plus space under is limited. COOL RATING: --. (2024)
1963 Fisher X-100-B valve amplifer ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 15w-24w Valves.
One we got to rebuild for a customer. We've liked the Fisher early Transistor amps 600-T & 440-T as below, so to hear a 15w valve version is a good one to know. Actually the Fisher 1963 book "The Handbook" lists this as a 1963 amp with 24w RMS per channel, so many misleading values & dates on this. 24w RMS per channel is a little vague for early specs is it both channels playing or the one channel playing misleasding one? It sounded like a 15w amp so we'll quote as 15w. 7868 output valves on 435v, the 7868 max 19w plate dissipation. The amp we got was in very high grade like it was NOS unused until 10 years later maybe & it has a later or repro case as the back grille space & mesh is different, if another one found online. Fisher being a Premium Brand & only sold by one London Shop in the Mid 1960s means you'll rarely see UK Voltage Fisher, so this 110v to use a step down transformer is no bother in use. Seeing other aged corroded ones to see this cute one in high grade inside & out with no signs of heavy use is a rarity too. The back Phono connectors are a little odd spaces as L on the top of the chassis & the R on the edge, the L cables near the output valves. quite a small unit, we thought it'd be bigger 400mm wide 146mm high 313mm deep, fascia is 384mm x 122mm, if about the same size as the Rogers HG88 Mk III that the customer considered too, if the Fisher is a looker & more sophisticated in design. So what does a good working one sound lie, all original except the bigger axial capacitor underneath. It's not to a modern upgraded sound, the rich warm Retro bass with limited Treble is noticeable, but to use Tone to alter that reveals it is a sound of quality. It sounds soft & slow, but still very nice in it's 1963 aged way & interesting to hear a 1963 valve amp on original spec as often they are repaired or with issues. Stereo is wide & overall the sound is smooth. Deep Bass won't bother it by the design spec & the slew Rate is modest with peaks played if kept small in size & the L+R balance isn't too even. So it sounds aged, soft, slow but nice. This is the sound that a working Vintage Valve amp will bring, but you may find it's original charms appealing, or you may want more out of it as 15w in valves we found to be the power needed to give a sound a modern buyer would like. Much to upgrade & circuits to learn, but knowing how Valve Amps done properly sound, it'll come to life with our Upgrades. The X-100-B has DC heaters on some stages if there is a background noise once volume is turned up higher with a mostly AC ripple sound for the 1963 spec. Putting the preamp shield & ECC83 cases back on the hum is halved so the design is still Hifi for it's era. The Output valves are '7868' which are bigger than EL84s if not as big as EL34s. 7868s are still made new which is better than the Rogers that use obsolete valves & the output valve is an "IC" of sorts ECL 86 with driver & output stages in one valve. The Rogers uses obsolete ECC807 that aren't quite ECC83, but Rogers price to Fisher price. The transformers are in Ultra-Linear configuration. The X-100-B is very nicely made, to upgrade there are no parts diagrams, to learn the circuit is required, if not so hard once you've worked out the Trio WX-400U. Some of these Fisher have a "TY" code transformer that can be wired to 240v, if the regular "T" code one is 117v only. Unlike some later Valve amps, all stages are Valve, no Transistor Phono stages here. The original wooden case has a squared-off back grille with a steel square-holed grille, as the Fisher 600-T has. But for the fact many were built into consoles, it appears good repro ones have been made for years too, possibly even in the 1970s, if the back grille shape is more curved with aluminium grille that warps with the valve heat. Sound as Serviced but Original: To try this 1963 amp on 1969 Tannoys shows it's a perfect match. The Bass may be a little Retro with the lumpy bass & the Treble may not be as fully extended as a rebuilt one, but it does sound wonderful as the midrange is precise. A big room filling effortless sound is laid out in front of you & for the bigger output valves on the "B" version the amp has better control so delivers loud bassy transients as on TV often with surprising confidence for an amp so old. A sweet sound here for sure & upgrading won't alter this delightful sound but will enhance it bringing the deep bass & higher treble out more naturally. Didn't expect it to be so good, if this amp does appear in high clean grade with little signs of use so hasn't had a hard life like some aged corroded non-original transformer ones can. But next day hoping to try it a bit more, the good try of it as all original left the amp weary with one channel lower volume. 1963 Valve Amp it still is with original aged parts so in reality to get one good try out of it was good, but it still needs a rebuild. The old main High Voltage capacitors were in poor condition as on the July 2018 blog. All Recapped to find the sound a lot more pleasing, it sounds Fresh & Lively with decent Bass, not the deepest Bass though. Fisher circuits are cleverly crafted to keep Signal:Noise ratios away from Hiss & Hum. The Audio Path from Aux to the Power Amp stage does go through a few high value resistors if there is a little shaping in the circuit to keep the sound right & for the first play of it a pleasant hour was spent, giving a detailed sound for the 24w rated. The 20w (?) rating has to be 'Music Power' on the original design compared to the 30w of our LX33 valves. Stereo width isn't as wide as our LX33 based design & the sound is a little Retro but done so nicely to see what Fisher buyers heard in the 1960s, if our Upgrades modernise the sound a lot, the capacitors as said were very aged. As with Valve Amps as we found with the Trio WX-400U & LX33 you can spend years redesigning to get the best out of the amp & for how pleasing this sounds now, it sounds great if not with the extended treble & bass that we can match with some Transistor Amps. Biased right after some use brings the Treble into focus far better. A good amp to get to upgrade & having heard it on the Tannoys now it sounds spot on for a 15w valve amp is enough to fill the room. On Speakers. We tried it on our Tannoy Golds & initially, as with valve amps usually, it's not as trebly as transistors. A bit of a Retro sound again but very pleasant for it. Midrange is more upfront than transistor amps & we know that from our Luxman LX33 also, if treble is crisp & bass is extended. It's the sort of sound you need to listen to for a while on good speakers to understand, it took us 5 minutes as we know Valve amp sound. To use Headphones, you MUST set the slider to 'Speakers Off' as this puts a Balancing Resistor Load on the Output Transformers. To Set Bias Voltage of 40v on Pin 3 of the 7868s showed ours were very well matched. BUY-RAW RATING: Age will mean the main capacitors are nearly failing as with any 1960s valve amp & there are multi capacitors in two cans to deal with. Beware if the L+R sounds unbalanced as the Volume control could be faulty. REBUILD RATING: Very advanced as redesign needed plus space under is limited. COOL RATING: 8 Fisher 1960s gear is always great looking, simple fascia if nicely done. (2018)
1963 Trio W41 valve amplifier↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Excellent. 10w Valves.
This is the earlier amplifier-only version of the WX400U receiver without the FM tuner. Shows in HFM 1963 Trio adverts. A cute little amp 313mm wide with a gold-grey lid, gold fascia with lid colour panel, embossed lines & red power light line gives it a bit of style. Still heavy for the casing & transformers. Top row of small sliders, headphone socket & the rotary controls have solid cast knobs, all very classy looking. We got this to rebuild for a customer so get to put our WX400U ideas in it if possible to make an excellent amp. This one does work if we're not playing it for long as it's probably not been played in 50 years & has mains hum & a little crackle. The W41 is the USA version with a 100-117v switch. The W41U is the 117-240v multivoltage one with three bigger transformers for the higher voltage else both are the same, the "U" is shown on a sticker but to only realise this on seeing the amp. The circuit diagram we have suggests all are multivoltage, but that's gambling for you. No problem to use a step-down transformer & it works right. The looks of this are like that Lost In Japan look you see on some early Hifi sites, the best stuff never exported & for the lifting of Trade Regulations shortly before 1963, the USA & Japan could export their best gear to new markets, if only Pioneer, Fisher, Trio & Sherwood appear in the Hifi Yearbook listings on our pages. For a 52 year old amp, it's seen very little use, no signs of darkening or aging, if the capacitors knowing how bad the WX400U was aren't to be trusted, if the voltages read well. The Tone controls are unusual, four in total as L+R have a separate control, leading to the ganged controls of later amps. This has the old conical phono sockets, no good for modern cables as no grip or they'll break the plugs as too big, to redo these is a bit of a job. To recap one of these amps takes redesigning & sensitivity to keep it looking tidy, for the small size of this, it certainly is a challenge. As often happens with very rare amps, another turns up. One supposedly serviced by an "expert" looks still 52 years old & entirely original to us, buyer beware. They say it sounds "lush warm & powerful", no, it'll sound very thin, humming, aged, low volume & disappointing, ours did & it had little use. It needs a full rebuild. The difficulty here as with most pre 1970s valve amps is the main capacitors are double & triple ones, these are not buyable & to recap isn't easy. This isn't our amp, it's a customers but we'll keep working on it until it's perfected. Having upgraded it with a lot of rebuilding, it now sounds fresh, lively & bassy. The original valves have burnt into the old spec & it sounded awful until revalving & then the good sound appeared. Once completed, background noise & hum using headphones was acceptable if not as low as later valve amps & the specs on these reveal this. But in use on speakers we heard no noise if you might do in the dead of night. For what it is, a 10w valve amp, it sounded nice on speakers if perhaps would suit ones of higher sensitivity than 95dB even. On the Tannoy Golds it had enough volume which showed it's sweet sound that will certainly please, if not really much more volume. But to buy one of these AS-ORIGINAL (Once Serviced) & use is not recommended, we found some caps in ours were dry & like the Rogers ones they could get issues if regularly used. BUY-RAW RATING: As 52 years old to recap is required before even first trying it, the usual warnings on pre 1969 amps. REBUILD RATING: This we rebuilt to a degree for a customer & their price level. It sounded good but seemed like there could be much more in it, but at 10w to keep it realistic. COOL RATING: 7 cute looking smaller amp but very nicely made. (2015)
1963 Trio WX-400U valve receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Excellent. 10w-16w Valves.
One of the first Stereo FM Multiplex Receivers. First in HFN ad in Dec 1963 for 99gns price. Reviewed in Aug 1965 HFN stating '18w continuous' if they read just 12w (into 8 0r 15ohm?) & were a bit sniffy about it, but they were wrong: a 1964 ad states 10w (20w USA), the volume on speakers matches the 10-12w it actually is. There is no Kenwood equivalent, despite others guessing there is the KW-70 which is incorrect, just look at the underside circuit & extra display valve even as proof they differ, if there is similar in others too. The WX-400U was an Export Model it appears, not sold in Japan, only EU possibly though it has a 110-240v switch. There is an amplifier-only version that looks very similar inside, the W41U we have had since. Original spec as will now be too aged is strangely very limited and soft sounding & hides the high quality in here. The grey signal capacitors must be replaced as voltages can be way too high. What it needs is everything rebuilt & upgraded as certain parts are too far gone to even try it perhaps, but it does pay off and can deliver sounds way better than you'd think a 1963 amp should with a fast crisp treble, solid bass and huge wide soundstage that sounds way more than 10w now though it's rated 18w music power. Looks Very Good too, easily the best looking valve receiver with it's USA 1950s Diner looks. The hardest amp you'll ever tackle to get it sounding right as much needs upgrading including to redo the oversized phono sockets. The balance control isn't zero loss midway which limits fidelity. To fully recap, redesign the power supply & much more gets it rating high, if you fancy the full rebuild work including much redesign to do the pre & power amp stages properly, try to find better in vintage valves. For the ease of familiar ECC83 & EL84 output valves with 350v it's way ahead of the Sansui 500A & the Trio has a valve phono stage unlike the Sansui. This receiver as we rebuilt it is now one of our Reference Amps and does get used often by us & improved constantly as it never complains. We put DC heaters on phono, tone & driver & DC bias in this which is a big improvement, losing the lousy Hum Balance compromise. You can go even further & add adjustable bias too once it's DC bias. The most upgrade-friendly 1960s valve amp we've found, yet other amps don't have the capability. After having done this, looking at other similar valve amps it wouldn't have worked out. Read more on the Valves page, as the story hasn't ended. Interestingly if you searched for "Trio WX400" on ebay in 2015, you get a surprising related search. Thinking of this amp in 2017, we did a huge amount to upgrade it just to see how good it'd be. we'd not want to try a Valve Receiver again as the amount of work to get to a standard we'd want & for the fact 10w in Valves is fine on Headphones, but on 95dB Tannoy Golds it didn't quite have enough power to drive them. BUY-RAW RATING: Don't even try to use it before some recapping. Huge amount of work required to rebuild this, but it'll be worth it as it can sound remarkable. This needs rewiring with 3 core Earth mains cable for the safety of you & it. REBUILD RATING: All valve receivers are a major job to rebuild properly, to the point it's probably way too much to do. The results can be great, but to get us to rebuild another WX400U is just too big a job. To do certain parts to keep it useable will just reveal how weak the design is. COOL RATING: 9 of all the valve era receivers, this is the winner on looks by far. (2012-15)
1964 Sansui 1000A valve revceiver↑
AS-ORIGINAL (Once Serviced): ---. UPGRADED: ---. 40w Valves.
A Genuine 40w RMS Per Channel Valve Receiver. There aren't really many 1960s Valve Amps over 30w & Fisher seem to be the only ones on Receivers or Integrated Amplfiers, beyond Separate Pre-Power ones like Radford. For How Hifi Is, to be onto this one "Rather Late" for seeing one to Buy, if missed it. Fate sends it our way & we have it now. Other Sansui Valve amps we've had didn't please, but the 1000A is "World Class" and we're very pleased with it. Age means it'll probably be too Aged to use, ours to change just a few Caps to get it playing as Near Original which is important before Rebuilding & Upgrading. The Sansui 220 & 250 were low power Budget items, the 1966 Sansui 500A we review below wasn't very impressive, seeming a Rush Job when Sansui had the 1965 Sansui TR-707A All Transistor (Germanium) receiver. So over Ten Years Later to wonder about this 1000A. Seen forums complaining about it, but there are at least 5 versions oin the run. Some have a 'Ssansui' plate on the rear of the top lid, earlier ones don't & no trace of one. Seeing another on ebay, slight differences put it as a last version, if overall the amp is much the same, all have the Conical Input sockets showing 1964-65 built. Buying a Matched Quad of Output Valves takes away the need to have the 4 Bias Pots. o prefer an earlier one before others altered it perhaps.Earlier "1000" Model. The first Sansui 1000 & Sansui 500 were from 1963. The Next Is Based On Two Longer Blogs before we got this, answering concern since getting it. Sansui 1000a. A Heavy 20kg unit, the size of the Transformers is impressive. This has 470v on 7591 valves, these are Buyable New or NOS still, there isn't a UK Equivalent. 'The Valve Museum' site shows they are smaller EL34 sized & 400v 'maximum voltage' if often valves got pushed further as deeper looking at Spec Sheets tells. Capable of 37w-43w in Push Pull, no Ohm ratings if assume into 15 ohm. THE EL34 fits in the socket, it would need wiring differently & 6A for 4x EL34 would be too much for the 4.2A the transformer offers for the 7591 & others on the circuit, as in you'd upset voltages & damage things in that risky 'Tube Rolling' way. The Power Amp uses a Dual Pentode-Triode 6AN8. This is the same Valve the Pioneer SX-800A used & was considered 'not very crisp sounding'. Here Sansui use it better so it does sound Crisp unlike that Pioneer, a Gamble in getting this amp. Phono is two Transistors which Sansui often did in these last Valve models. Looks like the TR-707A Phono & can have Germanium or Silicons. Not having a Valve Phono makes design easier, if it's not fully a Valve Amp like those Pioneers have. Tone uses one ECC83 per channel with Passive Tone between each half of the ECC83, rather than just one valve used for L+R tone, this has Gain before Tone. This is 4 Valve stages in the Pre-Tone, unlike just 2 in most other designs by Trio & Pioneer, if this is a 40w amp. Filters the High one uses 3x 50K resistors on the signal, not great but found not to limit the sound. Low Filter uses signal through three capacitors in a 'T' Bass type filter. The front panel shows a 'Presense' control that Boosts certain Frequencies, not Midrange but 50Hz Bass. Has the typical Loudness that doesn't affect anything if turned off. Power Supply has the usual Voltage Doubler to make a single HT for the Output Valves but them several resistors dropping from that one Voltafe to get 120v-180v for other stages. Transistor Phono gets it's own winding as do Bulbs & Heaters, some Heaters are DC. Compred to the Pioneers, a better design without lots og Big Resistors & not the excess of Capacitors. Output Valves design not the Ultra Linear. Sansui 1000A Variants. There are versions of this, HFE has 2 main versions if to spot the Earliest Ones. Generally the Earliest ones are by the Origiinal Designer, the later versions are often another's alterations. As long as yours Works right, either of the Several Versions will do. Earliest One is with "Courtest Of Sansui" on lower left. It shows a 4-8-16ohm Speaker Outputs version without the 4 Bias Pots. Has the Round Multivoltage & the 1ohm resistor on the 180v TX. Puts 2SB381 for the Phono Transistors which others don't show. The Rear Antella is a different 'stick' type. like the TR-707A has. Second has the Beam AM Antenna at the back, not the Sansui 3000A type one. Also has the early Multivoltage round block that needs tags soldering as a TR-707A showed. Third which is ours with '2-65' dates on the Output Transformers, has the later AM Antenna, the regular Rectangle Multivoltage Block & the early Bias, not the 4 Pots one. Fourth has the 4 Bias Pots underneath but not the White Stick Resistor like the Sansui 3000(A) has for 4-8 ohm use. Fifth has the White Stick Resistor underneath & the 4 Bias Pots. Be sure there are more changes on Tuner over the variants, but to stick with more obvious changes. Is It 40w? A Manual confusingly gives only 33w into 8 Ohms. The Output Valves '7591' are capable of 37w-43w. 40w it is & the Manual gives this rating, 40w/40w which may be 40w RMS one channel or two playimg. There Are Schematic Circuits In The Lid. This is a Tiny Browned version of the Diagrams. Far too small to read with even a 10x Magnifying Glass. It's Bubbly & uneven if does Scan Up reasonably, so we'll use that Version as it does match. The Diagram shows the Rectangle Multivoltage block, the Single TX Speaker Output not tje earliest 4-8-16 ohm windings, the R177 1 ohm. Ours has the 30w Resistors at the back which are shown correctly as R179 & R181. Doesn't show the Deleted-Added symbols one circuit does. R128 as 8ohm 10w earlier long thin style. 'Last' shows R189 & C169. Our Circuit seems to be the One Before the 4 Bias Pots. Recapping. To look at the Underside Capacitors to see why Most only Recap Like-For-Like & don't bother doing the Larger Capcitors. False Economy bordering in Insanity to Trust 60 year old Electrolytics reading up to 493v here. If you do only do Like-For-Like, keep the Values identical or it'll bring Problems. These Problems are what gets us Upgrading & is a Design Based Highly Advanced job, on nearly 500v, Don't Risk High Voltages unless Experienced. Circuit Errors. Some Amps do have Errors, Component Numbering, Values & more. Here one Capacitor is misnumbered & another is said to be where it's not, a result from Circuit Changes over the Run & looking at the Early Info. To Correct Errors needs circuit knowledge & tracing. Be Sure C999 (example) is where it's said to be. If It Was Easy Everyone'd Be Doing It. Prior to Testing the Voltages to Recap & after our FM Tuners compare in Aug 2024, turned it on & it went Bang! within a few seconds, despite working days before, Bang It went. What do you expect with 1960s Valve Amps? For us to at least be able to hear it Near Original after previous problems, but Two Bads & we'll not use it until Rebuilt. Not worth Risking it & you do see Valve Amps with a Replaced Transformer as one got Damaged. What went Bang wasn't a serious item, but thee are others that work on higher voltages than can cause Damage as we found withing a few Minutes of First Use.
BUY-RAW RATING: ---. REBUILD RATING: ---. COOL RATING: --- (2024)
1965 Akai AA-5000 amplifier ↑
AS-ORIGINAL (Once Serviced): --. UPGRADED: -- 35w.
CC. See the main review on the 1966 AA-5000 S below, this a 2021 'update'. This is the earlier Multivoltage version without the "S" on the fascia. The thing is we had the AA-5000 S since 2018 & as an 'ornament' visible daily since redoing it. On checking before posting this, sound was still decent plus to not like selling it, if to remember one on ebay March 2021 & for liking the looks, very stylish Mid Century Modern, not just Retro, want it back. Loft find by the condition which is still decent inside. Seller tried it to say it 'works a bit' so worth having, if when we'd rebuild it knowing the "S" version, to be seen. Got the 'Operator's Manual' giving the specs & a circuit diagram on the back if to compare how it differs later. Specs will only be found on this so it's rated 35w x 2 as 'Rated Power' into 8 ohms & 23w x 2 into 16 ohms. Music power is where the '110w' comes from, 55w x2. This one supposedly All Germaniums & they quote Noise Levels to be less understandable, as Background Noise on most Germanium amps is quite high to be audible on 95dB speakers. Tape Head-Phono 'below 30mV' plus Tuner-Aux-Tape 'below 15mV'. Tone is ±14dB Bass 50Hz & ±11dB Treble 10kHz. This Multivoltage version later than the 110v only version as the Specs shows updated data. 17w no signal to 160w full volume. We have the Akai X-150D User Manual & Schematic & the papers for this show it was bought in Singapore likely in a Forces Shop as found with other 1966-68 era amps, bought to send back home. Akai known for Open Reel tape machines to make the AA-5000 & the AA-7000. The Guarantee card is dated 'January 1968' so the AA-5000 & "S" version seem to be sold as long as stocks lasted. What's Different? The non "S" version clearly built earlier, has Carbon Composition resistors instead of the /\ mounted bigger resistors. Our User Manual has circuit numbered 'No.AA-5000721' if another as 'AA500036' code if all show a mix of Transistors for both versions. Circuit shows only one real difference in a coupling capacitor on the power amp & the non-standard resistor values like 4K ohm & 600 ohm instead of standard ones like 3.9K & 560 ohm. Clearly the preamp has to have Germaniums as designed with NFB, we tried Silicon if the frequency range too wide caused bad oscillation if the Power Amp can update to Silicon better. Cadmium (gold) plating keeps the inside case nicer & a damp stored amp will work better, if the silver painted top lid is aged with a spidery rust lines pattern. What's Inside? Power Transistors are 'Bendix BI70008' with '6732' date code, the ...7 one in the AA-7000 & we found a datasheet showing these are 120w Silicon as are the other output ones, if '22557' maybe a RCA one if no data. Drivers 2SC614D are Silicon, if the PNP one on a extra heatsink bracket & strip is a Germanium as was the "S" one. Resistors are all '4.7k' type series later ones. Amp not useable as R channel bad if as described. L channel sounds 'right' if it's why they need a rebuild, odd noises on turn on-off. Difference Overall AA-5000 to AA-5000 S? Beyond the T6-T7 coupling cap, Absolutely Nothing, beyond the variance in same-type Transistors. Both have a PNP driver & Preamp PNP transistors as Germanium. Outputs always Silicon as 35w. PNP driver with Heatsink or not plus other minor component differences. Similarly a UK Amp Truvox TSA 100 or 200 claims to be All Silicon on the later one if similary is no different. Marketing Trick to sell the same amp for a few years, Akai only introduced New Models in 1969. Revisit The AA-5000 We Have. It has the Bendix B170008 'orange' output transistors with a '67' date code. The other Transistors much the same as the AA-5000S below, 2SB440 Germaniums, 2SC693 Silicon, more 2SC440, 2SC414D silicon, 2SB54 Germanium on the heatsink as Bias. Drivers are NPN/PNP as 2SC414D & 2SB421 on a heatsink bar & tab, different to the AA-5000S. This Does Work, if one side very quiet, so we've just left it a few years until a 2024 revisit. One to find the fault & hear it As Original, used to just recap these if faulty, but worth hearing it as close to 1965-67 as possible. Only the L channel plays, R only crackles a bit. The L plays a crisper sound than the AA-5000S gave & improves if clearly has issues to click & vary volume. To not play any more & the Power On-Off is a bit noisy. One to Recap for sure now. Early Resistors. This uses 5K, 2K, 20K etc if 'preferred values' are mosty used, such as 4.7K etc.
BUY-RAW RATING: 1965-66 amp may work but not very well as too old. Risk of Big Issues if you try to better it. COOL RATING: 9 pure Mid Century Retro Cool as with the AA-7000, very few amps this stylish. (2021-2024)
1965-66 Akai AA-5000 S amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Very Good-Excellent. 35w.
CC. We've known of this amp since getting the bigger AA-7000 receiver version as reviewed below. Not one that turns up if oddly two on ebay at the same time, one a 110v only one in worn grade as the earlier AA-5000 version, which comes as Multivoltage too & a nice Multivoltage 5000 S one which we get, not cheap with the import fees but it's our game to try these Classic Era Amps in search of the Best ones. There are 2 versions, the AA-5000 & the AA-5000 S not much different. The "S" version seems to be a late 'cheat' as the AA-7000S exists, both still are with Germaniums. Cautious of it on 'Other Amps' page as no info was found to know it's Power Rating if only recently we got the Circuit Diagram. Rated as "110w Music power" when the AA-7000 is "100w Music Power" suggests the rating is somewhere 30w-40w if the AA-7000 tested like a 40w amp on clean Sine output. We Blogged on this in Sept 2018 on seeing this amp, priced a bit high to import if it nags at us "Try Me I'm Nice" so we give in & it arrived mid November. To see the circuits are quite unusual if at least it's a 30w one means it's worth a try. As we blogged before... The list of Transistors is shown, such as 2SB440 (Ger), 2SC362 (Sil), 2SB54 (Ger) with a selection of output transistors like 2SD46 (Sil) & 2SC493 (Sil). So is it worth trying? There are 2 versions, AA-5000 & AA-5000S with Silicon if little different, see above, the same Bendix output transistors the AA-7000 uses. The Aux goes through a large resistor into the Phono stage, but "Tape In" as often with this design bypasses the Phono stage. Circuit shows quite a lot of limiting, NFB & sound shaping. It is Capacitor coupled if with a very low 500µf axial that we can see is fitted on the board similar to how the AA-7000 does it, No Transformer Coupling here unlike the AA-7000. It works on 75v HT which suggests about 20w-25w at least. For "Tape In" use, the circuit goes to Passive Tone direct as the AA-7000 does. T1-3 are the Phono-Inputs stage, T4 & T5 are the Preamp transistors, with T6 onwards is the power amp. The power amp is very strange as was the AA-7000. It has to be tried, the AA-7000 is a very specialist one & we have one here as an upgrade which adds to the interest in comparing, after all the AA-5000 predates the AA-7000. They do appear in 1967-68 Hifi News Ads & were shown at the Audio Fair together, they will have looked Out Of This World for the styling. Got It Now. As it sits on the desk warming to Room Temperature from the 3°C overnight, it certainly looks way cool Retro in that very 1965 way, we like it. Bigger than expected as even inside pics don't really tell, it's 422mm wide, 135mm high & 270mm deep if 296mm deep including control knobs & the Blanking Plugs on the rear. All original higher grade suggests it's an estate clearance item with one owner for 52 years if not much used. Top lid that unscrews from the rear under edge is silver-grey with grille slots that don't let in too much dust with ours. The Fascia has a aluminium panel with a dividing line that has the power Bulb in. Top Controls are Bass, Treble, Balance, Bass & treble so L+R Tone as did some early Fisher amps. Bottom row is Headphone socket, sliders for Power & Speaker, Mode inc Stereo & whatever 'Monitor' means is likely Tape input, Volume, Loudness, Liw & High Filters & Input Selector. Deeply engraved lettering filled with black. Has a Retro Industrial look with some very 1966 design that will certainly appeal today & probably didn't look that old fashioned in 1980 even. Rear panel has a line of Input sockets of the standard type to fit modern cables, DIN plus Phono sockets for tape with the old Tape Head input plus Phono, Tuner & Aux. Screw outputs for Speaker & the usual akai 6.3mm jacks for Speaker. Voltage selector behind a panel has you dial in "1" or "2" & then the other voltage to suit, apparently giving 14 options 100v-240v. also 2 Mains outlets if not saying Switched or not. Underside is part of the chassis with bolts & screws attached. Inside is interesting, it's basically a Mono Integrated Amplifier on one board with Outputs on the Heatsink frame done as 2 identical units, Stereo separation should be good. Capacitor Coupled by Axial Caps on the board. Output Transistors are later than the Manual ones, 2SD83 with 50w at 6A are all 4 & inside it's untouched as the fine non-smoker layer of dust tells. Unusual they use higher voltage ones 2SD83 are 150v when similar 2SD8x are 30v-200v. Transformer with 54v (AC) marked on both taps is about a 50w amp sized one, smaller than the AA-7000 if that had the Nuvistors to power plus the Tuner. The Nichicon main capacitor is 2000µf 80v plus a smaller 200µf 75v cap for the Preamps. Seller says 'Tested & Working' & the Power Lamp shown lit, if what Working on a 52 year old amp is actually is to be discovered. Rough & Noisy if plays a bit on both channels, but far from Tested, the usual "ebay buy", but we expect that knowing as many amps as we do. Needs a Service before trying again. very loud crackly noises are a little offputting. As typical 'Tested & Working' means the bulb lights, to us that's at least something. Now partly Serviced, it plays music fine, if unserviced it was bad & any non tech buyer wouldn't be pleased if they'd not buy a 52 year old amp perhaps. . Sound As Original & Part Serviced. Only giving it a quick play for the aged before taking apart more, Transistor hiss & a slight hum if the Music sounds aged but still lively & punchy, Stereo is wider than a usual 'raw' amp & Rock has some weight to it, midrange focus appears good if some treble blurring plus it is playing Aux through the large Resistor into the Phono stage. AA-5000 S vs AA-7000 as Original compared to the AA-7000 with some recapping to hear it near-original, the AA-5000S is noticeably the better sounding, so to get the AA-7000 again to be sure. Bit of a clunk on power off suggests the Power Supply needs attention, but to be expected as 52 years old. AA-7000 on, quite a noisy background with volume up a bit, only a quick try on two tracks, the AA-5000 S has a more punchy sound, the AA-7000 is more restrained & doesn't really get a hold of Rock too well. The AA-7000 has less amplifying stages in the preamp, it sounds more like a Passive Preamp if that sound can be a little too soft. The AA-7000 looks very different inside in components even, if the 5000 does have 'Akai' marked boards. More Inside. The Main Pre & Power boards unscrew from underneath & then off the heatsink but not easy to work on, all apart job from the back panel. Shop sticker underneath shows a PS Diode was all they replaced. Original is a SW-1 round type of about 1.2A as in many 1960s amps, if they insanely put a 1N4037 62v Zener Diode of just 20mA, these TV repair types are a menace, 'Florence Electronics' of SC 29501 sticker, a shop area address, metal as aged under the shiny sticker so probably a 1990s 'repair'? The front Amp stage has lots of wires going underneath, should be tied, but one squashed between the metal parts is just as you'd expect, as is losing 1 screw & 4 washers. Top Lid screws are strange, don't undo them fully, just undo half a turn & slide back the top, else if you undo the screws fully the lid must have the captive nuts hanging down to get the screw back in. Now To Upgrade You. Getting to see the Main Circuit Board with Phono, Pre-Tone & Power Amp, this has Nichicon capacitors & silver mica capacitors to show quality. Ours must be later with AA500023 board & 2SA/2SC485 as were used in 1969 Pioneer etc. T8 is on the Heatsink used as a 2 wire Diode. AA5000S implies it's All Silicon, it's not, of 12 Transistors per channel 6 are Germanium. Preamp is all Germanium except one & Power amp is all Silicon except T8. To assume the AA5000 non 'S' that will be from 1965 was Germanium entirely. Care needed as the Boards have values marked that aren't as fitted. Now All Recapped with Upgrades if the Circuit unaltered, the sound with Germaniums in the preamp like the 1965 Sansui TR-707A we completed only just before is smooth if as it has NFB in the preamp it sounds less open than the Sansui. But it still sounds Great, Wide Stereo as Pre & Power amps on separate boards, not quite as Bassy (yet) as the Sansui but Rock Guitar sounds full bodied as midrange is solid. Volume comes after Tone & into TR4 so with Volume at zero you hear no Germanium hiss if up louder it's quite a Sea of Hiss, Sea sounding, if not full range white noise. Neither the AA-5000 or AA-7000 are with silent backgrounds as the specs tell also. Going onto Phono input the 'Sea Noise' is quite high on both channels equally & will not be acceptable perhaps, if we've not tried a Turntable on it & put the Blanking Plug back which makes it quiet. After a long play of this & seeing a few changes to make, Bass is much better & still using the Aux In as it sounds good. One Bassy track really hit hard showing this amp has some kick to it now. But it's Germaniums & they are typically noisy. We'd leave it as Germaniums as with the Sansui as the smooth sweet sound is worth hearing, if to tell a potential buyer of the noise on this Stylish Mid Century Rare Amplifier, which is the appeal of it after all. We initially rated it 'Very Good-Excellent', the Music itself is Excellent, if the Germanium noise makes it less modern. Aux goes through the Phono stage if using Tape Monitor input it bypasses that & sounds just slightly cleaner if bass is slightly better if that can be improved. Different to the Sansui TR-707A but as good a sound. A Few More Changes got it into 'Excellent' & On Speakers it sounds very decent with barely any turn-on sound & no hiss with just a tiny bit heard with volume midway that Silicon amps have similarly. Comparing Akai AA-5000 to AA-7000: see the Dec 2018 Blog page for comparing both together. Testing The AA-5000S reveals it is around 35w for a clean 25w sine output. On testing both channels, the Germaniums are what they are & a slight rounding of the lower sinewave at any power shows, not clipping & not for us to try to perfect Germanium design. 2020 REVISIT the same Amp. Amazing it went unsold for the looks, if we did put 'Retro Sound' as it scrapes an Excellent played Normal Volume, if Up Higher it sounds a bit 'Germanium' plus the slight hiss. Based on how good the 1966 Akai AA-7000 & 1966 Sansui TR-707A are, this as a 1966 amp needs a better look & a deeper upgrade, hissy limited Germaniums are OK, but the Circuit is what makes them good. Some NFB that's a bit overdone perhaps, the Splitter stage is a Transistor, unlike Transformer Coupling-Splitter of the other two. It was a bit hard to work on, so it got forgotten until late Aug 2020 when we decided to do more with it. Very Odd 'Protection Circuit' which just Mutes the Preamp to warn, a pointless thing perhaps, if the AA-7000 one similar & not a problem. To look deeper before deciding what to do. Got It Apart. Very early in places, Resistors with Hand painted lines on only a few, values printed on the board are early like 5K, 8K if 4.7K & 8.2K used. 2SC293 Can Drivers are Silicons if 2SC485 used, 2SB421 is Germanium, the 2SB440 are the PNP TO1 size Germaniums in the Preamp-Phono counts only 5, a 2SC693 NPN silicon also. 2SB440 at £15 each on ebay, if Guitar Amps can use these. Suggests a 1967 built amp so to just do all our way to update it. Changing Germanium to All Silicon. Big Warning on this, altering the amp in any way will give extreme issues as we found before, if redesign may sort it. Silicon are much wider range than Germanium. One this age may need new resistors if noisy, we've found resistor noise already. First got it Two Years earlier, the design '5000S' based on the 1965 '5000' with more Germaniums. But the Modern Buyer doesn't want Germanium hiss, neither did we with the TR-707A which is all Silicon now & better for it. Who knows what this hides, it was very decent already. We tried, but it needs too much redesign to get it right, the Silicons cause huge instability as broader range to the higher NFB design & higher HFE. Put it back, only tried one side. Got to try, the TR707A was surprisingly trouble-free if appears that's the exception. If the boards were easier to work on could try more, but ultimately it's a sale amp. BUY-RAW RATING: 1966 amp may work but not very well as too old. Risk of Big Issues if you try to better it. COOL RATING: 9 pure Mid Century Retro Cool as with the AA-7000, very few amps this stylish. (2018-2020-2024)
1965-66 Akai AA-7000 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
CC, Transformer coupled. A later AA-7000S exists with the wood edge grilles, a red tuner background plate, if it'll be no different as with the AA-5000S, see above. "Akai" were branded as "Roberts" in the USA in the 1960s, to apparently hide the Japanese name. Whether AA-5000 or AA-7000 exist as "Roberts"' branding is unknown. After success with this brand finding the 1970 Akai AA-8500 below, to look out for more. This is a slimline designer looking receiver, the sort of modern design Bang & Olufsen will have seen. Thick wood sides with a dust trapping solid cast grille. Fully featured receiver, if no Filters which is unusual but these can compromise a design. First appears in Hi-Fi News April 1967 in the 'Audio Fair Preview' shows a picture, price was £147 5s, despite Akai having a London showroom as did Sony, they mostly sold Tape machines. On getting the not-great circuit diagram, as it's 1966 it has 6CW4 Nuvistors for the Tuner stage still. The circuit in transistors is Phono x2, Tone-Pre x1, Power Amp driver x3, Transformer coupling splitter to Output pair. The schematic is awful blurry with little detail to know even the components which makes it tricky. Appears in the 1967/68 HFYB as '40w music' for £156, if it's 40w RMS from giving 27v clean sine & the brochures say it weighs 13kg which is heavy for the slim size & the high price is in the range of the Fisher receivers. Not expecting this to be easy, but certainly worthwhile. The AA-7000 & AA-5000 brochure suggests the AA-7000 has germanium outputs if they aren't, the slighly later AA-5000 seems an updated design with silicons & no coupling transformer but only 8kg. AA-5000 first appears Apr 1968 in 'Hifi sound' mag advert, rated 15w for 75gns (£79). The AA-7000 is actually very large 52cm wide, 11cm high & 44cm deep. On getting our new coffee table, aka this huge amp, it's very impressive 1" thick solid wood sides aka veneered ply, huge glass tuner display, Silicon outputs the same as the Sansui 3000A had the Bendix B170008 'orange'. The tuner has a space for '102' but even the ad shows it's not included, strange. The top is in two parts with the power amp output stage on the front one with 2 cable plugs. We've seen some stylish Hifi but this one will have delighted the women as it looks so cool, not some plain box thing, this is a designer piece. The transformer is a block one the full height, the size you see in 50w amps. The recess for the AM antenna which is usually a pain on receivers is mostly out of the way. Multivoltage switch & plug under a small cover to set to 6 voltages, ours was sold for 110v, can't see many UK buyers after this in 1966. The input phono sockets are the good not conical ones, Muting & FM gain switches, Speaker out is like the AA-8500 via 6.3mm mono jacks or more typical screw connectors. Amps like this need to be in Museums as Mid Century classics like Eames chairs, why is Hifi so underappreciated for design? All amps pre 1969 seem to need a full recap, after that the quality must have improved, but a 1966 amp needs a full rebuild. Still has the small grey hollow resistors like valve amps use & some are handpainted for the value lines. The power amp top lid section has 'Riken' large capacitors called "Dry Electrolytic" which doesn't quite make sense, cutting them open shows they are a typical electrolytic cap if dry & slightly crusty from age if smells different. Amps like this keep our interest in this alive. To get to the fascia etc, lids off, sides off, tuner part off & then 8 bulbs which are 6.3v bayonet type. To be extra careful of the tuner glass blue-grey & white lettering is important: if it looks 'bubbly' it'll wash off with just water as ours did, we know how to redo it. To recap this to our standards is a tricky one too, the 4 large caps are one single, one double & two triple so 9 caps in 4 cases. This amp has had a full recap on all but the 4 largest caps including the tuner, reveals an excellent sound, wide stereo & deep full bass shows it certainly is worth the effort. The "P85" driver transistor is in the AA5000 also & that's the full name, P85 specs unknown. We initially left the 150v tuner ones as original as they get light use & having cut similar apart, they are still good, if it could be redone fully. The 3 larger caps were barely damp but not crusty so one you could get away with using occasionally. There are two minor versions, the side boards are solid veneered ply on the early ones, later the ply was machined out on the inside, holes in the metal sides made & metal runners added on the top edge which are vents for the inside, this is original & appears a rarer version from ones found online. There isn't much heat inside only the NuVistors, the top lid is the amp heatsink. The later one adds a resistor & transistor to the output stages, but the glue rusts the transistor & ruins it. As the manual doesn't show this addition, it appears to be the nearly the same as the Sansui 3000A output stage adding stability, if it works fine without it. The sound as recapped & upgraded on the Tannoy Golds is extremely good, rating a very high Excellent. The solid bassline this amp has as well as sweet crisp treble & a midrange smoothness & dynamics that rivals our valve amps. A tricky amp to get right, but a real winner if you have the space for it. The 1966 TX Coupled Design got a Revival in 1972-73 Akai AA-6300 & AA-6600 at about 25w-30w. The Transformer Coupled Power Amp also revived in the Nikko TRM-1200 from 1972 which was an update of the earlier TRM-120 from 1968. The AA-6600 is 30w, the 50w rating is Music Power, the AA-5000 works on 75v HT without the TX, the AA-7000 has 75v caps so will rate somewhere 30w-40w if we'll confirm that shortly. REVISITED 2018. We get one to upgrade for a Customer & on seeing it as original after the last two arrived 4-5 years ago, this amp is so ancient inside. The design gets the insides too hot with no ventilation & this one we only plugged in as the sales pics showed the lights on, the previous two were too far gone to even try. 1966 amp using parts more like 1964 amp, Nuvistors for the Tuner front end, amazingly the Tuner worked, if the amp hummed loudly, played R channel only & gets louder on turning off, it's way far gone. Still a great looker, but rather daunting seeing it as original & our final redone pics which aren't the ones on the site, this amp more or less needs 'the lot' updated if you want to use it daily. It's possible as we used ours for about 3 months daily, slight hum is still heard as the S:N ratio of this early design is more limited than what Sony TA-1120 got in 1965. Crazy amp, will never work for the hot resistors inside so to recap it partly to try it as near original but to just get L with loud Hum if R plays. so to do more. Now sorted & playing both channels to Play As Near Original as some recapping with upgrades & some new transistors can be. It's listenable with Bass it'd not have played before, still with the original Power Supply Caps. still some hum & transistor hiss as the Tone not done yet. Treble goes crisp if it's otherwise quite soft sounding with Stereo not very wide, if does improve with some use. The big resistors on the Power Amp driver board in the lower half of the amp get to a high 80°C & the 4 green Resistors on the Top Lid Power Amp get to 60°C which actually is Normal as designed. But this is with the top lid off, all closed up it'll be at least 20°C higher. As far as it's upgraded it sounds OK but far from the focus of similar amps. Plays Rock convincingly beyond the limits, a sound we tried a lot to upgrade & put the hot resistors on the top lid if that then ran at 40°C. A fairly loud 'click' noise gets us turning it off, after all the main caps are still 1966 ones. But to try the Tuners, FM not perfect if it plays Stereo of sorts if with distortion. AM works. Of the three we've had now, this one to have both working is unusual, the others had only FM in Mono or AM & still rather distorted even once the tuner boards recapped, which have the same too-aged cooked capacitors. Now All the Audio Stages Recapped. The 4 main capacitor cans contain 9 actual capacitors which is a challenge to recap properly. That done, the amp does still have background noise, a slight hum & turned up louder some dull hiss. this is the best we got out of the first one & it's the best the amp can be. It sounds on Headphones if on 95dB speakers it only slightly sounds in the Night quiet. The main caps were tired as 1966 vintage & those redone the amp sounds a huge amount better, beyond the background noise. That fast crisp sound is here & volume is adequate. Has an interesting 'Retro' sound for the unusual Power amp stages, certainly has a good Bass. Rock has an interesting sound, has enough weight if a strange mix of enough bite if quite relaxed too. Scores high on Musical Pleasure if to the level of upgrade this 2018 one has, it's not the most precise or focussed, but it still pleases as we found with our one on speakers for a few months. Our one got a lot more upgrades over more than a year to deserve an 'Excellent' if to be fair this is in the 'Very Good-Excellent' range. It has that sort of 'Germaniums' sound like the 1966 JVC MCA 104E had, not the most precise but very sweet which was always the verdict on our AA-7000 from before. Fascinating amp, great Mid Century looks like No other & it Sounds Great once rebuilt, which is a big job. Amp Compares. Later remembering a design change we did to our one reduced the hum quite considerably that also tightens up the sound that was a litle blurry, it was a bit noisy on speakers. Very strange amp, we've never read a review of it or the AA-5000, to wonder what buyers at the time thought. We test a few Upgraded-Recapped amps against the AA-7000, before the later change above, it's sound compared to the 'Best' we tested is interesting, a big open soundstage, not as crisply focussed as one a lot more upgraded, but certainly more pleasurable than a few we were surprised at for not liking so much. The AA-7000 does leave you wanting a bit more volume from it, if a sound that really makes you listen plus a very solid bass, despite the background noise. The Tone Stage is almost Passive beyond the one transistor for gain on using Tone gain, so if set Flat it's not adding gain. As different as a Valve Amp sounds in it's presentation & the amp we tested before it was the LX33 valve amp. Two amps we tested only got a very brief play if the AA-7000 stayed much longer. It suits certain types of music better than others, Rock guitar sounds a little soft when other tracks sound great. The more you listen the more the not-typical sound opens up. It's why we used our one on Speakers for months, it's a hypnotic amp. Comparing Akai AA-7000 to AA-5000: see the Dec 2018 Blog page for comparing both together. 2022 Opinion. Got our 2015 one back in 2018 & rebuilt it. There is so much more to do to get this sounding great, it's possible to sort Mains Hum & Noise to get it very quiet which reveals the Beauty of the Minimalist design. Years to get it like this & sort the excess heat for several hot resistors, ours runs only slightly warm now. 2023 Opinion. This is the Most Minimal Amplifier ever & has such a clean sound, but only once hugely rebuilt. The Annoying Background Noise is part Earthing issues & part the Volume Control wire picking up noise. After 8 years, we finally have ours so Quiet with Volume to Zero, not totally silent in the Quiet of Night, but a good improvement. More Chance & Luck than anything planned & at the point of giving up & let it sit another six months. The FM tuner works on ours now, it was making bassy rumbly noises so to sort it out. Is there another amp that potentially can sound this good? BUY-RAW RATING-REBUILD RATING: Will need a full rebuild & recapping as too old & it's got other tricky issues, but well worth the effort. We've had three of these, to rebuild is an advanced job as so much needs redoing. To fairly say this Amp is the one that needs the most redoing just to get it to be reliable. Very Advanced Job here, if Pretty Looks Mid Century Modern may attract, the rebuild job condensed into a customer job is an extreme one even without our redesign. COOL RATING: 9 the first 'designer' styled Hifi, unique looks with high quality build, made to impress. Treat it kindly & it'll not disappoint. (2015-2016-2018-2022-2023)
1965 Fisher 600-T receiver ↑
AS-ORIGINAL (Once Serviced): Great. UPGRADED: Excellent. 45w
Direct Coupled, SC, PARA, Transformer Coupled, Hybrid: Valve-Nuvistors-Germaniums-Silicons. We had a Fisher 440T long ago but it was such poor grade, no lids or case it got parted out very easily. It intrigued us for it's early style build & at last we've found one worth getting, and a 440-T too, see below. Most were sold as chassis amps to build into consoles as Fisher was a top brand in the USA. London shop 'Imhofs' has this in Nov 1965 for £226, later the "REW" shop has these too. These have a black metal lipped base & top grilles with the wood case & gold top grille. The 600-T comes as either a 110v or a 220v compatible, the 440T did but this is a 110v as expected but a 300w external step down transformer will power it. The 220v versions have extra striped wires on the transformer. One valve & two Nuvistors for the Tuner front end, mostly Germaniums with some Silicon if Germanium outputs, 8 in total to get 45w. The build inside is one to scare many off, it is very densely packed with hard wiring & early components as well as being deeply fascinating. This sort of amp played The Beatles 'Revolver' & 'Rubber Soul' so will have been much enjoyed so to find one for a reasonable price, not a $1000 delivered one, with most of the print on the front & the gold knob caps is not so easy to find. Looking at the photos of the 440T this is far more sophisticated. In the top section, seeing Transistors in push-in holders is unusual, only seen this with Fisher. Two transformers for the push-pull splitter stage as the NatPan SA5800 & Sansui 3000A used. The two top TO3 transistors are pre-to-power amp buffers and the two ceramic posts are resistors for impedance matching as the Sansui 3000A has. Two larger main capacitors in card outer casings are 3000µf 40v as this is a semi complimentary amp like the other 1967 ones. The rear silver capacitor is a triple one for the valves-nuvistors. The underneath is similarly packed with Phono in the rear corner, the two mid ones are Preamp-Tone & the power supplies in two places. It uses cable trunking like the early Sonys do, axial capacitors & the orange squares are ceramic capacitor blocks for Tone & EQ, if not the best quality, these are used in McIntosh preamps too & can be upgraded as we've done before. The amount of work to assemble this by hand will be huge, it is very impressively made if still much hardwired. The cast aluminium back panel, similar to the Heathkit below. The sockets are tightly spaced if ones a modern cable can use if it's the slimline type. A linked socket pair marked 'Rev' is for a Reverb Amp loop, or Graphic today, not really a Pre In-Out though. Tape Out is Line Level, Phono Hi (Ceramic) & Lo (MM) with Tape Head for a open reel player. Tape Monitor, Aux Hi goes through a 220k resistor if Aux Lo is direct. Speaker outs for two pairs via the same type the McIntosh MC275 uses so those Gold Posts we recommend on sales pages fit, if rather closely. Four 2A fuses are the only protection. Our one is Estate-fresh from the USA & this is how you want complex amps, to avoid the repaired or fiddled-with ones. To use a mains transformer is no bother even for long use, just keep the original plug on so there is no confusion about voltage. Looking online there are various versions. Ours has no output stage adjust pots but diodes & the eight TO3 outputs, any with wood fascias are not original. The nameplate is sprung if what for, nothing behind it on ours which is a late 41100 series one, not a chassis version, if an early one shows there are trimmer pots. There are apparently 4 versions of this with manuals, very highly rated and beyond McIntosh we read, we'll find out soon. Look for the Fisherconsoles.com site if navigation is vague, downloads are there. Finding a 1964 Consoles catalog reveals why so few have wood cases, they were supplied in a custom furniture type cabinet, but these are valve amps, not the 600-T. It looks 1965-66 to us. The earlier Fisher 600 is a valve amp of an all-valve design. To recap an amp like this for advanced folks only, the amount of hard wiring to PCBs is not so easy. Pity it uses ceramic blocks for Tone EQ & High Filter and also the main preamp caps oddly are W. German ones like EU radiograms. Would be nice to get a perfect fascia, but screen printing with lacquer over will wear on the Power-Volume & Selector. If Hifi restoration was more advanced, you could get these redone. First try with the 110v external transformer at least is as described, it works, after one duff looking cap temporarily replaced & the FM tuner importantly works. We're not trying it for long as it is 50 years old but there is a pleasing sound here if clearly substandard by the aging caps. 'Aux Lo' is the input we use & L+R seem swapped compared to other amps with our cables. To hear bass is limited & clipping shows it's best to work on it, amps like these pre 1967 ones are only for advanced users. But the treble is clean & smooth showing this will sound very nice once upgraded. After how nice some 1965-67 amps are, the randomness of hard wiring here & axial caps is less appealing, but the Trio-Kenwood TK-140X still had lots of axial caps. The Tuner stage Valve & Nuvistors work on 114v-152v & the one can has 3 capacitor stages in it. For the fact if it works we'll leave that one be. Four axial caps in the mid top of the amp are for the FM Stereo bulb & four amid the back transistors are part of the power amp. The Interlock on the mains switch appears to be for safety in console ones with no cases, usually found disconnected. Overall not too hard to recap & not much, if the skill is in doing it right. Getting ready to recap, our opinion whether it'll stay longer is unsure, it seems reliable & a popular amp, though how good it really is will decide. It's more like a valve receiver & kooky things like transistors mid air in plug-in holders all seems a little alien. After recapping the preamp boards & the output transistor ones, time to try it, L+R balance corrected now. Despite the power caps still original, a lively sound far better than expected for the kooky construction. Known strong transient aka kicking tracks are delivered surprisingly confidently. It is surprising that this funny looking amp sounds this good. The biggest underside capacitor was dry & had vented if not crusty. The two main caps were still good. The only minus with this amp is it's semi hardwired making working on the PCBs a bit tricky. We've recapped ours now as well as giving it a better gain. Very clean precise sound with a valve-germanium smoothness, proper bassline now as the original design didn't bring much. As with the 1965 Sony TA1120 it doesn't sound 50 years old at all if has a certain retro sound to it that appeals, no grainy sound here & a precision few amps can offer with a circuit that isn't too typical but it sounds great. Having it 110v & needing a step-down transformer is no bother, no hums or limits to the sound, to find a EU 220-240v is probably unlikely. But it certainly it brings musical pleasure & will be a hard one to liberate to the world as one we've wanted to try. Working out the path of the signal from Aux is very complex if very unusually it has buffer stages. The 2N2613-2N2614 are Germaniums as are the RCA 35144 TO3 output eight set. The preamp to the board mounted drivers then coupling transformer then to the output sets. The audio stages are therefore all Germanium apart from the last two on the preamp! So you can imagine after liking the JVC MCA104E & Duette SA500W amps with Germaniums, why not do this 45w all Germaniums? Some to redesign as some is a bit poor, large signal resistors on the preamp limit the sound freshness, but the fun of it really. Actually worked very well, if one for the advanced tech only to try, there is much more in this amp. All Germaniums done right betters valves, but don't tell anyone. One oddity is the Inputs L+R are correct to Balance control, but as with the Heathkit below, the Headphone is wired the wrong way round to all other amps. The Phono stage is cleaner than nearly all amps, very musical, no thick muddy sound here. Looking at the first manual compared to our late version, the amount of changes are huge with 7 preamp transistors, a totally different power supply & much renumbered, surprising they didn't call them Mk I etc. The Tuner stage with a valve, two NuVistors, The IF & MPX boards is as smooth & detailed as a valve tuner. Ours needs some adjusting to get Stereo if the beacon lights & the FM spread is wider than the dial. You can see how we rebuild amps, as close to original, but imagine the horror at what some person on the AK forum did to theirs, utterly clueless & they actually put an IC on a new board for the phono stage. Not good to mess so heavily with a great design, adding lots of new PCBs even, but still leave ALL of the poor circuitry we upgraded to bring the real sound out is still in their crazy idea. They took it totally to pieces even the selector switches, yet missed the basic weaknesses in the design. Well that's our opinion & after some subtle redesign ours sounds wonderful & looks still very original. Theirs will sound deep-bass-limited and compressed as the original design is. Having had two of these, a Mint one for a customer to upgrade, they are not so easy to work on the preamp boards which are hardwired in & some of the cable sleeving melts off too easily. The 1968 Fisher 700-T & 440-T are clearly later versions if far less interesting, not semi complimentary but the easier capacitor coupled design, if still some Germaniums. On Tannoy Golds it sounds exceptional, for our rebuild-redesign not heard any transistor amp sound that involving. Shortly after, as the Fisher 440-T review below shows, we got both as very high grade ones, the 600-T was barely used. The sound of it as all-original after hearing our upgraded one after does show the limitations of the original design & ceretainly worthy of a 'Great' the flatter soundstage & slight roughness is apparent even on first play, with us used to other amps. Plenty can be upgraded in the 600-T without redesign to better the sound, but ultimately the original design will limit the top fidelity. But the smooth involving sound even of an original one is still a delight. BUY-RAW RATING: As 50 years old some recapping could be essential, don't risk the rare output transistors. Complex hybrid tuner here. REBUILD RATING: To recap it straight without much upgrading in design brings good results, to really upgrade it to be it's best involves a lot of redesign that is too much of a job in real terms. COOL RATING: 8 classic vintage hifi style, but needs the top & base covers and the walnut case with the gold mesh back. (2015)
1965 Fisher 440-T receiver ↑
AS-ORIGINAL (Once Serviced): Great. UPGRADED: Excellent. 20w-25w
CC. This is the next Fisher receiver after the 600-T above. Mentioned in the Dec 1965 HFN mag as 25w into 8 ohms, that issue mentions the elusive 100w RMS 'Mattes SSP/200' that we'll look at on the 'Other Amps' page. Comes in two versions, the early one has transformer coupling like the 600-T & case mounted power amp driver transistors, the later one has no transformers but adds a pair of power amp boards, some have the black heatsinks which need the separator as voltages differ on the smaller heatsinks, but don't get much warm anyway so they omitted it later it seems. 20w only if plays as loud & has a simplified circuit to the 600-T which we found needed a redesign to be it's best. This is the same size amp as the 600-T if is otherwise still in the same style, cases are the same size. The 600-T power amp stage is unusual, the 440-T is a more typical design with a power amp driver board & separate output stages, the 600-T doesn't have a driver board in the standard way. 440T is Capacitor Coupled, other Fisher are Direct Coupled. We had one of these in 2011 without the wood case or inside metal cages as these were often built in. This first one was a 240v one as the one now is if we saw how much of a mess it was & just parted it out & to get this one 5 years later is strange, what would we have thought of it then? The one now is a delight, all bright & 9/10 grade & it certainly looks very smart. The Aux as with the KLH & other amps, if not the Akai AA7000, goes into a resistor & is amplified in the Phono-Tape Head & Tuner output board. We can use Tape In direct bypassing this if as original the Aux input sounds the better. In comparison to the Fisher 700-T in similar top grade we got for a customer, to compare both 600-T & 440-T together is a rare opportunity, see the 600-T for it's review as the high grade. The 440-T just has the output capacitors changed so is almost original. Using Aux the 440-T is the better sounding & it has a little more volume than the 600-T if only 20w compared to 45w of the 600-T, if it has doubled output transistors. The sound is smoother & better defined than the 600-T. Deep bass is noticeably missing for the design limitations if it's certainly not thin. Our 240v one has a 2-core mains cable, this should be updated to 3-core with care on the Live-Neutral using the 2-core on EU plugs as the case on ours reads 11v AC or a full 240v AC which is not good, meter on case to a ground point reveals this. Back to the sound, adding a bit of deep bass on the Soundcard EQ the sound via Aux is actually not too different to Tape In if Tape is slightly better on the bass. The Aux is a good design if it still puts Audio through a 220K resistor, as the original amp, unlike some of these large resistor to Phono stage designs, this has the fidelity. Headphone sockets on USA early amps are always L+R swapped. The first one of our 440-Ts had two black metal heatsinks on the power amp drivers which sat on top of the round smaller heatsinks, but never having tried the first, there are varying voltages on the round heatsinks of 0.5v, 24v & 48v so any metal would ground them ruining things, so as they barely get hot, the later serial numbers, ours is a 65xxx one, must have omitted these. Recent amps we've played are the Akai AA-7000 & Nikko TRM-1200 as well as the 600-T & the 440-T even all original gives an excellent sound, if it needs recapping, has a hissy transistor as well as L+R imbalance. Not a semi-complimentary design, as similarly Sansui abandoned SC after the 3000A. Still has the transistor sockets, not a good idea you'd think, but like the HH Scott below, they stay put & no problems or noises. The bigger version of the 440-T is the 700-T with 42v and 57v HT respectively, 20w & 40w rated if basically the same amp boards inside. A problem now & ago will be the Speaker connector screws. Even a small fork connector as on a 'T' aerial can move & short the outputs. The Gold blocks have the same problem. The best solution is to use THESE ring connectors as we mention on our sales page. Getting new caps for this despite being in high grade, a few were bad, the speaker coupling ones replaced long ago & the main cap was actually dry & crusty inside showing the Fisher regardless of grade need recapping. On recapping this, all electrolytics need replacing, we found a few duff ones on our very hifgh grade one, but it's the most difficult one to work on as boards are hardwired in multiple times. One for the pro only. Further along with this after issues sorted, the way to adjust is insane, we're not pulling transistors out. It can be adjusted for midpoint voltage (L pot) & Bias (R pot) easily enough so we do it our way. Now upgraded & finished, the sound quality here on big Tannoys is very special, shows how these were much wanted when new if our upgrade brings the best out in this fine amp. REVISITED 2018: So to see what went wrong, they used only the Left Speaker screws so overloaded the amp by not using the Right speakers, up to them to understand amp markings or ask. The Output Transistors we assumed were Germaniums, but on testing them, they read as Silicons do & no Fault on those. RCA TR1007 are Silicon if earlier ones will be Germanium. Did we have the later 440-T manual? The ones online have the earlier Transformer Coupled version only, ours with the amp board & pre driver underneath isn't shown? It's actually the same as in the Fisher 700-T manual. Transistors replaced gets it going right again.
BUY-RAW RATING: Will need a recap as noted above & it's a very tricky one to work on. REBUILD RATING: We didn't like the plug in transistors on the power amp, quite a lot to do on this one if worthwhile. COOL RATING: 9 looks great in the wood case, very stylish. (2016).
1965 Pioneer ER-420 valve receiver ↑
AS-ORIGINAL (Once Serviced): Not Useable. UPGRADED: Excellent. 15w (17w-18w) Valves.
First advertised in UK in June 1965. 15w into 15 Ohms will be about 17w-18w RMS based on the EL84 specs on 300v. Rated as Push-Pull the EL84 rated 17.5w, ER-420 uses 335v HT. We've known of this one for quite a while, if after the 1963 Trio WX-400U to not fancy trying one again for 6 years is telling, huge job to do & results not always as good as 1965-67 Transistor Amps. But a Customer wants the SX-800A below rebuilt. To see the ER-420 is the earlier 15w version to the 35w SX-800A, if that one is overdone for the Updated Tuner & Muting, to need a ER-420 to make sense of the SX-800A. The ER-420 underneath is still a Complex Amp which will scare many off, but once understood from Circuit reading, no circuit layouts on Valve amps, you have to work it out. Most will just replace like for like which makes an amp that's not all that to Modern Tastes. ER-420 is 'logical' as the WX-400U was once understood, if to be realistic, 4 years work in that, so not an amp to rush. The SX-800A we got playing well if it was ours it may go further, if we got the ER-420 instead as the SX-800A is just too cramped. Looking at the ER-420 covered in Dust & Cobwebs, it looks Dead, leaking capacitors similarly offputting. But the SX-800A looked like that too & it's now a Trusted amp. The underneath is otherwise clean, nothing damaged or burnt. The point to point hardwiring here is much more manageable. Two Versions. The first has the Hum Adj rear pots, the second has just one Hum Adj pot inside underneath with none on the rear. The Cathode Voltage changes 11v to 20v. The Voltages are slightly different, V5 is 85v then 88v (not 188v). In designs the first one is generally the better one, why the alterations? The design is Phono x2 valve L+R stages, Pre-Tone x1 valve stage. Power Amp is x1 input, x1 splitter & the x2 output valves. 12AX7/ECC83 x5 & 6BQ5/EL84 outputs so all easy ones to find. To get a Valve Amp with Readily available Modern Made Valves is important, we'd not go for the Rogers HG88 III ourselves despite it's great sound as the valves are obsolete if lots still around, so don't avoid it. Our 'Other Amps' review sees good in the amp if only having the Amp here to Circuit Gaze really tells. AC heaters is a pity, the SX-800A actually only has AC heaters on the 2x Phono, the Power Amp Gain & Splitter is over 2x ECC83 which is much better than the obsolete 6AN8 of the SX-800, why they used that makes little sense. The 'Hum Dinger' is an old idea Balancing the Phono DC Heaters with the EL84 output Bias, it's crude. Bias here is fixed beyond the Hum Adjust pots on the rear. Fixed Bias on EL84 not so crucial if buying Matched Quads but Biasing individually is far better as we put in the WX-400U if what can be done here? ER-420 works on 340v HT & the SX-800A on 460v. Both are Pentode Mode which sounds better than the Ultra Linear mode that uses NFB to make the design easier. The Tone stage much like the SX-800A. The 2x ECC83 as power amp driver-splitter instead of 2x 6AN8 are a better design & more spaced if still busy. ECC83 to 6AN8 gives 2.7K or 22K NFB. Valves with the Higher NFB here seem to sound better, the LX33 has 2.7K, HG88 III has 4.7K as it depends on the Driver gain, 6AN8 less gain therefore. Says 15w into 15 ohm, 2x EL84 in Push pull 17w max. 340v here sensible unlike Sansui 500A pushing 420v into EL84 uprated 7189As. What To Do With It? Firstly Recap main parts just to see what it sounds like as near as Original as possible. No hurry on this one. We've seen better design in here compared to SX-800A, beyond AC Heaters & Fixed Bias-Hum adjust. The SX-800A seems to try to overdo it, 35w in a case just 1cm deeper. A 1966 valve amp, same year they made the first SX-1000TA & by 1967 the SX-1000TDF is a great Transistor amp. Seems the ER-420 was made with care, the SX-800A made just to compete with higher power & Tuner needs. ER-420 has 2x single caps C101-2 but 2x triple caps C99+100 are 20+20+40µf. A Caution on some Valve Amps is beware using on Headphones, To use 'Speakers Off' to put a Resistor Load that if done correctly as the SX-800A was, it'll not affect gain, but is Required due to how the Output TXs are wound. The ER-420 uses 10ohm internal load & the SX-800A uses 16 ohm. The Sansui 500A uses 8 ohm which does affect the output. The 500A not a good amp in several ways. Rebuilding we need to Do Quite A Lot to even Dare trying it, bad leaky capacitors are not for plugging in if the seller did which shows they didn't even bother to check it. Upgrades to make this to Please a Modern Buyer needs a Ton of Learning, Identifying Components that are just a 'Rat's Nest' underneath. Still a lot to learn to get it right. Got it Cleaned up nicely now awaiting the new Capacitors. a problem was the Bass control the spline Rod was half broken off so the previous owner glued & soldered it back if the remaining bit was weak too. Possible to do Surgery on it, if it'll always be a weak point, don't get it knocked. But to get it working to Hear it for the First Time. AC Heaters in places, is it Good enough for us to go Further on. Just ordered the major parts first. Be Sure to Check the Power Switch inside the box. Redone The Power Supplies. Play It Half Original on 1966 Valves. Couldn't try it as it was & too precious to gamble on known bad caps. Seller as typical lied to say 'it works', as the Circuit Breaker chucked it straight away if the unexpected fault found. Upside down to watch for Smoking, no problem here. Sounds rough & wobbly initially if good in there too. The ECC83 & EL84 sound even with aged parts sounds more towards the HG88 sound. Still on the Rest as Original, some light crackle is better than some Valve Amps we've tried as original. Got to be a Gambler to Mess with Amps like this, if usually they haven't had much use or any Alteration. The Power Supply is Hugely Improved if the Rest as original shows what it sounds like. After about 10 mins it sounds more together, not a caase of getting used to it, the spitty treble is now surprisingly crisp. It sounds way better than the rushed SX-800A below & much better than the 1963 Trio WX-400U. Fast crisp Treble, the SX-800A suggests the different Power Amp Valves weren't designed optimally, the ER-420 by the Pleasing Sound is. Be sure to Switch 'Speakers' to "Off" to add the Load Resistor in Circuit or it will 'complain'. Could be bettered as the Volume Gain is slightly affected. Treble is very decent so far. Bass is still the original design if the Bass sounds decent. The idea how good this could have been in 1966 would be a Great Amp, if our Upgrades improve what would not have been as Impressive, but in 1966 terms, a good seller tells what Buyers thought, yet Shelved it by 1968 on getting into Transistors. AC Heaters not a problem, V3 & V4 are Tone, Driver & Splitter, no extra noise surprisingly. 1970s Reggae is great, to try the Joan Jett 45s to hear the Amp as it is Currently does very well, not the Bass weight yet but a Clean Sound, unlike some Grainy Weak Amps can play. Volume up halfway is a good level & go louder past midway if that may be into Distortion, but it's there. Stereo width is great too, even on the Old Grey Caps if we'll Replace all those, but to Enjoy it near Original matters, if not for Speakers yet. Pleased with this one. Be Aware it'd not sound this good on Original Power supply. The valves seem Good too, if the Right Channel slight crackle could be anywhere. To use this for a while 'Reforms' the Capacitors, but don't be Fooled, next time it'll be Rough & then risky issues show up or it goes Bang. We'll not use it again until more done. AM works if no FM. At this similar 'midway' point, it betters the SX-800A, HG88 III, WX-400U, W41 & LX33 easily. Why not try the Luxman LX33 next, 6 years upgrading that. Interestingly the ER-420 at 15w compares well to the 30w LX33. The Bass is quite close, the ER-420 sound is a little 'retro' on the Bass but very well done compared to some. The LX33 has Zero Retro Sound limits, if it's why it took 6 years. ER-420. What A Great Amp. Getting New Preamp Valves it shows a quality sound if still much more to do to get to an Excellent. A lot of work in these. Now Done. A big job to do & needs a good power supply to sound it's best. Needed a Tuner valve for the FM, coukd do with a little work. The Audio Stages are Extra Good on this, a crisp rich sound with depth & speed. It's more musical than the 1979 Luxman LX33. Not tried Phono yet as these are typically not quite right, as in Bass isn't right. These need a big rebuild with redesign, to see a higher grade one with the original box & capacitors sold as working is a risky one for the age & voltages. What's It Like with Our Upgrades? To go further with this one to see how good it can be, if plenty more could be done. Beyond FM tuner quirks, the Aux in is the main thing. It just sounds fresh & modern, a fast clean detailed sound with a nice Bass, nothing grainy or Retro Bass here. The SM-83 (SM-500) amplifier is a version of this if with the 6AN8 more like the SX-800A (SX-2000) below with is more 20w RMS than the confusing ratings. Plays very quiet on the background noise as rebuilt. The ER-420 in design is the Best Pioneer Valve Amp with the Tuner stage. Sold quite well as it must have sounded great in 1966. On Speakers As Our Rebuild this sounds awesome. Very clean 'front row' sort of sound. Huge Soundstage with Wide Stereo & a sound like we heard with the JVC 4ch Bridgeable amps. Far from the Old Wallowy 'Valve Sound' this is fast & precise, maybe not what you'd expect, if other Valve Amps we've rebuilt are not unlike this. Valves. Ours has Hitachi 6BQ5 aka EL84, three with the logo at the lower edge & another with it at the top. These actually sound good to suspect they were replaced when it got a repair. Saves us £80 as they'd not 'burnt in' to the limited bass like original ones would. Needed a Tuner valve as one heater dead & the Tuner only picks up the upper half of the FM tuner range so probably another valve to replace. Hum Adjuster on the rear panel. Two versions. The User Manual doesn't show these two adjust pots if they are on our one. On the Service Manual these do show as VR5 & VR6 but the Diagram has alterations by the Output Valves, if another Diagram version shows the original version, VR5 & VR6 are on the Transformer windings, the later one explains why a single VR5 adjust pot by the TX inside underneath. The earlier two-pot one adjusts Hum on the Phono. Tuner. A Valve Tuner can sound extra good. Here the Tuning Scale only brings channels on the higher end of the scale. It may be the first valve faulty, if half works suggesting it's something else. BUY-RAW RATING: Too far gone as typical with all old valve amps, if ideal advanced project amps. REBUILD RATING: Advanced needing redesign to do properly. COOL RATING: --. (2020-2022-2023)
1965 Pioneer SX-600T receiver ↑
AS-ORIGINAL (Once Serviced): Too Aged. UPGRADED: Excellent. 25w.
Germanium Transformer Coupled Power Amp, Direct Coupled Output. This is The First Transistor Receiver by Pioneer. A Germanium Receiver with only the Outputs as Silicon as with other Higher power Germanium Amps & Receivers. 25w was High Power in 1965. The fascia is very like the Pioneer ER-420 just above, a few differences on the lower left if much the same, much nicer all silver. Transformer Coupling on the Power Amp with No Capacitors on the Outputs so Direct Coupled. Not many use this design, the Pioneer here is like the Sanyo DC-60 with Autobias. The design is quite like the 1965 Sansui TR-707A, both are rated 16w but into 16 ohm, so 25w into 8 ohm. The similar earlier SX-1000T seems very rare, this SX-600T is certainly rare, one on ebay USA for $100 early 2024. Big Rebuild needed. Other Germanium & Early Pioneer. The Amplifier version Pioneer SMT-84 has a TX number 'AT-5245' which is earlier than the SX-600T with 'AT-5299', if this can mean it was designed first but sold at the same time, the SMT-84 with Germaniums mostly is the amp version of the SX-1000T, beyond the last 2 stages which are Silicon. A SM-83 (not SMT-83) appears in HFYB 1966/67, this is a Valve Amplfier. All are in the HFE '1970' German Brochure, if it's a 1966 one really. As we have the ER-420 valves & the 40w SX-1000TA which is a design used on a few SX-1000 & SX-1500, to compare them to hear which is the Best, which based on the other two, will be a challenge. SX-600T a Multivoltage one as Pioneer usually are, it was in the 1966/67 HFYB for £180 which is more than the 35w valves SX-800A for £171 as reviewed here too. SX-1000T was £204 (not TA). Both the SX-600T & SX-1000TA are in the 1966/67 book, to see which is the earlier. SX-1000TA has a Valve & Nuvistors in the Tuner, all Silicon Transistors the SX-600T has 4 Nuvistors if not the familiar Speaker Plugs the SX-1000TA has. *The 12w SX-300T is all Germaniums & is capacitor coupled. Pioneer making two models at once as Technology was changing fast. Germaniums are a 1965 design based on ones we've had. On the HFE site, a 1966 Brochure wrongly dated '1970' features this & another SX-1000T with Rocker Switches. Silicon transistors on 1000T, so after the SX-600T if looks very like it, rated '45w music' when 600T is '20w music' into 16 ohm, so earlier than the SX-1000-TA. Pioneer used 'SX-1000' again in 1986, HFE have that one, the SX-1000TA, SX-1000TF & the more common SX-1000TW, but not the SX-1000T. More confusion no doubt. The first SX-1000T is on Google images at least twice so it exists. The fascia is the same as the 600T if it's FM only as is the tuner glass. One site says the Pioneer SMT-84 is the same design as the SX-1000T, looking it has Germaniums, if 2SC147 is Silicon, so these are later than the SX-600T. Sort of Overwhelming to see So Many Pioneers pre 1970, how did buyers cope? What Transistors Are In It? Germanium PNP Transistors 2SB347, 2SB345, 2SB54, 2SB383, 2SB379. 2SD47 which is a Silicon NPN & the Output Transistors 50w 5A rated. The SX-600T shows the Top Layout with the Tuner parts & Power Amp last stage, the Preamp & Power Amp other parts will be underneath. Transformer Coupled with Fixed Bias as other 1965-66 Amps are. Some Germaniums are very low spec, here the 2SB ones are of a better spec like the Sansui TR-707A uses. Tuner is All German iums as is the first Sony tuner. Seems this Germanium amp was a limited run as the Silicon amps soon arrived. The 600-T was still advertised in late 1969 by 'Swisstone' selling off old stock, see the Blogs. Design is as quirky as the TR-707A to see what Pioneer did in Germaniums is a must. Power supply uses 3300µf 35v for the + and - voltages. Aux goes through the Phono as was still the usual design. Tape Monitor isn't quite Direct as it has a Resistor in-line. Phono-Inputs is a two-transistor board. Tone-Pre is two transistors then Volume. Then another Transistor after Volume. The first Preamp transistor is a Buffer stage. Power Amp has two transistors, one a larger Driver then the Coupling Transformers meaning no Splitter or Bias stages as in later designs. Main NFB is 120 ohms, the TR-707A used 100 ohms, compared to later designs, this is a High NFB. There are similarities to the Akai AA-7000 & the Sanyo DC-60. The Pioneer SMT-84 mentioned just before has design different to the SX-600T. Smart unit with the appealing 'MS Mincho' font like the SX-1500TDF has. Same size & lid as the ER-420. Inside First Look as only seen the line drawings. Lots of blue capacitors with the Triangle logo. A Relay is a surprise, it's part of the MPX switching, similar to the early Sony tuners have. Tuner boards have smaller adjustable coils like 1970s tuners have, these weren't in 1966-69 Pioneer. An assortment of Output transistors, 2SD47 or other early ones you rarely find still in amps, we do have similar Vintage ones to use. The top boards are marked with the components used, unusual to see even the Transistors noted. Has original Nichicon 4000µf 35v main caps fitted. What's Underneath, never seen any Photos online. actually not that much, the Tuner & Amp boards have the components on the top side, underneath has the Nuvistor 150v capacitors, one very leaky looking if dried. The Transformer has a AT-5299B code. A Square Bridge rectifier block 'Origin SP(02)' is the original one. High quality build quite different from the more familiar SX-1500TDF type boards'. We Like It. Thought it'd be a good one & an interesting one, which it is even without plugging in yet. To have a 1965 Direct Coupled Transistor amp with only the Outputs replaced variously & one 0.5 ohm power amp resistor changed is good going. Antenna bracket the parted SX-1000TDF can supply. For Advanced Buyers wanting it Rebuilt. Speaker Outputs are a screw block with spacers like the 1968 Sansui 3000A uses, if these bigger with holes to solder wires. Interesting to see a great design like the Sansui TR-707A yet only a 1965 one & never reused. The Case being large for a Transistor amp. The ER-420 has an AT-5296 numbered transformer so Pioneer created both of them at the same time for 1965 sale. The ER-420 was much advertised in Hi-Fi News if no mention of this in ads until UK's 'Swisstone' bought an old stock batch, so minimal sales. What Does It Sound Like? To estimate it'll be in the league of the Valves ER-420 & the second SX-1000-TA is why we got it. Power Button like the Sansui where on-off looks the same. Beyond expected roughness on controls & power supply hum & a bit of transistor noise one side, it actually plays Music giving the idea it's a good one, if noises & a sound not too loud past midway is much like the ER-420 as original. In 1965 beyond the Tannoy Silvers probably not many speakers to do it justice. Badly needs a service, so try another time. Amps like this for Specialists, it's not for the sort who buy & just plug it in 'hoping'. Dual Mono Design. Hearing it rough but listenable, to notice Stereo was Very Wide & amid what we heard, a fresh clean sound is apparent. You'll have heard of Dual Mono Power Amps, even ones with Double Power Supplies with Double Transformers like Harman-Kardon used. But Never are the Preamps Dual Mono, they always share some of the components to both channels. The SX-600T doesn't, they are two distinctly unlinked Preamps after the Q19 regulator, if the circuit misses a 'joining dot'. Never seen this before, if go to look at the TR-707A to confirm, it uses several voltages if they are not unlinked. The SX-2500 is linked. So Unique Design here on the SX-600T, it only uses the ±HT on the Output Transistors together, the rest is Dual Mono. Have wondered long ago, in 2014, on the Pioneer SA-9500 why their Preamp couldn't be like this. The SMT-84 Amplifier is similar & likely the first SX-1000T is too, if no info found. SMT-84 adds two Mains Chokes on the 48v DC. Once Serviced, Not Recapped Yet. Still needs Volume on Headphones past midway. To hear Amps As Original matters, to not be able to play an amp means you have no reference. It's a bit rough with minor treble slurring & no real Bass. One channel treble spitty a bit & the other with the Germanium roar as the TR-707A had. Quality is in here if well aged & a strange limited bass showing even in 1965 they were Scared Of Bass. To play Dynamic Rock tracks shows the SX-600T as it stands is struggling, but still it's quality shows. Too aged to use, a bit of Hum, one Heatsink side a bit warm, but more the Big Hiss. We'd expect it to be like this & the idea is to Rebuild & Upgrade. Certainly not for a Non-Tech buyer as it's basically a great amp from 1965 on it's last legs. It can hopefully be Rebuilt well. How many of these Amps are getting Upgraded Properly? Only Our Ones. To us, it's a good amp to at least have to try. Main Caps Replaced. A Hum in the Amp solved, so what are the old caps like inside? 35v ones surprisingly still wet not crusty on either. For 58 year old caps you could still use, but they are clearly past their best to Hum despite not dry. To Recap & Upgrade more. Recapped & all the messes sorted, to think it was way ahead in Sound Quality for a 1965 amp. To use 'Tape In' as sorting Germanium Noise is hard to do so leave it as it works. Gain is still too low & later altered it brings up the Germanium noise like the Sansui TR-707A has playing the same volume. Previously it was very quiet on 'Tape In' but not loud enough & it's hiding the real sound if the Germanium noise isn't offputting on speakers. all those amps claiming 'Improved Sound quality' over the Next Decades clearly haven't heard how good this one sounds. It's not Perfect as of reviewing, the Bass needs Tone gain to fill it out, early days on this still. The Real Thriller on this amp is how Clean & Precise the Treble is, not heard this on any other amp if now A Sound to try to upgrade others to give. Further Work Done. A 1965 amp is now 59 years old as of 2024. It's had a lot done now. Germaniums done right is a Real Treat as it's so clean & precise. Most Geermanium Amps are Hissy as the Design hasn't dealt with ways to Not Be Hissy. The SX-600T played via 'Tape In' is very quiet, bringing out how detailed & wide Stereo the amp plays. This open trebly sound is not like any other amp, to try on Speakers once the Bias is made better. The Volume control is balanced until past midway when the Loudness part is gone past, leaving it unbalanced. To get another Volume Control, or just adjust Balance to centre it seems more sensible. Interestingly for such an old amp, the sound is so Fresh & Modern, if no Modern Amp sounds like this. Tuner nees recapping as uneven & boomy, the Boards in the amp & Manual have totally different numbers. IF Board 'AM9127B' if 'AM0123U' on the manual etc. Once recapped nice clean sound, FM Stereo with ease, the Relay clicks are an odd one. Valve or Nuvistor Tuners are often the best sound. Nuvistors & Germaniums are certainly a special sound. Seems We've Finished It. A lot needing doing here, certain parts 'no good' so not used but left intact. DC Offset with a test Speaker on is 49mV on L & 8mV on R. Not going to be perfect without Matched Transistors, but this is fine in Use. One further change we've left until last to see what it does & it brings a very Tidy Sound. Germanium background noise is minor. A Neutral Sound with very Precise Treble & Bass is right without being too heavy, no info found but sounds more a Damping Factor of 30 than 15 of other early amps For a 1965 Amplifier, it sounds 'More Modern' for such a clean precise sound, but you'll never get anywhere near that on actual Modern amps.. Volume Control is fairly even L+R until midway when the Loudness ends & then it goes off Balance, but it can be altered with Balance & you'll never find the correct Volume pot, so leave it be. But Not For Long, to find the Nikko TRM-120 fitted exactly having a longer Spine-Threaded part, fitted that & properly Balanced. Worth the cost of the Nikko, impossible part. The 1966 Pioneer Advert said it's the One Dealers Buy For Themselves. Not hard to Hear Why. But it needs a Big Rebuild. Germaniums To Silicon. This is Possible if you understand the Issues it'll bring. BUY-RAW RATING: Probably on it's last legs for the Age. REBUILD RATING: Germanium Hiss & Roar is likely if Tape Mon as Input will usually be better. COOL RATING: 9 one of the best lookers in our 1963-1980 interest. (2023-2024)
1965 Rogers Cadet III valve amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 10w Valves.
Important starter amp into the world of valves, but don't pay too much, £300 for an unserviced amp is too high. Looks nice in high grade though the one part amp often looks look tired. Always needs restoring & careful buying as many used for a long time & often found altered. Quite a small basic amp with tiny output transformers so bass is limited though for 10w it's adequate, the HG88 is the bigger version if power is needed. Best buying the later one part version as the 2 parter can be tricky with that connecting cable, our high grade one sparked & had other issues. Plays like a 30w transistor amp with a strong clear lively sound, but ultimately limited by the power output. The thing is these are now very old & many have been used & messed with for decades, making the prices buyers pay seem excessive as they all need proper rebuilding as the main capacitors are now dried out & ready to fail. A serviced good one worthy of 'Very Good', based on our early 2 part one. Treble is a little ragged due to the spec but a fine sound that will be addictive. Read more on the 'valves' page. All the Rogers valve amps have ECL82 triode-pentodes, the preamp ECC807s are long obsolete & the large Aux 220K input resistor will limit the sound as it then goes through the Phono stage flat. This & the HG88 Mk III are good starter amps into valves, but don't bother with the earlier Mk versions, leave those be if you want to play them. BUY-RAW RATING: Risky for aged parts & old work or alterations done on them. REBUILD RATING: Never rebuilt one of these. An involved job to redo the main capacitors needing redesign. COOL RATING: 4 as the styling has no real flair to it, plain basic fascia in a formica box is functional. (2013)
1965 Rogers HG88 Mk III valve amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 15w Valves.
A higher spec Rogers amp that sounds nice but is still limited by the old design ideas. It can be made to sound ageless and the sound can be modernised with remarkable results, capable of a deep bass beyond the limited original design. Very Good is the 'as-is' serviced rating though it can go to excellent with much design-based work. The main HT capacitors are always dried out. Only the high value input resistors limit the fidelity & it's ranking. You must try a Rogers to hear valves & if you upgrade & know design. Plays like a 50w transistor amp. Again it's nearly 50 years old & will need much work done as the main power capacitors at the back are dried out & ready to fail. More capable of improving than the Cadet. The only minuses are the case has poor ventilation making the rightmost valve get to over 100°C against the case & scorches the wood case & the high input resistor for Aux. To overcome the awkward triple capacitors on recapping can be done. ECC807 valves are similar to ECC83 if pins differ & minor resistor changes required. The bias slider is too coarse to set properly. Read more on the 'valves' page. All the Rogers valve amps have ECL82 triode-pentodes, the preamp ECC807s are long obsolete & the large 220K input resistor will limit the sound as it then goes through the Phono stage flat. REVISITED 2018: We help a Cusytomer get a nice HG88 III for us to upgrade. Buying these amps is difficult, missing cases, bad repairs, rusty chassis but here the first one found is a good one, working if "Restored By an Expert Tech With 40 Years Experience. On getting the amp, 40 years TV repair guy, the Menace to electronics who does it as cheap as possible with zero care for quality. Not surprisingly the work is messy, they use cheapo Yageo & MIEC capacitors, the Made In China junk we'll just bin & just recapped like-for-like with the 5 main caps still in place if the China caps fitted haphazardly underneath, some with long leads so close to other points it's a bit of a worry how it never shorted. We rebuilt one of these as on the Gallery in 2012 which took a lot of working out to make a good upgrade & this one will get refinememts on that. The Original Sound of the amp as arrived was told to the Customer as "Bright & Screetchy" as well as Overloud with no subtlety, no bass & a flat unpleasant sound. To recap & upgrade plus fit some new output valves as this had mismatched ones as well as 2 of the ECC807 were Pinnacle brand ones. The Build quality on these Rogers amps is neatly done on tags onto the casework & it's a heavy item for the size with the transformers, the Output ones being far more substantial than the feeble Cadet III ones. The Speaker outputs are a line of 6 screws, it's not an 'E' for a Turntable Ground, it connects to the output transformer, why the 'E' screw exists makes little sense, just use the '+' and '-' with the right 4,8 or 16 ohm impedance being selected. Aux preset lets you adjust the level to stop it being too loud if that does lose some of the quality too & the Aux does still go through the 220k resistor to the first valves which are used for Phono also. The Mains cable is still the old Green-Red-Black one which is out of date & may confuse, Red is 'L', Black is 'N' & Green is 'E' but as the cable is 50 years old it needs replacing. First Try as Recapped & Upgraded. Still using the Original Valves, ECC807s wuill stay if a new set of ECL86 Edicrons will be fitted, these usaed to be sold by Maplin in the 1990s so we know the brand is good. This uses the Headphone box on the speaker outputs. No hum or hiss & just the occassional light crackle from an ECL86. A little Loud on Aux so adjust the rear inputs to have the screw horizontal & use a 470R headphone resistor not the usual 100R as the Volume isn't balanced at the lowest levels on the control as typical for this era. Pleased with the sound, it sounds like it should, proper bass, not harsh or thin, not scratchy & grainy. This upgrade is based on our 2012 upgrade with a few tweaks & sounds very decent indeed. The 220K input resistor does slightly compress the sound if the Amp itself as Upgraded is so lively it takes an aware ear to tell that. Sounds as good as other amps we've upgraded to sell. Would say it could do with a better focus for Rock, so to try the new Edicrons as the difference Old Valves to New Valves on the EAR Yoshino 2000 year amp recently made a good improvement. Let them sit to burn in for 10 mins & try. The ECL86s all hit 100°C with the rightmost one less ventilated a bit higher. Not an amp to build into a cabinet which was a selling option as 'chassis' model without the case, as you'll raise the temperature too much. this amp needs to be freestanding in the cabinet. Valves warmed up to full operating as high treble is contained not spitty. Much better with the new valves & going back the 100R setting to hear it at the right level, it's very smooth. HG88 III was the 'midprice' version of the 'budget' Cadet III if both are far better than the quality of midprice-budget by the early 1970s. Of course we're reviewing our Upgraded amp but this is what it can be if you spend a higher upgrade cost on it. Not quite the Bass of an EL34 amp & you'd not expect it. Vey Fresh 'Modern' full range sound now, what a difference to the 'Original Sound' opinion. It sounds as good as any Upgraded Transistor amp & the fast punchy sound is far from the usual slow 'Valve Sound'. Getting quite a few songs played. Stereo is wide, if have heard wider. Fast Enough to cope with 60s Ska, if again a bigger power will better it. The "E" Connectors by Speakers: These do go to a Ground Connection if not Direct to the case, the right E goes to the outout Transformer & via a wire to the Mains Ground. the left E goes to the Inpiut-Phono stage ground further up the case. This will both give a different ground potential, to choose which is the best. Later amps just offer Ground to the Case which works fine. Base Lid & Cabinet Screws. These are an old style Imperial thread that has been obsolete for Decades, but you can buy this Threaded Bolt from USA if finding one to fit right probably is very difficult. Compare HG88 III to LX33. Both our upgrades & both gave ideas to each other. The Luxman is our design beyond the basics, LX33 brings out detail & a larger soundstage if the balance of the sound is quite similar, we based our Tone very much on the HG88 III one as the LX33 one was poor. The 220k Input resistor does still compress a bit & the LX33 without this is a more open sound. Back to the HG88 III after hearing the LX33 which is based much on the HG88 III upgrade, takes a little longer to get to optimal voltages, if is fine after 1 min. How similar they sound. A Rogers HG88 III rebuilt our way will take on any Modern Valve amp & better it. We recently did a Fisher X-100-B 15w amp from 1963 & the HG88 III does better it as the Fisher amps do have complex designs. On Speakers. With 1967 Tannoy 15" Golds that this amp maybe wasn't a natural choice at 50w, the early 15w Tannoy IIILZ probably used more often. to use the Gold 4mm blocks if to add heatshrink as too risky to just tighten as no grip lugs. It actualy sounds awesome. Not what we'd expect having heard other Vintage Valve Amps, but to remember the design is what we based our LX33 on. To us it's the sound we search for, it's clean, crisp when the Treble Tone is turned Backwards for Gain, not the usual Clockwise way. Deceptively not that Bassy as stated above, but on speakers with TV shows that chuck out deep Basslines it packs a punch that is unexpected. More domestic sounding than our LX33 version, this just sounds so good we want to keep it, if we have one transistor amp of a very similar design that betters it. Rogers HG88 III upgraded is the Best Vintage Valve Amp you'll hear, Vintage as in pre 1977, the 15w is enough to fill a medium sized room on efficient speakers if 10w isn't quite enough. Great amp, Great Upgrade by us. But if you like that soft wallowy aged Valve amp sound, that is called "Valve-Like" then this is far from that as it's fast fresh & a joy to hear. 2018 Customer's Verdict was they said they read the review a few times for hearing how good we rated it. On them getting to play it they were beyond pleased. It's one of the Best Sounding Upgraded Amps we've had, not many sound quite that good. BUY-RAW RATING: Risky for aged parts & old work or alterations done on them. REBUILD RATING: We rebuilt one as our Gallery pages show, if that was a few years back. With redesign & good upgrading it gives very good results, if this is quite a big job to do right. COOL RATING: 6 as a bigger unit just rates a little higher than the Cadet III if still very utilitarian looking. (2013-18)
1965 Sansui TR-707A receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. At least 25w.
CC, Transformer coupled, Mains Choke, All-Germanium preamp. The Very First Sansui Transistor Receiver from May 1965 actually was the Unissued TR-707, a reader sent us the TR-707 advert & the fascia differs with what looks like 7 push buttons on the left. Inside top with less tuner boards & layout. FM only, the 'A' adds the AM tuner. It Appears To Be a Prototype only & the Ad says to 'Wait for it'. The TR-707A is their Second Solid State likely later 1965 than 1966. The TR-707E seen in HFN ads adds a LW tuner stage, the TR-707A is FM/AM only. Amplifier or Receiver, predates the Sony TA-1120 by 6 months if really only the Fisher Transistor amps are earlier. Rated 18w if our tests show it's in the league of 30w amps, likely rated 18w into 15 ohm as this isn't noted, 8 ohm speakers in 1965-66 were rare, so at least 25w. To get a nice grade one with very stylish looks, the basic Sansui 3000(A) styling if just a bit more classy with those long tubular & 'Rocket' type control knobs. Rocker Switches moves on from awkward Slider switches. This amp appears to always be Multivoltage as it was a Japan-made amp for Export Only, so we gambled on a shadow of the voltage block being such & it was. But ours is still very early, Jan 1966 date & the TR-707A was made until the Sansui 400 below replaced it in Feb 1967. One we have seen so it must have sold fairly well, if not as easy to find as the 1968-69 Sansui 3000A. Bigger than expected, knowing the Sansui 400, it's 450mm wide, 150mm high & 353mm deep if 382mm inc fittings. Ours has a minor repair & 2 replaced output transistors if otherwise a good one. The design of this appealed, inside pics show it's the Transformer Coupled design, big resistors that the 3000(A) similarly has, plus oddly it has a smaller 'transformer' that's actually a Mains Choke more what Valve Amps used. Still on the original Elna capacitors, it's said to be working. On first try it does work, but with noticeable strong Hum & the front lights are dim. The same 'boink' noise as the 3000A does on turn on if a steady hum & lesser hiss, hardly useable if works if the L+R channels drift levels showing it must be rebuilt as so old. FM & AM works if rather vague on the controls as usual if it plays both channels. A fairly crisp if rather Retro Bass sound with Deep Bass limited. Plays Reggae adequately if Rock shows it up too much, to service next. So as of typing Nov 2018 we have two very early Transistor amps, this & the Akai AA5000, who else would get amps this early to review & upgrade. Should be interesting. Manual Variations. For an Amp first out May 1965 as TR-707, ours is TR-707A Jan 1966, the Manual findable is a bit later. Ours has C177 as 400µf not the 800µf plus 2 extra on the Power Amp Driver board underneath. One labelled Photo online has the Rectifiers as Black not Silver & only 2 coaxial Capacitors, ours is the earlier like another photo with 4. This board has the Capacitors very close to the base lid which can cause problems if the lid bends. 1965-66 Version. On getting one soon after to rebuild for a customer, Dec 1965 code date, it doesn't have the Sony-type Multivoltage block, it has a small valve type plug. What to do seems impossible, it's an Export-Only design but the Schematic in the lid on ours & this slightly earlier one shows there was an option of 3 plug-in pieces, one used & the others get lost, if not hard to rewire to the 240v version, if to remember the wiring is looking from the outside, not the soldered inside, so it's flipped. without that it'd take ages to work it out & still not be sure. It's in the lid. 2 or 4 Capacitors. The early ones have 4 capacitors & 8 smaller resistors on the underneath Amp Driver board, later have 2 capacitors & only 6 resistors, as the design got tweaked, or dumbed down perhaps. Ours is the 4 cap & the pdf Manual is a 2 cap one so to see the differences. The 2 cap board loses the 2 taller 1000µf 6v caps to stop the board getting broken as they are too near the lid, ours has 4.7k ohm which is R231 not on later amps plus other slight changes. The 500µf 6v cap isn't on the manual though if it's before the NFB resistor, so there are a few minor alterations. Again the Circuit in the Lid is earlier than the pdf service manual one. The 2SD245 version has a few differences to the 2SD46 one. The Design is fascinating for so early, this only really had Fisher amps to refer to & it copies none of that. PNP preamp transistors with a -HT is unusual & based 'possibly' on Germaniums (read on...). Some design ideas are ahead of their time with the Phono-Inputs board as two boards to keep them separate. Strange non-standard early Capacitor values & for the PNP design things are different. on the underneath Power amp board a big resistor gets to 70°C if it's right next to a large capacitor if the other parts stay under 40°C. Another hot resistor gets to 60°C by the diodes if the Main Heatsinks are cool. Sansui used the early Conical type Phono sockets as with the 3000 & some 1967 dated 3000A plus the 400, these need the older type of cables with 4 open-bendable ground tab grips on the plug, we got some with other amps, if the Modern Cables won't connect right. Lighting with LEDs is subtle. Output transistors have one side with likely early originals gold edged Sony 2SD46 5A 50w if the replaced pair are totally unknown WTS423, Gold Pins so 1960s if no info found, if possibly custom ones taken from a Console Gram etc. All other pics of the outputs have replaced ones. Clean Sine Output on both Aux & Tape Mon is 20v on both channels so the WTS423 are adequate & sound good so leave it be. 20v Clean Sine is what other 27w-30w amps rate. Speaker output fuses do have plastic covers over if they don't grip well, later amps had a metal part over them. Tone gives about +13db Bass boost & +15dB Treble boost show the manual's graphs, if the Power Ratings aren't quantified so our reading it as a 30w amp tells the 18w is into 15 ohm which was standard in 1965 still. Another Graph claims it to be Flat over 20Hz to 20kHz, to later hear how extended the Bass is with it picking up missed Sub Bass on a BBC TV show reveals this amp is a bit special. For those into design, the main NFB resistor really is that value, it's not a typo. Mostly Recapped. It Needs A Full Recap as rather tired sounding. Each stage recapped improves the sound if only the Outputs & 2 Main Power supply caps to arrive. Sound so far on being able to play it properly it has an unusual sound with a very Rich Sound if Treble is still crisp with Stereo being quite wide. There still is some Hiss & Hum if overall it sounds Retro but nice with it. Why Retro Sound? Looking at the Spec Sheets, the Black PNP Transistors are Germaniums, 2SB378A & 2SB381 if the 2 Driver Board ones are Silicon. Explains the Minus Voltage HT as thought just above & what's more surprising is they are Sony ones, Drivers are Sony too, if manual 2SC292 are the original ones, but ours has 2SC470 which appear original on the earlier '4 cap' versions. Outputs are originally 2SC245 if ours has 2 different pairs. Now accepting the Germanium Preamp, to understand it better, the only other successful Germanium amp is the Fisher 600T if it has a lot of Sound Shaping, here the TR-707A is with better spec so no need to compromise & explains an unusual design. We'll keep this Germaniums even if it still may slightly hum. 'Aux' goes through a large Resistor into the Phono stage, to use 'Tape Mon' input plays louder & sounds better for it if otherwise not so different, if comparing back, Aux is very slightly more on the mid bass & just a little less fresh at the same playing level. Main Caps Done. These fitted & the background Hum is much reduced, not totally silent but on Headphones Hum is not much now. Main Cap was dried out & starting to go crusty. More use makes the Hum level very low if Germanium Hiss shows. Verdict Now Done. As this has Germaniums & an early design there will be a background noise that's not as silent as later amps. Aux goes through the phono stage which slightly compresses the sound, but the 'Tape Mon' input is direct. 1965 Transistor Amp before the Sony TA-1120 came out is a bit of a Gem & with low NFB it's much fresher than the TA-1120. The sound compared to the 1967 Sansui 400 is similar if the TR-707A betters it for rich sound & the Germanium sound is different if as crisp & detailed. Great Design just needing Recapping-Upgrades if nothing else changed beyond the odd early Driver Transistors. The SE-1.5 Selenium Rectifiers we've kept also the Germamiums as it gives a nice alternative sound. To keep it good to use as a Daily amp the 18 Tuner Board Capacitors we'll recap as they are 1966 vintage too, if hard to work on the Tuner. Really didn't expect the TR-707A to be this good, but it certainly is. On Tannoy Golds. This has to be the Best Sounding Amp we've ever heard, it has it all when other amps can only do some of this. Effortless wide-open sound with nothing unbalanced, solid midrange with wide Stereo & a sense of 'all veils removed' from the Speakers. Rich Natural hypnotic sound with Deep THX type Bass like you've always wanted with Treble as Clean & Crisp. All from a 1965 Germaniums Amplifier rated 18w if into 15ohm as it tests like a 30w amp. Aux or Tape Mon doesn't make much difference on Speakers. After-Midnight listening reveals a slight 'windy' noise from the Germaniums if not hum. For the extra-smooth but punchy sound, it's a small compromise. Upgrade to Silicon? The difficulty is the Germaniums are low gain so to use typical Silicons you'd have far too much gain that'd be much too loud & spoil the sweet sound. The design is correct for Germaniums & any alteration just wouldn't be easy or give the results you wanted, so leave it be. But to find the right gain ones is possible, for another time. Another One Already. A customer saw the above reviews so got one for us to rebuild. This is the 1965 version with the 8-pin Valve style Multivoltage plug, we recapped the tuner so now AM works, FM works now too with Stereo too. See the Feb 2019 Blog for hearing this amp near to Original. Onto 2024 Sale. We've used & Upgraded this a lot more since Upgrading To Silicon as thought in 2019. We use a Range of Receivers & Amplifiers as well as hearing "New Sounds & Ideas" with other New Arrivals. Ideas get tried, the biggest one is finding the Hidden Extra Power due to a design error or done deliverately. We're not going to detail this as it takes quite a bit of redesign to make it the 45w amp it should be, compare Transfrmers TR707A to Sansui 3000(A). This with further tweaks is a great amp, if one we decided to sell on gettimg the 1964 Sansui 1000A valves of a very similar look. With Silicon instead of hissy Germanium, it's a very different amp, again with further changes. It's not totally quiet in use like a 1967-69 one can be, we used it after midnight, but none of that Germanium Hiss that can be bearable if can get too much after midnight. TR-707A, you were a big step up in Hifi Quality & led to buying more 1965-66 amps. BUY-RAW RATING: Too Old to use reliably or perhaps even safely now, needs a rebuild even on a nice grade one. REBUILD RATING: Lack of Board Layout diagrams or markings needs care. COOL RATING: 8 classy looks & 1965-66 Mid Century Modern cool. (2018-2020-2024)
1965 Sanyo DC-60E receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: n/a. at least 25w.
SC, Transformer Coupled, Direct Coupled. We have the Sanyo DC-66 from 1969 at the same time by Dec 2020, a customer sent that & we'd been looking at both online. Known Sanyo of this 1960s range are DC-60A, DC-60E, DC-66 with a DC-70 appearing before the DC-66. To see the DC-60 to just snap it up if the Odds of getting the Service Manual at the same time from another seller is the Luck of Us Wanting this. Sanyo in UK are only known for Budget Portables if made a Good Range of Hifi into the 1990s on researching via HFE. Sanyo not considered as much if they deserve a new look. This is their First Receiver with the slightly earlier DC-60A very similar. The DC-60E likely updates the Tuner & adds Multivoltage. Seems Sanyo didn't sell these 1960s ones well, the 1968/69 HFYB shows the DC-60 if not A or E, these are pictured if we never found anything before. Oddly the 1971/72 'Radio & TV Yearbook' lists this in 'Unit Audio'. Poland seems to have these, maybe sold off in the early 1970s as several Japan brands made it to UK etc belatedly. The looks possibly suited the Polish market better, Industrial with charm & a smart wood veneer case. These aren't budget amps if they are rather kooky in build, see the DC-66 review. This looked bewildering, the bouncy Tuner board was broken across if fixable & AM at least plays now. A Nov 1968 HFN Advert has this confusingly as 15w RMS per channel, the Manual says 50w (25w per channel). £99 price. Later Tresting shows this Outputs 24v Clean Sine which is in the 33w-40w range, far from the 15w Rating that means more like a 16 ohm rating & 25w is a modest rating. A Sept 1967 Ad says 30+30w per channel, Effective Power 25w+25w yet really only 15w RMS per channel. Are We Going To Play It Raw? A 1966 Amp. Got to try it, it is very tired & rough, if runs quite hot but lasted 2 hours at a steady temperature of about 55°C as the sound from it was appealing. Behaved itself, the aged capacitors awoke to give a pleasing sound, needed Bass on Tone if the Sound was surprisingly decent beyond much noise below Music Level. 1966 Amps & Receivers are the First Generation, we've found these difficult but giving a very Valve-Like sound, simply as they were designed with Valve Ideas. Design. It's Transformer Coupled for the Splitter to Push-Pull Outputs & those are Direct Coupled to a speaker, no Capacitor outputs, as with the Sansui 3000(A). DC offset actually read safe to use, there are no adjust pots, it's autobias so more advanced than the Sansui. Uses the same Hot Dropper resistors like Sansui 3000(A), Akai AA-7000, NatPan SA-65 & others. Oh and it's all Germaniums beyond the Outputs. 2SA202 & many 2SB400. Volume to Zero is silent, so no Germanium hiss with a 'shorted input', the Sansui TR-707A with it's Germaniums was very hissy. But this sounds very decent with a strong clean treble amid it's aging. Together with Autobias, this is a very interesting amp. Without the Circuits you'd be lost, build is with Phono-Inputs as in Aux through Phono, Tone & first Power Amp stages on one packed board. Bypass Phono if with DIN only as no Tape In by phono sockets if there is an output. Design uses NFB in stages so it might be tricky to do as Silicons as the Akai AA-5000 was. To recap it & leave those. Well Used. This has had good use, the Hot Resistors are untidy, if it works. Amp board with a few repairs including UK Germaniums, if the plastic case ones which are sealed better than usual UK ones. Two OC71 & a OC45 work fine which shows not all UK Germanium are bad. 2SA202 (OC45 equiv) is around, if 2SB400 (OC71 equiv) are long gone. Whether they are the right replacements to be found. Front Panel. Volume on top left like Sony do, paddle to select inputs, vertical row of Rocker Switches for AFC, Loudness & Tape Monitor. Two more are High & Low Filter as 'Noise' & 'Rumble' which is a liitle quaint. Rotaries for Power, Balance, Bass & reble. Another paddle selector for Mono L or R, Stereo & Reverse, if not L+R. They call L+R 'Channel 1+2' which is quirky. Meter for Tuner strength. Rear Panel. Light Grey with Phono Sockers for Aux, X-Tal & Mag Phono & Tape Head. Recorder Out if DIN for Tape in & Out only. Speaker screws that will take VOSO ones direct, Multivopltage selector, 2A fuse, AM/FM connectors & a AM antenna fitted in a pull out piece leaving open space for tiny animals to sleep inside. Do We Expect To Get Hifi Out Of This Thing? It's a bit overwhelming to see it minus the dust blanket, if to recap with upgrades to see how it goes. The very early original capacitors are marked "+" with the line, not "-" as caps usually are, very rare to see this & 'Rubycon' ones. Main Caps are for ±HT & are 4000µf 30v Sanyo ones, to give 25w RMS(?) both channels playing. Transformer looks a 50w size one, Power Supply & hot Resistor board at the rear. Manual shows 50w (25w per channel) at 1% (THD) for 8 ohms, for 4-16 ohm. Is this a bit advanced for 1966? Sanyo sold themselves short on amp that still sounds good after 55 years & to give good specs. Noise level stated at -10dB at 10kHz & 50Hz, if that's not what we heard with Volume at zero if noise as it is today hidden with typical music level. How will it upgrade? To sound great but be with background noise like the Sansui TR-707A? The Music Quality is what got us playing this 2 hours on Headphones, we compared it to other Amps, for this as Original to sound this good, lacking Bass if otherwise sounding way better than other 1966 amps as 'Raw' makes this one a Bit Special. Recapping. Very advanced job, all needs a rebuild. Hot messy resistors at the back, Main Amp board has the Caps marked '+' so care needed & to recap, the board must be removed. A lot of Capacitors to replace here, we counted 42 if the Germaniums standing taller are the Transistors looking similar. Lots Of Chances To Go Wrong, one old axial blue 'Philips' type cap (C325) the 1970s repairer put the wrong way round, if an earlier repair (C347) got it right. C325 is with no voltage after the Volume control. C347 across output to the coupling Transformer. TR21+22 replaced with 'OC71' TR31 (2SA202) replaced with 'OC45' which are both plastic case ones so as sealed better don't go bad like the UK metal cased ones always seem to past the 1950s ones in Portable Radios. 2SA202 we found NOS same style. TR31 part of a power supply. Suspect these repairs part of the "show something changed" scam commonly found with repairs, if older components may fail early, the thing still works. Serviced & Working But... it's not one we're going to rebuild, the amount of work in such a crude design will be at least double it's sell price. These are around in non UK countries for not high prices, probably still working. The very cramped 7cm x 17cm main board with Phono, Aux, Preamp-Tone & power amp is a bit much. The upright resistors are messy, old repairs are messy, the non working FM if MW works. Looks smart cleaned up in a nice wood case, it's like a lot of early Audio, a shelf filler rather than one to use daily. BUY-RAW RATING: May still work, ours did. Actually a great sounding amp as is the DC-66 below. One that's not an economical rebuild though. 2024 Update. We have the DC-60 Manual & now the DC-66 one. Leave it be a while & in the meantime getting more Germanium Amps. This one changing to Silicon needed more learning, we have done other Germanium to Silicon & it's extra work to stop Oscillation of High & Low Frequency as well as other issues. The DC-66 uses low spec Germaniums that made it too much to rebuild, if to know how do it far better as Silicon, it'll get a try sometime. COOL RATING: 8 has a great Retro look. But to keep more as an Ornament for the while rather than use daily. (2021-2022-2024)
1965-66 Sony TA-1120 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Very Good-Excellent. 50w transistor.
CC, PARA. The First Mention of this is actually for appearing at the New York Hifi Fair in Sept 1966 as 'Newly Introduced' not mentioning the TA-1120 model but can be the only one as a '60w pre-power amp'. There is no mention of it before this, only Sony tape machines. It could have been as Japan-only in 1965 as it was the first All-Silicon amplifier. 1965 TA-1120 has 2 lights on the front, 1967 TA-1120A has one light & a headphone socket Both have "1120" on the fascia if the rear label confirms "A" or not. The Very First Sony amplifier from Nov 1965 & Historically very important as the First All-Silicon transistor amplifier & a very high 50w. The Sony TA-1120A was the revised April 1967 version rather swiftly after, as the 1120 was too good. Sony ads by their London W1 showroom in HFN only start to show the TA-1120 in May 1967, only showed tape recorders before as Akai did, so chances are the original amp was only offered in the UK very briefly if the 1120A arrived a month after & would have been the one supplied. Aug 1967 Sony ad shows it again plus the rare TA-1080. Sept 1967 HFN actually reviews this first version as it mentions the 'Safety Light. TA-1120 likely from 120w Music Power rating? The ads only show Amps, Cartridges & Turntables for a few months, no sales meant back to tape again. The 1968 Audio Fair had a Sony stand with a very brief note in the June 1968 HFN saying "They gave very clean results and were remarkably natural sounding on speech and singing... FM Tuner ST-5000W looked most impressive" showing these were noted as being top quality but never reviewed & probably few shops stocked them. Possibly only their display model of the original 1120 was the only one that made it to the UK, soon replaced with a 1120A? This is the real early one with a green "Safety" light, beware these bulbs look like usual ones but are 100v 30mA as they work off 80v. If the bulb has failed as ours did after using for a while, to put a lower voltage bulb in with a certain value resistor in the circuit will get it lit again. There is no Headphone & "Solid State/46 Transistor" logo on the front. The manual states Serial 1000-4001 if ours is just over 5100. the TA-1120A numbers differently with an added '1' to start at 51011 if ours is higher than serial 5101, unless they goofed. Later came the 1967 TA-1120A & the rare 1971 TA-1120F looks like a cross between the 1120A & the 1130 as it's a Semi Complimentary output, probably like the STR-6200F is updating the STR-6120. The TA-1120 inside differs with a complex start-up that relies on a clean start on the circuit, but the manual warns it doesn't quite get it right & can take an eternity to start if we've not had this yet or had any issue. The Safety light is a little confusingly always On, rather than it being 'On' when there is a fault, it'd need a circuit fault to zero the lamp's voltage. No Headphone socket at all, though the TA-1120A one was useless as we state elsewhere. The back is the same if with screws not rivets. On testing Phono stages, we found the Output from Phono 1 to be very low if Phono 2 wasn't working. actualy these are 2 independent circuits, Ph1 has 5mV sensitivity & Ph2 has 1mV. TA-1120A has 1.2mV for both if they share the same circuit. The 1968 Dokorder 8060 has 2.5mV phono sensitivity, so the TA-1120 level will need comparing which suits best. Phono 2 uses the Tape Head input & both have EQ stages so are for MM. Early transistor circuits are interesting as based very much on Valve designs. Transistor count is Phono x2, Pre-Tone x7 including filter stages & a buffer, Power Amp x9 inc doubled output transistors. It looks ancient as well as very ahead of it's time & this is the first one we've seen for sale having looked for quite some time now. The seller had been reading the TA-1120A below (now edited) based on half-assed ideas they tried, always the risk. It rustles like a 1930s radio so some recapping required for sure, the 3 smaller rear ones look bad & leaky, the main one still has nearly 90v. It doesn't appear it'll play music if it does start to hear the noises which is a pity as we can't hear any idea of what it's like if voltages are there. The 1120(A) having no wood case does get very dirty inside with the open grille. Nearly 50 years old is a little scary for Hifi, so ours will get a full recap and upgrade if keeping as much original initially to see how good the design can be. The fact all resistors are Silver band shows the age if these aren't noisy & the value of the Volume control is surprising. 2SD45 original transistors here too, these are only 50w rated so are doubled in the design. Going through the design to recap shows how far ahead Sony were, with nothing really to refer back to, so the amp has busy preamp boards with L+R halves clearly seperate, with Tone Bypass a first as is the Pre Out-Main In. Phono is with 2 seperate stages with different EQ per stage, to be revealed. A rather daunting amp on seeing a messy one, but logical once learnt, if not too easy to work on. The 1120A simplifies the Phono stages & 1 less transistor in the Preamp plus far less capacitors. The 1120 power amp is a better design on the early stages, the 1120A loses one transistor but not in a good way. Looking to upgrade, the right preamp board with strange parts are early carbon resistors with stripes that look like ceramic capacitors, the others are less good carbon composition. The lighter red rectangle & cylinder are mylar capacitors & the dark red is mica, so all are good. The odd silver can at the base is a very early tantalum. The design is very well though out for an amp really leading the way with no references & it was soon simplified as the 'A' version, this certainly is a fascinating amp & is expected to sound much better than the 1120A which has all the sophisticated design removed. In terms of finding one, the Nov 1965 TA-1120 is very rare as only available for under 17 months in a market not into Transistors yet & the Apr 1967 TA-1120A is at least scarce. First proper play of it fully recapped & undoing previous owner snafus reveals a meaty bassy sound with good detail with high musical pleasure here. Very much a valve style sound with a well balanced punchy sound as Rock guitar proves, that sound is heard in very few transistor amplifiers. The first impression is this is an excellent amp to upgrade & if you found a high grade working one, it'd rate at least as shown based on the work we've done to get it working. On turning on, the relay clicks within a few seconds & the sound drifts in after about 10-15 seconds. Looking at the specs, -110db on noise still sounds right with not excessive noise up loud with no signal. Damping of 70 here sounds more like a 10-15 valve amp for the open bass, if recapped-upgraded now. The TA-1120A had a very feeble volume on both we had, this is not the case here at all, if the volume control needs to go halfway due to the contour. This amp must have caused a stir on how good it will have sounded in 1965, compared to the valve gear even 2 years later this is remarkably advanced. Is this the best amplifier ever? No wonder they released the dumbed the 1120A down quickly. Very rare to find, all Google shows is the 1120A with the headphone socket beyond old photos. For how excellent this sounds recapped, to leave the rest of the circuit as original shows how good this design is. Many amps need things altered to remove weaknesses, the TA-1120 sounds just so right. On speakers it has a very rich detailed sound, a sound that is unlike any other transistor amp. A hint we'll tell in hope to keep these alive is if the 100v front bulbs go, drop the voltage before the 6v or 12v bulb rather than do anything else as the bulb circuit isn't obvious. THE ST-5000 TUNER matches this, see the Tuners page for a review. THE WOOD CASES are now rare on these, Sizes are 432 W x 155 H x 303 D. front sides 14mm, rear sides 19mm adding spacers, the case is 12mm ply with a walnut veneer. The grille space is 369 x 121mm. 2020 REVISED RATING. we've thought on this a few times so to rate as VG-EX. The design is a bit tamed & too advanced to upgrade just to sell on. Great Sound if a little soft, it still could upgrade more, we did sell ours on. Would suit brighter sounding speakers best. BUY-RAW RATING: Advanced: Needs a full recap-rebuild as it's 50 years old which is far from easy. Bulbs are 100v & need a new design to use 12v ones, the 2 Microswitches on the Power switch may need replacing which will differ. This is a very complex & costly rebuild, the results are Excellent, if in reality the design is more a prototype & the TA-1120A is an easier amp to buy & upgrade. REBUILD RATING: This is an advanced expensive job to bring up to our standard. So much needs replacing & working on it is difficult. Look how ancient it is inside. A rare amp, but in real terms the later simplified TA-1120A is an easier upgrade to give results just as good. COOL RATING: 9 if only with the big walnut wood case, very strong looking amp with subtle classic style & nice layout, without the wood case a 7. (2014)
1965 Trio-Kenwood TK-80U receiver↑
AS-ORIGINAL (Once Serviced): Too Aged. UPGRADED: Excellent. 32w.
Germanium, Valve & Nuvistor Tuner. Kenwood TK-80U in two versions, Nuvistor & Valve Tuner with Germaniums then a later version with a Silicon Amp. The One We Have is the Very Rare early Version with the Valves & Germaniums beyond the Output Stages. To tell Early to Second version, Early on the Fascia has two lights over the meter, meter has smaller numbers. Tuner runs 80-108 on the first 'TK-80U' version & 88-108 on the 'TK-80' manual & second Silicon one. Easier to tell by Top Left Control is Mute on the first Valve Tuner one & Volume on the second. The Early One has a Printed Fascia, the later Trio have Embossed & Painted in details, Be sure the lettering has all worn off as our was. None seen around or sold of this early one until looking deeper on Google, still very few of either version & a TK-80 is a modern unit too, so just buy it else never see it again. YouTube has a Video of the early one from 2020, ours works now & the base cover inside barely needed cleaning. Theirs has an "80w Sticker" & still has the fascia lettering, if has a bad tuner. We appear to have had All the Top Germanium Receiver Models by various brands, ones 20w-45w, so this was a must. Researching Trio-Kenwood as the Apr 2024 Blog shows finds the TK-80U Early One as their Best & Highest Power until the TK-140E arrived. Retro Looks on the 1965-66 Trio far nicer than the 1967-69 ones before the KA-4000 smart styling. Havimng the TK-60BU means we could create New Graphics for the TK-80U & get a clear sticker printed, so thinking ahead. What's Inside. This is built to a higher quality than the 1966-69 ones, it impressed us. The Nuvistor & two valves, a more packed item than the TK-60BU which led them to make Trio & Pioneer receivers a smaller size, 450mm width here & styling not unlike the 1963 WX-400U. A good range of lager Capacitors, a Power Amp board with Germaniums on the Heatsink sides & an upright board which is the Tuner Mono-Stereo lights soon abandoned on the later version. Nearer the front a Can over an upright board is the Phono with the Preamp-Tone one transistor. Decent size Transformer like a 50w one. One little oddity is the upright board behind the Tuner. As with the TK-140E it's an Asbestos board, it really is. You don't want that & it needs disposing of in a responsible way. as it sits, it's no real risk if it is bare asbestos & if cracked that's where it gets risky. Out it goes to wrap up safely. Why it needs Asbestos behind the Power Transistors seems to be they are worried it'll have issues, but there's no need for it as the other side is near the Capacitors & nothing to go bad. It's the less risky 'white asbestos' a crean colour with the pressed fibres look. Serious Bit Of Kit was the first opinion, there is Quality here. Tidied the fasciaif leaving lettering mostly gone as expected, so to just write in info until we decide what to do. An amp bought as a Keeper & of little use to everyone, except one who has Researched Trio to see this one is real good one. Condition of a 1965 Receiver. It's in very decent grade otherwise, to dare try it. a 2A fuse softly blown & the seller tried no more. One bigger capacitor a little drip-leaky if it could have been 50 years or more ago. To check it over & not find signs of much use, old repairs or damage. Rear Cages on the top cover the Heatsinks that are made of a cast metal, interestingly it has space for 8 Transistors if only uses 4. A Doubled Transistor Output probably first designed until the 'Sony 2SD46' Silicons became availavle. No need for the Asbestos. Underneath looks very tidy, not much used. a 25v Power Supply capacitor 'C18' is the ones a bit old-leaky & has a deep hole so will be dried out, if not made mess beyond a few minor drip marks. First try brings a few issuesa but No Sound, if Crackles heard on using Switches. Then to test more, to try to hear it As Original. We Get It Playing In Stereo after some work incuding Repair to try it. Beyond very noisy controls is a sweer Germanium sound with crisp treble. Some Germanium noise if not too much. Played it a few songs after more work, it gradually gets more distorted & rough sounding, but it is 59 years old. The TK-80U Early Version is an Extra Good sounding amp, even raw & rough. It's why we got it. A Customer with one of these would need to be aware it's a Big Rebuild job, we'll go Further with this as we did the 1965 Pioneer SX-600T. The TK-60BU below being basically the TK-66 is more one to recuild to sell. Next Day, the aged Capacitors 'reformed' by use & sound isn't Distorted. Sorted Tuner Glass Foams & LEDs in look smart on Blue & Gold lettering. The Fascia Text, we wrote in some by hand & it'll do until perhaps we can get something printed. Certainly needas a Full Rebuild, the Balance isn't central & other typical issues. Tuner Works at least in Mono with the Light Squares giving a smart look, later Trio-Kenwood weren't this attractive. Germanium Hiss more noteable & like the Pioneer SX-600T the very Crisp Treble maybe a bit too crisp until Recap-Upgraded. This is an Important Receiver to find. After about 10 mins play the Sound starts to fade away, so best not play again until Recapped. Part Recapped as the Kenwood TK-60BU is, try it to see if it fades again. A Bit Noisy beyond Germanium noise & the Balance not in the middle, but the Germaniums sound is just way ahead of the TK-60BU with Silicons. Not an easy one to recap as still quite a bit is Hardwired, Heatsink cool on Left & only slightly warm on right. The Germaniums Treble played on Rock shows it needs a better Bass & Weight to the Sound. The TK-80 is better built than the TK-60BU as to see costs cut on the later one. Based on the 1965 Pioneer SX-600T Germaniums receiver we rebuilt recently, the TK-80 seems ahead at this stage, if the SX-600T had several issues. The Sound Quality starts to fade again so more to do, how it will compare to the SX-600T when finished to a level will be interesting. The TK-80 is probably the Best Trio-Kenwood, how much will the background noise improve? Power Amp. Notice this has three PC-1 to PC-3 items on the Circuit Diagram, these are a Capacitor with a Resistor inside which are 'Elna' parts but unseen before, R15-45, R15-46 & R15-48 which aren't values but Elna Code Numbers. To wonder why they bothered, just adds to the Rarity for ones that didn't survive. Beware there is a big solder blob to join tracks underneath, no bit of wire, else the amp is silent. More to do still, the Sound is Extremely good with little Germanium noise. Phono & Preamp is under the metal box on the top, most is Phono with one transistor per channel for Preamp. Has the strange PC-1 type capacitor-resistor units, six of them plus four Black Rectangle ones which are EQ ones of non-standard values. Sophisticated amp for sure, just keeps adding 'points' making this the Best Trio-Kenwood, if an advanced one. First version has the superior Passive tone & no 'T' Bass filter unit UA13081 boards permanently fitted. Later Silicon version has NPN type Tone. Oddities. Ours has two large green 4 ohm resistors underneath by the Transformer. Not shown on the Circuit, these are Speaker Load resistors for using Two Speaker Pairs which is unusual for as early as 1965. The Power Amp has one that could surprise on the Output Transistors, it's designed like that & like no other amp. Tuner as with the TH-60BY it works. Two Valves, One Nuvisor & All Germamium beyond a 2SC401 Silicon in the Muting. Plays FM Stereo on the edge of some Stations if one by '96' is truie Stereo, needs slight Alining. Pleasing Crisp Sound with the design if the Ceramics will always limit how clean it can be, but this is very decent on the original Tuner Board capacitors. Try It On Speakers. 4mm Voso screw right in the Screw Holes as Trio often allow. All done beyond the three top Tuner boards. Resistor-Transistor circuit as original if Power Amp resistors redone. Played the 1965 Pioneer SX-600T before & onto the TK-80U the bigger deeper dynamics show more on Speakers. 32w the Highest Power Japanese Germanium Receiver does show a fuller sound. Germanium Noise is the Minus & it does show quite clearly at 6-8pm time. L Channel is Noisier which doesn't tell much on Headphones. It'd involve doing what the 1965 Sansui TR-707A needed, spare Germanium Transistors & swapping them about to find the Noisy One. 2SB439 & 2SB421 you might find used or NOS ones on Ebay, no Guarantees they'd not be Noisy too. One to Consider doing as Silicon as it doesn't use NFB to cause issues. Adjusting. Just One Pot on the Power Amp, VR1 & VR2. as typical no info given. The later TK-80U version shows one in the same place plus others. This is for Balancing the Output to Clip Symmetrically at Full Power, adjusted right it gives us the correct 24v Clean Sine rating which is modest for 32w. On our Early TK-80U there is an added Diode block & Pot underneath as the Later Silicon version has. the Pot adjusts over a Thermistor so will be Bias. Germanium to Silicon. All the Work we've put in this & a Big Gamble Buying it as it was, to have Germaniums too Noisy on Speakers despite it sounding extra great. Sometimes to 'not be pleased' gets Results so we've done the Audio Stages as Silicon, before the 24v Clean Sine Rating done. Much better as Silicon if strangely has a Germanium type Hiss on the Left Channel & a slight 'Sea Noise' overall with Volume to zero. Otherwise the Amp is on the Original Resistors design to listen to what for sure is the best sounding Trio-Kenwood. For Germanium design it is designed for Germaniums, to keep it 'Original' to hear How Great it was made, rather than try bettering it when it's ahead of others. Now As Silicon. Be sure a 1965 Receiver-Amp needs a lot redone. Redo Capacitors, Transisrtors as Silicon, Resistors to redo & Bias stage to sort out. ProBably a job too far for most, but The Sound of it is a little bit special. A Bassy Lively Amp, as in Deeper Sub Bass not Boomy Thick Bass, with Clean Crisp Treble & a Midrange that plays Voices extra clean with a Reality rarely heard in Hifi. There is No Background Noise at all as Rebuilt. Certainly the Best Sounding Amp by this Brand & by a Huge Margin, it's why they made so few & swiftly updated it. Now What? We've used this on Headphones & Speakers a few times too. Currently it's not getting much use, for the great fact of it sounding So Great as "Original Design" beyod Recapping & changing Germanium to Silicon. It & the 1965 Pioneer SX-600T are both exceptional & both in a similar 'original' way. To try them more later, it helps decide to sell some too. BUY-RAW RATING: Probably too Aged to test much. REBUILD RATING: Needs Doing properly & it's an involved job. COOL RATING: 10, a mix of looks & 1965 sounding this good. Fascia lettering can fade. (2024).
1965 Armstrong 221 valve amplifier ↑
AS-ORIGINAL (Once Serviced): Hopeless. UPGRADED: Hopeless. 10w valve.
Mar 1966 HFN reviews this & finds it's only 7w, but it's just not very good. This mediocre UK made crappity amp is as far apart in quality from the Rogers valve amps above you can get. It needed a full recap as cheapo plastic case capacitors long since failed. Very basic design sold as budget gear when new probably to upgrade from a Radiogram. Hifi ours certainly wasn't even after recapping the nasty thing. It wasn't worth the effort as the design was poor and the sound was messy & very weak on treble as it was severely rolled off & bad harmonics on the treble. Swapping valves didn't help. Silicon transistor phono stage & a very average amp indeed, felt a bit time wasted on recapping it, but you got to try to know. UK 220-240v only but a US buyer went for it, probably thinking it was worth a try. Average crap appears to be the norm with this brand, so avoid. The Armstrong 222 is a cheaper version from 1963 without a MM Phono, someone way overpaid for one in Apr 2014. As with any amp there are those who love theirs in blind ignorance of better, but you do get the idea they paid a tenner for it & got it working, which is good as they'll be trying more vintage, but Armstrong is only a first step in Hifi, so don't overpay. This is a 2012 rated amp, but it's poor quality in many places stands as fair comment & we'd not dream of trying one again. REBUILD RATING: The design is just too limited to bother with it. we rebuilt ours in 2012 & you can read the opinion. BUY-RAW RATING: Poor. Needs full recap to even try it & then agree it's crap. COOL RATING: 7 actually quite decent looking with the perspex front & the full wood case. (2012)
1966 Coral A-550 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 18w.
CC. A rare early Transistor amp and all Silicon, it must have been bought overseas as a very rare hifi brand. One oddity is it has no power amp adjust pots at all suggesting it's 1965 or 1966 as other 1967 have them & the hand painted resistor lines as well as caps marked - or + randomly. Only 18w apparently but still interesting enough to try & the others by this obscure Japanese brand look interesting, as shown on audio-database.com & audio-heritage.jp. A UK Midlands dealer must have bought old remainder stock in Oct 1970 as they advertise this in HFN mag. Only the Coral A-707 35w £78 appears in the HFYB & the brand is gone from the UK by 1970, we noted it as 'interesting' on our List of Amps page. Other Coral are '25w' A-7 amp if only 70VA so 15w probably, 35w A-707 amp, bizarre looking 30w A-1000 amp, 30w AX-3000 receiver, a later looking 17w TA-5000 receiver possibly a 1969 one, also a TA-3000A will be lower power & TA-7700 a 50w receiver looking rather like the Sansui 3000A from the back view sold as Hanimex also as found on AK site. 1974-75 HFYB lists Hanimex in receivers but no details. The A-550 actually has a MC stage, as there is a Coral MC cartridge, which must be the earliest, the 1969 Trio-Kenwood KA-6000 also has a MC stage. Appears they continued without Amps under the Coral brand until the mid 1980s with Loudspeakers of a high quality. Their CP-701 turntable has that Japan only cool 60s styling that never got exported. Audio-Heritage site shows more detail & it has early black dome silicon like the Sansui AU-999 uses, these can get hissy. With the MC stage & pre out-main in, it's predating the KA-6000 again. Interesting to see what an early amplifier made by a quality brand that didn't survive long will be like. The Coral TA-7700 at 50w is one to find if the circuits look so early, more a historical piece. as 18w only in the league of the similar small Trio-Kenwoods below, but not quite, the build quality & the Moving Coil Phono show a very interesting design. On first play, the high quality sound the NatPan SA-65 has as original is here, smooth & detailed. Punchy little amp with a proper volume if Deep Bass limited as 18w would need. But yet another early gem proving the earlier ones are the best sounding for pure musical pleasure. For those wondering, 2200µf 50v main cap with 44v HT on it, Nippon capacitors, no disc ceramics if there are early tube type ones of some sort used upright & Alps pots. The Phono stages are 2 boards under a metal can. Transistor count per channel is Phono: MC x1, MM x2, Tone-Pre x2 with an extra as an SCR, Power amp just 6. Transistors are CDC-13000-10, CDC-8002-1-C & CDC-10000-1E. Output transistors are Sanken 2SD92 Silicon 20w TO66. Sound is very clean, lively & more punchy than 18w would suggest, no grain at all, Bass is limited by design but is not unappealing. Our neon had failed so to fit a NOS 7mm flat top one inside the bezel works to keep it looking right. Even has the tie tag warning about the MM stage, rare! A collector's piece indeed. After our first use of it, leaving it a few days it woke it up deserving a higher rating than "Very Good" of before. For an 18w amp the volume is still very good with no lacking at all in the sound beyond deep bass, it's just accurate, fast & clean on the orig spec. Can even cope well with busy Rock to a decent level, all on the apparently low spec, remarkable. On the Tannoy Golds it sound Very Good, bearing in mind 18w is nearly halfway on the volume, but loud enough for most with a beautiful accurate sound. Speaker connecting allows 2 pairs but not together & L+R are not the top row, but 2 up 2 down if not marked clearly. Plays very wide stereo on speakers, once balance centred. Another 1967 "Excellent" as original winner. You'll struggle to find a valve amp sounding this sweet. The only problem with an amp this early is the spec wanders due to age, with the preamp & the power amp being 41% different on output voltages. We'd not really wanted to upgrade this, but as it sounds so nice but imbalanced, it has to be done to balance it properly. Originality isn't possible, though it works, the balance is off. Recapping sorts it a bit as a few looked bad but putting in 4 closely matched preamp transistors sorts it. We kept the original parts & 2-core cable in case the buyer wants to match the old ones to keep it still original. The buyer wanted capacitor upgrades rather than keep it original & once done volume is better with no background hiss & with the Bass control at +1.5 it sounds very good indeed. We later heard the buyer found this is more musical than 'silly money' amps. Are we surprised? In 2017 reading through these this amp is remembered fondly, nice little amp of high quality. 2021 Comment. Rare amp not seen since, we get a cheeky message wanting to know what we sold our Rebuilt one for 7 years ago. As if we'd tell or suggest any sale pricing of our unique rebuilds, there is far too much overpricing raw & rough amps as it is. BUY-RAW RATING: Good if early parts can be off spec. This amplifier needs a proper 3 core mains + earth cable, see above. REBUILD RATING: Not too difficult for a Pro, but no Service Manual diagrams keeps the full design from being understood. COOL RATING: 7 not the prettiest amp but in the wood case it has serious Bachelor Pad looks. (2014)
1966 Duette SA-500W amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Very Good (as no Manual). approx 16w-18w all Germaniums, Direct Coupled.
We champion the deeply obscure & forgotten gems such as amps like the wonderful Coral & early JVC amps show. This Duette is another obscure one, if actually one with zero web presence beyond us so we research it, to the point it didn't exist anywhere not even on Japanese sites hidden in translation. The brand we saw in the HFYBs on doing the listing pages & it was imported as a bargain clear out for a Discount store as the early JVC ones were, as it appears belatedly in 1971-73 as imported by a JJ Silber Ltd London EC1 distributor but didn't sell as too old looking as were the JVC. Oct 1970 HFN mag has a full page ad looking more like another item starting with "Du..." with an unclothed couple sitting slightly immodestly with "Duette for lovers of pure sound". Silber do 'Duette' adverts for 13 months in total gone by Dec 1971 if the SA-500 is only in half of them, the later ones still with the same theme but receiver & speaker combos, so there must have been sales or a bulk advert buy hoping for sales, but why so totally unknown? The Feb 1972 HFN shows only a shop that advertised regularly, 'F. Cave' with 4 shops in London had these amid other more known ones. There also were Duette SAT260X & SAT460(X) receivers both noted 12w again wrong power ratings, again looking like decent 1967 looking designs as all pictured in the HFYB. The HFN ad adds SAT-4370 black fronted receiver & 2 small speakers. The range in the HFYB is SA616 6w £20 actually is 6w as back label says '20w (VA) max & very basic, SA400 6w £32 & SA-500 10w £40 but the power ratings aren't always correct as the SA500 case shows 70w total power as is the JVC 5010 that is 16w with a tuner stage, so expect at least 16w here. There are two versions of the SA500, the advert one is silver front with a metal lid & an extra rocker switch, the black fascia one we have is in the wood case with 3 rocker switches, losing the High Filter & moving headphone & power switch to the left. The styling looks 1966-67 with rocker switches & it having TO3 transistors on the back panel suggests it's worth a try. We see it says 'Made in Japan' on the back so odds are it's in the league of the Coral & JVC amps which we liked & worth a gamble. It has a 'Tape Head' input which was abandoned by 1969 on amps. As expected, this is very early. 2SB126 which are 40w Germaniums Others are 2SB400, 2SB173 & AC128 all Germaniums AC128 is a EU Philips one aka 2N2706. Sound wasn't much as the seller stated if the sweet germaniums sound still obvious. Needs recapping as some are swollen. Reading the voltages it works on ±24v & with no output capacitors. It has power amp to output stage coupling transformers like the Sansui 3000A & NatPan SA65 have. This means no Output Transformers on the Speaker outputs as the 1.5A Speaker fuse comes from the output transistors-resistors. DC offset is good too so a very unusual design here. It has Tape Head, Phono Mag & Cer, Tuner & Aux inputs on standard size phono sockets, Tape loop if no DIN socket, one speaker pair, a Mains outlet & 3 fuses, the Mains one is 2A. The main PCB has 4 transistors for all stages plus the AC128 on a heatsink, so just 5 transistors plus the output pair, so Phono MM & Ceramic-Tape Head, Tone is passive on Line Level, Power Amp x3 inc the heatsinked Driver plus the splitter transformers & the outputs. Hifi of dreams pure valve design in Germaniums if not too dissimiliar to the NatPan SA65 circuit. This is 240v only so likely bought cheap into the UK after sales failed elsewhere in Europe, by how unknown they are it might have been just 6 of each model. It uses Matushita, Sanyo, Cosmos, Atlas parts plus Lily(?) & Orion caps, the 2 main ones grey with the Δ logo & Nasu film caps. Pictured in metal lid in HFYB if this has a walnut veneer case. After working the circuit out to recap, replaced just the one bad one & played it properly as original if serviced. All Germaniums is a remarkable sound with such a minimal but high quality design. Very fast, accurate & crisp with proper bass weight on guitar riffs and very wide stereo even on the orig spec if a little hum if the 2 main caps not upgraded yet. Playing Germanium transistor Amps like this make you realise Hifi only got worse sounding as it "improved", the sound of this even original is extreme. It sounds quite 'dull' if then you listen & hear the treble is untainted & crisp to a limit as below, as is found with valve amps, no Silicon transistor fizz. This sounds so good even original perhaps we should keep it quiet... It does surprisingly have 47k on Aux-Tuner inputs, allows more gain & probably why what looks a 16w amp is limited to 10w as their specs in the HFN ad show. But without them it makes awful noises on start up! Also can't hear anything over 13kHz so the AC128 must be aged & the noisy one so we get a better spec one & find the noise is still there if the HF range is improved. But background noise keeps what sounds sublime down half a grade as the noise on one channel is 14mV if the side that is silent on 95dB speakers is 8mV, it appears to be around the output stages. Now upgraded it gives 17v clean sine so is about 16w-18w, just as we expected. Amps like these are fascinating, the design is very early so best not to go too deep into it if give it a bit more gain. Beyond the minor noise & whistles on turn on, the sound is sublime, sweet effortless & detailed & it has enough volume for the Tannoy Golds. In 2017 we remember this as a bit of an outsider, it had a pleasing sound if a bit Retro-Aged sounding. The buyer said it was a bit wild on their speakers if a fascinating sound for it. BUY-RAW RATING: Ours needed some recapping to even work right as so early if generally ok beyond that if can be much bettered by upgrading. REBUILD RATING: No Service Manuals keep it a bit limited in understanding if not too difficult we found. COOL RATING: 6 quite basic small looks but what a sound. (2015)
1966 Grundig SV 80 M amplifier ↑
AS-ORIGINAL (Once Serviced): --. UPGRADED: --. 40w
Direct Coupled. Shortly after getting the Revox A78 to try one of the Better-considered EU Amplifiers, this one turns up too. We've not liked the EU & UK amps much & have tended to avoid them as they aren't so great. The truth is many UK & EU amps are Budget or Midprice so hardly showing the EU-UK Hifi scene at it's best. The 'shock' of all DIN sockets plus Hardboard backs was overcome before it arrived, if it does remind of the cheaper Radiograms & those "Radiogram Innards" Receiver-amplifiers of low power. Just got this as the circuits looked good & to find it's as early as 1966 & apparently a Classic in Europe if how unaware UK buyers are of these amps. The earlier Grundig SV-50 appears in the 1965/66 HFYB for £82 to assume it's 25w by the model number. The SV-80 is in the 1967/68 rated 30w for £97 & they continue into 1973 with other amplifiers in the SV series if not after 1973 for amplifiers. Densely built on a strong chassis if how to get to some boards looks difficult, lots to unscrew & then twist metal tabs to free the board from the frame is not good, it looks like it's not made to repair. The front preamp stage unscrews & appears to hinge up to get inside if the long central board looks difficult. Doubled Parallel Outputs with 2N2148. Germanium transistors elsewhere & the poor EU ones. Using lots of axial capacitors with some with that strange 'on end' wiring. To recap one as with the Revox, new capacitors are much bette quality on HF which can cause a lot of problems. Circuits look good mostly so it would likely sound good was why we tried, if Aux goes through Phono stage if this sometimes sounds acceptable. This one had been too messed with on the power supply so to write it up if never hear it, so no ratings on this one. Would we get another one to fully recap & upgrade? No, the Revox is a nice amp but this has all the 'badness' in construction & strange obsolete parts that really isn't economical to do what looks like a huge job & then not get much more than £500 for if in high grade as buyers aren't keen on DIN sockets & Hardboard backs. The rebuild job in this would be a lot higher than sell price, so not for us. Maybe to try a late-run working one & just service, but the reality is issues crop up, so best to leave. Trying this & the Revox to see what EU amps are like, they will have appeal in EU, but to try to give them high quality upgrades as with UK amps of the same era, not worth bothering. BUY-RAW RATING: Probably OK if some caps look a bit aged. REBUILD RATING: Not worth us rebuilding & would be a tricky job for construction. COOL RATING: 5 not a bad looking amp in nice grade which is why we tried it. Hardboard back & base is poor though. (2018).
1966 JVC MCA-104E amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 16w
CC, Germaniums. Early JVC Nivico are/were totally ignored for the Graphic EQ feature, but read the 1967 JVC 5010U for why these are not reallly that different to a Tone Stage. The Japan sold ones were branded 'Victor' explaining the stuck-on JVC Nivico badge. The Japanese version was the 104 with 110v, the 104E is the export version with 240v multivoltage. Audio-Heritage.jp site shows the MCA series was 102 6w, 103 18w upright, 103B usual, 104 15w, 105. The brand is an exciting find. Having liked the two JVC receivers below, to look for a JVC early amp. The 105E manual is findable, it's a 32w amp so whatever this 104E is will do was the idea. But it's not what we expected, it's a much earlier amp as it has Victor 2SB407 PNP output transistors. They are 30w rated so must be around 15w-20w, but... they are Germaniums! Yes, Germanium TO3 output transistors & the 4 drivers are 2SB22 and 2SD30 NPN-PNP pair looking like a capacitor on 3 legs meaning Germaniums here too. 2SD30 is still used by hifi & guitar amp builders. How old is this amp? We've put 1966 but it could be earlier. The Armstrong 526 below was Germaniums but the awful UK ones, the Japanese ones were in the driver stage of the Trio TK140E below but not a particular problem, so to hear this will be interesting. The small signal transistors are the usual Silicon 2SC458 still used in 1969 Trio, but higher power ones as Germanium though the 1965 Sony TA-1120 is all Silicon. The JVC MCA-105E is all Silicon. The 1972 HFYB lists "MCA-104E 16w £72", the TVK site actually shows it's the JVC MCA-104Z which they say is the March 1971 update to the August 1968 '104' though it's possible the 104E is 1965-66 as JVC wouldn't be using Germaniums in 1968. Hifi News pictures this in July 1970 New products but in Dec 1970 only a Strand, London shop has the 104E for £72, JVC maybe exporting old stock, but expensive compared to the Leak 70 35w for the same price. A Dec 1970 Denham & Morely ad shows a JVC range but only the MCA-105E that replaced it. Not expecting too much, music on, crisp & lively with a bit of a bassline not too limited by the 470µf output caps. The Safety button is strange, Green light always on like the TA-1120 but press it & it cuts out quicker than Power off, it's a circuit breaker. No Loudness or Filter switches which is unusual. HT is 44v on a bare metal cased Elna showing it's unusually early. As you can gather from the two JVC below, the sound is going to be good, but Germaniums? Even dirty & dusty it sounds like no other transistor amp as all-original, what a clean honest sound. Transistor count is just 6 on the Power Amp. As with the Coral, no adjust pots confirm it's at least a 1966 design. Guitar guys like Germaniums & this amp has transfixed us & it's still untouched. Forget the lousy UK Germaniums that age badly, the Japanese ones are much better. The lack of silicon grain perhaps though it can be more the design. The 104E is "Smoother and Spongier" as one site says about Germaniums as well as effortlessly revealing layers of mush now gone, or what? Not how the other two JVC sounded, this 'effect' can go too far in hearing bad UK Mullard AD, OC etc Germaniums as in the Armstrong 526 where it turns to wading through treacle if oddly interesting to hear. Germaniums store a charge too so capacitance could be the smoothing, if detail is as crisp, the hard silicon wall sound has been knocked away. Fascinating sound & one to blow the mind. Once serviced it just sounds so right. The apparently low 470µf output capacitors don't limit even 30Hz if just about 5% down on 20Hz, impedance differences. Even as all original, and with ceramics, the sound is noticeably smoother & wider on high treble than the Heathkit amp which sounded Very Good days before. The minuses are background noise is pretty high & balance is midway at +2 to the left. But for the sound, this gets 'Excellent' & gets other amps rated back a little to reflect the new heights. No circuit diagrams, but Phono is the right board, power amp the middle one & preamp is in the metal case. Now recapped just the power amp board, some leaky ones found, but the bassline this amp now puts out still on the original caps elsewhere is rarely heard in valve amps, damping factor of 25 here. The Silicon transistors were hissy, but the Germaniums are silent almost, replacing the silicons doesn't lose any of the sweet sound. It sounds excellent on the Tannoy Golds, the effortless is noticeable & very pleasing to hear. With the 4 main caps upgraded, the sound is just so effortless & delicate if with enough bassy punch too, if certainly neutral & very honest sounding. It resolves busy rock tracks into what you'll not have heard before, so smooth, open sounding yet extra detailed, a hack reviewer would call it the much misused "valve-like" but what it is is certainly a delight for the ears. Can any transistor amp better this? After a few minor alterations, the smooth precise sound is still here, usually with silicon drivers there would be a little edginess on the design, but clearly Germaniums have similarities to Valves with harmonics as the Power Amp is otherwise much like a Silicon design, if the sound is unlike silicons. On speakers if you play the Tone flat for your preferred sound, this will sound as good, if needing Tone Gain the EQ is less broad than a Treble stage leaving it not quite giving the same gain where you need it. The MCA104E is 16w, the later MCA 104Z is 16w, MCA105E is 32w & a MCT-105E tuner matches. The range also has 5340 40w speakers, GB-1E ball speakers, 5250 turntable & CHR-250U 8 track player-recorder. In 2017 this one remembered as a great one as with the Coral amp. Sometimes amps get sold on a bit fast, but to look out for another one. 2018 Slight Update: One on ebay makes a high £138 after lots of 'fake' zero bids who oddly never win, likely based solely on our review. It's a sweet 16w amp with Germaniums & the best of the Germanium amps we've had (by then). It's very smooth & precise for sure, it's not going to kick much & 16w is adequate on 95dB speakers. But it could be very hissy & there is no Schematic available, ours we got via JVC Japan on the basis it wasn't shared, tight on the copyright for some reason. BUY-RAW RATING: Good. REBUILD RATING: A basic design that's not too difficult, we did get a Circuit Diagram to understand it better. COOL RATING: 7 no wood case made & for it being a metal case can't really rate the looks higher if it looks smart with the black fascia with retro appeal. (2015). .
1966 Nikko TRM-120 amplifier ↑
AS-ORIGINAL (Once Serviced): n/a. UPGRADED: Sounded Great but Not Trusted. 45w.
Silicon, Direct Coupled Outputs, TX Coupled Splitter. This One certainly Interested, but ultimately it's not one we Trusted to even try on Speakers so couldn't see any further in it after a Full Recap as not of Sellable Quality. We've had the 1970 'TRM-1200', as below, which was an Updated Version of this TRM-120. Has proper Square Coupling Transformers, not the strange Round Open ones. This is a Rare Amp, HFE has no Info on it & therefore it's not known compared to other models by Nikko. Purposeful outer design, still the awkward Mains Plug idea. Inside is what Intrigued us to get it, an open frame type of build that has 'Obscure Japanese Amp' styling, but later found to be Not Well Built with some Poor Design. HFYB lists it 1968/69 to 1971 with the TRM-1200 replacing it in the 1972 book. Got It Here Now. Smart looking unit with a solid aluminium fascia, solid metal knobs & rocker switches. Size about the same as the 1966 Pioneer SX-1000TA at 390mm wide, 115mm less feet & 297mm deep not including fittings. The 'TRM-120' model number isn't on the front at all, only on the back lower down. Front Top has 'Function' with Mic, Tape Head, Phono 1, Phono 2, Tuner & Aux. Then Volume, Balance, rocker switches for Tone Control In-Out, Low & High Filter. Speakers for Off, A, A+B & B. VU meters for L+R which is unusual on amps until the mid 1970s. Lower front has 'Mode' for R, L, Stereo & Rev if not Mono as the TRM-1200 has. Rocker switches for Tape Monitor & Loudness. Rotary controls for Bass & tone as 4 controls for separate L+R. 'Speaker Comp' as we'll discover more on later. Headphone socket & Power switch rocker. Rear has the awkward Nikko plug socket pins for some sort of Plug, always missing if to redo like we did on the TRM-1200. It's originally a bracket fitted to the top case lid if it breaks probably why never seen. Here they used the Screw blocks if left bare Mains cable showing, Speaker Connectors are Screw Blocks that will take the 4mm Socket Gold Blocks. Input Sockets, Meter Adjust, Centre CH output & Circuit Breakers. These aren't Multivoltage if marked 240v on the Serial Number label, if later we find it isl. Underneath has a label about the Mains Interlock system. Multivoltage switch hides underneath so will be 120v/240v. No Manual on the TRM-120. Not such a big deal as the TRM-1200 is findable. To understand it, we worked out the Board. The two small Boards fitted to the Three Front Rocker switches are C621-623-625 that are on the Board of the TRM-1200. This is a 'T' Bass Filter shown as "TTF" on the TRM-1200 circuit. Sadly the ideas of the time, an early one for 1966 if a 1965 one cuts the Bass which becomes an Industry Standard. A 'Speaker Comp' switch on the fascia to Boost the Bass back, done better than the TRM-1200 one if pointless. Inside on the left: the Selector at the back, then Phono. Towards the front the Regulator with the Tone Board the narrow upstanding board that fits between stages on the Main Board. Both Tone & Regulator boards are the same as TRM-1200 ones, only the TRM-1200 Phono is different with the IC, so there is no TRM-120 Phono details. The 'Speaker Boost' alters the Preamp NFB before the Tone stage. It does affect the Sound & these 'Features' do spoil an otherwise Decent. DC Offset on the Speaker Outputs is a bit High at 1.4v to 1.8v. This is a Common Issue with the Early Direct Coupled Amps, as in not Capacitor Coupled. The 1965 Pioneer SX-600T needed Redesign to get it to a low DC Offset, under 100mV, once connected to Speakers. Circuit Differences TRM-120 to TRM-1200. The most obvious is the IC for Phono, TRM-120 is Transistors. TRM-120 has the 'T' Bass filter on a front swtch, TRM-1200 builds it into the board. For some reason, the Main Board board omits a 6.8K resistor that is tagged underneath, the board misses track & the hole required, not found that sort of error before. Aux & Tuner Inputs. These go through Phono via 1 Meg & 330K resistors. This stage is hard to get to & very untidily done where resistors can short out causing this & several other things to give up on it. Tape Mon is Direct as similar with other early amps. Playing 'Aux' it sounds good but Volume needs Midway, compared to Tape Mon at Quarter Volume. Still makes Noises on Turn-On, bit of a Howl, then Sea Noise then quiet. Turn-Off a slight Bloop & small Hiss. Phono Stage at rear leftis 2 transistors per channel, 4 capacitors, 6 resistors & a ceramic pf cap, but different to the TRM-1200 IC replacement Phono board. Final Damning Verdict. Even after spending ages Recapping & First Upgrades, the Turn-On Noises were no better & certainly Not Sellable together with a Bloop & small Hiss on Turn off. Design is quality to sound very decent, but Rubbish design is too often. High DC Offset needing Bias Redesign that the 1965 Pioneer SX-600T needed too, but it's a a much better quality build & has had Speaker use for a few weeks as it's Direct Coupled Design is trusted. The TRM-120 uprated to the TRM-1200 with Boards done tidier but a Relay to stop the Bad Noises until Voltages settle, the Power Supply only starts with the Power Amp Output Stages, the rest turns on after a Delay. Putting just one Secondary TX Winding & taking the +ve HT from what drives the Power Outputs is bad design if we've seen it before. It is Annoying to get an Amp that you were playing thinking it sounds Great just a few days ago, but Bad Inputs & other issues make it one to just cut the losses on as it'll not be Trusted or Sellable. Other Tricky Amps can sit ages & returned to, but this one just had too much not working right, poorly built & the bad Noises. Other Nikko are much better, but the TRM-120 is best avoided. Similar story with the 1966 Rotel 100AMP below, some amps are just Not Very Good. BUY-RAW RATING: Probably Too Aged & Not One We Trusted. REBUILD RATING: Didn't Trust It. (2024)
1966 Pioneer SX-800A (SX-2000) valve receiver ↑
AS-ORIGINAL (Once Serviced): Too Old. UPGRADED: Very Good-Excellent. 35w Valves.
A Genuine 35w RMS Valve Receiver is a Real Find, it's also the Pioneer SX-2000 which appears to be the non UK Voltage one. Actually a Hybrid of Valves mostly, if a Nuvistor in the Tuner & Transistors in the Tuner MPX stage. The Circuit Diagram shows both Model Numbers so they are the same. SX-800 is the earlier one with 7189 valves, SX-800A is updated with bigger 7868 valves increasing power. First heard of this Nov 2018 to have the diagram & to get one here by Oct 2019 is nice, if it's a Customer's Amp. Valve Receivers are very complex if rebuild up very nicely, but they really need The Lot redone as we did with our Trio WX-400U. The Trio sounded great if 10w really isn't enough, so this at 35w is going to be interesting. 35w says the diagram with 23.7v into 16 ohms, so on 8 ohms it may appear to rate higher. The output valves are '7868', no real exact data found on these USA designed valves, 30w-35w seems the maximum. 7868s are still made if plenty will do risky Tube Rolling hoping to 'better' but pins & specs differ. The 7868s with 'Shibura' brand are not as big as the EL34 & with thin pins. All perfectly good in their day if revalving can get expensive depending on what you want. Beware Websites saying "xxx" is an equivalent, they are cheating you with incompatible NOS ex-Army supply ones. Design says 7868, use 7868 or bias can be way off & half trash the amp, see the 1963 Trio WX-400U review. Beyond that, the SX-800 is way more impressive than the 10w Pioneer ER-420 that we've seen but never fancied trying. Not unlike the ER-420 fascia if more switches & rotaries gives it an impressive look. Rear has the usual inputs if to read the label to not just assume what things are. Large Mains transformer like the WX-400U has, the 2x Output TX for 30w are fairly small for the power, if older TXs are of a different more precise quality. Big Heavy Receiver with all that Metal in it, less Tuner Valves than the 1963 Trio & the Front End is typical 1966 style with a Nuvistor & Valve. Mains Choke is a nice old style touch if Transistor amps beyond the Sansui TR-707A didn't use them. The Top Lid being off looks quite tidy, but Valve Receivers with the Base Lid off are another thing. It's all Hardwired to Tags & Valves, there is no Parts Layout diagrams like Transistor PCB amps, you need to work it out yourself, if having done the learning on the WX-400U we're ahead on this one, if this is Highly Advanced Work, meaning most would just replace a small few capacitors & put up with it sounding way off it's Best. But we're going to Rebuild it needing redesign on the Power Supplies to take it into a different league. Possible to go really deep into it & rebuild the Tuner & redo all the Resistors which as we found with the 1965 Sansui TR-707A really does make a big difference. The trouble is to redo the amp fully is a Major Job, well worth it for how good the WX-400U sounded, if we'll likely not go that far on this one. Would We Choose this Amp for Ourselves? To see it, we want it & in fact it is ours until we finish it & give it back, so for the fact this is a big job, it'll be here a while. We use the Luxman LX33 often for Vinyl, the design is all ours, the LX33 design is lousy. It uses easily found new Valves. The SX-800A uses 2x ECC83 for Phono, 1X ECC83 for Pre-Tone, as used in many Valve Preamps. Power Amp gets less easy, a 6AN8 is used as the Input Gain & the splitter stage, in one valve is a triode & pentode which if redesigned could be done with an ECC81-82-83 as no real need for a pentode, if to redesign is far from easy. 6AN8 is obsolete if loads of NOS ones around as likely used in many items. Outputs 7868 already mentioned. Ideally EL34s would be better, but again you'd need to redesign it with new valve bases & then realise the valves are too tall. 7868 to replace from USA with 'Electroharmonix' brand are £128 delivered for a quad set which is reasonable. The SX-800A therefore has a decent valve lineup, compared to some Valve Amps that use obscure & obsolete valves. As for Tuner Valves the WX-400U from 1963 had all original Tuner valves showing these use such low power they'll last as long again most likely. Valve Amps past 1963 & some earlier use Diodes, so can be upgraded well, the EZ81 type rectifier valves aren't much good for what we do in upgrading. To Work On The Underneath. This is very packed in, to find space to work in will be tricky, if so was the Fisher X-100-B if it takes time. The Build Underneath may seem impossibly chaotic if once understood it becomes more logical. There is a PCB on the side with 'Balance' on the fascia, this is a Tuner MPX stage or Muting, not on the pdf as they only scanned one page. To redo the resistors on this whole amp would be too much of a job, the Rogers HG88 III we redid the resistors & underestimated the work in that quite a bit, the SX-800A would be insane to do & not to risk on a customer's amp, what we do is tried & tested on our own amps before trying, to avoid issues which do arise. This is a 1966 amp, less than a year later Pioneer making the SX-1000 shows how much easier a transistor amp is than this. Fascinating amp though. What Does It Sound Like Nearly Original? Very loud Bad Cap noises needs some work, if the idea is to hear it on Speakers sounding as close to 1966 spec, to see what it's about & where it needs upgrading. It's a bit of an unknown, 1966 design if not so unlike the 1963 Trio WX-400U. The 1967 Pioneer SX-100TDF as original we've blogged on & to tell it's original sound shows what a 1967 buyer may have heard. Serviced It To Give It A Listen. To at least Service it to try again how it sounds the next day as it's Fascinating. Bad crackle gone surprisingly, leaving a fairly loud Hiss and Hum background. L&R channels sound unbalanced, but to see Tone has 4 controls for L&R to adjust flat. Volume is top Left which is unusual on any amp beyond early Sony. Sound is interesting, it sounds light on Bass as the circuit suggests if Treble is quite crisp. Turn it up a bit louder & it sounds Flat & Shouty as the Power Supply is Poor & Aged, but overall for a Raw 1966 Valve amp it sounds Musically promising, if after 5 mins the Louder Hiss returns on the R channel so best leave it be. OK to try briefly, but not for longer use when noises return. Gambling with Aged Valve Amps can Trash Output Transformers or Fry the Mains TX, so care & respecting it required. To know what it's like before Working on it is useful. We'd like to try it on Speakers, but Too Risky for the Amp really, plus it needs 3-Core Mains Rewired Cable to be Safe on Modern Floating Earth TV Audio. Rebuilding. Valve Receivers need a lot updating to sound the way we like them. Trouble is 4 cans have 7 capacitors in total, where & how to fit these with upgrades is very advanced. The amp is far too crammed to do much making it a difficult one. Underneath allows no space to really do much & the raggedy loose Axial caps underneath will be a tricky job to even get part upgrade to fit, which may need the amp not upgraded as much, rather than overdo things. This takes ages to sort out right. To try ideas & see most don't work out puts this amp into the sort of amp we'd take up to a year to get right. It's a Customer's Amp paid to a level with the option of going further, to at least get the best from it & keep it tidy. as you'd expect, amps that don't work out as expected get put aside to do other amps & still think on this one. Round 2 on this will be soon, we want to hear how it sounds. Understanding. The SX-800A is the later 35w higher power vesion of the 15w ER-420. We've looked at this a while back on the 'Other Amps' page & now see it differently after the SX-800A. The problem with the SX-800A is they've added far more Tuner Circuitry, both are FM & AM but here adding Muting & complex FM-MPX including a PCB with transistors. It cramps up the underside making it impossible to upgrade to our way as the Trio WX-400U got as it has far more deeper space. The Tuner as perhaps the last Valve Tuner should be very nice, if upgrading it more is just too much as a paid job. ER 420 is more logical as pics online show & we now like it. SX-800A is a very tricky one to redo & offer a quality product, if it is still an awesome amp. Once Rebuilt & Testing It. The underneath is so cramped it makes any work very slow to get the best fit with keeping it tidy & stable. Ours is Now Done, we've played it for Several Hours & have Trusted it to try on our Tannoys. We have the 1979 Valve Luxman LX33 to compare to, a Transistor Amp sound is different as is the 1966 Rogers HG88 III sound. The Upper Bass & Midrange for the Upgrades is very decent on Tannoys, likely both Built for Each Other. The Midrange is very smooth, it's more listenable than the LX33 with the slight Retro Bass strangely, if LX33 wins for Precision & Treble being crisper & more Focussed. Retro Sound can be pleasing if once knowing Non-Retro to want that which is hard to get, it's Experimenting, not for this amp. A 1966 Output Transformer we've also noticed matches the Tannoys better than the 1979 LX 33 or 1993 TT 100w. The SX-800A we could hear amid the noise it had a nice Sound, so we got a Pioneer ER420 15w earlier version to help understand the SX-800A & to go further with ours. The amount of work to better the SX-800A is not going to give value for Money in a way the Current Job certainly has. To spend the same amount again for about 15% improvement when the Amp is good enough Rebuilt is the Curve on Cost vs Fidelity. We played the SX-800A for over 30 mins on TV & liked the overall sound. On Treble it is still 'Retro' to us as Rolled Off, plus the slight Retro Bass, but the Customer will like the sound compared to the more Upfront HG88 III. Good sound, but issues still. Headphone is far too loud, Volume isn't zero-ing & unbalanced until quarter volume. But on Speakers over halfway for a decent volume, if that shows gain needs altering, but again the cramped layout makes us not fancy doing that as start one thing & another few need altering. To do a Economical Job but warn of it not being so Hifi perhaps. Actually on Speakers No Hum or Hiss. As with any Job at a price, we'd like to go further, if picked the ER420 for that. DC Heaters. The ER420 has the Old Hum adjust pots on the back. The circuit shows this is only for Phono V1 & V2, as V3 onwards, Tone, Power Amp gain & splitter are still AC. We put DC Heaters on the Trio WX400U which was more luck for a spare voltage winding. Pioneer SX-800A a good amp to know, Nice Overall Sound if it could go much further. The design into the Amp case with the extra Tuner & Mute stages is too much, it's just 1cm deeper than the ER420. Rating of VG-EX means the amp needs much more rebuilt if there is certainly Excellence in Midrange & Bass, just the Treble isn't so good yet. BUY-RAW RATING: Too far gone as typical, if ideal advanced project amps. REBUILD RATING: Too cramped to Rebuild easily, caught us out. Big Job to Rebuild valves. COOL RATING: 8 all metal casing, sane if a bit industrial looking, but solidly made gives it high Bloke appeal. (2019-2020).
1966 Pioneer SX-1000TA receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
CC, Hybrid Valve-Nuvistor-Transistors. The First Pioneer Transistor High Power receiver? Not quite, a '1970' German brochure with 1966 amps shows a SX-1000T with a different fascia. This is a real hard one to find, could never find one in USA so to get this in the UK a cool find. Inside it's not so unlike the SX-1000TDF if the SX-1000TA has the Early Tuner with a Valve & 2 Nuvistors like early USA Fisher receivers. Underneath was the unknown as no photos online, if the Board layout is the 1967 style if the board wires face towards the front on the rear 3 boards. The Power Amp is basically the same if the Circuit is different. 1966 amps one speaker set so Power is a rotary by itself. Problems? A good amp to get if obvious untold issues like Loudness broken & replaced Volume control & repainted lid would usually be very unwelcome, if the failed 1000TDF can supply all those parts, but you'll never find them otherwise. Just removing Loudness will upset the sound gain a lot, so why it was cheap. No repairs or messing beyond that on the fragile board track. Differences. The 1966 'TA' is the first version with Valves & Nuvistors in the tuner, the 1967 'TDF' is the All Transistor tuner with ICs in early stages, the 'TW' is a 1969 version with an updated tuner & Power Amp with components side showing. TW has passive Tone but high NFB that spoils the sound of the earlier ones. Phono board W15-005 same as TDF, Tone W15-006 different to the 031 & 047 TDF ones. Power Amp W15-007 different to the 027 TDF one. Full run 005-006-007 of original boards. Same curly heatsinks & one extra capacitor on top for the Tuner extras. Minor Design differences in Tone & Power Amp boards. One thing the Manuals don't say is about the Pot on the board, it should be left fully Anticlockwise. The TA version is different on the Power Amp regulator that puts a small delay on the Start Up to hide any noises, later ones are different. What Does It Sound Like? For Loudness removed it'll be overloud, if to try it works, but to replace parts. Amateur messing as Volume noisy rarely needs putting a new one in. Actually works well for 55 years old, Volume overloud if FM Stereo all works & lights, picks up lots of Stations clearly even with a 'T' antenna. AM good too. Pioneer often work on the 1960s ones if other brands can be long gone. Crisper sound than other 1967 Pioneer as original, an aged sound if a punchy sound, if Bass limited by that rear board. FM Stereo plays great & a nice Tuner sound here. We have the SX-1000TDF as spares, to get a real Pioneer volume & switch, but in reality all values differ. Now Loudness & Volume Repaired. To hear it as Original, as near as possible. The Crisp sound is still here with it playing at the designed volume. Retro Bass a bit for the 'T' filter that we've heard with a SX-1500TDF on speakers as in a Blog, it sounds Bass vague on Speakers if better on Headphones. The 1966 design gives a more precise sound, why did they change it? Because it's far too good. 1966 Amp Working & Useable. This is a Rarity, if other 1967 Pioneer have been working too with the original 'Nippon Chemi-Con' large capacitors, including two 160v ones for the Valve & Nuvistor. No leaks is very unusual, how long it'd stay good is another thing, we'll recap it sometime. Output Transistors are 2SC793 if two have been replaced with early looking 2N3055. No other repairs show. On Headphones it sounded good, the Bass on speakers will be far from what we'd like for the old spec & Bass limiting. We tried an original SX-1500TDF on speakers, Bass was hopeless & it sounded a bit vague for lacking what upgrades bring. To try it on speakers perhaps? Mostly Recapped & finding out the Start Delay issue, to give it a play as Recapped beyond the Tuner 150v section. Sounds very smooth, not unlike the valves ER-420 sound. Does sound nice, the 1967-68 SX-1000 & SX-1500s aren't as fresh & punchy as this one. Valve & Nuvistor Tuner on the Front End. 6HA5 valve and two 6CW4 as in other 1966 Tuners. Rest of the Tuner is all Silicon Transistors, the Valve & NuVistor sound much better than other Tuner Designs, so smooth & crisp sounding. Picks up Stereo with ease & still on original capacitors. Probably the Best Tuner we've heard & picks up a signal better than many tuners just using a basic 'T' antenna. COOL RATING: 7 Smaller Amp, would suit a wood case the later TW ones had. (2021-2023).
1966 Rotel 100AMP amplifier ↑
AS-ORIGINAL (Once Serviced): Mediocre. UPGRADED: n/a. 15w Germanium-Silicon.
CC. Very early Rotel amp that was in the 1970-71 HFYB if it's certainly from 1965-1966 for several reasons, this was only £45 new in 1970. Cute weeny amp 331mm wide x 207mm deep x 108mm high just on the very nicely made teak veneer wood cases, if the amp inside with it's impressive wood effect metal lid is even smaller. Must have been one unsold for the Japanese market for the classy wood cases, other pics show this without them. We got the Rotel 120ST Tuner for AM/FM is cute, no ICs in this design if a 1969 date code shows it was available for some time, if why so rare on both? Read on to find out why. In 1970-71 HFYB £49, 2.5µV FM sensitivity. Amp & Tuner Multivoltage 117-230v switch inside so always intended to be sold Worldwide if one we've not seen before & realising it could be an early one, got to try. It's wrongly described at 'Silicon Outputs' in the HFYB, unless they were altered, if nearly the whole Pre & Power amp is Germaniums, the usually superior Japanese ones, if just one Silicon 2SC828A per channel hidden near the back. Sanyo 2SB407 30w PNP outputs, 2SD72 & 2SB405 are the TO1 drivers, 2SB173 TO1 early stages on the Power Amp. The Phono has 2SC644 which are early Silicons, the similar ideas in other early amps to keep noise low on high gain. Very 1966 fascia for long thin metal control knobs like the 1966 Akai AA7000 & early style slider switches that were rocker switches by 1967-68. The Amp back panel says 100VA meaning 100w full power drawn from mains, HFYB rates it 15w if a 32w later Rotel was rated 150VA so possibly 20w here? No info found on this amp, the model number is unlike any others, it must have been their first Model & Tuner in 1966 as not even Japanese Hifi sites list it or similar. Both Amp & Tuner must be considered at least "Rare". Rotel made no Valve amps so like Sony with the 1965 TA-1120, this has to be their first. No Circuit Diagrams, no Board Markings make this an amp for advanced Techs. 2200µf 63v main cap if with 40.2v if modest 470µf output caps reading about 20v, all Elnas. Knowing other Germanium amps, a surreal if pleasing sound, all rather low spec but fascinating is expected. Mains plug typically has a 13A 3kW fuse in, a 3A is best. Sound playing Mono tracks is better than expected, a decent sound balance if deeper Bass noticeably lacking. Controls all vague & typical unserviced effects and crackles. Be sure the UK 1970-71 buyer of this got a great sounding amp for very little money. Certainly better than the Duette amp & has a crispness to the sound that will put it with the JVC & Coral 1966 ones & perhaps ahead of those. Playing Mono tracks, Background noise is audible on headphones if not too high, hiss not hum. Not many amps are listenable to us as original & unserviced, as well as on 50 year old capacitors, if this with Germaniums is a good sound, surprisingly bassy for the spec, if a little Retro sounding. To recap means to understand the tiny board that has Pre & Power amp, all 70mm x 100mm of it, to drive you insane is a risk to recap, so we did the resistors too. But after letting it sit for months, to refit the original transistors, the waveforms were clipped, the Bias on one channel kept it silent as found before. It's just a very poor design, we try if it doesn't always work out. To sell it as a working Tuner & an 'ornament' amp to keep it alive seems best. Vintage Hifi doesn't always work out. BUY-RAW RATING: Ours with Germanium Transistor issues & resistors on a high grade one can mean problems. REBUILD RATING: Amp is just not a good design, best to use it to fit a modern amp module inside. COOL RATING: 8 Great Cute Retro looks in the Teak Cases, probably very rare in the Wood Cases. (2018).
1966 Sansui Model 500A valve receiver ↑
AS-ORIGINAL (Once Serviced): Average-Recommended. UPGRADED: Not Worthy. 20w.
Frst for sale in Dec 1967 says one site, if more likely Dec 1966. it seems a very half-hearted Budget Effort, far from the Quality of the 1964 Sansui 1000A. A disappointing rushed effort by Sansui, the 500A was issued before the 3000A, despite one site's date errors, we saw it in a late 1966 Hifi News advert & was their last main valve series if nothing since the 1964 range previously. The 3000A is one of the best amps ever but the valve 500A is lousy. It's got some very poor design such as awful tone controls & filters as well as the HT being much too high for the 7189A valves making it easy to trash a valve. All valves are obsolete ones also. The input sockets are the useless oversized conical phono sockets, not the typical sort. As-is the amp needs the aged coupling capacitors replaced, our one had a these few replaced with the same low values. It sounded soft & weak if hinting that better was there, and based on the quality of the Sansui 3000A we spent much time upgrading it. But the design is very poor & with AC preamp heaters once getting away from the deliberately low spec that hides the weaknesses it revealed more issues each time, look how rubbish the tone & filters are to see lack of care in design. We just gave up on it & were glad to get rid of it, sometimes you have to cut your losses as it displeases. It did appear again for sale after the buyer spent a lot finishing it but they didn't get back their investment, our review pulls no punches & shows this was the only amp we decided was too lousy to complete, beyond ones that didn't survive. We'll not bother with the 1000 or 1000A if this is how poor they are, valve forums we've read on the 1000(A) say design is bad there too, this is Sansui who made great Transistor amps but Valve amps with issues. There is the valve AU-111 that looks great too, see the Other Amps page for more on the 500A & other Sansui valve, we have researched. Buy it to use just with new coupling caps for a soft retro sound, but don't even bother upgrading it as you can see it failed. The headphone circuit is rubbish too, it lacks loading circuitry that the 1963 Trio above have was realised, so don't use it on headphones seems best as it's illogical as you'll find & why it trashed valves. Bad design by a brand that excelled with the wonderful Sansui 3000A below. We'll point out the problems as amps good & bad teach us more. The HT is very high for EL84s & with the Headphone design weakness the output valves get destroyed way too easily, this suggests with speakers it might not be as stable either. Tone & Filter circuits are very poor to the point the High Filter just nulls the Treble. BUY-RAW RATING: Usual bad coupling capacitors, but much more is poor too. REBUILD RATING: The difficulties are based on poor design & non-standard valves compared to ones still made. Not one worth going too deep into sadly. COOL RATING: 7 in the wood case, now this is very similar to the 1967 3000A but this loses points for the cheap plastic control knobs & grey fascia half, without the wood case it's a 5. (2014
1966 Sansui Model 3000 receiver ↑
AS-ORIGINAL (Once Serviced): Probably Too Aged to Use. UPGRADED: Excellent. 45w.
SC, Transformer coupled, Direct Coupled. There are Two Versions of this amp & to see they need to be put into the rare 1966-1967 "3000" & the findable 19671969 "3000A". So see the Sep 1967 version for our earlier opinion & more info. First seen advertised as 'New' in Dec 1966 HFN with Sansui adverts & by Jan 1967 'Lasky's Radio' ads show they became the first UK distributors. Damping factor of 15 gives it a valve amp styled bass. Dec 1967 Sansui ad shows the 3000 if by Jan 1968 the 3000A is mentioned. The 1966 one appears to be the same on most boards visually if there will be differences so we need the 3000 service manual. The 1966 flyer shows the lower fascia as medium grey with black print, if ones online show black with white print like the 3000A is. The 3000 is much rarer than the popular 3000A that sold in the Army & Navy stores so it's quite a common find on USA ebay, if prices are still modest as the amp being so old on either version does require a full rebuild which is advanced work & costly. Transistors on this differ, the Power Amp Driver six are a strange type with a flange but much smaller than the TO66, the 1965 Sony TA-1120 has similar & long obsolete style. Actually they are TO5/TO39 size fitted in an oval heatsink to fix them. 3000 to 3000A Visual Differences. Overall they look the same if there are subtle differences, the Volume & Balance are swapped positions 3000 to 3000A, the lever switches get swapped around, 3000A loses the AFC tuner switch to add 2 speaker pairs switches. Tuner glass is mostly white on 3000 if light blue on 3000A. Typeface on the model number, Solidstate vs Solid State, extra rotary control graduations on 3000A, plus "Function" on 3000 is renamed "Selector" on 3000A. Rear Panel only differs for One or Two Speaker pairs if the 3000 has a L+R Centre out socket the 3000A lacks. Also the fixing screws on the 3000A are typical mix of - and + if the 3000 has smaller + ones & - ones on the speaker panel. All of minor interest, but it helps spot alterations or replacements. 3000 vs 3000A Circuits. The 'Protection' circuit that shuts off the Preamp is different TRW3A with TRW3B on the 3000A. Some components differ, diferent diodes on the Power Amp, different 800 ohm resistors plus the difference of 1 or 2 speaker pairs. Both have the Ceramic column which is 2x 2 ohm resistors for using on 4 ohm mode. The Preamp-Tone & Power Amp appear to be identical to the resistors as does the Power Supply. It was a great design to start with as early as 1966 which is interesting. Coupling Transformers. The biggest difference 3000 to 3000A are the Transformers for the Splitter state in the Power Amp. The 3000 manual says "Primary 500 ohm, Secondary 50 ohm" if the later 3000A manual has "Secondary 30 ohm". This will alter the sound & an Impedance difference could make the earlier one "too wild" if the 3000A after sales feedback was tamed more, or to not make it too good. Lower Secondary Resistance means less wire used so fewer turns, a 40% reduction is quite a difference, the output voltage will be 40% lower which will mean sound resolution will be lesser. 411-5293A/B is the 3000A one as on the 3 we've had. The 3000 is 411-5249 A/B as in the manual photo showing the difference. Driver Board Diodes. Some of the earliest 3000 have 4 diodes on the Driver board, so without the extra 4 across the Adjust Pots, ours only has the 4x SW-05 on the board if not the extra 4. Getting It Speaker Ready. Ours works now, sounds good but the rear heatsink does get a bit warm & the DC offset isn't reliable enough. Ours has old replacement 1960s Sylvania ECG 162 with '126' codes. The datasheet shows these are TV 'Vert Defl' drivers, 500v, 3A, 100w. Amp works but they aren't really Hifi ones, a typical TV repair guy repair, use what they have rather than order in the correct ones. Amp sounds better with new outputs of the right spec but the amp still gets extra hot. Redesign somehow to solve that, if we had similar with the 1966 Akai AA-7000. The 1966 version of this amp is much 'rawer' sounding & why they tamed the Coupling TX. Bias issues to solve on this one. Revisited Dec 2020. Not looked at this in over a year, if playing it with other 1966 amps, this still sounds great if with issues. The earlier Sansui TR-707A sounds great if this early 3000 is a little more accurate & without the background noise. So to try to get it useable again, in light of how it compares with the 1966 Akai AA7000 & the new arrival 1966 Sanyo DC-60 that sounds great even as raw & very aged. Sounds great, but Bias rises & gets hotter, even with a Speaker Load. The 4 Diode version will have worked for it to have been sold, if quickly updated to the 8 Diode version, but either is still too hot. Revisited July 2023. Getting success with other difficult amps, to finally get this running cool & sounding so sweet & crisp sounds like we're dreaming. But it happened. One of the Best Sounding Amps after playing the TR-707A the day before, the 3000 has the better coupling transformer, the 3000A was never this precise & crisp. To play the amp for an hour with no heatsink heat. Looking inside, to see it got fully recapped including the Tuner, but things like the Protection Stage that usually lights the Bulb on the Fascia after 30 mins, none of that cutting out here & it's still wired as made. Never really got to play this & this typing on the second play reveals the difference the 'Monobloc' styled Dual Power Supply from One Transformer makes, ideas similar to Harman-Kardon did with Two Transformers, the Stereo Width isn't compromised as L+R work from different ±HT supplies. Not expecting it to be this good, one to keep. To wonder how many of these got thrown out for the same issue we had. COOL RATING: 8-9 nice in the rare wood case as on our Solds Gallery. (2018-2021-2023)
1966 Trio-Kenwood TK-60BU receiver↑
AS-ORIGINAL (Once Serviced): -- UPGRADED: --. 20w.
CC. Kenwood 60 BU. This later TK-60 version got reused as TK-66. We've not tried earlier Trio-Kenwood beyond a few years ago, the Early Ones pre 1967 just aren't around beyond the 1967-68 ones that can be Low Power 13w ones. Early Trio-Kenwood is shown in a Apr 2024 Blog we done of what HFN advertised. We get this one & then see the TK-80U. The TK-60BE is in the HFN in ads Jan-Mar 1967, why BU & BE isn't clear, if Multivoltage 117-230v. Don't remember seeing this or the TK-80 if the 1967-68 ones more around. The One We Get looks a Long Sleeping Amp, the Tuner Knob & Post broken off long ago, so looks like a Barn Find, if inside is thick with dust, the top lid & fascia dirty, unusually it's very clean underneath & the base outer cover is good grade. Seen enough Trio-Kenwood to know a heavily used one, this is unusually clean. Plug shows a 55p Woolworths sticker & barcode to assume last looked at Early 1980s. But No Fuse Holder screw cover on the rear. Part supplied by the KR-5200 we have as a parts amp. Check it over, nothing wrong, so a bit of a Service & Plug It In with the usual Safety. Meter lights up, no problems either. Plug it in with Audio Input & Headphones. Tuners work going through Inputs & Aux plays in Stereo. Clearly 'Shelved' for the Tuner Rotaries issues, the Tuner Cord is mostly still Whte, it will have worked early 1980s as it does now, maybe missing the Fuse Holder Cap got it put away British Folk often kept Good Things in the Attic rather than throw away & only later House Clearing brings them out. No other lights show but it Powers Up & Plays. But not for anyone but a Tech aware of 1960s amps, it could easily be much more aged. It plays Stereo, sounds Tired after 40 years unused but will Revive nicely. Day it arrived. to sort the lack of Tuner control. KR-5200 supplied the post bit & using a 1967 parted Trio to get the Tuner knob looking acceptable. Haven't even washed it yet, fascia has embossed lettering & the '60BU' badge is bolted on. The Earliest Version has all 5 big capacitos the same value if the Manual is different. Takes the 29mm LEDs if early Trio need new foam by the lights. Trio TK-60 is actually quite different. HFE manual shows the fascia is marked 'TK-60' no BU or BE & the inside is different to the early 1967 HFE advert of the TK-60BE. Ours is a 'Kenwood 60 BU', no TK code anywhere. TK-60 Tuner Meter has smaller numbers, two FM Lights for Mono or Stereo, Push Button Power Switch. This is clearly earlier as boards marked '816' '818' '820' & '821'. Two capacitors visible from the rear, 60BU has one & a line of 4 further in, plus the 0.5 ohm output resistors on the top, not underneath. 60BU has '821' power amp, if 'UA13241' tone with two Tuner boards 'UA14023' & 'UA12-024'. Even the 1966 Brochure shows different versions inside to out. 1965 Brochure shows more 'unknown' transistor ones. So What is the '60 BU' version? Only the Power Amp the same. The Tuner 'UA 12-024' has 2SA234 PNP Germaniums. 'UA14023' has 2SC281 NPN Silicons. Phono-Tone UA13241 has 2SC350 NPN Silicons. Power Amp Silicons beyond the 2SB89A usual PNP Germanium Driver. Outputs 2SC664 High Power 5A 100w, original ones paint sealed still. Germanium PNP Tuner board on the TK-60 Germaniums Tuner has a + voltage. Well known that Trio forever changing Designs, the TK-140X two versions & the KT-5000 with boards different in both we've had. Tuner front end is 'UA11-023' with 3 Germaniums 2SA240, no FET, similar to the earlier TK-60. IF board 'UA12-024' same as TK-66 with Germaniums, MPX is 'UA14023'. Have A Listen. Minimal Servicing & a swollen dry capacitor replaced, to hear it as near original to see what it has to offer. On Turn on a wobble & the R channel has a Hum, if it plays Stereo. No good to Use as it's struggling. But it has a nice sound & some weight to play Rock. Turn-off it's rough again & best not using it until Recapped. The other 1967 ones we had like the TK-66 (20w, 2016) & KR-33 (17w, 2012) weren't thought too impressive, the TK-66 got a big rebuild & the '821' power amp we redid the resistors even, same board the 60BU has. That Answers It. The TK-66 is much what the 60BU is, same Power Amp '821' & Phono-Tone 'UA13241' if a 'B' version. Same Power Transformer too, 'TO1-156' & 2SC664 outputs. Probably in 2016 we'd not had enough Neutral Amps to show how good the TK-66 is, if the 60BU 'raw' shows a nice sound. Maybe the odd looks of the TK-66 lost interest, the 60BU looks much smarter & a bigger case. Reading the TK-66 review seems it was the first Trio receiver we got, it showed a good sound. The 60BU sounds decent too, if rather rough as original & needing Upgrades that were not yet in our 2016 ideas with the TK-66. Part Recapped & Serviced to give it a try part done, as in Power Amp & Tone-Phono to still do. It's quite a thick Bassy sound that's not really our taste, Treble isn't so precise. Hum gone though. Reading our TK-66 review from 2016 shows that opinion was before the KA-6000 & TK-140X were here. Soon finding the KA-6000 a bit lacking compared to others if the TK-140X either version were much better sounding. To revisit the early Trio-Kenwood needed doing, to hear a Sound that needs Our Upgrades & the TK-66 was the first one we went further with back then. The idea was to Redo this & sell it on, here we're now wondering what's Not So Hot here, recapping the TK-66 in 2016 only got it a 'VG to EX' rating. The KA-4000 we have at the same time sounds better half done, so let the TK-60BU sit a bit longer. Power Amp Oddity. The TK-66 circuit diagram uses the strange combined Capacitor & Resistor as does the TK-80. Board is marked 'R15-47' meaning a 100µf capacitor with a 2.2k resistor, but they only use the Capacitor if on this & the TK-66 there is the resistor added underneath. Play It Mostly Recapped with the Phono-Tone board to do still, give it a try as not played any Silicon amp in a few weeks to learn the Germanium sound. TK-60BU has a fresh sound overall with a crisp sound, but it's less smooth than Germanium by virtue of how Germaniums are. To remember this is the First Play as Recapped & amps need use to awaken as the Compares below tell. TK-60BU isn't so different to the TK-80U if that's a far more sophisticated 32w amp. The TK-60BU still based on Germanium design. It's a better starter amp than the KA-4000 we have here currently, to wonder what to do with it as it is interesting & likely the last of the 1965-66 larger Trio-Kenwood receivers. It looks nice with the embossed fascia text, if probably won't find the right tuner knob on a rarer amp. Compare to Other Trio: KR-6170 & KA-4000 as on the KA-4000 review. It's a 20w amp but a 1966 one has a sound fresher & more open. Not comparing to Germaniums which are a in a different league as are Valves, the TK-60BU is bettering others & lets us sell the KA-4000, if to hold the 60BU for longer as it compares so well. The 60BU is a lot better compared amid it's Silicon brethren. Very Wide Stereo on the 60BU beats the 4000 easily. Compare to 1966 Sansui 3000 which is Silicon if redesigned. testing the same day as the 4000-6170 compares. 3000 currently on Speakers after it comparing well to Germaniums. Interestingly the 20w '60BU' has a little more 'listening pleasure' to the 45w '3000' on headphones. To compare back, the 60BU has a richer sound & the Stereo wider than the Sansui 3000. First compare of this way better than expected, the TK-140X & TK-66 weren't thought this good, TK-60BU uses TK-66 boards. What's different Early TK-60 To Later TK-60BU/TK-66? Now the BU version is more familiar, the Boards are numbered differently if look much the same. Phono has the early Black Rectangle 'CR' units on the first 60, the 66 has simplified values & other minor changes. Preamp-Tone on the Board is no different. Tone controls almost identical, ie 0.03 compared to 0.033 as components standardised. Power Amp is as near as 'Exactly The Same' as possible with the odd minor value change if '821' boards on all. Manuals show Photos of inside top & base. TK-60BU is much tidier on the Power Amp with the Output Resistors underneath. Tuner is tidier on the 60BU explaining the inside photo on the ad as it looked more professional. Resized case on the TK-66 as less parts on the 60BU & much less than the TK-80U. The '60' & '80' mean 'Music Power' in those days, 20w RMS is 30w Music Power & 32w RMS is 40w Music Power added to make '60' & '80'. The Tuner. Once the Pre-Phono recapped, it's ready to try more. Tuner oddly is still 80-108 like the TK-80U, at '84' it finds something to quieten as it's a signal, but nothing Broadcast. Do get FM Stereo playing with the Green Light lit, on around 100 the Classical station. Germanium tuner has a Nice & Precise sound. The TK-60 manual shows it has the FM Lights Mono & Stereo as the TK-80U has, but TK-60 is 88-108. The TK-60BU isn't exactly the same as the TK-60BE as in the Jan 1967 HFN ad, to see 60-BE has different numbering on the Tuner Window. Also the BE Phono-Preamp board has visual differences. More TK-60, TK-60BU & TK-66 Differences. As there is no TK-60BU Manual findable, to have to compare TK-60 & TK-66 then look at our TK-60BU. TK-60 to TK-66 Phono has a few minor differences plus what looks like an extra EQ on the TK-66. Pre-Tone is exactly the same. Power Amp minor changes on Q9 Protection Stage if otherwise the same. Power Supply basically the same without the 'Beacon' board voltage on the TK-66. TK-60BU has the later Phono as the 'UA' number suggests. Has R34 fitted & R35 underneath. Has the TK-60 Capacito-Resistor unit with separate parts if the Board shows 'R15-47' still, with the Resistors underneath. Biasing. Trio never say what the Pots are, beyond the VR1-2 being the Adjusting the Clipping AC output at full power. VR3-4 are Protection Adjust so leave them as set & VR5-6 are Bias. The Left one is lower turned Anti Clockwise & the Right one is lower turned Clockwise. The Pot on the Phono-Tone board is 'Separation' giving the idea the Extra EQ is as FM Tuner goes through this board, tracing the FM MPX output it does go into this board.
BUY-RAW RATING: Probably too aged to use. REBUILD RATING: ---. COOL RATING: --- . (2024).
1967 Dynaco Stereo 120 power amp, PAT 4 preamp & AF6 FM-AM tuner ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 35w.
CC. The rating here is for the Power Amp only, This we got in an ugly home made cabinet with a high grade Garrard 301 grey-grease for £30 the lot in 1998. The tuner didn't work, the preamp we thought wasn't very good though it could have been faulty, but the power amp we liked. It does need a high 1.5v input, unlike the usual 400mV most power amps had which may have meant we never really got the best out of it. Capacitor coupled design with a strange wire wrapped around the output caps like an inductor. Used 2N3055 transistors & had a power amp board per channel. Nicely made on bright chromed base with a solid mesh lid, with a lit power switch, Phono sockets & some sort of better speaker connectors. From memory it had a nice clean accurate sound & probably got used with the Rogers Cadet III as the preamp. Dynaco came as a kit too as Dynakit branded. The AF6 tuner dates it to about 1968. We've seen this again to add this in 2017, the Preamp & Tuner were pretty average we remember, the Power Amp was a good one for it's age, if looking closer at inside pictures to get one to rebuild sort of loses interest as the build is a bit crude, using the output capacitors with wire coiled as an output coil. But overall the whole system seems a better buy than the Quad 33/303 that we don't like as the "Other Amps" page reveals. BUY-RAW RATING: For the Stereo 120 it was still good in 1998. REBUILD RATING: Not had one in ages, expect the main caps which are visible through the top mesh would not look so good redone. COOL RATING: 8 for the power amp is attractive with it's chrome & metal mesh lid, 4 on the pre & tuner are plain looking & oddly the power amp was meant for hiding in a cabinet as ours was.(1998).
1967 HH Scott Stereomaster 344-C/13 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 32w.
CC. Another one of the Big USA brands that saw limited distribution in the UK. This turns up in the 1970 Hifi Yearbook rated as 32w. Not a lot of info on this one or pictures of insides if we can get the Service Manual so worth a try. Looks like the other early USA Fisher & KLH type 'unique' build & certainly these early USA ones influenced the early Japanese gems. Even trying this as-arrived, the very clean USA sound is apparent, compared to how rough UK ones sounded, finesse & high quality build is certainly the deal here. The 344-C is the main version of the 344 range that started in 1965 with Nuvistors in the tuner stage & an identical looking higher power 384 adds MW & a rear antenna is 50w. Ours lacks the wood case as often these were built into consoles or cabinets, but with the leather effect top lid it's still smart if it has no feet so we'll add some. Aluminium chassis like the KLH if it's still quite a heavy amp. Transformer mounted on the rear panel for rigidity & the large tuner window is perspex so no glass to worry about like McIntosh have. Volume is called 'Loudness' and to use it Flat to press in the 'Volume Comp' button or it's in what we know as Loudness mode. The back has plastic covers over 2N3055s which is an early show for those & with a '67' code so original. this has a 110v-220v switch on the rear, a little too easy to catch it still. Speaker sockets for 2 pairs only have 3 screws per channel, double up on the 'O' ground one, strange. 'Preamp Sens' is for Phono gain, not actual Pre-Tone gain & it has 2x 'Extra' as Aux inputs. An unusual 4 pin socket on the rear is to measure bias to adjust inside. Pre-Tone & Power Amp share one board & it uses those tiny 1/4w carbon comp resistors like the KLH 27 has. It uses black plastic capacitors which aren't the lousy ones UK amps used like the Leak Delta 75 below, though they are aged & we'll recap it. Small transistors are plugged into sockets like the Fisher 600-T uses on some. All wires are single core, no shielded cable anywhere if it's twisted as pairs signal-ground & close to the casing so no hum. Of the Fisher & KLH this is the neatest built one & most like the early Japanese amps for it. On first play of it, slight background hiss as usual on early transistors. The sound sounded a little soft but turning volume past halfway brought it to life as did some use. Bass as always is lacking the deepest bass, hardly any amps dared to risk rumble from cheap turntables, but the sound was very clean, good detail & unusually good dynamics for an amp this early as original. The KLH 27 was soft & blurry, the Fisher 600-T sounded limited but this was unusually good. Addng some Soundcard EQ on the deep bass to fill it out to a more usual sound it still sounds better than some amps we've spent ages upgrading. On trying tracks with strong dynamics, it copes as good as a 65w amp, we've had 50w ones that can't deliver the kick without clipping. Manuals unwilling so we work out the circuit ourselves to recap it, the black electrolytics actually are the same Eire made Callins that are awful on some early 1970s amps, here recapping just the preamp half already hugely improves the sound. On doing the 3 bigger caps, the main one was dry & crusty so it wouldn't last long. The mysterious switch on the baseplate is to test the preamp as L, Normal & R. Now all recapped, the sound is certainly a quality one, a tight but fast fully extended bass, clean midrange, crisp clean treble & fully wide Stereo. as it's still on the original transistors as it sounds good speed, a little background noise if it doesn't intrude. As always with USA amps the Headphone L+R is wired the other way so we swap it as the Fisher & KLH needed. For music testing, Reggae sounds great, Rock is solid if not as weighty as 32w, but a tiny bit on the Bass & a little Treble cut reveal how accurate it is. Volume on headphones is as good as a 45w amp before it flattens off gently but it can deliver a good kick without wimping out. Not many amps are that good at any wattage, the buyer is in for a treat. We'll certainly try more HH Scott amps. On the Tannoy Golds this sounds exceptional, a real matter-of-fact sound with a very solid midrange, sweet treble & deep bass that gives what few amps can. It's 32w yet is as confident as higher power ones for the sound. Remembering it in 2017, one we never got the Service Manual for. Odd construction in Aluminium & no wood case, but a great sounding amp, if a little crudely built inside with push-in sockets for transistors. COOL RATING: 6.5 bachelor pad looks if would rate higher at 8 with the wood case. REBUILD RATING: No manuals found on this, not too complex to work out if the plug in transistors & awkward Phono stage could be bettered. BUY-RAW RATING: Needs a recap as the caps age too much if it should be working, if it'll be below it's best. (2015)
1967 JVC Nivico 5010U receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 13w.
CC. Ignored for too long, look how we rate this amp. Not had an early Nivico branded JVC Japan Victor Company amp before though they were a big name in the late 1970s-early 1980s. The Japan sold ones were branded 'Victor' explaining the stuck-on JVC Nivico badge. This is a small receiver with mostly black front with green tuner lights & a 5 row SEA "Sound Effect Amplifier" Graphic Equaliser type tone control as JVC used on all at the time, but don't skip on just yet. These early JVC are seriously underrated, assuming they are similarly good as the 5010, the Graphic certainly puts buyers off thinking it's some IC junk, but it's not, it's a High Quality circuitry as so early & defeatable. It uses one transistor per channel with resistors & inductors, even if set flat it's better switched out. Full Treble tone needs the 5th slider max & the 4th midway to sound clean & no different to a regular Tone stage. Power rating says 40w on the front, this means 20w per channel continuous & we read a clean 15w sine so 20w is right. Oddly it appears in the 1972 HFYB, unsold remainder stock no doubt. The 5040 originally had Germanium tuner diodes, so the slightly later upgraded 'U' notation without them is probably from 1968. 2SC1061 output transistors are 25w rated if more used as regulators or drivers. One 2000µf 50v main cap & coupling capacitors a lowly 470µf 35v, higher power ones still only used 1000µf. Quite a heavy vinyl wrap wood case, very retro looks not dissimilar to early National receivers. The back has pre out-main in sockets & unusual link connectors for normal use, Phono inputs & a DIN tape plus 2 speaker sets on typical screw connectors. Another Very Good little amp. Plays loud for just 20w as based on valve design, so as 'loud' as a 20w valve amp & we've been playing it like a 40w amp & find it hard to trip up. Inside the Phono, Preamp & Power Amp are all on one long board. Bass with the lowly output caps uprated it reveals a far better sound overall, clean wide Stereo width worthy of 'Excellent' already, high praise indeed. It surprisingly does Rock well where other low power amps wimp out & even a hard kicking track like The Jam 'Start' is delivered as good as you'd want which defies the 20w rating more than a little. For how good this sounds all original & the minor uprated ones made a big difference to the fidelity overall, to recap is the only option, but no Service Manual & only a part 5003 to find online. Transistor count is Phono x2, Pre-EQ x2, Power amp x6. Recapped it is a lot crisper & later comparing the 5010U to the 5003 from 1969 noted below the sound is very close, as recapped it's cleaner on the treble but 20w to 50w isn't noticeably different until turned up loud. With the main capacitor uprated it sounds excellent, a very accurate solid midrange, crisp detailed treble & bass still strong going deep without too much it sounds as good as any 35w amp with deliberately played loud bass gently rolling off rather than clipping harshly, not many amps do that. On the Tannoy Golds, before getting the big main capacitor upgraded, it sounded a bit soft, but once the new cap fitted it again sounds like a 35w amp on the speakers for the clean precise sound. The JVC 5010U gets a 3 page review in March 1971, at least 3-4 years after it was first out. Rated 16w into 4 ohms, 13w into 8 ohms £135.93 new & they rated it just 12.5w, it read very low on power on 20Hz just 3.8w but that’s why we upgrade these amps as bass is always limited as is treble power. But it is loud enough not to clip out & sounds like a 30w amp. Watts don’t always mean volume though. They seem to like it for use and looks, but said it was too expensive & just about said not to buy it as you’re paying the extra for the SEA ‘novelty’ that you don’t really need, explains why JVC are rare. The mainly technical review doesn’t say anything about the sweet sound though. A remarkable amp currently deeply unappreciated elsewhere, but not for long... REVISITED 2016: Got one of these to recap & upgrade. This inspired us to get the other 1960s JVC to to hear one upgraded again reveals how great this amp is. For just 16w the sound is full bodied & musical, with clean crisp treble & extended tight bass. We've had a few great amps since as the list above shows, but the sound of this amp is a true benchmark for how good Hifi can be. The bigger 5030 & 5040 may have more power but this at 16w is a sweeter sound & still has adequate volume. The buyer of the first one still rates it highly we've been told. JVC kept this quality into their 1973 range as the designs aren't that dissimilar, if later ones we've not tried yet. It is only 16w & it can be heard smoothing off loud peaks, but it does it gently like valve amps do, none of the low spec 'Pioneer' roughness here. REVISITED 2021: A Customer's amp, sounds nice on first use, very lacking bass & rather low spec if the crisp sound still shows how good these early JVC are if to need upgrades to bring a better sound. HFE actually has the Schematic now, it's hidden in the User Manual, if there it is. Rates as 13w for our uses if it doesn't seem just 13w for a good volume. 13w into 8 ohm, 16w into 4 ohm as IHF continous power working on 42v HT, 21v mid voltage as capacitor coupled. Actually easier to recap without the manual, it's a bit of a fiddly one as no board layout, if this is our 3rd one. This one a 220v-only model with 3 fuses under & no AC outlets. Once Upgraded it has a very clean sound with an amount of Bass to sound good if 13w it can only go so far as Bass can need a lot of Power, this is fine for 13w & better than you'd expect as we first found out in 2014. On Speakers seems we've not tried before as Upgraded. Speaker Screws take the 4mm Gold Blocks. Quiet turn on, Sound is very decent with wide stereo, clean open & crisp with Bass to fill it out right if not the Real Deep Bass at 13w. Sounds as good as other JVC & drives our Tannoys well. If you don't need the Higher Power, the 5010U has the sound. Great little amp. COOL RATING: 6 a little awkward looking in the big wood case loses it style appeal if the green tuner ups the score. BUY-RAW RATING: Good. (2014-2016-2021)
1967-69 JVC Nivico 5030 or 5003 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 50w.
CC. Aka the 1967 JVC Nivico 5030 & 1969 JVC Nivico 5003, just the Tuner is updated it appears as well as the styling. Ignored for too long is this brand for the fact it has a Graphic EQ instead of Tone. The Japan sold ones were branded 'Victor' explaining the stuck-on JVC Nivico badge. As with the JVC 5010U from 1967 above, the EQ is not a hideous IC based 1980s style mess, it's a one-transistor tone style one with inductors. See the 5010U section for more info. It sounds clean, can be fully switched out easily and once recapped sounds no different in or out. We had to try another early JVC after finding the 5010U so good, so this 50w slightly updated FET tuner version of 1967's 5030 and is a good one. FETs being just the first two in the FM tuner front end. These amps are totally ignored, except by us, but they are well made & sound Very Good. The boards are well spaced out, rather like the Pioneer SX-838 to SX-950 receivers, unlike how cramped the Trio-Kenwood TK-140X is. Large transformer, 2200µf 100v main cap & 1000µf output caps typical of the era. A red power switch and small white rocker switches are unusual, the back panel is very neatly set out. Turning it on, leaf-green display, very 60s retro pad styled & enough controls to scare. Very like the 5030 if it adds Tape Head & is rated 230VA not 190VA, just different fascia styling. This is often Multivoltage & the front sticker boasts "140w". Long time sleeping amp needs a good service before really telling how it sounds, noisy switches & the like. Not the easiest amp to get to the front controls inside though. First sound try reveals a sound unsurprisingly as good as the 5010U. Needs running in but clean, punchy, fast & accurate with wide Stereo imaging. Clearly as good sounding as many of the 1967-69 competition, oh how these have been unfairly ignored. Comparing to the 5010U now mostly recapped the sound is very close, recapped it's cleaner on the treble, the 5003 having a very solid midrange rarely found in any amplifiers. Circuit diagram findable, but it misses the power amp part. The power amp is the left rear board, the Phono, Tone-SEA & preamp is the right rear board, mid board is the power supply. After looking deeper, construction is quite bizarre if effective, never seen another amp like this & it was a 1967 design for the 5030 so they had little to learn from. The wood case is a very heavy weight with veneered ply. A large amp 53cm wide, 15cm high & 35cm deep. Fascinating amp though & with a very solid neutral sound. For it's 50w rating, 140w sticker (70w+70w) it puts out 33v clean sine, more like a 60w amp & runs on 88v HT. Only part of the service manual is findable, no power amp or power supply info. After recapping the pre & power amps as well as the power supply, the sound is very addictive, just so neutral & accurate with a clean treble, decent bass & unusually wide stereo. Does need accurate Bias adjusting to bring the sound out. Pioneer were never this good yet JVC despite being popular when new in the late 1970s are now almost ignored. Nivico is Nippon Victor Company, yet JVC is in the logo too. **The correct power ratings of these revealed in a Oct 1970 HFN ad, if the wattage is added L+R, so for our uses the 5010 is 16w, the 5020 28w, 5030/5003 50w & the 5040 is 75w. 5030 & 5003. We've had both of these now, the looks differ with switch & knob variations if the inside is similar beyond Tuner differences & an extra board between the 4 main caps. BUY-RAW RATING: Switches need a good servicing before working right, otherwise good. REBUILD RATING: This one is more involved to work on, the rear upright boards are hard to work on. 'Soggy' build quality is a little offputting. COOL RATING: 6 a big amp not so pretty in some ways, the big case is a bit clunky but the sound matters here. (2015)
1967 JVC Nivico 5040U receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 75w.
CC. We've certainly liked these forgotten JVC Nivico amps so finding there is a genuine 75w version, to get it is the deal. Very rare, huge & tricky is this one, ours will be made out of two to get one good one as happens sometimes. The size of the amp in the case is 530mm wide x 390mm deep inc fascia-rear & 150mm high so outdoes the Sony STR6120 in the wood case by 20mm width. The first one had a bad selector which sort of finishes it, if it did work through Tape In. The sound as unserviced was very impressive & the dynamics of 75w on such an early amp was a bit special, even though the sound revealed weaknesses of age, the quality was easy to tell. The power amp is just 6 transistors which is remarkable. 8ohm continuous is rated 82.5w into 4 ohm. The JVC 5030 is the smaller version & we had the 5003 which is the same is a new tuner & minor visual changes. There are a few versions amid the same number on these. The one we got to make one good one out of shows the 5040 to 5040 Run 2 differences are Tape Head or Aux2 & the SEA is 10dB or 12dB gain, both here are the same. The Phono EQ circuit on the first is an IC of all things, but a MC-4080-1 is a 16 pin IC if ebay finds them for $48. What's inside it is probably very simple, if unknown. One for Phono (X601,603), one for Preamp (X607,609), an IC usually kills an amp but this is a 1967 one & in upgrading it, the IC is just a double transistor per channel with all external components so no bother at all, if it may be a Darlington like the Heathkit AR1500 preamp has. The Phono stage IC stage mostly corresponds to the 'Run 2' version' with 2 transistors not the IC to confirm it's a 'good' IC, we drew the circuit to compare. The Preamp IC is a gain stage before the Pre Out-In & the mid board 2 transistors are a buffer before the SEA stage. Dare we say the IC version of the preamp is superior, the Phono stage conforms to the Transistor version showing the IC is basic. Sophisticated if very kooky amp, there is a buffer stage in the preamp, like the 1965 Sony TA-1120 & Fisher 600-T uses, if ideas forgotten until the 1977 Yamaha CR-2020. The Preamp stage Inside the boards are fixed to the case so the height mostly is the transformer & capacitors. Odd with heatsinks on Diodes, never seen that in an amp & the first amp ran cool. It has an IC on the MPX board yet Germaniums in the IF circuit. The power amp is TO66 drivers with TO5/39 size others & 2SD41 output transistors which are remarkably 200w 10A TO3 silicons. The JVC Nivico 5010 & 5030 were reissued as 5001 & 5003 with an updated tuner, if there is no 5040 update. Now to recap & upgrade it as this one has the manual findable if only the Run 2 one so not exactly. The 'Protection' board is the Power supply board with extras, same on both versions. The transistor amid the main caps is the 'Caution' circuit & the big resistor drops the HT to the preamp. This sort of circuitry isn't dissimilar to the 1965 Sony TA1120. It recapped up very well & we'll keep the working parts amp intact as this amp is too good to part out & very rare too. No speakers in 1967 could take 75w so why buy it then? Biasing isn't explained well, meter on one of the 0.5 ohm rear resistors, set the plastic pot on the power amp board to the lowest value it can be, aka AC bias, then set the front ones to 40mV. Biasing is important as the sound can get rough. Recapped & upgraded, the sound is beyond what over-used words can say, but playing loud Punk & heavy Bass Reggae, we've not heard transistors sound this clean, effortless & precise with the highest musicality. Pity it's not such a great looker, more functional than stylish, but the sound is there. But for 1967 really 75w? Yes it puts out 35v clean sine so well in the 75w rating. Comparing to the 130w Sansui AU-G90X the rich sound of the JVC leaves the Sansui sounding as loud but cardboardy lacking the openness of this wonderful JVC amp. The only minus for us with these great sounding early JVC is the SEA Equaliser. It in itself is a good design, but it doesn't have the same characteristic as a Tone Stage so we didn't try it for long on the Speakers. quirky build of these early JVC, but a great series to find. REVISTED 2019: Rare amp if a customer found one sold a bit vaguely as they didn't realise the Pre-Main connectors need a link piece to connect pre to power amp. This one is a slightly later one than the above, the "Run No 2" version as the rear label shows swaps the blue IC for Transistors if the IC was just 2 transistors per channel as the outer components are much the same. Tuners changed a lot from 1966-69 so there will be differences there. Quirky amp we liked apart from how difficult it is to get the facia off if undoing certain screws underneath just gets space to get to the lower edge screws without taking the tuner cord off which is always a despair-inducing thing even with the winding diagram. Huge Transformer in this amp is impresive, we still have a parts amp from a few years bak as it's too good to get rid of or break up. Run No. 2 version has fiddly screws instread of the better hex headed screws, if to put 4mm sockets is required. The 75w dynamics on a Raw Amp made this a good first try as stated above, if the SEA switch needs quite a bit of taming as designed, it should have had a buffer stage but it goes straight to the Power Amp inputs. Interesting to have this & the NatPan SA65 both here at the same time to compare. The SEA switch is not designed well as it switches circuits directly before the preamp X 607-9 that has to very tamed on the power amp not to cause instability on switching. There still is NFB in the amp, the SEA is just a Tone stage. Quirky messy insane design, the casework is bits screwed together. Works on 98v HT on the main cap, certainly an ambitious design if some dumbing down to keep it stable with SEA switching is a bit of a shame
BUY-RAW RATING: An issue on these is the selector & speakers controls have brass cast rods so can break & also the selector bits inside break off if dry, so parts might not work for this. Beware it needs a Pre-Main "U" connector or plugs else you'll hear no sound. REBUILD RATING: Easier to work on than the 5030 in some ways if the front section is very hard to get into, the 2 rear pre & power amp boards are hard to work on. COOL RATING: 6 a little awkward looking in the big wood case loses it style appeal if the green tuner ups the score. (2015-2019)
1967 KLH Model 27 receiver ↑
AS-ORIGINAL (Once Serviced): Average (needed recap). UPGRADED: Very Good-Excellent. 30w
CC, Silicons, Germaniums, FET in Tuner 110v only? HFN Dec 1967 announces this as a New Amp that had 2 years in development, Germanium power amp drivers with Silicon outputs & still sold into 1970 by US trade ads that rate it 25w. A very 'James Bond' looking receiver with fine geared vernier dial tuning via two large independent controls for FM & AM. It also looks like a 1960s Electric Cooker too. Size is 34cm wide, 35cm deep & 12cm high, or 13" square LP size almost. The circuit diagram is available if a $15 one but it's needed. This has a FET & Germanium FM Tuner front end, has to be The Earliest One with FETs, unless you know better. This amp is Henry Kloss designed & he's an important name in design, if went beyond Hifi by 1967. Kloss, Loe & Hoffman is KLH. He quit KLH in 1968 if made those cool Tivoli radios years later, their 'sound shaping' design in less-hifi terms was better than any portable before. Supposedly the same as the "KLH Twenty-Twenty (Plus)" from 1965 minus the turntable. Looks like the sort of amp that would have been fixed into a Console as was the usual design. The Tuner works, the rear panel has a strange plastic 'shelf' which is just the AM antenna & the output transistors are under a cage when the antenna is undone. 3 fuses & 2 AC outlets, 2 speaker pairs, Mag Phono only which is unusual this early if a gain switch, Aux with 3 gain settings switch & a Tape loop. It has a mysterious "12v test" socket also which is the Tuner voltage. Ours is an early one 0011xx series if the schematic dated 1968 shows a minor change made at 003461 with R50 680R then changed to 470R. Output transistors are RCA 38272 Silicons TO3 size. No coupling transformers like other early amps. a Dec 1970 Electronics Review mag online wrongly says KLH 27 has no Headphone not seeing the 6.3mm socket under the Tuner verniers. It's rated 32.5w in tests at 1kHz $320 new in 1970 so to call it a 30w amp is fair. The side panels we lack appear to be plain walnut veneered particle board with hidden fittings & 2 screws near the fascia, to make a set not too hard. As Original it sounds very aged, a soft dull sounding low spec type of sound with thick bass. Cabling is a bit random wth a loose red wire 'sausage' midway shielding the cables, if they are not individually shielded as the Fisher is. Preamp is all Silicons 2N3392. The neon bulbs are very dim strangely with the fascia off & beware the 4 tiny orange display pieces as they are loose when cleaning. The side amp board underneath by the selector is for Phono with all Silicons for Aux & Tuner. Tape In goes direct to the Tone-Pre. Kooky heatsinks on the drivers if they only get slightly warm. A sign of classy design is the 4 control knobs on the left, with the splined-grooved fittings, find the right one for the control & it matches perfectly. Speaker connectors need a narrow Fork connector crimped to cables or a Ring one as the screws remove. Upgraded further to reveal a fresher sound it gets rated. For the ratings, to be fair on what you'd hear, as original spec it was no better than Average if needed work. But after a tricky time needing to lose the Germaniums as the design was too weak, it now sounds far better in just playing it for itself, clean crisp treble, solid midrange & correct bass weight going very deep. The design itself is good, bias can be set low to run cool. It's now fast sounding with a nice kick for a 30w amp if beware upgrading this amp as it reveals many weaknesses in the design. The 2 main diodes are 25A rated which is way overspec. Mono doesn't work on Tape In, which we use as direct input instead of through the Phono-Aux board that has Aux level settings as early. The Aux input is actually decent sounding, using Tape Monitor it sounds a little less trebly & more bassy. Headphone L+R is always swapped on earlier USA amps. On playing Rock with heavy guitar, the weight is unusually good unlike some scratchy sounding amps. This does rate very high for Musical Pleasure, stress-free listening, stereo is wide & detailed. The Tuner sounds good with the verniers nice to use, MW, FM & FM Stereo all working good is unusual. The smallest 30w FM Stereo Receiver there must be. BUY-RAW RATING: As nearly 50 years old recapping becomes required & the spec as original is too aged for our taste if care is needed as we state above. REBUILD RATING: Probably too advanced as so much needs redoing including poor power amp design & crappy tiny resistors. COOL RATING: 9 a real cute LP-cover sized amp if it needs wood sides which aren't hard to make. (2015-16 edited 2018)
1967 National Panasonic SA-65 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 50w.
SC, Transformer coupled, Direct Coupled. Updated 2019: Looking back at old reviews of amps we've not revisited doesn't quite put them in the right context of 2019. We had this amp 2013-14 & sold it in early 2015 at the same time we had the Sansui 3000A & spent a lot of time on both to upgrade. The early Panasonic-Technics were badged National-Panasonic & these are rarely seen in the UK with ones we've seen of their 1967-72 era always in Germany. After rebuilding the first one, we remember it needed a lot to get it working right, avoiding instability & keeping the Direct Coupled Speaker outputs set as near to 0v, the Bias & DC offset needs critical setting. Fitting new parts was a tricky one as spacing not ideal including redoing the main caps. A few hot resistors next to the Transformer that puts heat through the lid had the one who bought our one asking why, if they liked the sound of the amp & redone the dry varnish on the tight-fitting wood case. The one we get in 2019 has a messy recap by an amateur with wires all over the place, we really don't like getting amps like this & won't even trust it to plug in or waste hours checking it. We just clear it all out & start it afresh, you'll never find a proper restorer who is happy with anyone elses work as it makes ours look poor. If the customer doesn't want messy mismatched type resistors doing properly as on one Rogers amp we put the resistors weren't ours if were adequate otherwise, as we put our name inside. In 2014 we put that it sounds the best "as original" we'd heard at that point, we do get amps that sound good, but to listen further & find this "nice" sound is a mix of aging & design taming to have it sound nice, If it was so good, why rebuild it? Read the Yamaha CR-200 opinion, this still happens. Beyond looking at crappy work by another, it's still a great amp. The Green Tuner light bar is a ribbon on a pulley & a very stylish fascia which seems the best looker in the Nat-Pan range which has a 1966 SA-52 valve receiver if the 1969 SA-46 is the later version of this. 1971 HFN ad has this for £190 as they clear old stock as was often in the 1970-71 ads. A semi-complimentary design on ±35v HT. Clean sine is about 26v & the manual states 50w RMS. The Tuner IC is LM703L if still with the Germanium diodes. 2 power supply Transformers, the small one just for the bulbs, 2 phase splitter ones & one on the Protection board if not on the revisited one as they updated it. Output transistors 2SD218 early Silicons. 2014 Opinion: This was before we rebuilt all amps & this was a good amp to learn from, but as with the Sansui 3000A both got recapped & upgraded a lot learning how they sound & what isn't so good. Opinions from 5 years ago is 'early opinion' in terms of what we do now. To rewrite this was required as it's got forgotten how out-of-date the opinion is, if the amp is still a great one. To think it wasn't as Bassy on Speakers as the Sansui 3000A is because of the Sansui design being more 'designed' with NFB stages to sound as it does, if the design here is not so different. So to get another one to hear it with Fresh Opinions, these early amps were ones we upgraded first after using them as Original to learn the sound & what could be bettered. 2019 Opinion: The Central board from Right To Left is Phono-Inputs, then Pre-Tone then Power Amp. Aux goes to Preamp with other inputs to the Phono-Inputs stage, it reads 68K from Aux in to Pin 32/68 if the circuit doesn't tell this. The design is not unlike the 1965 Sansui TR-707A & 1967 Toshiba SA-15Y. Complex & unusual design with NFB stages, Passive Tone stage into the Pre-Power Coupling with the Transformer Coupled Power Amp not unlike the Sansui 3000(A). Looking at it after knowing other amps including the Akai AA-5000 to see where ideas were 'borrowed' is noticeable. The looks of this amp perhaps the winner of all 1960s receivers, just so cool, if the 2019 one has a brown tuner line, not green. Interesting Crazy Amp. Looking closely at the circuits after not having one for 5 years, to see the circuit isn't unlike the Toshiba SA-15Y, Tuner final stage is the Phono stage if Aux goes to the Preamp, not through Phono as some do. Design is quirky with stages of NFB & other design a little unusual with sound shaping like Fisher early amps, not one to alter too much as the big line of resistors would give alterations away. Transformer Coupled like a few other early amps with Direct Coupling that needs careful adjusting as does the Sansui 3000(A). Looking to Rebuild 2019. This is a kooky amp, some build is a bit crude in that 'hard wired' way & putting the 4 hot dropper resistors similar to the Sansui 3000(A) right under the main capacitors meaning underneath isn't great, this one is rather blackened if shows smoker's use. This was recapped partly by another, all long wires & messy, not for us to even plug it in as why spend ages checking messy work, so out goes the lot, tidy & make sense of it then recap those areas to our standards. The main capacitors are about 52mm diameter & only 60mm high, a size clearly custom made for this amp. Once Rebuilt. Being a little unsure of it even once rebuilt, to run it in 12 hous oif not a problem. Runs cool beyomd the cluster of 3 red resistors in the top & the 4 underneath that all reach 100°C if they are positioned not to be a problem, exccept don't put an LP on the top case lid. The sound is fresh & lively, a tight sound with NFB if it's not a flattened sound, it's a punchy amp. The Bias Settings are the 4 screw pots underneath insoide by the Speaker outputs. One of ours read 35mV & the other 4v & to test it, you can easilyget 8v DC on the output, so it needs testing & adjusting. How to Bias as with the Sansui 3000(A) that uses 4 adjust pots isn't described, so we just try it as numbered L-R with the rear of the amp facing as 2-L-1 7 2-R-1 to adjust the pot we numbered '1' first & just let it sit on the multimeter via the speaker outputs, once it's adjusted to be stable at 100mV or less with no speaker connected, reading DC offset under 50mV is ideal if hard to get, fine tune with the '2' pot. The Gold 4mm screw posts adding heatshrink as they sit a bit close, see the pic. Once an 8 ohm speaker is connected this reading drops. Beware once one channel is good on first adjusting the amp then the other will be a bit off so it takes a while to get this right. With an 8 ohm speaker the -50mV/+50mV will drop to 2mV so as you'll never get it spot on it's not important in use as the adjust pots need only the tiniest adjust to jump the voltage up & also on turning off to use again it slightly varies. Even if it goes to 60mV the speaker load drops it to 3mV & 120mV drops to 8mV which is fine to use & be trusted on speakers. On Our Tannoys now Finished. We've turned the amp on & off several times to see the voltages stay fairly stable so trust it on our speakers, the amp is direct coupled & previously that day we'd used the 1966 Akai AA-7000. SA-65 has a clean neutral sound, crisp treble, good wide stereo. Needs a little less Bass than some amps if otherwise a pleasing sound with no Hums or Hisses. To test the DC offset with speakers connected to see it's under 100mV, ideally under 10mV means it's trusted. An amp that's a bit specialist though must be told. BUY-RAW RATING: Will need a recap to work now, in 2014 ours was borderline on seeing the caps cut open, now it'd be past it. REBUILD RATING: An early design with some tricky bits & difficulties in problem solving here. COOL RATING: 9 the fascia is one of the best looking ever, if the wood case isn't quite as good as some brands, but still a 9 overall. (2014-2019)
1967 Pioneer SX-700TF receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 25w.
CC. Very early transistor amp but a sweet lively sound if only 25w see the SX-1500TF for the 45w version. This has to be the sweetest 25w amp you'll hear. We didn't upgrade too much at the time we had it & it could do as well as the 1500TF below if the power difference limits it. T= USA 110v version, TF = EU-World version. The only minus is the old preamp transistors can be a bit hissy & to put in better ones is worthwhile. Bachelor pad looks & the TF version has wood veneer on the fascia. The earliest 1966-67 Pioneer transistor receivers we've not seen in years, so clearly rare & now we've helped vintage along others will be trying them. The SX-700TF-SX1000 versions & SX-1500TF we do remember in 2017 as being interesting amps, never really did upgrade one as fully as we would now. What Is It? On the underneath a metal case covers two strange glass items, the circuit calls them "RW 1 & 2" if what they are isn't explained, but are on the Amplifier outputs after the coupling capacitor & before the Output Connectors. The symbol used is the same as the Thermistor so must be some sort of Safety feature, if not a mention of it as possibly it's only on some of the run. BUY-RAW RATING: Good. REBUILD RATING: Never rebuilt ours, if Pioneer from this era do show their age with hissy transistors & some quirky design. COOL RATING: 8 this with the wood veneer fascia & the side cheeks looks cool with it's Bachelor pad looks. (2011-2012)
1967 Pioneer SX-1500TF receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 45w.
CC. Not to be confused with the 1969 new styled 1500TD. Very clean & musical sounding amp we expected to be good as the SX-700TF, this even all-original is very sweet with such an open sound, but the balance is a little bright which we noticed on first getting it. Recapped & with new low noise transistors it scores very high in musicality. But it does have some issues & like with the 1500TD the power amp board is messy making it a little risky if it's had old repairs as we found out. There is some crude design here that ultimately limits how far the pre 1969 Pioneers can go, look at the heatsink for a start, a bent-shaped flat piece of aluminium. Same as 700TF above with the hissy transistors. A rare early amp together with the SX-700TF, they still aren't in the league of other 1967 receivers we've had since, we rated this very highly until getting the 1967 Sansui 3000A which outdid it. Two versions of the tone board exist, the early W15-031 one or the later one like the SX-1500TD uses. One thing the Manuals don't say is about the Pot on the board, it should be left fully Anticlockwise. REVISITED 2019. We've had SX-1000TF receivers recently & the SX-1500TF is exactly the same amp with an updated fascia. The SX-100TD-F below is earlier than the SX-1500TF. See the SX-1000TD-F for Biasing info. BUY-RAW RATING: Good. REBUILD RATING: One to be careful of if it has old repairs, the Power Amp board can be a pain. COOL RATING: 7 just a point less as no wood on the fascia, needs the wood side cheeks to rate. (2012-2013-2019)
1967 Pioneer SX-1000TD-F receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
CC. We used to find the early Pioneer in 2011-12, the SX-700TF was our first, then the SX-1000TW, then the SX-1500TF if only seen the 1969 era SX-1500TD or SX-990 redesigned style ones since as the 1967 ones aren't around. The "F" means multivoltage. The SX-1000TD-F is an updated 1967 version, based on a "1267" code on the second of these we got. The SX-1000TA 40w, the first 1966 one with a valve & nuvistor Tuner front end noted by the lever switches not in one group, then this SX-1000TD 50w by 1967-68 noted by the tall MS Mincho style tuner print then the 1968 SX-1000TW will also be 40w with IC for Tuner as some are still labelled & smaller tuner glass print. Pioneer never put Mono for Phono or Aux which is a bit of a limit & again those plug-in blocks for thin & light speaker cable do put buyers off these as they were even on the 1972 SX-828 if finally updated to spring connectors on the 1974 x3x series. It should be possible to fit the small 4mm sockets as on the Sales page if one to try or not hasn't been decided. The inside is like the SX-1000TW with the pleasing matter-of-fact build with the bizarre crinkly thin metal heatsink & still with hard wiring & some unusual design. A small rear corner back board appears to be a Bass filter if it's not on the circuit diagram we have seen one in Pioneer before. It's the W15-010 board as on the earlier SX-1000TA & it is a steep "T" bass filter, "PTF" they call it, between Volume & Power Amp, which is going to ruin the bass & sound poor on speakers like the Sansui AU-666 did, see that review below for more & below as we tried the second one on speakers to hear. The SX-1000TW on our 'Solds Gallery' had a big wood case, we got that one from USA, if the wood case seems too big if SX-1000TW pics in adverts show it. The SX-1000TD-F has a black metal lid. Bulbs are various types including the old bayonet type, there are LED variants around if AC on LEDs flickers wildly. The SX-700TF & SX-1000TW we sold early on as original & serviced, if the SX-1500TF was unreliable with old repairs. This still has the FET IC 130w shop sticker on it, FET & IC tuner & 130w Music Power as in 65w x2. 1970 Pioneer catalog shows these were long gone so the early three models of SX-1000 may be limited sales as the 1969 SX-1500TD with the new design replaced these. 2SC793 original outputs are only 60w rated explaining the rather low "Music Power" of 65w/channel as in the "130w" front label. In the interests of keeping amps like this alive, changing the TO3 outputs is very tricky & beware the plastic isolators which fall out easily. The output stage has some odd design as we wondered about before. The circuit shows it's the first ones that Pioneer did, the Power amp is unusual with alterations added on the track side & the pre-tone board on ours is a W15-031D which isn't the later W15-047 one with NFB the manual shows. Pioneer early amps we've found boards with quite different designs in the same amp, the SX-1500TF above had the same W15-031 board if it's manual shows a W15-090. So we worked out before that the W15-031 is just about the same as the W15-006. A search found a W15-031 board schematic so to not have to stare at the track to work out the differences helps, in fact it's just one resistor value altered. W15-031 is the early 'no NFB' design as in the 1967 SX-1500TF, the later W15-047 is like the 1969 SX-1500TD so why the SX-1000TD & SX-1500TF so similar? One thing the Manuals don't say is about the Pot on the board, it should be left fully Anticlockwise. Bulbs are 6.3v 0.15A Bayonet type as found on ebay, replace with the fascia off. Biasing is on the 0.7ohm resistor on the + of the output capacitor (L is the outer edge one) & adjust on the pots near the main caps (R is the outer edge one). The 2 Board pots leave fully clockwise, at highest resistance, as the paint marks show. Added Bit? This is on the power amp, it's not on the circuit so to find it's B-C of Q809/810 with 0.47µf connected to 2.2k, R to C & - to B. Told in interests of keeping these amps alive, no info found. Power Rating 50w RMS per Channel? 1000 rated "50w RMS per channel" 1500 rated "55w RMS per channel" which usually meant one channel playing, not both. The 1969 SX-1500TD confirms this as it's rated "58w each channel driven", which means you buy a Stereo amp & only play one channel? Trio KA-6000 rated "58w each channel" if "45w both channels". so the 1000 is a 40w amp into 8 ohms by the 45/58w difference. Confusing board numbers & misleading power ratings. The first one we've not got working yet so let it sit, but if it was a Customer's Amp we'd have put 20 hours plus many new parts & still end up like this which shows the difficulties in Hifi. But we have since REVISITED ANOTHER AMP NEARLY A YEAR LATER. Being 'unpleased' by the other one, to see another to try it again, the other one still here to compare to. This one in high grade, not much used, dusty, seized controls but cleary left in a person's house unused for decades until the place gets cleared. To find Seized controls, the Mode one especially needs care else you'll break it, which could be why the other one failed. Seller says it was abandoned in a place he got, the Mains plug as below tells why. This one direct from the sideboard, all the Speaker plugs including Fork Connectors a a bit of the 2 core mains that was used as Speaker Cable, rare to see that to see how it was used. 2 core mains cable if they wired the Phono Ground connector as Mains Ground using a 1960s mains plug without the finger guards on the pins & a typical 13A fuse, all undisturbed since new & a loose N wire meant it didn't work if no-one checked before us. Capacitor Coupled capacitors usually leave a tiny voltage so plugging in Headphones tells if it's been used recently, no typical small noise so never worked in decades. Headphones in, 'plunk' as it powers on. No smoke or bad noises, music on & it plays in Stereo, or at least both channels as the Mode switch is seized dry. As so unused the Retro limited thick bassy slow sound is what you get on amps this old if it's got no obvious problems. Mild background hiss as it typical of an early Transistor amp if not too far gone. FM Tuner works & stereo lights, if still Mode stuck on 'Left'. Pure Gambling here as with the other one & many other amps we get, seller being vague to not say it works or not if overall the amp would be useable once Serviced, it is still a 50 year old amp. TIred Amp Now Serviced. Not heard a 1967 Pioneer in a few years, so this all Serviced & Gleaming. Slow wallowy Original Slept for 40 Years sound now replaced with a more accurate sound, a lot crisper than before. A little thin sounding so a bit of Bass gain needed. Reveals it had replaced output transistors on one channel if the driver board untouched. Still a mild hiss but a 'friendly' one as we've not heard that 1967 Pioneer sound & the amp reveals why we liked these early on. As with the non-working one,. this has had little use, how it'd last on the 1967 capacitors is another thing, but we have found early Pioneer with Nippon Chemicon capacitors do last or age better than other 1960s brands. Very nice sound on this amp for all original & you can read what servicing brings. See a Sept 2018 blog about how good two 1967 amps sound as original. In use the Heatsinks are slightly warm as it wakes up, so to Bias once it's awoken more as it settles to be cooler after 30 mins use, because it's a good listen. This one has the early W15-031C Tone board & to be fair beyond Bass-light it's better than some amps we rate Excellent once upgraded, so 'better than Very Good' is fair at least for headphones, if a well used one won't sound like this. But as a Sept 2018 blog shows we tried it as All Original if Seviced on our 1967 Tannoy Golds so to keep it as 'Very Good'. The "T" Bass Filter is an awful idea, it blurs the lower Midrange & creates a One-Note Bass that sounds rather strange once you're used to more open amps. It'll get a Recap-Upgrade & lose the limiting Bass Circuit. Otherwise in 1967 to hear it on Tannoy Golds the sound will have 'amazed' the buyer if we can hear further to notice high Treble lacks the power. 1967 amp As Original on 1967 speakers. See the Oct 2018 blog for this, it sounded great beyond the Bass filter. Now Upgraded losing the harsh "T" bass filter, it sounds great & tried on speakers the same day as the Sansui 400 above. Another great early amp, one we'd keep if collecting. Sound is clean with Wide Stereo, Bass is now correct & goes Deep sounding great, why the heavy Bass filtering as designed? Fresh sound here isn't really heard in the later Pioneer as the brand got into the Discount stores to sell too cheap so got priced to the penny. On Rock Guitar it's full & more convincing than a lot of Amps & sounds fast. On Tannoy Gold Speakers this Amp sounds awesome, on trying a batch of amps this was tried after Marantz 2385 & Sony TA-1140 & the sound was rather different. A lot more upfront if not overloud with very wide Stereo & Tone gives a large amount of gain. Very lively sound that is rare to hear as most amps are made to sound softer for Domestic use, this has a more Pro sound. To look deeper to see how this amp sounds like this, it's really only the 1966-67 Pioneer that sound this good & why we liked these early on, if didn't try on speakers back then. How To Bias The SX-1000 & SX-1500 1967 Models. These all have 2 white resistors with adjust pots by the 2 main capacitors & a line of 4 on the Output Capacitors. The Power Amp board has 2 more adjust pots on the corners. These we've seen paint sealed at 1/3 a turn off full clockwise, this is AC adjust of the 2 drivers on the board. The Bias Resistors are, with the amp front facing you, the 1st & 3rd of the line of 4 white resistors. The Adjust Pots are by the other 2 white resistors with 'L' being the nearer one, adjust to about 20mV. BUY-RAW RATING: As with the Sansui 400 above, it still worked fine, if usually a 1967 amp is too aged. REBUILD RATING: Hissy transistors need redoing if otherwise nothing difficult. Fine board track needs careful soldering. COOL RATING: 7 smart looks on this, the big wood case as on others we've had is a bit chunky, by itself still looks nice. (2017-2018-2019)
1967 Sansui Model 3000A receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 45w.
SC, Transformer Coupled, Direct Coupled. This is the revised Sep 1967 version, for the 1966 Sansui 3000 see above. A forgotten gem we've discovered, this tricksy but endearingly wonderful Semi Complimentary amp can be upgraded into a really wonderful sound and with a effortless smooth bassy but detailed fresh open sound. Others are buying this amp now based on reading of it here & are pleased with how Very Good it sounds even all-original. First seen advertised as 'New' in Dec 1966 HFN with Sansui adverts & by Jan 1967 'Lasky's Radio' ads show they bacame the first UK distributors. Dec 1967 Sansui ad shows the 3000 if by Jan 1968 the 3000A is mentioned. Damping factor of 15 gives it a valve amp styled bass. Looks Very Good in the wood case too. Of all our amps when we had more here, it was played the most, though others come along & can confuse, it is consistently a winner & with fine clean honest open effortless detail. Even for it's age the Elna caps should still be good. One of our favourite amps & our 3000A we've done much to in search of bettering it. Minuses are it can be a tricky amp, the DC offset can go high if it's not had the 1971 mods or if accurately adjusted. The 1971 Bulletin Alterations Aren't All Necessary. These are a bit 'scare tactic' but as with other things similarly, it's to cover them from complaints as few bother to service or check their amps. The idea here is if DC offset voltage is not adjusted right you can get about 6v DC on the speaker Outputs. This is an early Direct Coupled Design that wasn't used again until 1971 when an "easier" design not with Coupling Transformers for the Push-Pull & Biasing. the adjust pot only alters DC offset, there is no Bias as the transformer does that & rather well too. Hot 800 ohm resistors on the upper power amp is as designed & a tiny few amps use this design such as Nat-Pan SA-65, Nikko TRM 120/1200 & Akai AA7000. It's no different to having a post 1971 direct coupled amp, set the DC offset right with a Speaker Load attached & it's reliable There really isn't any need to add the 10 ohm resistor if it does make adjusting DC offset slightly easier. The Diodes of 0.5A in the 3000 & 1.5A in the 3000A they say to change to newer 1.5A ones which is worth doing. Why Were The 1971 Changes Made? A Forum from 2009-2010 tells that once damaged the full DC voltage of about 40v would appear on the speakers to ruin them & many were brought back from the Vietnam war so these were popular for the great sound. But this is only half the story, if often you find these with repaired Drivers & Outputs, the amp will need User Misuse to damage it in the first place. The diodes on the Power Amp board need upgrading to 1.5A ones says the Bulletin & this appears the main problem, the SM150 are 1A. The same forum has a repair guy since 1972 who says the Diodes spec was fine but the Production quality was the problem, similar to Transistors going hissy. Hearing talk from techs around when these amps were new is helpful, else we have to work it out ourselves or just upgrade parts which gets rid of issues before they happen. The early 1966 Sansui 3000 uses SW0.5 likely meaning 0.5A & some early ones only have 4 diodes not 8 as not the ones across the Bias Pot. The Fuses were reduced in value to try to help. The "Protector" stage is far from the sophisticated 1965 Sony TA-1120 one. But the reality is nearly all amps after 1971 are Direct coupled & Damage or Failure by User Misuse has better Protection as a look at the 1970 Sony TA-3200F power amp shows it has more than one Protection circuit to cut the voltages if required. A Sansui 3000(A), like any direct-coupled amp, if misused can still trash your speakers, but we trusted our 2014 one on our Speakers for months as ours was all recapped & adjusted right. The 3000 is mostly the same amp if only one speaker pair & minor switch position changes. For the 1969 Tannoy Golds, this amp is a Perfect Match, it sounds awesome. Input Phono Connectors. On the 1966 Sansui 3000 & some of the 3000A there are oversized conical phono sockets fitted. These are too big for Modern Cables as they will bend them wider risking breaking the cast ones. To use Vintage Cables with the 4 open ground lugs that bend out to fit & hold works fine. Tuner varies from early Germaniums to a rare 1969 version with Ceramic Filters, the tuner is reliable. The Protection Circuit is difficult-useless as even on the one we got in 2018, after 20 mins the protection cuts in, if there's not a problem, but this seems to affect the amp now & alteration is needed. This is useless to save your Speakers, it just Mutes the amp if the Power amp is still live. It just cuts power to the 4th transistor on the Tone board to Mute. Phono Stage is a good sounding one as a 1966 design. Tone Controls need to correctly midway to get Flat Sound as even half a notch out if the knobs aren't fixed on midway will fool you. The Power Supply is interesting as it uses Dual Windings from One Transformer with ±HT for each of the Power Amp channels, an idea long before other amps used the similar Dual Transformers which is as the Harman-Kardon 930 uses & the later Sansui G-33000 Monster Receiver uses. Biasing is best to ignore the awkward Fuses partly out idea, to read across the Output Resistors & the DC offset on the Speaker outputs is the best way. We did differently on the 2018 one, it had the 1 ohm resistors plus the extra 10 ohm between driver board & outputs, as per the Bulletin changes. To start with line up the 4 pots so the screw line, on looking front inwards, has the clear pot tab to the right & with the screw slot vertical towards you, this is how some are locked by paint after all. The earlier 3000 & possibly some of the earlier 3000A have black pot screws so is different. The issue with this amp is DC offset can get high if adjusted wrong. Put the Multimeter on the Speaker Outputs with Left is the Leftmost pot & Right is the Rightmost pot & set to as near 0mV as you can get it, under 100mV after letting it settle is about the best you'll get & putting a speaker on will reduce the 100mV to about 5mV. But amps without the alterations may not be this easy. To check mV across the white 1 ohm resistors then showed very low mV as the Outputs are correctly biased, DC offset is when the voltages aren't balanced. The mid pots you can leave set & the outer ones are the Bias Adjust to balance, you don't want to adjust both pots as neither will be a reference & it'll go over 1v DC offset. Once set, turn the amp off for a while & try readings again to see they keep adequately stable. We trusted our 2014 one on our Tannoys for a few months so it's safe once adjusted right. REVISITED 2018: Not had one since selling ours over 3 years ago if it's always been one remembered if they are only around in the USA now. A customer gets one sent to us to Upgrade so we can learn it all over again as we did use a 3000A on our speakers for several months as it was liked. This is a later run one with the '1971 mods' already fitted if hard to tell if it's Factory done as the resistors are 1970s looking ones & the 35v 1000µf bi-polar output capacitors. It's had a clumsy repair in TV Guy way & just put any old output TO3s isn't good. Very clean amp inside though, not had much use. Very Advanced amp for 1966-68, see the 1966 Sansui 3000 review to see the differences in the versions. Power Switch is unusual as even when off you have no idea if it's switched on or off, a rotary type switch keeps it at the same position instead of less shows meaning 'on'. So first try is a gamble unless you meter test it, which we did to ensure it was 'off'. Another quirk is revealed, the Volume Control doesn't track too evenly set very low & doesn't totally silence which is how the others were too, it's 1966 after all. Then the Rocker Switches can be intermittent & needs some attitude to get L+R playing. On First Try as Unserviced. Bass is rich with some of the Retro Bass if the Damping Factor of 15 keeps Bass more open than most amps. In 1966 this amp was competing with the likes of the Fisher 600-T & for it's more 'natural' design, the 3000A was a great buy. To hear a little used one with a xx904xxx code means Apr 1969 shows how great this amp will have been new, but now it's old & to use an amp of this age often will bring problems eventually. We remember the circuit is 'tuned' to sound as nice as this but if trying to upgrade more we found it brings out 'the age' of things more & became difficult. Undeniably still one of the Best Amps, if it's getting old & is a quirky one for the DC offset & other early issues. Care Needed. For the want of keeping these alive, a few pointers as we've had 3 of these now. If it cuts out after 20 mins, it's not faulty, but it's the protection circuit playing up, this is typical as original or upgraded. The Power Switch looks the same on or offm, see above. To be sure the DC Offset with an 8 ohm load is under 100mV to keep it safe in use, to read it with no speaker load will mislead. The Tuner Glass does remove, undo the 2 bulb holders with the fascia off. the rubbers on the glass are not glued to either the bracket or the amp body, but the rubber ages to sort of stick solid. don't force it, don't unpick the glued glass rubber, but a bit of knife action in the gap between rubber & the bulb plastic bracket will free it. The glass print survives a wash always too. The 4 Power Supply fuses we've seen big 30mm fuses in that barely touch, UK 25mm mains fuse fits fine. FM Ceramic Filters. In a Sep 2018 blog we noticed these started being in 1969 Tuners & the one we have here has a later "FAMT 103U" Tuner Front End which has 2 of these on. Looking at the 2 of this amp we've had before as both on the Solds Gallery page, neither have this. Looking at the Serial Number, the 3rd number is the Year & the 4th-5th are the Month which reveals "904" meaning this one was a late one made Apr 1969 as the Ceramic Filter idea was introduced only this year. Sansui Date Codes. From info found online pre Sep 1967 an 8 digit code has 2nd number as the year & 3rd-4th as the month. On 9 digit codes past Oct 1967 the 3rd number is the year & 4th-5th are the month. Sound As Almost Original. See the Sept 2018 blog for more. DC Offset with speakers connected just needed a slight adjust to keep under 10mV without doing a full bias. Not scary to use, you can see we trust it, if we did use the earlier one for months so are familiar with it. BUY-RAW RATING: Beware of DC offset levels, capacitors in this even with a little used 1969 one showed as faulty on speakers, it needs recapping to be reliable. REBUILD RATING: An early design with lots of quirks & difficulties to bring the best out of it, much can be done with this amp in upgrading. These are advanced amps to upgrade, they are findable in the USA if prices are reasonable as these do age more than some amps. COOL RATING: 9 one of the classiest looking amps in the big wood case, very mid 60s Bachelor pad with solid aluminium knobs adding class to the 1966 500A above. (2011-2019)
1967 Sansui Model 400 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 20w.
CC. An obscurely numbered Model 400 receiver from Feb 1967 is a smaller version of the Sansui 3000(A), the numbering part of the 1966 Valve Sansui 220 & 250 model series that were the midprice ones, 400 aka SAX 400 from Feb 1967. This one coming after their first Transistor receiver the 18w Sansui TR-707 from May 1965 that we've seen but not tried yet. £124 new in the 1968-79 HFYB, the 3000A was £186 in 1970. Replaced in 1969 with the 22w Sansui 800 with the Sansui 4000 styling. This one all transistors. Looks like the 3000(A) if smaller at 418mm wide x 143mm high x 363mm deep. 20w power if the transformer is more like a 50w amp. Build quality is similar if a narrower amp so the tuner mechanism is mounted vertically which is unusual. Actually comparing the Power Amp designs, the Sansui 400 & Pioneer SX-1000TD-F have the same Power Amp Circuit with only a few minor changes, Pioneer first did that design in 1966 so Sansui copied it if only for this amp & the 800. Power amp design is 2000µf Capacitor Coupled with no Transformers for the Push-Pull stage coupling as the TR-707 & 3000(A) do. This therefore is a more modern design & the next Sansui was the 1968 Sansui 5000 that had several later versions. Aux goes direct, not through the Phono stage as some do, Phono is x2 transistors, Tone comes after the Volume into a Transistor, a passive Tone stage & onto the Power Amp which shares the Tone stage. Power amp is a Gain Stage, Driver stage, Bias into Push-Pull Drivers & Output PP Drivers. Finding a better Circuit scan, the Circuit is quite like the 1969 Sansui 4000 if things got a bit more tamed down by then. 1967 Sansui 400 on the design is far from a Budget-Midprice amp, still having the pre 1969 qualities that make a great amp, if typically need a lot redone, the basics are good. Transistors in The Phono-Tone Power amp are Silicon for low level ones, if the PP drivers are 2SC281 (Silicon) & 2SB89 (Germanium) as early Trio-Kenwood used at the time. Outputs are 2SC244 75w 4A Silicons, again High spec for the 20w rating. HT is 50.8v which is similar to ±25.9v in later designs without the capacitor coupling. To compare to the 20w Fisher 440T from 1965 we got back recently that has 46v HT if the circuit still has limitations, the Sansui 400 has a very decent design & probably sounds fresher than the 3000(A). Unlike the 3000(A) this one didn't sell so a hard one to find so it's obscure. The 400 got redesigned by Oct 1968 as the Sansui 800 if by then the poor Aux into Phono via large resistor idea, if the amp stage is similar. 1967 ones have the Conical Phono sockets only suitable for earlier cables, by 1968 the standard type are used. Power Supply is a Half Wave rectifier, as you see on Valve Amps if not too often on Transistor amps, the DC is made of one AC half wave & then a blank section as the other half is unused so needs a bigger smoothing capacitor, the Full Wave is better as less work on the capacitor if then the Voltage is less, so it has to stay half wave. Here the amp has a 2000µf main cap with 51.1v DC with 41mV AC ripple which is quite low considering & no problem. After looking at the classy build quality of the 3000A we have here, the 400 is quite a lot less quality, if can be bettered, it looks like the Sansui TR-707A & the first Sansui 500 valve amp. Fascia has the 3000 look with a Gold & White lettered tuner glass, a 'Protector' & still in "MC" as Megacycles not Megahertz. Two speaker pairs, Headphones, a "Noise Filter" that simply grounds off high frequencies so is a sort of High Filter, Mono-Stereo Mode, Tape & Loudness. Plastic control knobs look like Fisher if ours lacks one metal cap & seems to be an issue with these looking online. Rear shows the original NEC 2SC244, Speaker Screws like the 3000A, antenna, DIN for Tape & the row of 10 input sockets if as it's a 1967 one are that conical type that need the older cables like we blogged about Sep 2018. Our serial number dates it to Oct 1967 so is just past the 100th one made. This one got used into 1978 by it's careful owner for the BBC updated station stickers who also left their name & address sticker on so we Google Street Viewed it, must have just been cleared out as the seller was unaware of it to sell it at that price. Underneath looks busy with green coloured PCB bases plus the Phono board. Axial caps x4 for the power supplies & another for bulbs. Power switch is that odd 3000(A) one that looks the same on or off. Quick hum on turn on & a gentle hiss. We tried it before just to see if it worked and now partly serviced. Rare to get an amp pre 1969 that's useable but this works fine & the design as expected does sound unusually dynamic. Seller clearly never tried it for the sticky power switch as sounding like this you'd not sell it so cheaply. Fresh dynamic sound reveals little of it's age as it's unusually crisp, not as rich & bassy as upgrading will bring. Wide stereo & a deep soundstage. We always listen to the amp as original to understand it & this Sansui 400 has to be the Best sounding as Original, by great design & lack of use. As for the Protection circuit, no issue after over an hour playing the day it arrived after servicing, the circuit samples the Power Amp Outputs not the strange 3000(A) design that cuts out after 20 mins. See The Oct 2018 Blog for more. Biasing isn't needed as the Amp is Autobias, if there are 2 adjust pots that aren't mentioned in the Service Manual, VR 709/710 are similar to the KA-6000 with UA1384 board which set Midpoint Voltage which was way off on ours. VR 711/712 is AC balance. FM Tuner sounds great in FM Stereo, meter light on means Stereo if one bulb needs replacing, all Transistors Tuner as is the 3000(A), some Germaniums in the tuner inc 2SA101 & 2SA102 very early ones if updated to the 3000(A) one. Now finished except for a few visuals, tried on our Tannoys. Clean sound with good volume, sounds as good as any 40w amp really & much the same sound as the 1967 Pioneer SX-100TD-F we tested the same day. Another great find. BUY-RAW RATING: Despite age ours was working fine, if 1967 amps can be far gone. REBUILD RATING: Needed some improvements to bring it to the quality of the bigger Sansui 3000(A). COOL RATING: 6 pleasing small version of the Sansui 3000(A), not sure if it had a wood case. (2018)
1967 Sony TA-1120A amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent 50w.
CC, PARA. 1965 TA-1120 has 2 lights on the front, 1967 TA-1120A has one light & a headphone socket Both have "1120" on the fascia if the rear label confirms "A" or not. See the 1965 TA-1120 above for a deeper look into these two amps. The 1120A is a totally different design inside to the 1120 if the outside just varies from a protection lamp to a headphone socket. Sony ads by their London W1 showroom in HFN only start to show the TA-1120 in May 1967, only showed tape recorders before, so chances are the original amp was only offered in the UK very briefly if the 1120A arrived a month after & would have been the one supplied. The ads only show Amps & Turntables for a few months, no sales meant back to tape again. The 1120 has some very good circuitry that the 1120A more or less omits. Be aware the headphone socket needs doing properly as it's not a standard design, it's not suitable for any headphone as it runs unamplified from the preamp. But once recapped & much subtly improved it elevates into a very different amp. Therefore Very Good for upgraders & one of the best Sony amps but only if you work it. Capable of a fine rich sound when done right if not the most focussed on the treble keeps it down on score. The sound is rich & bassy if losing the circuitry of the 1120 original loses the treble sharpness to make it not as modern sounding as you may like, very strange why they took all the good ideas out. The odd red capacitors are of high quality, no need to alter them, if they limit deep bass. Overall it has a very pleasing sound but is just very soft on detail, if the one noted in the Update was very different. Classy looking amp with the very 1965 looking brown levers still here though it was updated for some markets to a later design TA-1120F which we've never seen. In terms of finding one, the Apr 1967 TA-1120A is at least scarce, the Nov 1965 TA-1120 is very rare. UPDATE: Got another of these, this one only ever used on 117v if these are always multivoltage & on first try with 240v it sounds much cleaner than the previous 1120A. Still unserviced & just testing what it's like. The Headphone socket is still hopeless but to use our Headphone box on the speaker connectors shows a sound much closer to the 1965 TA-1120 with a crisper sound than the blurry one before. This has the earlier 2SD45 outputs, not the later 2SD88s & the screws on the back input plates, not rivets, an early 52000 serial number one here, when numbering only started at 51000. Unusually untouched amp, a survivor amp & so clean it could be left all original, grey capacitor caps still on & the transformer top is perfect even. But the capacitors inside, on deciding to recap as the buyer wanted to use it, were surprisingly very aged, but it gets the 1120A a much better rating for an early little-used one. Now issues sorted & run in, this sounds unlike the last one which was soft & blurry, this is nearly as good as the 1965 TA-1120. Either very low use or minor changes on later ones is the reason why, this is very crisp & focussed. The only real difference are the red coupling capacitors limiting the deepest bass, else it's a joy. Playing it on Tannoy Golds, it's the same volume as the earlier TA-1120 & not far off the sound of that either. The TA-1120A is a great amp, but for the age these could need a lot recapping as the early blue-white capacitors used in the 1967 ones don't age well like the grey Elnas in later ones. 2021 Thinking. One available at the same time of seeing the STR-6065. It looks rather old for all those red box capacitors, are they Hifi enough for a Big Rebuild with some redesign? To look at this to redo a lot more thn before including board resistors. But to decide not to remembering many issues to update & the useless Headphone socket that's only from the Preamp not the Power Amp. Well worth having one rebuilt if we have done the TA-1120 & 1120A before. Minor issues with the selling one like the Power Light bezel missing, rear Pre Out-Main In sockets being broken-glued & a connecting piece not quite right. The STR-6065 is something new, the 1120s we've done & sold. Another day perhaps. THE WOOD CASES are now rare on these, Sizes are 432 W x 155 H x 303 D. front sides 14mm, rear sides 19mm adding spacers, the case is 12mm ply with a walnut veneer. The grille space is 369 x 121mm. BUY-RAW RATING: Good but low volume is how it's made. REBUILD RATING: A much easier rebuild than the early TA-1120, but the headphone socket is not a standard design. The main caps at the back can be expensive to do to look right. COOL RATING: 8 looks as good as the TA-1120 if being more findable, best looks in the wood case. (2014-2021)
1967 Trio-Kenwood KR-33 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 25w.
CC. Similar to the TK-66 if lower power and one early with us. Bit industrial looking but the sound on the early Trios is worthwhile & if we had one again it could rank higher. Again, the quality of these early Trio can't be hidden, even with a 2011 review. See the Tuners page for more info. BUY-RAW RATING: Good. This amplifier needs a proper 3 core mains + earth cable, see above. Tuners on these early ones often not working right, the Trio-Kenwood tuners are not so good despite the amp stages being quality. COOL RATING: 6 as with other Trio receivers noted above (2011)
1967 Trio Kenwood TK-140E or U receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Very Good-Excellent. 50w.
SC. Direct Coupled design but CC. White lever buttons, no IC wording on the tuner glass & a silver metal back panel. The "E" version is EU 220-240v only, the "U" one is multivoltage. 140E first advertised Apr 1967 rated at "130w" with 50w per channel, if possible this is 50w one channel playing meaning more like 42-45w if that's still high for 1967. The highest powered domestic amp in 1967. Appears there were a few versions of this model. See below for the 1969 later 'X' version As original it hides it's potential with a soft blurry sound keeping the as-is rating lower. Another Very Good early amp with more than a few oddities along the way as you'd expect this early which makes it a bit less accessible than the KA-6000. Perhaps the E & X version are the best of the Trio-Kenwood receivers for it's sweet sound quality & strong sound, the buyer of ours was surprised how loud it played on speakers as do other early Trio-Kenwood. One for the experienced tech really as some of it is a bit quirky to upgrade, as in asbestos fire screen boards by the power amps & tone board oddities. The metal case with no wood outer made leaves it a little plain if the fascia is nice. Early Semi-Complimentary design like other 1967 receivers had, if quickly abandoned until 1971. This was a difficult amp, some redesign was needed & we never felt we got the best out of it as it was a bit quirky. Germaniums we've found since 2013 are fine if they are Japanese or USA ones, but the UK-EU ones are the poor ones. 2017 memory was it was a bit crude in design, the Tone stage as with the TK-66 was not very good. Odd lack of a centre ground reference to the ± HT could give very odd results as imbalanced. But as it's 2017 writing, one we could certainly do more with, but it's always the Dead Tuners on these 1967-69 Trio receivers that spoils it a bit. BUY-RAW RATING: Will need recapping as early & not an easy one. Tuners on these early ones often not working right, the Trio-Kenwood tuners are not so good despite the amp stages being quality. This amplifier needs a proper 3 core mains + earth cable, see above. REBUILD RATING: Some odd design in this & odd transistors, probably a bit too quirky to get the best out of, try the later TK-140X instead. COOL RATING: 7 but there are 2 versions, the black lid looks less appealing so a 6, but the brown wood effect lid looks better, a little lacking in style if still Bachelor Pad looks with the wood veneer front & nice lever switches. (2013)
1967 Trio-Kenwood TK-150 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 13w.
CC. Again like the other smaller power Trios, budget price amps with a pleasing fresh sound, if modest power only keeps them lower in the rankings than the sound quality itself. The TK-150 is the same amp as the KA-2000 for different countries. The similar TK-250 is 20w. Again, the quality of these early Trio can't be hidden, even with a 2011 review. See the Tuners page for more info. ** See the 1971 Trio KA-2002 below for a similar amp that we upgraded 2018. BUY-RAW RATING: Good. REBUILD RATING: Not done one of these, quite a basic amp so should be much like the receivers with the power supplies taking work. COOL RATING: 5 average retro looks if functional & a small size amp. (2011)
1967 Trio-Kenwood TK-66(U) receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Very Good-Excellent. 20w.
CC. Early receiver with that sweet airy open sound if power limited, nice sounding like the early Trio range & if we had one again it could rank higher than this ranking. Had this very early in our amp exploits. October 1968 ad shows this as 20w for £115, the receiver version of the TK-250T amplifier & TK-350T tuner which are £49 & £56 each. This brand pre 1973 are always good value & offer a fine sound. We had this very early on in our amp testing & it did stand out from other amps around then so deserves the rating, if revised with the revisit below. Again, the quality of these early Trio can't be hidden, even with a 2011 review. REVISITED 2016: This was one we got very early on in writing this site, a lower power version of the TK140X, so to find one again well worth seeing what upgrades will do as it certainly is worth upgrading a 25w amp having had success with ones of lower power, if only on 1960s amps does it appear worthwhile as the overall quality is still high. We gamble on a rough working one if the risks of bad Tuners are sadly what early Trio amps have, if the separate tuner that matches the KA-6000 we've had twice it worked fine. On looking at our old pages, it appears we only sold the KR-33 below, the first TK-66 was a wreck & didn't seem safe to sell & too tatty. But the 2016 one looks untouched & has the original box, nice to see one again. Has the paperwork too, never seen this with a Trio & online data is usually very basic. This is "20w Continuous", Damping Factor of 23 & Tone is ±10dB & the manual is dated 1969, probably a US import as a Kenwood dealers sheet too. Works after a quick service if bulbs in need. An amp like this is a good gamble as found, but as 47-48 years old it'll need a full Service to be useable & well worth recapping & upgrading. The big worry with the pre 1970 Trio-Kenwoods is the tuner, we've had problems with these & this one works on AM, FM shows meter movement but very low volume, if at least this is a start. It's sat on a table to be looked at before we start on it, the kooky Bachelor Pad looks with the wood front section are rather pleasing, the wood effect painted metal lid much nicer than the black rough paint lid. Dating these Trio is a little tricky, this has 2SB89A Germaniums in the Power Amp, the rest are silicon & early 2SD180 silicon outputs when new Germanium TO3s were still being made, so this is really more a 1967 amp & it's more like the TK-140E inside, same heatsink & tuner meter, if no Asbestos like the TK-140E has. The TK-66U is a multivoltage version, on our one a switch on the back for 240v or 110v with a tab screwed on to avoid switching, later amps put this sort of voltage changing inside. The fascia is gold anodised in colour, subtle if you'd not notice away from other metals. The power amp board has lots of changes & without the schematic, you're stuffed really. The Power Amp board is far too small, one to avoid if it's been 'repaired' as our first was. It has a regulated power supply for the first stages all cramped onto a 13cm x 6cm board & 6 adjust pots if the manual doesn't say what they are for. Power amp recapped interesting to hear the amp sound thin but then fill out as the new caps awake. Revived the TK-140X below the day before & the sound here is basically similar if 20w, a pleasing sound with wide stereo, not unlike the JVC Nivico 5010U with similar power. Not recapped anything else yet, but to see what it needs, Rock needs some Tone adjust to fill it out but it's delivered cleanly if not much weight to it at 20w. Despite the main caps being low spec it doesn't fail on bassy music, if limits it. The TK-140X similarly only recapped on power amp (& preamp) has a much huger dynamic sound. The Tuner here works, AM is good, FM is half the volume & it uses Germanium transistors of very low spec which are probably why the 1967 Trio tuners fail. Now main caps all done it's properly upgraded as some spec & design is very aged & the Fisher 440-T was another 20w early amp, if this is the fresher sounding with crisper focus & now it's had some play Bass is full & extended. 49 years until it Came Of Age & sounding a lot better than the feeble thing it was before. A classic case of OK but small sounding as all original but upgrade it & reveal a lot of weaknesses to further upgrade. We have the 53w TK140X here at the same time & it'll be compared once ready & also the 25w Goodmans Module 80. This TK-66 we got the service manual to try fix the previous rough one & the newer one has the full user info too, not quite the same as the TK-88 as it's higher power & differences are noticeable. The 6 adjust pots aren't explained, but once the amp is running cool, just have them set L/R the same, the 4 row outer two VR 1/2 are bias, to be balanced L/R together with the ones nearer the heatsink VR 5/6, the mid 2 are more to do with AC bias or uneven gain early transistors. Sound is lively if not designed to be too 'powerful' sounding, midrange a little softer than the 53w TK-140X but for our upgrades the basic pleasing sound is here. UPDATE 2017 on the same amp with ideas that improved the TK-140X bring this amp to life even further. Odd Tone stage is passive like the WX-400U one & once upgraded more the Low Damping Factor sound shows a pleasing rich sound if with crisp detail & turned up louder the kick for a 20w amp is unexpected. The Tone stage isn't as good as later ones if does give a bit of a Retro sound that's a change to hear. Update 2024. Not had one of these since 2016, but to get the 1966 Kenwood TK-60BE, it's the same Amp beyond the Tuner. Same Power Amp, Phono-Tone & Power Amp, same Transformer. To hear the 60BE as Original & Rough, to hear the Trio quality of sound. Opinions above saw it as a good sound, if the 2016 one got recapped as the Solds Gallery shows, it was before we Upgraded more & that TK-66 was the first we redid the Power Amp Transistors on. TK-60BU/BE a larger case size & much smarter looks. Power Amp Oddity. The TK-66 circuit diagram uses the strange combined Capacitor & Resistor as does the TK-80. Board is marked 'R15-47' meaning a 100µf capacitor with a 2.2k resistor, but they only use the Capacitor if on this & the TK-66 there is the resistor added underneath. BUY-RAW RATING: Good. This amplifier needs a proper 3 core mains + earth cable, see above. Tuners on these early ones often not working right, the Trio-Kenwood tuners are not so good despite the amp stages being quality. REBUILD RATING: Small boards are fiddly to work on if the rest is easier. Does upgrade well. COOL RATING: 7 Trio receivers were never as pretty after the 1963 valve one, Industrial functional mixed with Bachelor Pad looks. (2011-2016-2017-2024)
1968 Armstrong 521 amplifier ↑
AS-ORIGINAL (Once Serviced): Hopeless. UPGRADED: n/a. 20w.
CC. Yes, it's true, we dare to try this brand again because even the worst deserve a second try. Not dared try Armstong since 2012 & three others on this page showed they are just not anywhere as good as other UK brands like Leak, Rogers & Sugden who we do like, if not as much as the Japan-USA brands. so here is our opinion based on trying some real gems in the last years since. The amp itself is the 526 receiver less the tuner half so it's 292mm wide and 274mm deep. The teak case is better than the Leak ones, more like the Rogers transistor ones. Four rotary controls & a line of ten push buttons on a silver & black fascia. Plain looking but functional. The back shows it's age after the front & case being decent, the Phono sockets are the very tightly spaced ones & you need slim cables not the commonly found ebay ones which are too bulky. the Speaker outs are utterly useless with that old UK 2 pin plug that requires wires soldering. When we sell it, we'll fit something a buyer can use, these are hopeless. Inside the left has a row of plug in vertical boards similar to Leak, with two pairs for Phono-Tone-Preamp plus one at the back with Fuses on that is a Power Supply board. A very small transformer for 40w & six blue capacitors of which one is bigger. There are 5 transistors on the sifde, 4 for output & one as a regulator. The plug in boards have a top securing rod velse they wobble about as the fitting isn't so solid. The first two boards are C16 'control unit' boards, the two Phono inputs are for MM or Ceramic probably, a Tuner input goes through a resistor & the Tape input goes direct so will be the best choice. Parts used are typical UK style if two of the dodgy EU Germaniums here which is poor, these are AC191 plus a silicon one ME4102 possibly. The capacitors are axial ones used like radials, we sigh & wonder why we bothered, but to do it properly is why. The A15 driver board has all silicon TO5 size BSV44A if the A14 earlier one has Germaniums with the winged heatsinks. The Z17 power supply board has Germaniums AC138 with the winged heatsinks coming very near resistor bare ends. the 5x side TO3 transistors are AL102 which are Germaniums of 30w & 6A, so the 40w rating & the tiny transformer suggests this is more likely 20w. Overall the case looks nice but the insides are pretty lousy with ancient looking UK parts thast are more like valve era ones. To use Germaniums in 1968 is an insult when the other brands used Silicon & the EU Silicons suffer from "tin whiskers" so often sound blurry & weak. Henry's Radio catalog shows the EU Germaniums were unwanted & going cheap so be sure Armstrong bought a huge batch & conned the buyer with this junk. On trying it, thankfully it only worked on one channel whatever we tried so the nasty thing went back. Utter rubbish is our opinion & we are glad it wasn't working so could get rid of it. Do NOT buy this rubbish! BUY-RAW RATING: Poor. Aged UK inferior Germaniums & other issues, lousy quality inside is a big issue, don't bother. REBUILD RATING: Not worth bothering with. COOL RATING: 5 the amp is less tacky looking than the receiver but nothing special. (2015)
1968 Armstrong 526 receiver ↑
AS-ORIGINAL (Once Serviced): Hopeless. UPGRADED: n/a. 20w.
CC. The deserved Armstrong backlash Part 2: Nasty UK made crappy aged UK-EU Germaniums thing means the sound was ailing with bad harmonics on the treble but perhaps not awful if you spend forever changing it to Silicon with the voltage changes needed, recap it fully, but who could be bothered? Cheaply made with ancient parts that looked 10 years earlier as UK parts, shameful. Will relate to Armstrong 521 amplifier & Armstrong 525 receiver. To be avoided at any price says we, yet they still sell for small money to those unaware just for being old amps. We had one, it had plug in boards like Leak but constructuion was messy & a mix of mostly Germaniums bought wholesale & very cheap as Henry's 1970 Radio catalog shows they were unwanted by anyone else. Germaniums age badly & were unreliable when new, the Mullard AD140 TO3 output transistors are notoriously bad. These were sold cheap in the Comet Cut Price type retailers in the early 1970s so they are plentiful, unless it's the same one being resold over & over as buyers realise their mistake in buying it. Please don't buy one, there is so much better. The lousy build quality in many places & many Germanium transistors means this will always be a duff amp. BUY-RAW RATING: Poor. Aged UK inferior Germaniums & other issues, don't bother. REBUILD RATING: Don't bother, made of TV grade junk. COOL RATING: 3 sadly it just looks cheap and nasty with no design appeal at all, 3 is being generous as it has a veneer lid. (2012)
1968 Dokorder 8060 amplifier ↑
AS-ORIGINAL (Once Serviced): Great. UPGRADED: Excellent. 40w.
CC. An obscure Japanese amplifier with matching 8070 AM/FM tuner. The back gives the brand as "Denki Onkyo" but it's not the Onkyo brand if predates it by later association. Some web presence on this & the later black fascia 8060A. The 8060 is a grey fascia amp with sliders for the L+R volume, 4 lever switches & Tone is on rotaries plus Filters if you pull the controls out. Nothing familiar in construction here at all & it's quite small if heavy at 7kg, 366m wide, 130mm tall & 215mm deep inc fittings. Open grille on top means 48 years of dirt inside. Some poor old TV-repair-guy type repairs as typical with high power amps, it's like they just use any old part regardless, it'll work-it'll do lazy thinking. Didn't expect it to work, but it does & works fine. No Aux input which is unusual if Tape is Phono sockets & Tape is a DIN plug. The back panel has an "Ext" socket, the manual reveas this is for a box to screw onto the right side, 4 unused holes on ours shows it was optional, and you could add 3 more Tape Recorders by DIN sockets. But it has no Mono switch for vinyl. Didn't expect it to sound too good as 1968, but even raw & dirty it sounds great wide stereo, decent bass, clean mid & crisp treble with a precise balance giving a pleasing sound. As with Akai when they made the wonderful AA7000, the Dokorder is by a maker better known for high end tape machines, much like how Sony started out too. The original specs state 15Hz to 50kHz bandwidth & 0.5% harmonic distortion at full power. For the clean sound here, harmonics are not an issue even on 48 year old spec. It has 2 very early ICs like the JVC 5040 does 'IC A-1' & '2SD189' silicon TO3 outputs at a time when Germaniums were still produced so could be 1967-68 in date. Online finds their quality tape machines & a 60w Dokorder 800x 60w receiver from 1971. No UK sales of this as not in HFYB but Germany got these if the 8060A seems more common. Compact design to match the tape players series if well designed & built. The IC is on the Preamp-Tone & is 2 transistors plus 7 resistors as the circuit is shown, much like the JVC 5040 one, more a selling gimmick as enough space surely to do similar in transistors. The main cap is only 1000µf 80v but nothing else at the time would fit, unusually low value. Now serviced with tidying of old repairs if all original otherwise, the sound is exceptionally good for original spec, precise clean sound & the circuit is a bit different to others this early. AC ripple on the 1000µf cap is high at 96mV so a slight hum here, but it shows spec isn't so important if the design is good, and it has ICs in the preamp. Sort of makes a mockery of things, for densely recorded Ska from the original 45s sounding so focussed & clean, the midrange here is very precise without being dry. Not bad for an amp that must have been called "Dork Order" at some time. So we buy an unknown amp that 'doesn't work' and yet find a gem yet again, it doesn't always work out well either. It'll be upgraded as always though what else it can bring will be interesting. We upgraded & rebuilt this fully down to the resistors to see how good it can be, the result was an very capable amp that we used on the Tannoys for a few weeks. The L+R volume slider is easy enough to use & the sound was rich & detailed with a very decent bass for the clean design. Far better than we expected it to be & stood together with the Tuner it has an interesting semi-Industrial look as the early Japanese amps do often have. A rare pair tuner & amp. For the sound this should be selling for more than we sold ours, but the Hifi market is still quite young, but the buyer gets one of our experimental amps at a great price. Amps like this keep Hifi interesting. BUY-RAW RATING: Good if the age & power could mean recapping needed. REBUILD RATING: We rebuilt this fully unsoldering all the main board wires as too hard to work on in the case. Access is difficult. COOL RATING: 7 Tuner & amp together have a nice industrial look, if maybe a little stark for woman appeal, until she hears how great it sounds. (2016)
1968-72-74 Ferrograph F307/20+20 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 20w.
CC. Same amp repackaged into 3 amp models, 1968 most common one, the silver 20+20 first appears March 1974 in an ad, then a November 1976 HFN/RR ad shows the grey fascia one with orangey vinyl wrap that seemed more a c.1973 design but the ads prove otherwise, but it appears the silver one returned & was available until about 1980 as the HFYB pics show. We've had the second & third ones, but both were 99% the 1968 amp inside. Good volume for 20w, but it sounds rough & blurry with little quality or definition you get from Japanese amps, any £50 late 1970s Japanese amp would better this. They were popular when new if they usually sell for under £100 as they are what they are today: Budget Gear. Open rich but certainly fuzzy mediocre sound if a little too raw as British Hifi usually is. A bit of a fuss-hype about Ferrograph but they are nothing special really, certainly only budget price amps. Aka the Ferrograph F307 Mk 2. They are Average Rough sounding things, there is much better out there, UK Sugden are better quality. Even the build of the 60+60 we thought was lousy & because of the hype prices are high but no takers. Don't believe the hype or high prices, a while back an ex-employee with money to burn was bidding high with no real interest since, ahem. The 20+20 has a huge +17db bass gain which is insane, vinyl wrap not veneer, obsolete transistors used. No ceramics but still did sound rough, but just musical enough. It has awkward UK style axial caps so not worth recapping for us. Awful basic power supply with very high 350mV ripple shows the lack of Hifi values here, if on budget speakers 'who'd know'. Made of low grade steel that goes powdery not rusty. We'd not recommend any Ferrograph as being much above average. They seem to be commonly found or perhaps the same ones being forever resold as the buyers agree. As it's a 2012 review, to think maybe the amp might do better if we got another, if no chance as just so much better. There is a certain quality here, 'Typical British Workmanship', but the low spec of the insides would still be obvious, it scrapes a 'Recommended' but we are only saying what we saw, not estimating. REVISITED 2015 Silver front 1974 20+20 version. This is still the 1968 amp 99% as is the c.1972 brown fascia orangey vinyl wrap brown fascia one. This still looks very old fashioned for 1974 but it was a Budget 20w amp. Still capacitor coupled which ended in 1974 for UK brands, but not lazy Ferrograph, it was still sold into 1980. The aluminium control knobs still have an unknown size tiny hex nut that no hex set will fit & the raw aluminium greys badly. The 'wood veneer' case is actually a vinyl and the most convincing one we've seen. The silver 20+20 is actually pretty rare, the 60+60 did make silly money as our "Other Amps" page shows, but not so rare. These were designed to match Ferrograph tape recorders & the 1968 version is commonly found on ebay. This 1974 version at least has teak veneer. But it's still all 1968, ceramic phono inputs & DIN speaker outputs. It has those "tropical fish" stripey Mullard caps, blue small axials which are usually still good if low spec & be sure the power supply is still the same lousy spec. To stop the messy out-of-line buttons on the previous version, they glued in 4 bits of paxolin to hold them in line, that's what the 4 loose rectangle bits are as glue fails. After the quality of USA & Japanese amps this still sold in 1980 is unusual, but worth finding out. HT is 65.8v with a terrible 154mV of ripple on another amp, betters the previous. First try of it now at least working if unserviced, the volume is too coarse so very low it's on one channel only before the other arrives a tiny turn later. The sound on this silver fascia one isn't as rough as the 1972 era one & doesn't sound bad, if that low spec sound most amps have. But finesse it ain't, if playing as unserviced, it's too loud & reveals the problems noted before, to turn it down as it's harsh isn't a good thing & the expression on our face is a grimace as we don't like it. Stereo isn't that wide but we really don't want to play it more after knowing better gear. For most users on lower quality speakers it's probably not a bad amp, it's just average audio gear just lacking any hifi quality. To upgrade it probably won't happen as it's all small axials which are only general quality so not really worth recapping. But to be fair, the sound does offer scope to upgrade, if at 20w we'll just service it & make it smart looking. Now serviced & run in, the volume is too loud by '1' on headphones & catches the volume imbalance low down. British Hifi was never our favourite, the dismal build quality & spec is way behind the USA & Japan amps, but in fairness for a budget-midprice amp this is good value for money if it's a cheap buy, it does have the 'vintage' sound & as such is a good starter amp so we've revised it to 'Recommended'. Based on this, if a 60+60 was found at a reasonable price, we'd probably try it. But seeing how it's made inside, not for us. BUY-RAW RATING: Good, but don't overpay based on old hype. REBUILD RATING: Not one we'd bother with, too much to do on an unmusical 20w amp, the power amp boards are tough to work on, just not worth upgrading. COOL RATING: 6-7 the 1968 original has a purposeful look if a bit industrial, the 1972 revival in orangey teak plastic wrap looks cheesy but in a good way, especially with the tuner with it as we had. The 1974 silver version is better but still the 1968 amp so looks very old styled. (2012-15)
1968 Fisher 800T (aka 500TX) receiver ↑
AS-ORIGINAL (Once Serviced): Not Possible-Too Far Gone. UPGRADED: Excellent. 65w.
SC, Direct Coupled. 800T seems the same as the 500TX if the 'Export' version has DIN inputs. 800T with the fascia top half in black, 500TX in silver. The Highest Power in the original Fisher range, before the Owner Sold The Brand to a company who made them more Midprice quality. Fisher Receivers we've had before, the 440T & 600T which you can read above. Expecting a Great Amp here, moving on from Germaniums. Dated '68' inside confirms the age, it must be pre 1970 for when the company was sold, so this seems their last one. A heavy solid unit, only a Vinyl Wrap case. Has Auto-Tune Tuner controls looking like an old TV set, the 1969 Pioneer SX-2500 has a similar Auto-Tune, if without the extra preset buttons. Tuner inside looks like the mid 1960s ones with the big tuning cans, if using those UK Mullard BC range transistors, the half-Hex ones, which we've known as problematic from the Leak 30/70 amps. The big problem here is they use the TV-Grade Plastic Cased electrolyics capacitors like Leak & Armstrong UK amps use, they dry out. Ones like the B+O Beomasters use too. To look at the Circuits, the Tuner uses a Varactor to tune & some strange ICs that are a FET of an obscure type, actually a MOSFET. Preamp uses those Mullard BC147 & BC149. Fisher use the Ceramic Capacitor large square blocks that also have resistors in, McIntosh use these too, USA ideas. Japanese amps use discrete components. Design shows Bass may lack if it'll sound Fresh & Lively, as other Fisher do. Phono named 'Preamplifier' & Preamp-Tone named 'Audio Control'. Power Amp has a Double Differential in a can, not an IC, just two transistors. Must be the Earliest Differential in a Hifi Amp, Teac used such in the 1969 ranges. Other Design looks early, the Bias Diode stacks, with two Adjust Pots for Bias & DC offset most likely. The Fuse on the output transistor Emitter is very strange, fuse should be on the Collector surely. Works on ±41.5v HT so it a Direct Coupled Amp, no output capacitors, Semi Complimentary. Again an early amp for this, the 1966 Direct Coupled amps had Hot Resistors dropping the voltages, such as the Sansui 3000(A). Power Supply is complex with Regulators & Zener Diodes. The Resistors seem to be a problem for Overheating. Later models only have 2 fuses on the board, not the 5 as the empty spaces suggest, it looks like someone altered it when later ones confusingly leave empty spaces. The 800T is the Export version of the 550T without the 550's black fascia. It adds extra wires to the Transformer so can be Rewired to 240v if this is very crude compared to the smart AC Block the 1965 Sony TA-1120 uses. This amp has a lot of Push On Pin connectors, to be careful not to break them, there are loads of them. Rear Panel has the typically Tiny Fisher screw connectors with the Reverb Socket loop you could put an EQ into, if why on a Quaility amp like this. A bizarre AM Tuner Antenna on the rear looks like a 1920s Crude thing, what were they thinking? Awkward & in the way on two hinged tabs. Is It Too Far Gone? This is a Non Worker as should be expected with the TV Grade capacitors. Someone has force-used it with Rods instead of Fuses, if the rear Case Fuse is all it has. The bad caps will be dry & shorted explaining the Power Supply board with black areas & torn track underneath. Not broken overall, but to repair & paint the black bits a Red-Beige PCB colour. To get this Amp seeing the Fuses issue & Burns is a bit extreme, to see other ones online with the lesser fuses if none burnt. A Customer's amp, another of those 'we'll not tell you it's a wreck' amps you'll encounter online. It took a while to understand it could be repaired once we heard they plugged it in on 110v & the lights worked. Without that the amp is left 'too wild' not knowing it's status & not wanting to risk. They plugged it in, we plugged it in & it did light up so to know the TX isn't damaged. Design Overall. It's trying to be ahead of other Receivers with the Auto-Tune, not many used this beyond the 1969 Pioneer SX-2500 & the B+O Beomaster 3000. Not hard to flick the Tuner across manually. The odd FET in the Tuner being a MOSFET is ahead of it's time, hope it works. First with a Differential as a Can IC style, hope it works too. The 1969-70 'Stereo International' Annual shows the Fisher 500T which is exactly the same as this 800T, it has a white top half on the fascia when the 800T has it in black. Ad says the 800T is for 'Overseas Military Personnel' so probably wasn't sold in the UK by 'Largs' who had earlier Fisher amps in Hifi News ads. The Ceramic Blocks containing certain parts like Tone, Filter & Tuner naturally have Ceramics, so may have that slightly edgy sound like the 440T & 600T we had. The questionable Power Supply Zener Diodes of up to 3w on 15v Tuner stages & a 30v 1w one for Muting aren't actually on Audio stages & are still buyable. Not as big as earlier Fisher, this one more the size of 1967 Pioneer. It's certainly interesting, to just get on with it to Recap & Upgrade, if the Tuner works a bonus. Quite a lot of 'Unknown' in this for the condition, we can only do our best. Checking the Power Supply. To see where it gets the Voltages, it may involve the Zener Diodes. Preamp-Tone is 'HH' & away from the Zeners, Power Amp is 'AA' & 'Z' ±42v & it does involve the 15v zener indirectly, the 'BB' point is +15v drawn from it giving an uneven load. The Aux Input. This surprisingly is into a 180K resistor in a Ceramic Block, with it going into the Phono stage. The '2019' Preamp board is for Aux, Phono & Tuner last stages, not so great, Sansui did this on most 1966-69 amps, an idea from Valve Days like the 1965 Rogers HG88 III does. To Bypass this is usually possible, but the 'Tape Mon' stage has 47K resistor & another further in. Fussy aren't we, to be a Detective on circuitry. The 440T is similar, the 600T seems different if 'Aux High-Low' hides the truth it's the same. To not have a 'Direct' input when the 1966 Sansui TR-707A has Aux into Phono, but the 'Tape Mon' is direct to the Volume. Recap The Thing. It needs all the Electrolytics replacing, they've dried out & ones with corroded legs break off showing those TV Grade Caps have been bad for Decades, probably by the late 1970s. Boards need care to not break pins, the boards are really not made for Easy Servicing at all & you'll be realising it's an Advanced job needing good planning. This really is an amp you'd like to hear playing, if the TV Grade caps won't let you. We can only do our Best on the several tuner boards. Of other Fisher, the 440T was liked best to work on, the 600T more awkward, but the 800T is a real nut job of an amp, after doing some to see the Audio Stages & Power Amp will do right, but the Tuner to just do it & try. Voltage Changing. This is terrible, it's a mess of quite vaguely coloured wires, to see what it's set at, 120v on ours, to be sure you call the Wire the right colour. Nothing in the User Manual or Service Manual, was there an extra item on this? Probably Fisher set this knowing which Country it'd go to, if not allowing easy change. It can be worked out once you learn it in an hour or more, but they don't say the Pins are joined underneath even, o---o, to put some to join & others to leave open. The User Manual has the Cheek to say they aren't responsible for Voltage Errors, actually they should be for Not Providing an Easy Way to do this, like Sony in 1965 did with their Black Voltage Block that many used. Down to the Retailer who probably had little idea unless they had a Repairs Service. If you don't trust you'd do it right, leave it as-is & use a Step Down External Transformer. We did our customer's one to 240v & it takes learning as no actual diagram of what to do. Rebuilt & Revived. One Rebuild later, no chance to do a bit & try it here. Still on 110v to see it Working, beyond odd noises on first try start up, next try 30 mins later it's fine. Aux & FM Tuner used, FM in Stereo was certainly unexpected as was it even working. For how Rough it was this plays surprisingly well, no background noise or crackles. Some heat on the Power Supply if mostly it runs under 50°C. Who else would Dare rebuild an amp looking like our one did? A Customer's Amp too, thought it was too far gone but take the challenge. as you'd expect, pleased with this one, still more to finish it. Sound Quality. 65w amp with a strong bassy sound through Aux & Tuner similarly bassy. The other Fisher 440T & 600T we've had were much Brighter & a bit Edgy on the treble on Headphones if better on Speakers. Wide Stereo & Strong Bassy sound here, if Treble isn't as fast or extended. Not an amp to try to alter, a One-Shot build here. Rock has the Weight if does sound 'Slow' from the lack of Treble extension like the 1973 Yamaha CA-1000 had a few days earlier. This leaves Treble a little Retro sounding, Treble Tone doesn't fill the Treble out enough as it's rolled off elsewhere. Biasing improves the Treble from first try. On Headphones Volume is midway & the Tuner is Louder, to alter gain is in the ceramic blocks, so best left. Set to 240v & Last Bits Done. An amp that needs Biasing to not sound Rough & may require different Bias values. The Treble can be not as Crisp as earlier Fisher if not Biased right. Big Problems? This amp can Oscilllate wildly on Speakers if not Headphones. It's not that you messed it up, the old style plastic caps are not as 'Hifi' as new ones. It can be sorted which is our ideas. BUY-RAW RATING: Probably too far gone for the bad caps. Advanced crazy build means most should avoid this one, other Fisher are slightly easier. REBUILD RATING: Advanced to Too Much: Ones online in nice grade seem not too bad, but one rough & overheated like ours is still Gambling, the construction isn't easy. Gambling can win, ours did. COOL RATING: 8 Serious Kit looks, Vinyl Wrap knocks a point, Classic Fisher looks here. (2022-2023)
1968 JVC Nivico MCA 104Z amplifier ↑
AS-ORIGINAL (Once Serviced): --. UPGRADED: --. 16w.
CC. This is the 1968 updated "32w" (16w + 16w) version of the 1966 JVC Nivico MCA 104E as we review above. It has Tape Head which was abandoned by 1969 so is earlier. Double the power as some state is inaccurate if it claims to be all silicon transistors. Says "100w SEA" on the front, Music Power rating added as one figure. Not too different inside compared to the 104E if the power amp board is much bigger. No circuits findable as always if we have the 104E one & the 105Z one is findable, the 105Z adds 2 more SEA sliders & puts the volume as a rotary, plus adding extra features & it's a total redesign to the 104Z if still 32w. Spec in the 104Z is still low, 2200µf 63v main cap & just 1000µf output caps. One on ebay 2018 shows "80w" on the back as the VA (max power draw from mains) which suggests it's 16w not 32w. The later 105 is 32w though as a manual is findable & it draws 145w. Power amp is 6 transistors per channel & the two round transistor-looking black ones are diodes. We can hear the quality in here, but the spec is low so doesn't reveal how good it can be, if the quality is noticeable. The 6 transistors on the board have panel mount heatsinks on which is strange if they do get slightly warm. But after seeing how rough it is we decided to send it back, we'd not be happy selling such a beat up amp under our name at any price. Pity as it is could have been another winner, but we'll look for a better one. To not be able to rate it properly for fear of failure & safety we decided. BUY-RAW RATING: Open grille lets in decades of dirt. REBUILD RATING: Worthwhile doing, access a bit limited, but it'll be filthy inside. COOL RATING: --. (2015)
1968 Leak Stereo 70 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: n/a. 30w.
CC. Always popular as easy to find these Leak amps, sounds are a Very Good intro to vintage hifi, like the Trios in this section. Sound is clean & very rich, but ultimately limited by basic designs & power. The Stereo 30 *Plus* & Stereo 70 are basically the same amp as the Delta 30 and 70 in an earlier design case, the early Stereo 30 (no Plus) from 1963 is different & not recommended as it has poor UK Germaniums, it is a one board amp, not the plug in boards. The Stereo 30 plus and Stereo 70 versions, both with the 4 plug-in boards can sound rough for the BC147/8/9 transistors used which age badly, rating based on one with little use after much running in. Not one we've ever upgraded due to the board sizes & axial caps limiting things. Any Leak except the Delta 75 is a Very Good starter amp. The Delta 70 is the same amp in a nicer case. Has that nice Leak amp smell with the plug in boards & thick card-foil lined top and bases. The matching Stereofetic tuner we found a bit crappy in sound & construction, but the amps are nice if they look better as the Delta rebranded ones. See the 1971 Leak Delta 70 as we ponder upgrading one. BUY-RAW RATING: Good if risk of rough sounding transistors. REBUILD RATING: Never redone one, to fully recap would need much changing & involved for what it is, probably not worth rebuilding & we've has a few of the Leak 30-70s. 2021 UPDATE. Saw one on ebay with inside pics, not had one in 8 years so forgot it. Still found it interesting, if know the later Delta updates better, if our page says we had one, maybe it was the Amp & tuner in the long case one that sold to Japan. So New Eyes on this one & it's a high grade one. The usual Blue Axial capacitors, the rear capacitors face down here & the TO3 heatsink is a small board with pieces on the back, later ones had a bigger shaped heatsink, if they weren't difficult to adjust on Bias. Dides just soldered on the transformer. Very tidy one with bright chrome & fascia lower edge all neat. Right side capacitor with '67' code shows this is an early one. Those plug in Boards tightly fitting here, that Leak smell is nice. The ancient UK type components like the resistors with raised legs. BC149 or later combinations were the limiter in these amps, the half-Hex Mullard transistors age & sound rough was a problem. the Power Amp board with RCA transistors that show no datasheets as were told in 1991. For a 53 years old amp, condition inside looks good, if more used ones will be failing. This one considering to be 'Modernised' on the Inputs & Outputs is the idea, as there must be a Demand for these Leak 30-70 amps to be made more 21st Century friendly & the forum ideas of Attenuators were never any good, the Gain needs setting right which is design we can do 2021 style. The original 'Stereo' cases looked very similar as did UK Sugden cases, a bit DIY shop look here, if no feet on ours or the rear top grille. Very long 12 ft long - 3m long 3 core mains with vintage rubber Duraplug, Neutral wire not tightened enough & a 13A fuse. Sounds Like. Tuner 1 is too loud, Tuner 2 with 'Lo' suits better. Balance goes the wrong way here. It sounds fine in it's loud compressed way. Grain not bad on this one, if they used to sound awful sometimes. Tone with Bass & treble gives a large amount of gain, background is quiet. But still the better UK sound compared to Goodmans & Rogers transistor ones. "Tuner 2" on "Lo" actually copes with peaks to not clip on high treble if "Hi" setting is not nice. Dynamics quite limited if this low use one is listenable which wasn't expected. Based on this High Grade Early Made amp, it deserves a "Very Good" to put it with the Japanese amps, if beware these can sound rough often. On Rock it has a rather soft tame sound lacking in weight if still clean sounding. Power on gives a bit of a thump if turn off just fades away. See more on two April 2021 Blogs. Thinking Out Loud if it's worth Upgrading, for the Sell Cost once Upgraded, to Decide it'd be Outpriced so to leave it be. The Inputs Design of the 30/70s is unlike the more modern Delta 75 receiver, if that one has failed too often, 4 bought, only one sellable. The 30/70 much the same, this 70 has varied limiting resistors on All Inputs except "Tuner 1" which is much too Loud for modern gear, it will only suit certain early UK items. All Inputs use different EQ/NFB settings which is why it's best left as-is. Pre Amp & Tone are NFB Tone with quite a bit of extra circuitry to tame it down from sounding hard. The problem if using Vinyl & Tape as we did in 1991 is the Tone must be Set Flat or you end up Recording the Tone as "Rec Out" comes after the Tone which is illogical. Treble Filter uses the 10mH inductor. Power Amp is more familiar compared to later Japanese amps & is likely the best part of the amp. Power Supply is modest if typical of the era. 75v HT on 2x 1250µf main caps, it's Capacitor Coupled on outputs, not a Direct Coupled ± HT design as still based on the original 1963 Stereo 30. Seems that this Design is much used by others.
COOL RATING: 7 for a High Grade one makes it a bit different. Cute smaller amp that still sounds good, if many won't be as nice now. (2013-2021)
1968 McIntosh C26 preamp + 1967 MC2505 power amp ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: n/a. 50w.
SC, DIFF, Direct Coupled design with TX outputs for 4-16 ohm Speaker, . This we last had in 2003 but it certainly impressed us on the Tannoy Golds. Transistor preamp & power amp. We got the C22 valve preamp & found the C26 more pleasing. These need the big Panloc wood cases to look their best & do they look pretty. The repro cabinets lack the class though. We got the amp from a UK seller & imported the pre. At the time we were impressed at how good the midrange was, very smooth & accurate, but the bass was a little limited & the treble a little soft, but oh... The midrange. Since then, one murky track that was deeply impressive has been tried on nearly every amp in search of that sound & it took quite a few amps to hit the quality. We had a good look inside & saw quite a bit would need upgrading, even with our 2003 ideas, ceramic blocks for the Tone stages & altering the NFB to try to get a little more gain brought up a high hiss background. Also the preamps when used on the TT valve amps had quite a loud hiss from the level mismatching, but C26+MC2505 matched perfectly. So there are upgrades needed to be done here & the price these were even in 2003 made us sell them on rather than be tempted to alter anything. The brand is the 'USA favorite' by the love owners have for Mac gear valve & solid state. We've not tried any other Macs since but they are up there on the 'to try' list with other big USA amps together with Fisher valve gear. The C22 preamp was a little bit on the early side with both C22 & C26 having an excess of controls & level presets & also the Bass Boost like the STR-6120 has too. Seeing the rear of a C26 in 2023, it looks like the C26 is a power amp, but it has speaker connectors to take the seperate Power Amp output & put it through the Preamp Switching to use Main or Remote Speakers. These appear 110v only, if they can be altered to 240v, if it's not a simple job or one to do unless a pro as you may get it wrong, most will use a 240v-110v external transformer. BUY-RAW RATING: Good when we had in 2003, but hard to find with nice glass & paint fascias. REBUILD RATING: Never done these, probably much like the Fisher. COOL RATING: 9 in the panloc wood cases these look wonderful with much care to style that is still on their hifi 40 years later, without the cases dips the looks as they look incomplete. (2003)
1968 Pioneer SX-1000TW receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 50w.
CC. Just slightly less musical than the SX-1500TD but still the first generation Pioneer styling. Seems to have sold well in USA & still has the qualities to call it a Very Good one. We didn't do much with ours as this was early on in our hifi page exploits as we had other Pioneers above, treble a bit soft but well made enough to be worth improving. Last of the early styled fascia amps. Confusingly there are actually 3 of the SX-1000 models: SX-1000TA (40w) is the first 1966 one with a valve & nuvistor Tuner front end noted by the lever switches not in one group, then the SX-1000 TD(F) (40w) by 1967 noted by the tall MS Mincho style tuner print then the 1968 SX-1000TW (50w) with IC for Tuner as some are still labelled & smaller tuner glass print. All pre 1969 Pioneer of the earlier styling strangely lack a proper Mono switch which is needed for Phono especially, offering only Mono of L or R but not together. As a 2012 review this still shows the early Pioneers are good & having the SX-990 in 2015 to hear again shows the early Pioneer sound fresher than the 1972-75 ones. COOL RATING: 8 in the wood case a smart looking amp as the SX-1500TF is. REBUILD RATING: Never done of of these if Pioneer often are hissy & quirky to work on. BUY-RAW RATING: Good. (2012)
1968-69 Sanyo DC-66 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
SC, Direct Coupled, FET. This is another Very Rare Sanyo receiver, see the 1966 Sanyo DC-60E review for more. The DC-60 was sold in the UK as the 1968-69 HFYB shows it, if this later model isn't shown. Power Rating was assumed about 30w as the DC-60 was rated 25w. Manual found 2024 hows 40w IHF Continuous per channel. But an ad shows the DC-60 as 15w RMS so the DC-66 can only be 18w RMS based on DC-60 ±30v HT & DC-66 ±35v HT. After rewading the DC-60 can output 24v clean sine in a 33w-40w range, the DC-60 rating of 15w can only be a 16ohm one. Known Sanyo of this 1960s range are DC-60A, DC-60E, DC-66 with a DC-70 appearing before the DC-66. These seem to have sold in Poland as ones on sale there as of typing reveal. DC-66 is somewhere 1968-69, Tuner box under shows '6925' code, no Tape Head & the styling is more Domestic looking in all Black fascia, with smart wood veneer case as the DC-60E is. . No Service Manual makes this obscure which leaves certain design unknown. Power Amp drivers are the MPS05 type UK's Leak Delta 75 receiver uses. Design. This is neater built inside than the DC-60. Power Amps have plug in cables to remove, if the preamp having short cables plugged into the preamp from the above level of the chassis from the inputs etc plus components amid the cabling & board connectors. With no Manual this is risky with nothing to refer to. To leave it in place is wisest to avoid bother. It's not the same as the DC-70 as a lo-fi circuit shows a different layout to either 60 or 66. Power Amps. These leave parts unknown as the amp stage is a ±HT semi complimentary design, no hot dropper resistors, no coupling transformers like the DC-60 if how it does this in 1968 is an unknown design to us. TO3 outputs are 2SD201. It's a Customer's Amp so to avoid taking risks with unmarked cables & no circuit to help. Not an easy one. What's it Sound Like? First try of this, it wasn't all that, muddy sound lacking much quality. Played fine if trying next time the sound was very different as it had woken up. Treble was now much better, the muddy sound gone, if Bass was rather lacking. Probably unused in decades, the seller from Italy had cleaned the dust out if it showed much dust in hard to get places. That Preamp. The Boards aren't marked on the top if a tiny bit on the track side isn't any help. Looks like Aux into Phono. Preamp seems to have FETs, small black domed 693FT unknowns. Two pairs of 693FT then under the mess of cables, two more 'D' shaped ones, one per channel as the tone stage, marked "U2 C C550" if these aren't '2SC550' as they are 1.5A 10w TO60 size if another 693FT amid the wires, possibly a regulator, if one diode on the board could mean it's Tuner related. The '693FT' is one on the Photax Concertone 333 receiver from 1972, the first input on their preamp used as a buffer, if again no circuit diagrams. No Service Manual on a design like this is limiting in what we can do, upgrades need the circuit known. Should We Even Bother? It's Advanced, it's got no Manuals & design is left unknown as with the Realistic STA-150 & 220. Both DC-60 & DC-66 look smart in the wood cases, the sound on both is above the usual 'raw' listen, DC-66 needed some use to wake up the aged capacitors. Well worth it on both. To look at DC-60E Circuits, the Preamp is similar in form, as in x2 transistors for Phono-Aux, then a Buffer stage before Tone if the power amp is totally different. Gather together unique info to make some sense of it, knowing many designs to see what's what to upgrade a certain amount. An Idea Of The Design. On your Own on this one, but still can be done. Power Amp has a few unknowns. The Preamp is very difficult to work on & see what's going on. It's a FET version of the DC-60 if adds extras & what looks like a regulator. Aux into Phono stage. To see what it brings in Sound, the Bass lacking as original. The 4 FETs by the rotary controls are the Tone-Pre stage, red wire the HT, the very busy right side hides 2 FETs if the other 2 of 'U2CC550' are unknowns if this assumed to be the Input-Phono stage. The board side has tiny 'BCE' markings on the 'transistors' but no info means FET or totally obscure Silicon transistor if why would Sanyo who make components use them. 'FT' has to be FET so can't guess. A difficult amp to work on if it reveals only on working on it. Setting Bias. Small Power amp pot is Bias across the large square white resistor. DC offset on speaker outputs is the wirewound pot. What Is It Like On Speakers. Despite not being able to upgrade more for lack of a Manual, the sound on Treble & Midrange is extremely good. Smooth & Precise with a Crisp Treble, No Grainy sound nor Hiss or Hum. Wide Stereo, it's a very decent one. Bass is a little limited with a slight retro sound if not thick or Boomy, it just lacks the below 50Hz bass notes if very listenable. We've got the DC-60 ourselves, this sort of sound is in it even as aged & noisy. These early Sanyo are a bit special. 2024 Update. We now have The Manual as one in Canada got the amp with the Manual. It's rated 40w & the Circuits are quite unusual explaining why it didn't make much sense looking at the Boards. This makes it very hard to Upgrade not knowing the Circuits. The DC-66 Circuits. Tuner is a FET then all Silicon Transistors with Two Ceramic Filters which is early for those, more used by 1971. Phono is two transistors per channel, direct coupled. Aux direct to Preamp-Tone via a Resistor. Volume & Balance before the Preamp. Tone is Passive which sounds better than the NFB Baxandall type. Higher NFB around the Preamp with design varying from Soft to Strong gives it an edge of quality if also some is lacking, but this was typical by 1969. Designed to sound smooth & pleasing, which it did as the review above shows. Power Amp is hard to make sense of & we looked at it again from Board Photos just a day before getting the .pdf as it interests to see how a Good Sounding Amp is designed. Now to see the Circuits. The Amp has a Retro Bass as we found on trying it without. Not knowing the Circuits, best to leave the Retro Bass as it sounded fuller. Retro Bass may please on early listening but once you know it, you want rid as a Marantz 2235B owner sent it back for after hearing it upgraded to not need Retro Bass. Buffer input to a PNP Gain Transistor onto a NPN Gain Transistor before the first Driver Transistor. Why the PNP-NPN pair is unknown to us if seen similar before. Bias has two Diodes & a Zener Diode for some obscure reason, more used in 1973 era amps. Driver Transitors with an Adjust Pot is unusual. VR8 VR10 Adjust Pots have No Info on how to Adjust, VR8 clearly Bias & VR10 probably to Balance the Drivers or Equal Voltages. Semi Complimentart NPN outputs with a Diode on one Emitter again design used elsewhere by 1973. 3A Fuse is the Speaker Output Fuse. Power Supply uses ±35v 3300µf main capacitors, no Regulators just resistors & capacitors. A right mix of designs here & some Obscure Transistors, Sanyo made Transistors & ICs more than Hifi & design ideas clearly years before other brands used them. BUY-RAW RATING: Ours worked if 1969 vintage. REBUILD RATING: Advanced. These may be around in EU countries like Poland. COOL RATING: 8 far from the Budget Sanyo of recent years. (2021-2024)
1968-69 Sony STR-6040 receiver ↑
AS-ORIGINAL (Once Serviced): --. UPGRADED: --. Rated 15w, Reads 18w-20w..
SC, Capacitor Coupled. A Rarer Sony for a few Reasons. Firstly the Size is 400mm wide like the TA-1120 etc amplifiers, not the 440mm width of a few models or the wider 483mm of the STR-6120 & STR-6200F. Secondly it's only rated at 15w. It's seen advertised maybe twice in 1968 HFN mag if never again with the STR-6060FW that was the First Sony Receiver. The STR-6120 wasn't advertised if the next STR-6050 was, STR-6040 15w £112. All NPN Transistors Power Amp, not a typical design if shows it can work. Power Rating seems Modest for the 52v HT, the 1965 Pioneer uses 25v+25v to be rated 25w. Lever Switches. The Service Manual shows the early Brown Block switch covers, to only see One on Google Images like this, the rest are like ours with the typical Round Tubular Metal ones. Tuner shows it has Six Ceramic Filters with only One FET on the Front End, the STR-6120 & STR-6060FW updates this a bit with more FETs. No ICs. Aux 1+2 Into Phono is almost the only Sony beyond the STR-6050 to do this. Two Transistors per channel. Crazily No Mains-HT Fuses at all in the 6040 or 6050. We'd use 'Tape Monitor' to get a Direct Input. The Phono-Aux circuit is like the STR-6050 uses, it's on the Front Right Tuner Board. Pre-Tone has one Transistor per channel & the Passive Tone Stage that sounds fresher than the usual NFB one. Probably gives it that Thick Lumpy 'Retro' Bass. Power Amp looks like it has a Differential by the Circuit Diagram, if it's not & a Capacitor Coupled design. The Service Manual says Q703 is a Driver Limiter, read the Manual for more. In normal use it's 'Off' so isn't limiting anything. Other Sony use similar in later amps. It's some sort of 'Protection' when the Amp has nothing else. Power Supply is just One Secondary Winding with 52v HT used by Regulators & Diodes not so unlike the STR-6120 design. It pulls Four Voltages from the 52v, as 32v, 30v, 27v & 17v, for Tuner & Preamp. Overall some of the Design Spec is rather limited to maybe keep it at 15w, if the 52v HT suggests it is capable of 'more' If that more makes it a 25w Receiver then it takes it into a different league as 15w is loud enough for TV use. Output Transistors 2SC895 of TO66 smaller size also used in the 1971 Sony TA-1130 & the 1971 Sony TA-2000F preamp if not seen later, these mostly used as Regulators. The STR-6040 used them as Power Amp Outputs & the Regulator which is probably Unique using one for Two Uses. 2SC895 are a little unusual, Sony designed, 180v max, 2.5A on 18w output, 180v is for the TA-2000f 160v uses. Got It Here. Unusual a Receiver the TA-1120-1150 Amplifier size. HifiShark hasn't got many even. Probably one not that well known. Transformer quite small, usual Multivoltage block. Compare to STR-6050. Our Solds Gallery page shows one we had in 2013. STR-6040 is certainly earlier, 'Solid State' on the Tuner Glass which is a narrower size if the Font the same. 6050 adds Speaker Switch, only one Set on the 6040. No 'Low Filter' on either. 'Mode' is just Stereo & Mono. Function & Aux 2 front panel 6.3mm socket input the same. Play It. The Loudness by the Volume needing to be 'Out' to Cancel else a horrible over-bassy sound. A Clean sound, if all Rather Modest & Small in sound, not particularly Crisp or Detailed, if certainly to hear 'The Sony Sound' in there. Stereo is decelt Width. FM Stereo shows the Sony quality tuner, Stereo lights. Sound is a bit on the Dull side, Treble is not especially Fresh or Open if deeper listening & circuit comparing shows it could do better. The 1965-66 Sony TA-1120 sounded similar, if one we didn't upgrade more. It certainly would benefit from Our Upgrades to bring it out better & be more Crisp. The reason it can fit in the smaller case is the Tuner being updated from the STR-6120 one. Test For Power Rating. Our Sine Wave Test put the 30w 6050 at 24v. The 6040 reads 18v with the Lower part slightly more squared whilst the top is still a true Sine. 18v rates 20w on Two on our list, so the STR-6040 rates 18w-20w as it is. HT reads 53v with about 23v on the Output Capacitors. Of course whether it, as original spec, could put out 20w into 15" Tannoys is another thing, current availabilty. Compare to 1971 Sony TA-1130. This one Recapped with Upgrades if haven't 'Optimised' it more. Approx STR-6040 18w compared to TA-1130 65w on Headphones. The 6040 has a Sweeter Sound, the TA-1130 is more Matter-Of-Fact that can sound a bit 'Flat' on the wrong speakers, despite Crisp Treble & a Solid Bass. STR-6040 looks smart in the earlier wood case, a little unusual as smaller on width. To Recap, Upgrade & Redesign. The Seller's Like-For-Like Recapping reveals what we've just told of, but without the Upgrades. Playing through 'Tape In' direct offers a Pleasing Sound, far from what it could be, but in the Pioneer SX-440 vs Sony STR-6040, the Sony is with the Smooth Sony Midrange that suits our 'Neutral Sound' interests, as that is What Hifi should sound like. How About The Earlier Sony STR-6060FW? The 1966 one with the Front Flap, 45w. Not had one yet, but Design Fresh to Compare. Phono & Aux inputs have Aux direct, not through Phono. Thehobo stage not so unlike. Pre-Tone has Three Transistors per channel & High NFB that made the Sony TA-1120(A) not ideal to us. Passive Tone is good, but not as Fresh for the Gain Stages. 6060FW Power Amp not unlike the STR-6120 with some STR-6040 influence, also some that's not quite right. A busy 'Protection Circuit' seems overdone for what it does, the Amp is Capacitor Coupled. To see the STR-6120 improved on this is clear from knowing Sonys. 6120 preamp better than 6060FW & the protection circuit simplified a lot. STR-6120 isn't perfect, but from remembering the last one we had, the 6040 is closer to the 6120 than the 6060FW would be. Recapping & Upgrading reveals the Tone Stage is much too Bassy 'done properly' one to look closer at.
BUY-RAW RATING: Probably quite Aged as 1960s Sony become. REBUILD RATING: --. COOL RATING: --. (2024)
1968 Sony STR-6120 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 50w.
CC. BEWARE: The Early Tape Head ones from 1968 are now too aged with bad capacitors. They Always need a Rebuild & NOT to just plug in to hope as you'll damage the amp is likely. The best sounding Sony receiver & a long time favourite of ours. Just so musical, precise & well balanced, it has put many to shame and still sounds great as we upgrade one Nov 2017. Much upgradeable too & others may overtake it but then the 6120 can take upgrades & still win. Very well built with quality parts, all mica in the audio stages no ceramics. A combination of their top quality 5000FW updated tuner & a modified version of the TA-1120A amplifier = STR-6120. It's 50w rated, if the Manual says 60w 'each channel' meaning just one channel used, a misleading rating. The 1970 version without 'Tape Head' rates the same as the first one, though has an extra Aux input to the earlier one. The STR-6200 & STR-6200F are similar but actually about half is different. One of the best looking receivers with it's wood case & hideously expensive when new £387 in 1969 means few are around worldwide except USA really. Why so much more than the others? Superior tuner, better power supply, advanced tone & preamp that differs from the fussier TA-1120(A) design. A top FM tuner once recapped can sound excellent. Later hearing a Tape Head version in unusually high grade all original beyond a bad power cap then replaced it sounds very enjoyable, the solid Sony midrange is there to set it apart from many. Bass on one with little use isn't so limited as once more aged which helps up the AS-ORIGINAL (Once Serviced) rating, treble is decent if a little lacking in focus to one recapped as is typical for the age, but nothing rough sounding here. The 6120 will have sounded exceptional when new for power & sound. The design uses low value coupling capacitors that create a 'Retro Bass' sound that is appealing, but can be made to sound more natural with a deeper bass. An amp perfectly matched to the Tannoy Golds & was probably designed for them. In terms of design, this is a fresher sound than the TA-1120 or 1120A. The phono stage is perhaps the Best Transistor phono stage we've heard using Ortofon & Goldring cartridges. We've had a few of these now since our first in 2002, the 1968 'Tape Head' one & the 1970 'Aux 3' are the same amp if that minor change & a different mains transformer. To put the difficulties with this amp into the next section, it's not an amp to rush into buying, if worth it if you do... BUY-RAW RATING: These are often well used & for the age & high power, to use raw is probably too risky except on the later 'Aux 3' version. REBUILD RATING: The 'Tape Head' 1968 version is usually in poor grade inside from heavy use as such a great amp. Capacitors will usually be leaky & to not try on mains is the best advice. Even a high grade looking one can still be very aged inside & not good to use more than briefly to see if it works. The 'Aux 3' 1970 version is found less often if the gold Cadmium plating of the chassis means it ages better inside visually but still the 93v HT will mean the main capacitors are too risky to use for long. To rebuild either one of these properly is a big job, all we've had were with old repairs & despite it being a great amp, only get into one if you want to spend for the big rebuild. It's worth it, but it'll not be cheap. Beware of loose wires on the power amp board if it's been worked on before, this can cause big problems. The 'Aux 3' one may be more useable 'raw' but the 'Tape Head' version isn't worth risking mains on until rebuilt. We have a look at this amp as we upgrade it board by board to see how it sounds instead of just doing the lot & knowing where most difference is made. COOL RATING: 9 in the big wood case either version looks very cool, the expense not spared look for your rich Bachelor Pad. Simple but strong looks, the pick of the Vintage Receivers looks wise. (2002-2017)
1968 Toshiba SA-15Y receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 30w.
CC. This is a rare 1968 early receiver that has great looks. Sold in the UK late 1969-early 1970 together with the SA-20Y which were both in Hifi News ads. By having FETs in the Tuner it dates to 1968 as the 1967 idea was ICs & in 1967-69 Tuners changed a lot, it's quirky like Early JVC if with standard Tone Controls. The amp works & has that luscious late 1960s sound not unlike the FIsher 600-T, if it's past it's best the tuner does work on FM & MW. The fascia is interesting, when off it's a black perspex 'blackout' design with an aluminium frame, much like the 1971 Pioneer SX-770 if that's only a 15w as not the later 1970s series. Rocker switches, Power switch for Speakers & for Headphones to move to the 'Ext Phones' 3rd notch. Rear panel has all Phono sockets & DIN duplicates Tape. Main speakers are typical screws which aren't too user friendly if the second speaker outputs are a non-standard 2 pin socket. Transistors behind the rectangular covers are 2SC793 'R' (red) 60w 7A made by Toshiba. The 1971 HFYB lists both these receivers SA15 30w £159, SA20 50w £189 plus a 15w SA2600 £63, distributed by Hanimex, London. No Amplifiers or Tuners listed, if a range of Turntables, Tape machines & Loudspeakers, in the 1972 HFYB but gone until 1976 with a new range. SA-20Y is found online & looks exactly the same inside too, so will just be higher power at 50w. Apparently there is a SA-10Y too. Build inside is good, resettable circuit breaker buttons on the rear & the Manual says part of the 'Boston' series & quotes Damping Factor of 100 with 30w/30w at 8 ohm if can drive 4-16 ohms. Tuner has 2 FETs & one of the very few No-IC tuners as all transistors otherwise. The 'Boston' is a Music Centre range of quality as various models online. Capacitor Coupled, boards look like JVC with white printed lines. Bigger size receiver too. Some build quality is like Fisher with the metal spring ground cabling trunking & the Input Selector at the rear corner saves lots of wires so the whole amp is quite tidy compared to some. HT is 68.3v which is healthy for a 30w rated amp. The minus with this amp is the Aux goes into the Phono stage via a large resistor, an old idea from the Valve era, if Tape In bypasses that for the more direct signal path. Has a proper 'Mono' unlike early Pioneer & also pre out-main in connectors which is unusual for 1968 beyond the Sony TA-1120(A). the bridge rectifier looks like the Yamaha CR-2020 ones, a 'Toshiba M9235' rectifier block, actually a 90v 4A bridge. Has a 3A main fuse, 1.6A circuit breakers. One on ebay Nov 2018 has differences with Power Outlets & is likely to be a 110v-only one as a SA-20Y seen lacks the Multivoltage block. Sound Quality As Raw. Playing input to the Tape In to avoid the noisy Aux stage, the volume is very low going past halfway to get some life out of it, a Mainsy hum & a bassy rumble noise tell you all is not well & for 50 years age in Hifi, rarely do you get useable amps this old. The sound is surprisingly crisp with very wide stereo & deep soundstage bringing out detail well. The Bass is a bit Retro Bass as typical. So to circuit gaze & see further if the schematic is rough to not read values too well. The great sound playing the amp for over 30 mins shows it's worth it, there is some designing to the audio as with the Sony TA-1120 but it does sound great. Does it better the upgraded Sony STR-6120 though? On later versions the Tape In-Out has an extra tiny PCB right by the DIN socket with a buffer for Tape Out, Tape In goes through 2 resistors with no transistor. Early amp with Phono, Tape Head & Aux 1 & 2 going to the Phono stage, Aux via large resistors as some amps do. But Tape In with the extra board is better as it can allow a Direct Line Level input with a little alteration. The Amp sounded good with no noises via the Pre Out-Power In loop. The amp uses 'Marcon' brand capacitors, not familiar ones but they were actually Toshiba's own brand if the name later sold to another manufacturer. Partly Rebuilt Verdict. Sounds great with Preamp & Input stages rebuilt, not touched the Power Amps or Power Supply yet. The LED bulbs are awful with the fascia off as they are on AC so flicker in a mindbending way. The amp is very fast sounding for 'only 30w' & plays upfront if detailed. Shows the rest is still aged though but a 1968 amp sounding this great already is unexpected, but how many more finds like this are there left? The 50w version of this would be interesting to know. To get the Original Manual of this SA-15Y to get the circuit readable as the pdf is a poor photocopy turned up the original printed one if £50 delivered was high but no other options. So we have the circuits readable now to understand it better. SA-15Y vs SA-20Y comparing? Sadly this is the trouble with trusting stuff online, the SA-20Y circuit on a German site is actually the SA-15Y as it shows exactly the same including the transformer number "PT -1006" which is the smaller one as in our amp. But two photos of the SA 20Y show the bigger transformer PT 1010(?), heatsinks on the Power amp transistors, an extra part on 4 vacant holes on the left by the Tx as well as finned heatsinks on the rear panel, an ebay seller had pdf manuals to sell in 2012. Tests on this show it can put out 24v RMS clean sine, but no trace of crossover distortion even on the new Scope. 24v is typical for a 40w amp, so underspec rating here, if ours is now upgraded. Upgraded Verdict. This upgrades nicely bringing out a crisp clean sound. A little redesign to bring it to our standards & that's often done in upgrading anyway. Good volume on Speakers & Headphones making it compare to the 32.5w Realistic STA-150. Trying again once listed For Sale on the Tannoys, after the Sony pair with them as a very neutral sound, the Toshiba is neutral too if a bit livelier sounding with quite a different sound, a little punchier needing less Bass & Treble Tone gain than some amps. In comparing to an upgraded Sony STR-6120 it actually sounds very like it, if with the earlier lower Damping Factor giving it more of a Bassline heading towards the looser Valve bass. Connections on the rear panel are mostly typical, MM Phono, old style Tape Head for Tape Players with no electronics, Aux 1&2 are available with the rear slider switch selecting between them for different input levels, Aux 2 is a tiny bit louder & brighter than Aux 1. Pre Out-Main In, Tape Rec & PB, the Rec Out has a buffer stage which is unusual & not on all versions of this amp. Speaker outs are fiddly screws that we put the usual 4mm connectors & an obscure 2 pin plug for Ext. Speakers, if few ever try to run more than one speaker pair. The 'Protection' buttons are a 1.6A resettable circuit breaker on the Power Amp HT. 200VA (200w) max power is good for a 30w amp. BUY-RAW RATING: 50 years old now & it will have issues. REBUILD RATING: A more complex one to do, even with the circuits, no board markings. COOL RATING: 8 looks good in the wood case with the black-out front that has a green tuner light. (2018)
1968 Trio-Kenwood TK-140X receiver (silver label + UA1343 amp) ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 53w.
CC. First in UK adverts in March 1969. HFE now has the Service Manual, if of the later UA1384 Power Amp version. We've split the TK-140X into Two Versions for 2021 as they are very different. The 1967 TK-140E is also as different as the two TK-140X versions, so Three versions of the TK-140. TK-140E has white lever switches & a silver rear panel. This section covers the earliest Silver rear label with the UA-1343 power amp, three board layered tuner UA1405K, UA1218J & UA1217K and the attractive 1967 style wood effect lid & the Silver label and the slightly later Silver label one with the drab black textured lid as the later Black label one has too. Guess which one looks the best. 2012 we first get the earliest version, these are usually USA only so we never got one having the below one twice. What Is Different to the 2nd Black Label Version? Quite obvious differences in Power Amp board, the 1st uses the KA-6000 amp board with the 4x TO66 underneath. Front looks much the same if lighter wood on the 1st wood effect lid one. Rear panel is with a different AM antenna hinged midway, not the rotating bar-end version on the 2nd one. 1st not unlike the earlier TK-140E layout, adding AC outlets & multivoltage switch. 2nd has 2x Phono as 'Mag', earlier has one only. Pre Out-Main in sockets moved & antenna also moved on 2nd. Trio tuners varied often, the Kenwood KT-7000 tuner on the solds gallery has a different one to the Trio one we have here. The ebay one showing the tuner screw posts & same lower tuner board as the one we're reviewing will be incomplete, missing the top tuner board. Power Amp is the UA1343K as the KA-6000 amp has. The 6 plug in cables are for the TO66 underneath, as the KA-6000 did similarly on the inside base. The board is a messy build always, here the R2-R6 linked resistors show even early on they didn't use the extra resistors that were like a filter on the input. the TO66 under are the same as Q11-14 unused spaces on the board. Six adjust pots for Protection, AC & DC bias. UA1343 vs UA1384 what's the difference. Audibly they sound much the same, if the later board is much tidier. Fitting capacitors over resistors & a ceramic capacitor is a bit messy, transistors Q7-8 go over resistors which is as made too. A Very Busy Amp. Haven't seen one of these in years as original, did so much to Our One we sold, it was a great one upgraded if the sad lid & dead tuner got us selling it. Trio tuners pre 1970 rarely work, the KT-7000 does as only used when listened to, if the receiver Tuner is always on. If this works, it'll be the First Ever we've had that does, if the Boxed TK-66 one faded away fast. This amp has an extra board & tag row "Low Filter" UA13081A, this board is actually a fixed Bass Filter, circuit not too clear, it's reduced output goes to the Pre Out-Main In links. The other one is part before Volume, C144 & R146, looking like a late add-on. First Play As Original. Not played an Original Trio in a while. The Quality in Treble & Midrange obvious, if Bass is very limited if not Thin sounding but a bit one-note. Sometimes these can be very Hissy if Volume towards Max only brings up a Background Noise, the 2nd one was this good too, a noise-free amp isn't always the case. Unserviced the Tone Controls are vague. This is an Estate find so one careful user with the Hot Resistor under not being too aged, to get a better idea of what this sounded like in 1968. Still on the Skinny Single Insulated mains cable with no Earth, to be careful to plug in connectors before Mains to avoid a 60v-120v Earth Potential without true Earth. A very decent receiver as we thought with the 2nd version, if no Tuner working holds it back. Silent background even on Headphones is unusual. On Rock it plays clean if a bit lacking in grunt than adding Bass on Tone doesn't help. Tuner. This one actually works on FM & AM. All the transistor tuners in receivers are always on & the front end seems to fail if later stages still work. But this early one with the wood effect lid, hugely nicer than the tatty textured black effort, the Tuner actually works. Owner has used it enough & it still goes which is a Trio first for us in a pre 1971 receiver. It looks only lightly used compared to the later Black Label ones we've had. What's Inside? The two-layer tuner is for this version only. The 'UA1343K,49K' power amp board is the same as the KA-6000 amplifier, the strange input section without all resistor spaces used as this originally had some sort of Bass filter if no manual shows it or the updates, the back of the right side has several added links as it's wired not logically as we found. Board components a bit messy with Q9/Q10 driver transistors on long wires away from the board & the Bias Q7/Q8 on long wires stretched over resistors. The 6 adjust pots, Prot & VR5/6 are best set midway & the mid Bias one to adjust. The later UA1384 one is much neater. The line of TO66 transistors underneath are the same as the unused ones on the board. The power supply in this is a very complex one all on axials except the 5 top ones, one secondary winding makes a lot of separate stages & one hot long resistor. Preamp is the vertical board at the front with what looks like another Bass filter, very similar to the KA-6000 preamp. As we found with our KA-6000 this can be simplified & tidied a lot, if it took years to get right. To not overcomplicate this one. The Tuner Works Here. So to hear what it sounds like through an upgraded amp. It has those can ICs similar to other brands on the IF board & pre the Ceramic Filters. Having heard the 1975 Yamaha CR-200 just the day before, the 140X is an older sounding tuner. The Valve & Nuvistor Tuners are fresher, the one here has a softer focus towards AM sound if it is crisp enough & not muddy. "You can ask your Smart Speaker for BBC FM" has it come to that, with the mindless 'music'. The FM red square in the meter lights often as we dial across, not very wide stereo if not to touch as Trio tuner pre 1970 rarely work. Big Job To Rebuild. Not had either 140X in a while & do the lot in one go shows this is an involved amp with hardwiring that had mostly gone by the 1971 ranges. BUY-RAW RATING: Good. Tuners on these early ones often not working right, the Trio-Kenwood tuners are not so good despite the amp stages being quality. This amplifier needs a proper 3 core mains + earth cable, see above. REBUILD RATING: Very upgradeable if the Power Supply to redo is quite a job, some awkward parts. COOL RATING: 7 but there are 2 versions as stated above, plus the black lid looks less appealing so a 6, but the brown wood effect lid looks a lot better, a little lacking in style if still Bachelor Pad looks with the wood veneer front & nice lever switches. (2021)
1968 Trio-Kenwood TK-140X receiver (black label + UA 1384 amp) ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 53w.
CC. See above for the first version & differences. Despite being the X version of their 1967 receiver, this is totally redesigned inside if looking very similar to the 1967 TK-140E from 1967 externally, noted above, with more power at 53w for 8 ohms both channels driven. HFE now has the Service Manual, if of this later UA1384 Power Amp version. There are 2 versions. Mk I has the UA 1343K power amp board, Mk II has UA 1384J, only the boards tell if silver label on Mk I & black label on Mk II. First advertised in the UK Mar 1969 HFN so is a 1968 release. Styling is based on the TK-150/250 & KA-2000 amplifiers. The tuner window shows 'Integrated circuit', the Lever switches are black & the back panel is black. This is a Capacitor Coupled redesign the same almost as the KA-6000. The metal case with no wood outer made leaves it a little plain if the fascia is nice exactly as the E version has. The back panel has easier to use screw connectors, pre out-power amp in sockets & a different MW antenna else much the same. Very packed insides & heavier than the E version and it's a smaller sized 420mm wide with hardwiring like a Valve amp, so still early looking compared to the Sony STR-6120 that was more PCB based. Some have the black lid & the long arm antenna, some have the wood effect one, short hinged antenna & a white Serial plate, if none have a wood case. We have both the 6000 & 140 at the same time to compare. The power amp board is UA1343K1 on the 6000, should be UA1343K2 on the TK-140X but ours is a later one UA1384J with just one adjust pot, no thermistors, simplified protection circuit with an axial 100v 47µf board capacitor. The UA1343K1 version has different tuner boards inside, one each AM & FM. So there are 2 versions internally of the TK-140X if the sound is no different as original or upgraded in comparinmg to our KA-6000. To spot the UA1384J & one tuner board version, the back label is black, the lid is usually black & a white wire is not visible through the top grille like the earlier version, but in compares of either X version both will be quite similar. Having the KA-6000 here & recapped it to the same level initially, the compare is interesting, the TK & KA have the same sweet sound, if the TK as with the original power supply & output caps lacks the fullness of the KA. There is a rightness to the sound that few amps do. Now fully recapped it has a strong rich sound with more bass than some, but still crisp and clean. On speakers the early Trio-Kenwood play louder than you'd expect, useful for less sensitive speakers. Perfect match for the Tannoy Golds. The pick of the Trio-Kenwood receivers for such a sweet detailed sound. The black label later version we have is very hard to find, if either 'X' version is the best of the Trio-Kenwood receivers. See the Tuners page for more info. UPDATE 2017: We had two of these at once, not so unusual with amps we like. We got the first one we got back again... it was still with the original power supply caps, Elna ones are still good we've found on cutting them open. Recapping this is a real tough one. After playing the TK-140X for a while, try the KA-6000 as we keep one as a reference amp. The 45w power makes a slight difference, the sound is very similar as both designed at the same time. After upgrading both TK-140X Mk II (UA1384J) & KA-6000 (UA1343K) they sound the same. How do you Bias the black later version? You don't, it's autobias. See the 1969 Trio KA-6000 below for a pre-power compare. The TK-140X Mk II we rate as sounding better than the KA-6000 for the 'black label' version. Looks aren't so pretty but it sounds excellent on headphones & 1969 Tannoys. The KA-6000 & TK-140X are the Best of the Trio-Kenwood early range & sound so great on big speakers. Actually the TK-140X Mk II amp was also used in the KR-6160 receiver. BUY-RAW RATING: Good. Tuners on these early ones often not working right, the Trio-Kenwood tuners are not so good despite the amp stages being quality. This amplifier needs a proper 3 core mains + earth cable, see above. REBUILD RATING: Very upgradeable if the Power Supply to redo is quite a job, some awkward parts. COOL RATING: 7 but there are 2 versions as stated above, plus the black lid looks less appealing so a 6, but the brown wood effect lid looks better, a little lacking in style if still Bachelor Pad looks with the wood veneer front & nice lever switches. (2014-17)
1968 Trio-Kenwood KA-4000 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 32w.
CC. First in UK in an Oct 1969 HFN ad with the KA-6000. This the First of this "Uptown" Styled Trio-Kenwood range, matching the KA-6000. The KA-2000 aka TK-150 was a rather cheap looking black fascia with Plastic knobs like the TK-140X, far better sounds than looks. Here Trio give a very nice Aluminium silver fascia & solid control knobs. Not yet the symmetry of the KA-6000, has 4 of the Piano Key switches & one of the first amps to have a larger Volume Control in the centre. In high grade these do look smart & with the matching Tuner. Not had one until 2024, seen & bid, but condition not so good usually to not be overkeen on one. The KA-4000 is earlier than the KA-6000, KA-4000 much neater layout if basically the Amp, Tone & Phono boards are the same. Phono UA1342K on both, Tone UA13443, 'B' on KA-4000 & 'E' on KA-6000. Power Amp UA1349K & UA1343K on KA-6000
if that has the 4x TO66 transistors o the case floor, the KA-4000 uses the spaces in the board. KA-4000 has one Transistor on the early Power Amp, KA-6000 has two. Various minor differences & a 68v HT compared to 86v on the 48w KA-6000. Has the 80Hz Low Filter, the KA-6000 with the 80Hz & 40Hz one complicates the amp if the Receiver TK-140X is more like the KA-4000. Transformer has One Winding like the 1970 KR-6170Jumbo, the KA-6000 does too, but the overhot resistor shows it should have been done differently. Has the same Buffer Stage the KA-6000 has if not the problematic 40Hz stage. The KA-4000 seems a better amp & we've not tried it yet, though it is clean inside looking never before opened. Have A Listen. After a little playing with controls & some Servicing earlier, Sound on both channels. Had a few KA-6000, these range from useable to very rough. This one is decent with no Hiss or Noises which is unusual on Trio. The KA-6000 never sounded like this, showing later versions of a good design often are the lesser for it, despite higher power. To get a better volume to go midway as the KA-6000 was. It's a Nice Sound, a few light crackles on the R, but a clean sound, not hugely Dynamic or Crisp, but probanly nearer the early TK-140X we had fairly recently, on it's first play once Serviced. Compare to Recapped KR-6170 Jumbo. This one 33w if with changes as a 1970-71 item, plus more changes by us. Comparing for 32w-33w on a Trio-Kenwood. A similar overall sound, if KR-6170 is crisper, bassier with Wider Stereo. What Upgrades can bring, if KR-6170 has had far more done. Reviewing Original to Upgraded & Upgraded much more, brings out the Quality of a Good Design. But usually it takes a Lot to get a good sound, undoing bad design, here the KA-4000 has a certain quality showing to us it's a great one, in the same way the Sony TA-1130 as original betters others. Compare To Others. The KA-4000 certainly has a Reference Sound, the KR-6170 leads on from it. Trying Valve & Transistors in compare, they all sound different, some are preferred one day & then opinions forever change. The Sony TA-1130 is still original, so compare those two. Both sound quite similar, they both are Amps that avoided the 'Dumbing Down' we spend ages trying to Undo. KR-6170 uses the KA-4000 design, one input transistor then onto Drivers. The KA-6000 & TK-140X both versions differ. KA-4000 has the Power Amp board marked UA1343-49, 1343 is the first TK-140X board & 1349 is the KA-4000 board less Q1-2 transistor with various alterations to the board itself, as was the first TK-140X, extra spaces used for a 'T' Bass Filter like the JVC 5040U 1967 receiver uses, no need for hard bass filters if several amps use them. TK-140X both versions put Q7-Q8 as TO66 drivers off the main plug-in board instead of 2SC281 that are fitted a little crudely overlapping resistors. KA-4000 has 3 adjust pots, Bias, AC balance & Protection. Board Marked components messy on the lower-input stage with R1,3,5,9,13 & C1,3,5,39 not used as expected. KA-4000 manual shows the Revised Layout, if the TK-140X has no Manual showing the Board layout. HFE actually now has a TK-140X Service Manual if only for the later UA1384 board. How Close To KR-6170? Interesting to find a very similar Power Amp on this 32w KA-4000 is in the KR-6170 frm 1970 at 33w. Board Layout differs, but the Circuit is One Input Transistor with the same Resistor values. Bias differs on Two Adjust Pots with Thermistor or Double Diode. NFB is done as One or Two Resistors, the KR-6170 using two if basically the same value. The Rest the same too. Tone differs, NFB type on KA-4000 & Passive with 'Mood' presets on the KR-6170, plus it's 'Mixer' Amp Board giving an Unique sound. Already played KA-4000 original with much upgraded KR-6170 on Headphones & they have a similar overall sound. The Problem With The Bass Filter Stage. KA-4000 has one Bass Filter at 80Hz, the KA-6000 adds another at 40Hz. This is the board behind on KA-6000 or to the right of the Volume Control on the KA-4000. The KA-4000 has the Muting, Loudness, Balance & lastly Volume Control with these Bass Filters after them. On the KA-4000 it makes no Click Noise in use, but the early KA-6000 has a Service Bulletin as the 40Hz one can be noisy. In use, if you actually needed a Hifi Amp using a Cheap Rumbly Turntable, but people did sadly. 80Hz takes too much out of the Music if 40Hz would be better. We have No Use for High or Low Filters, it's from Ago when other Components from Cartridges to Speakers weren't as good. The Trio-Kenwood were quality Items, but the Marketplace demanded Filters, as HFN reviews complained of how they worked, cut off points & steepness. KA-4000 has four Film Capacitors & NFB per channel, these are Bypassed if the Filter isn't used, if the NFB is always used. The High Filter is after this with the Buffer Stage required to 'Fit' the High Filter right, plus two resistors of low value. It's kept rather Tamed & seeing a Diode extra to other Trio, this would limit the Switch Click. Only trouble is as Upgraded on the KA-6000 the Switch Click is 'not good' & also the Power Switch Connects the Speakers, making a 'Click' on Turn-On. No Problems on an Original one or one Upgraded aware of this, but a much Upgraded KA-6000 with the Filter capacitors was just too noisy. To not be able to Sell Amps that have Features that could be much too Noisy in use. The KA-4000 to Upgrade aware of this to Sell It, but seeing it isn't far off the KR-6170, not to go further with it. To get the KA-6000 to understand both 4000 & 6000, the KA-4000 needs care not to get the Filter Switch Clicks. The TK-140X both versions is without the Filter Clicks as it's simplified. Adjusting. Manual shows what to adjust, midpoint voltage & Bias. We'd never use the mA & Black Plug inside idea, far easier to read across a certain resistor, if not so easy to do to not tell & let amps get damaged. Some amps are easier to Bias than others, but well worth doing as once rebuilt it needs it. Play It As Finished. On Headphones volume good by '3'. The 4 lever switches are good in use, no problems like the KA-6000 brought. No noises on switch-on with Headphones, to try on speakers shortly. The KA-4000 came before the KA-6000 & the TK-140X was based on this. The sound for the level of Upgrade is very decent, don't remember the KA-6000 sounding like this. A pleasing Neutral & Clean sound is better than expected, very listenable for sure. Detailed & properly wide in Stereo. On Reggae it sounds very nice, on 70s Rock in Stereo it reveals where further upgrades could go to give a sweeter focus & possibly more Kick, if that further upgrading takes a lot of time. Bass is decent, not weighty like the 1965-66 amps playing Rock at '4' on the volume, but not thin either. Tried much with the KA-6000 but to be cruel to it, nowhere near this for the power supply. High Quality 32w amp. We have the 33w Trio-Kenwood KR-6170 to compare. As with any compare, it's rarely what you expect exactly. KR-6170 more refined for more done, the KA-4000 has a fresher sound as a 1967-68 designed amp. KR-6170 has more weight & precision. Not to play too much to upset the balance of hearing, the 1966 TK-60BU can be tried too, if the TK-80U Germanium will be too different. TK-60BU is only 20w, it is a 1966 design reused in the 1967 TK-66. TK-60BU has an even sweeter sound if lacks some weight on Rock if it's still not had the Phono-Preamp board done yet, if +2 on Bass gets a better sound. Played As Completed. Surprisingly Great Sound after knowing the KA-6000 for several years. This one sounds very nice with a Clean Tidy Sound. Bass is Decent for 32w. Plays Bassy Reggae & Punchy Rock in Stereo nicely with a wide Stereo soundstage. Sort of wish we'd got this before the KA-4000. This out Early 1969 so a 1968 design with much improved looks to the Black Fascia range 1967-68. KA-6000 wasn't around until early 1970 by Ads. Very Classy looker, well made with a quality that soon faded past 1970 in amps. With the loid & side boards on it is once certain to please. Quite a lot to rebuild in this. BUY-RAW RATING: These can vary a lot from useable to very rough, as a 1968 amp it'll be needing a rebuild. COOL RATING: 8.5: a high grade one is a great looking amp, the KA-6000 with more symmetry just betters it in looks. (2024)
1969 B+O Beomaster 3000 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 30w.
CC. One of the all-time stylish classics & sounds the sweetest one of the 1970s Beomasters at 30w, a fine neutral sound here. Always needs good servicing & a nice grade one all original & of little use deserves a high rating. Average ones can sound rough though. Sweet quality of sound rather than loud & bassy. A more domestic easy sound than some, but with a pleasing sound still. A more used one will not rate this high as certain parts age & lose the fidelity those BC 147/8/9 again & will benefit from new transistors to get the higher rating. Sold well but are usually found in need of TLC as much needs servicing if not much to upgrade on this early model as the capacitors are usually still good. The 1972 3000-2 rates the same & is so similar it doesn't make any difference. Beware the bulbs must be 12v 30mA & the tuner meter one is 6v 30mA or they won't light evenly. Cloudy sliders are due to plastic aging on later ones esp the 3000-2, not dirt or smoke as the earliest ones are still clear. Can suffer from bad transistors that age to sound rough. Capacitors are usually good unless obviously leaking or split, but this amp needs a lot of servicing to sound it's best so many are found in need of work. We thought to upgrade one fully, but there are so many components on an awkward main board. A design that lasted until the 1977 Beomaster 4400 was ended in about 1981, it does suffer from crude construction with the power supply & associated resistors on the 3000, early 3000-2s & early 4000 being a mess with little grunt to it. But they did sell very well & once cleaned up looking nice they do have a lot of retro appeal. One oddity is the amp itself has FM scale of 88-104 but the ad in the 1971 HFYB clearly shows it goes up to 108, but only the later 4400 from 1977 had this. We've had some very early all-beige underboard ones & always 104. But one sold Aug 2014 of a Beomaster 3000-2 clearly showing 88-108 on the scale, it may be an unknown limited export model perhaps. BUY-RAW RATING: Always in need of a good Servicing, bad switches & controls are common raw. To take the front panel apart is risking insanity. REBUILD RATING: We never rebuilt one of these despite having several, The earlier ones capacitors survived better than the later models. Build quality is difficult in places & the design doesn't really seem worth upgrading, we did consider it but saw too many limitations to try, so we avoid B+O gear if we can. COOL RATING: 7 the unique styling sets them apart, the 3000 (-2) looks best with the teak lid as this is the usual lid, if found in rosewood & factory white sprayed too, but compared to the 4400 just dips it a point. (2014)
1969 Pioneer SX-1500TD receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 45w.
CC. Has the new Second Generation design with the side wood trim styling like the mid 1970s SX-950 amps & better design if still a little basic in places. The sound when we had one quite early in our amp testing was noted as not being as open & airy sounding as the 1967 ones, but trying the very similar SX-990 it still sounds Very Good. It's an updated version of the SX-1500TF with a good volume & clarity, beware the mic control must be set to off or it's hissy. Has a proper Mono switch. The power amp board is very cramped & has output capacitors on it that makes the amp less appealing to upgrade & hard if it's been repaired untidily. The Power amp is hard to repair it without unsoldering all wires which is not easy. The SA-900 is the amplifier version. Much later, on getting the SX-990 which is basically the exact same amp if a 28w version, we can see this amp should get upgraded, so see the 990 for how well it done. 2021 Opinion. Not seen one of these in ages, SX-2500 styling as is the SX-990. One Aux input if 3 Speaker sets. Those annoying Pioneer speaker plugs do put us off these a little to resell, if we have now Developed a Perfect 4mm Solution, see the Sales page. But reading here & seeing inside pics as on the Gallery, the Power Amp was the difficulty here, the rest was fine. To risk getting a tatty power amp isn't too appealing. Phono & Preamp-Tone boards with the components facing out rather than hidden is better. Hissy Mic input we'd update now if remember the one who bought ours had it removed & other silly ideas that they didn't like being criticised for. The fact to sell, beyond doing our 4mm Upgrade which isn't easy, to get the Pioneer Plugs at £25-£35 a set & they fall out easily does make these Pioneers a bit offputting, if they Upgrade nicely. BUY-RAW RATING: Good if power amp hasn't been repaired badly before. REBUILD RATING: Usual early Pioneer issues if the Power Amp board can be a nightmare if with old bad repairs & output caps on the board need care. Tricky one. COOL RATING: 7 new styling to the earlier ones if not quite the looks for higher rating. (2012-2021)
1969 Pioneer SX-2500 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 72w.
CC. This is The Highest Power Pioneer in their 1967-74 Transistor Range. Receiver version of the SA-900. This is a 'Deluxe' model as the Quality & Power is a big Step Up from the 1969 SX-1500TD that came before it & Pioneer improved over the years in build if Cost Cut & went to Tin Boxes by 1976, the SX-9500 Mk 1 amp seems to be their High Point until 1980s 'Spec' ones we've not tried. We'd noticed this before a few years back & looked further on a 2019 Blog. Hard to find one without the Speakers plugs being butchered by cutting the Panel. This being rated a little confusingly: 84w at 8 ohm but each channel, not played Stereo if at 1kHz, more Correctly 72w 8 ohm both channels at 1kHz. The Fascia. Looks-wise it's like the SX-1500TD above, it has similar control pieces if Silver push buttons with a ring cut as a detail. 486mm wide is a Big Unit for Pioneer, more like their 1972-76 ones with 145mm height. Auto Tuning is more robust than you'd think, a motor on the Dial cord with Circuitry to work. FM Stereo station & Local station Buttons, it works well, FM Muting, if ours doesn't mute. Auto Tuning finds the strong stations, can't be stopped & ignores 25% signal weaker signals. Tuner is a fresh sounding one, more lively than many tuners. This Auto Tuning was on a 1970 Fisher receiver, assume this came first. "Remote" input under the Headphones socket is for Volume & Auto Tuning, a Rare optional item. A&B Speaker on the Power switch, Bass & Treble as ganged controls, High & Low Filter, Mode for Mono-Stereo, Two Tape Monitors & Loudness. Volume & Balance on one. MPX filter, Phono1+2 button & Inputs selector. Pioneer often omitted Mono so Phono could only be Stereo, here the Mode switch sorts that, if Phono Mono only once EQd. It's a classy looking amp, the 1500TD is narrower with less controls, the 2500 just looks High End. On The Back. Quite like the SX-1500TD with a black panel. Noticeably A&B speakers when 1500TD has 3 Speakers. Check the Manual code: 2500 has R12-068, 1500TD has R12-054, the 2500 improves on the SX-1500TD therefore. Phono has 3 options uniquely. MC/MM, MM & Cer. The optional MM Transformer fits in a cutout on the case right side, no plastic cover as on later models. MC is very low output so for more amp gain, Hiss is typical as with the Trio KA-6000. Aux1+2, Pre Out-Main in plus switch avoiding connectors. 3A fuses for Power Amps. Two Tape Loops & Centre Out. Speakers are those awkward plugs & sockets, with usually no plug as still on the speaker cable, no thinking they should be kept. The plugs are fine for light skinny wire, but anything more heavy the plugs usually don't stay put. What to do? See the June 2020 blog. Case Lid is Walnut real wood veneer with the Grille not as solid as Sony did. Inside Top. Large Transformer, one large 4700µf 100v Main Capacitor, 2x 2200µf Output Capacitor coupled, plus the Tuner. The SX-1500TD tuner is still based on 1967 designs, here the Tuner is All New & larger with the Autotune stage. For 1969 this is Advanced. Power Amp stage under a Grille cover. A metal piece screws onto the Tuner lights box to stop the Tuner Dial wire from sticking. Be sure these aren't missing. Underneath. This is very different to the usual 1967-69 Pioneer with New boards on all. Power Amp board is like the 1972 SX-828 raher than the messy 1969 ones with their tiny Output Capacitors. Impressive Build Quality is Why We Got It, just so Different from any other Pioneer & before their Cost Cutting from 1971 into Comet. Power Amp unscrews from the case by the Heatsink, if rotate it once undone. Amateurish Repairs by one recently as the Power supply has, no skill in it as often, but stuff we'd redo anyway. No understanding of things & not all replaced either. Quite a small Power Amp board in comparision, but it's fine. TO3 outputs. A packed amp underneath, all neatly done on the Front controls, the Power amp wiring a bit random. We Bought This As Working. Could see a few new capacitors. USA bought so the shipping & import fees put it quite high, but try find a better one, this has top lid marks that'll need tidying else in very nice grade. Looks like a few repairs done if minor, get it going TV grade, but you can trim wires as you added parts & tighten screws. We tried this when it arrived, it did work, but it's Not Acceptable for Use as it Hums a bit & constant Crackly noises at low level show what "Working" means. No bother to us as we'll Rebuild it, but Hum & Crackle will get Buyers returning it. Anyone buying a 1969 amp expecting Use Daily Quality when nearly all original, buying 1973 easier amps, only 4 years older. Ideas that carried on into 1972-76 Pioneer noticeable here. Quality & Looks got our interest. Try It More As Arrived. A bit of Servicing to have it fresher, if have a listen. 2-core Mains as always, Aux input from the Computer Grounds it. Mainsy Hum on turn on if louder on R channel. Tuner lights up & also the pointer. Bass is -8/+12, Treble is -12/+8 which is unusual, stepped controls they are. The Hum is way below Normal Listening if noticeable. The Sound is actually decent for a Raw amp, suspect the Seller used it if sold for the Hum, it needs a Rebuild. Strong Sounding Amp, quite upfront & fast with Wide Stereo. +3 on Bass gives more of the 72w sound. Does well on Reggae, to Rock with the usual 'JJ' tracks, it has a blurryness only slightly if needs +6 Bass to sound Richer, For a Raw amp again it's better than many. Betters the 1967 SX-1000TDF as Original if 45w to 72w. Sound is more Loud than Subtle & Detailed, this is standard for amps, Finesse is Costly. Upgrades add the Finesse, this should be an awesome Amp. Not a typical 1969 amp at all for Sound. The nearest compare is the 1967 JVC 5040, this upgrades nicely if the SX-2500 as original would easily better it. As this is Capacitor Coupled we'll try it on speakers, or at least that's the idea, got no Pioneer plugs so too risky. That's a big Minus on early Pioneer, those Sodding Speaker Plugs if we'll sort out something that doesn't Violate our Sensibilities. "That's A Very Good Amp" said we on turning it off to go look at The Circuit Boards. To see the Build Quality & 72w was the Selling Point to us. Only briefly looked at the circuits aware of several other Pioneer. Quick look at what the underside front 3 boards do, left one with fascia towards you is Phono, small Muting board then Preamp-Tone. Behind is Power Supply. An extra board on ours not on the circuits if by the MM plug stages. W21-002 is Phono-Head Amp with 56K ohm loading which is rarely seen on earlier amps. Two gain stages plus a Buffer that's unusual on Phono if useful for 'Tape Rec Out' matching that is always overlooked. W15-050 is the Control Amp, ie Preamp-Tone. This has a FET input which is probably a first, if seen on a 1971 amp. Tone Controls are stepped with a design like Sony & Trio used, if oddly calibrated as above. Buffer Stage on Output again unusual. W16-027 is Power Supply with 8 varying Voltage outputs. Three separate HT stages from 3 Diode sets. Again very early for this sort of design it shows in the more Precise sound as original. Yamaha will have seen this Advanced Design. W23-004 is the Power Amp, has a Thyristor to Mute the early Power Amp to alert you if doesn't cut the amp off, stops it playing so should keep safe. Shows a little taming & 15K NFB. DC balance & Bias adjusts, circuit looks good. 4 passive switch boards, The Autotune circuit is complex with 14 transistors, if Tuners rarely fail beyond 1967-69 Trio ones. A Protector Circuit AWM code is likely the one by the MM block & different to the circuits we have. Extra Bits. The Remote Control as mentioned a small optional item that duplicates Volume & Tuning, The "Cds" unit in the right side of ours plugs in like a ECC83 valve, it says 'Lamp Unit' W58-001. Manual says used for Remote, does it affect non-Remote use? Another piece in the right side pulls out to show an EL34 valve base, this has 2 joining wires fitted 1-2 and 4-5. This is for MM Phono use, a separate MC transformer 'PP-402' is an extra for Moving Coll extra low output Cartridges. The board fitted at a slant in our amp is W18-029 a version of the later AWM 004, board shown on one pdf if not the other. The diagram shows it's a Protector Unit if designs varied a lot, it'll be similar if 3 or 7 transistors. All main boards are the Noted ones. The Tuner on ours matches the 'Owners-Service' one if the circuits show all different ones so the 'Schematics' one is for later models. Overall an Interesting design of Much Higher quality than Pioneer usually did, this amp seems a 'Best Pioneer' and shows many advances that are familar on later amps. A Fresh Open Sound, lacks some Finesse as do All Amps from hearing them later Upgraded, if has Qualities that are what make some 1970-73 amps sound so good. Amps like this make others seem less important now. The Circuits. Phono & Tone are similar to 1967 Pioneer. Power Supply more sophisticated, using Regulators if not many Capacitors on it, the Sony STR-6120 & JVC 5040U circuit ideas in here. A Bigger Amp size for the Extra Features, Autotune & MM option. Ideas carried on, if much more simplified, into the Pioneer SX-828. High Power 'State Of The Art' type Experimental 'Best' type of amp is the SX-2500. Not as Complex as it appears on the Audio Stages with Very Low NFB beyond the Main Amp NFB. FET not sure on yet if Buffer Stages will add Quality. Power Supply Circuit hard to read, these are often tiny on the printed booklet. Note R1 & R3 vary values from circuit to later board. The Blurry Schematics seem to be an Early Version. Recapping & Upgrades. Try it in a different order, Power Amp first, then the Power Supply if leave the Pream-Tone & Phono plus still the original Output Capacitors. Even with the original Tone Stage, to hear it's Limits, if no hiss, but the SX-2500 is very different for Pioneer, Accuracy, no safer more Cosy sound that the SX-1000TDF does, if that is a great sounding amp, this is 'Matter Of Fact' sound that in 1969 Pioneer started to get into NFB to give a Tamer sound, as in some like the 1970 SX-990. Experimental 'Best' Amp at £319 new in 1972 is up there with the Sony STR-6120, if the SX-2500 is a Rare amp, the STR-6120 can be found, if usually very tired now. More Natural Sounding than the STR-6120 is the deal here. What An Amp, even at this stage. Protector Circuit. All it does is Mute the early Power amp stages if a 'fault' detected. As original, it's no problem in their design as original, but the thing isn't good it's got at least 3 versions on manuals found. The Sansui 3000(A) one from 1966 not any good as told there. For the Interest in Keeping the Amp alive for others it'll fade out for no reason & make 'howling' noises that Tone Bass affects if the preamp board is altered in any way from their design. To us, it'll be removed from the circuits as useless. Looks an afterthought fitted clumsily as it is, one screw holding it at a slant was always questioned if the rest of the amp was great so we got one. Two wires from the Power Amp 'sample' the Output & the circuit cuts out as designed, the Orange Wire with the 2nd HT is what is switched. But Leave It Be as Original. Preamp Done Next. This brought unexpected issues, careful with this stage. It revealed the Protection Circuit is hopeless, to see why & even how to better it, if we have no need for the Crude Thing. Biasing. Pioneer manual gives no info. To Bias on the Second Big White Resistor & the Collector & use the outer two pots that show through once the cage is off. The central 2 pots are AC Clipping to adjust in a typical way. No DC offset on a Capacitor Coupled amp. We got 34v Clean Sine before clipping. Upgrading. We did a lot on this as it had a Hum, but found the cause much later, so our amp had a lot renewed. Big Job in this amp to get the Source Lights as LEDs plus doing much more like the Tuner caps & redoing resistors on a few stages. On Speakers. Having tried this before, to decide to sell. The Tone Gain on Treble is 8dB & Bass is 12dB, it sounds good on Speakers with it going loud as a 72w amp. Not quite enough Treble Gain for our uses. But That's Not All. To look deeper & see a lot doesn't seem optimised. Lots done, more Redesign than you'd ever think is needed. To finally get it sounding 'Right' after over Three Years is what Deep Upgrading can take, usually with never thinking you'll get there. A Clue was using the Trio KR-6170 preamp into the SX-2500 power amp which gets more Redesign done. Huge Amount To Upgrade & Redesign. This is one Pioneer didn't get right. They mismatched the Preamp & Power Amp so put a 100K huge limiting resistor between. Amp Grounding Loops & other issues had it Hum & so hard to solve. Then the Tone Stage wasn't right so sounded Thick & Lumpy on Bass. All Redesigned on our one. To do another to our one's quality way outprices it. Ours For Sale a great chance. We've had ours about 3.5 years, so it shows how hard it is to do some amps. BUY-RAW RATING: Higher Power amps got more years use so expect repairs or noises from aging parts. REBUILD RATING: Probably very tired by now if a Very Advanced Amp, lots to do & beware the pdf's contain mixed versions with components very different in places. COOL RATING: 8. Classy looker with the fascia lights & wood veneer case. (2020-2024)
1969 Pioneer SX-440 receiver ↑
AS-ORIGINAL (Once Serviced): Average-Very Good. UPGRADED: Excellent. 12w-14w.
CC. Part of a SX-440, SX-770 & SX-990 series. A Very stylish Pioneer & Unique for the Black Perspex Fascia giving a 'Black Out' look until turned on. £97 to buy New in 1970 prices it low in Pioneer terms. First Encountered one around 2013 making £200 on bids inc ours early on, buyer desperate for it, only found it was 12w later. 7.7kg build. with Teak Wood Case if not with Grille Lines on top. all Metal Case, no Hardboard. 405mm wide, 135mm high, 315mm deep not including fittings. Undated USA advert shows it was $299 reduced to $229, saying it was a Best Seller. Two Manual Versions show the Tuner was updated, the exctra Transformers are a Balum type FM antenna item. On closer looking this is a 'Lost' 1966 design as the design is a next-step from the 1965 Germanium Pioneers SX-600T, SX-1000T & the amp version SMT-84. Spec is very low on this Amp. to keep it 'Less Good to fit the Price & buyer of a 12w Amp, but not hiding the Sound from us.. Main Board has Phono, Tone & Power Amp, Aux to Preamp. Has 4x TO66 outputs. One Owner Amp has the original Black MK plug so refit it with 3-Core Mains. Amp probably unused for 50 years by how Rough it was before Servicing. Very modest Power Capacitor just 1000µf reads a high 160mV AC Ripple, yet still sounds decent. TO66 Outputs are 2SD226A 3A 25w. Not finding anything Cheap or Junk here, maybe nearer the 1965 'SX-600T' styling inside. Power Supply on two Regulators as the 1967 designs have, 42v with 24.5v & 11.5v voltages. What Does It Sound Like? After some Servicing, Compared to the Sony STR-6040 this is a much Crisper Fresher sound with Loud by '4'. Slight Hum on the Background. The Headphone Resistor is too Low, a tactic to have it sound 'shouty' when done right it's much better, even before further work. No Lumpy Retro Bass here, it sounds more like the 1965 SX=600T we have, different to the 1967-69 Sound. Tuner boards are W35-007 early on but W35-027 on ours. Pioneer first show Jan 1967 as a Jan 2024 Blog of ours tells. Aug 1969 is when UK gets the SX-440 first, a Swisstone marketed one who got the earlier Pioneers. 'Swisstone' distributors Advert shows SX-300T, SA-500 & SX-440 as 15w/15w at 93 guineas price. Rating it 'Average-Very Good' as Original, at lower Volume with the Original Headphone value it has a Quality to think 'Very Good' but with either HP value, it soon gets harsh & shouty which really isn't Hifi standard, it sounded awful. The design is very limited to not be too good as often is the way, but does upgrade to be much better. Compare to 1965 Pioneer SX-600T. 25w Receiver now as Silicon as was Germanium. With the replaced Volume Control now. Beyond being Recapped with Upgrades, they are certainly In The Same Bag sound wise. The SX-440 is likely to Recap-Upgrade to take on the Best Amps we have Soundwise, the 14w the only limit. Which if it & the similar power STR-6040 will stay & be used most? Recapped & Upgraded. Be sure it could go further, but at 14w not to overdo it as it'll already be played Louder for how Nice it sounds & easy to forget the Power Rating. To get a lower power early quality amp like this SX-440 & the 1969 Sony STR-6040 to see how good they can be. Proven right on the SX-440 for sure, the rather weak design given some better-ness does show a good design can be brought out. Has proper Bass & a nice Treble with a smooth Midrange. We'll not go further with it if to try on Speakers next & see how it drives 95dB 15" Tannoys. Haven't washed it or done Bulbs yet, the sound interested more to try it. Compare to 25w 1965 Pioneer SX-600T. After playing the 2019 Yamaha, step up in Sound to the SX-600T & really find nothing to criticise, Crisp Bass, Deep Sound & Dynamics & Strong Bassline. SX-440 we've Upgraded Quite A Lot as the 12w spec was weak. We could go further but compared to the SX-600T the soundi is really not so different. a little more Bassy on Upper Bass & Treble not quite as precise as the SX-600T, but it certainly is a Great Amp, but only for our Upgrades, it wasn't too 'Hi-Fi' as original. Be interestimng to put a 50w Transformer in it, possible, but lots to Redesign to Fit 50w into 12w. Compare To 1969 Pioneer SX-2500. Ours much Upgraded & still in 'Tuning' to perfect it. Three Pioneers to compare. Nearer the SX-600T but with the Extra Dynamics of a 72w amp. a very tricky amp to 'Optimise' as they got it so wromg in 1969. FCOOL RATING: --- REBUILD RATING: --- BUY-RAW RATING: --- (2024)
1969 Sansui Model 4000 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 45w.
CC. Another early Sansui gem, we hoped this would improve on the quirks of the wonderful 3000A & it does have a very similar sound even before recapping. These earliest SS Sansuis are high quality amps. This one is a more modern sound than the 3000A & has an unusual Aux input that is different to the Tape input, it actually goes through a big resistor onto the Phono board, to use Tape In is the best way for best sound. But is a precise 2nd Generation sound for it and only Sansui used the idea in 1969-70. Unusual design that needs to be restrained if recapping can make it less compatible with modern gear. A quirky amp with a fine sound, similar to the 3000A, but it's not for inexperienced users. 2020 Update. Not had one since 2013, would Upgrade more now, we'll keep as 'Ex' rating. Remember it as clean, a bit grainy & not weighty like the 3000A. BUY-RAW RATING: Good. REBUILD RATING: The plug in power amp boards are easier than some, underneath boards can be awkward. COOL RATING: 8 looks stylish with the wood case, also came with a glossy metal one that rates 7, the first blackout tuner design amps, use Aux & no tuner is lit making it a little plain, rating for tuner lit. (2013)
1969 Sony STR-6050 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 30w..
CC. Finding this was the same basic amp as the STR-6850 below, need to try the original version as the STR-6850 sounds so Very Good, if that had a few issues. It appears to be an updated version of the 45w STR-6060FW from 1967 that has the front flap & brown levers. It's rated 30w as is the STR-6850 but the output suggests at least 40w, as they put resistors to limit the 6850's output bizarrely. STR-6060 works on 80v, STR-6050 on 73v so 40w is correct, if the STR-6850 measures 84v. The STR-6060 is an earlier version of the STR-6120 but the STR-6050 is later but still the capacitor coupled design which the STR-6850 reveals as a fresher sound than the 6120 if the power supply right on the selectors creates hum & is a bit low spec. This could be the best Sony receiver therefore, if you don't need the higher power. The 6050 is a fresher sound than the 6120, if the 6120 is more sophisticated. Sony finally arrive in the HFYB in 1970 with STR ranges: 6040 15w £112, 6050 30w (40w really) £145, 6060(FW)45w £187 & 6120 50w £387. A minimalist version of the 1968 STR-6120 sharing no boards with it as well as smaller & lighter, if still a 220VA draw compared to the 280VA of the 50w 6120. A rarer one as we've seen a few STR-6060FW & 6120s, but never this one in the EU. Capacitors, not axial, fitted underneath with the largest 3300µf 80v with tabs being as tall as the cabinet height, so a good use of space. Tiny pre-tone board underneath if all the other boards are top mounted. Noticeable differences in transistors used to the STR-6850 board. The speaker connectors as screws aren't much good as the usual 4mm block that fits on others is too unsure here, it'd be better with updated ones. Volume control is split L+R on the one control, losing the balance control. First try reveals a clean lively sound that the STR-6120 never had as original, a very clean focussed treble we've heard in no other original Sony amp. It betters the STR-6850 as original easily too. Transistor count as the STR-6850: Phono x2, Tone-Pre x2, Power Amp x7 & the simple but Very Good circuit reveals it's an impressive amp even as original, though this is a light use one. It could recap & upgrade to higher quality still. The winner in this amp from knowing the STR-6850 is the power amp board. But after listening we wonder why it sounds a little strange after upgrading & find the Aux goes to the Phono board like Sansui used on the 4000 & 5000, so to use Tape In for a Direct input, if it takes a very trained ear to tell the difference unlike the Sansui one. The 6850 is Aux direct. By the 1971 range with the identical looking STR-6055 it was updated with the lesser differential & semi complimentary design. 4cm narrower than the STR-6120 & 6kg lighter shows it's had costs cut in the casework, but the circuitry is still quality. It upgrades as well as the STR-6120, a seriously good amp here. The same wood case the 6055 & 6065 has should fit. A ridiculous design fault here is that no fuses are fitted in this amp at all. Not on anything. We'd recommend you get one fitted inside on the Mains or at least be sure the mains plug has a 3A fuse on it. REVISITED 2016: We got one of these a year before & found for the no-fuses issue the transformer was totally frazzled. But the amp was nice grade & it deserved to live. New bought transformers aren't any good for the size, but we found a 1979 Eagle amp in poor grade & gambled that the tx was good. it was & looking at it a few weeks after fitting it, you'd not tell it wasn't the original, perfect size, if 240v only now. HT is slighly less at 62v instead of the 73v, so to fully test it to see it is correct on other stages to be sellable. On playing it for 30mins on fitting the tx it sounded fine, so to recap & upgrade it as these early Sony always sell fast. BUY-RAW RATING: Good if working, but read our Fuses comment. REBUILD RATING: Overall not too difficult if needs a mains fuse fitting as none in the amp which is foolish. COOL RATING: 8 with the wood case. A budget version of the 6120 in some ways if still looks & sounds Very Good. (2014)
1969 Teac AG-7000 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 65w.
SC, DIFF, Direct Coupled. A rarer early Teac appears to be a 1969-70 one & similarities with the Teac AS-100 from 1971 as well as being semi-complimentary which is early for 1969. A well made amp with fine looks. Sound quality is rich, detailed, clean on the treble, neutral & overall excellent and for the rating raw as-is the focus is just so high. A Very Good looking amp in it's wood case too. This amp 'as-is' gets a very high rating as it is just so good even all original (and better recapped). The few early Teac are highly recommended by us. Sadly most Teac you see are mass market modern systems, hiding the high quality of their amps from the 1969-71 era. See the Teac AG-6000 below for a later opinion of nearly the same amp. The wood case is a genuine Teac item, a June 1972 Hifi News ad shows it. TEAC actually used more or less the same design on all their 1969-71 amps so all will rate similar, the Teac AG8500 is a slightly later one with revised looks but still the same amp inside. BUY-RAW RATING: Good. This amplifier needs a proper 3 core mains + earth cable, see above. COOL RATING: 7 the wood case that comes with this looks a bit unconvincing, so the black gloss metal lid rates the same, the first blackout tuner design amps, use Aux & no tuner is lit making it a little plain, rating for tuner lit. (2013)
1969 Teac AG-6000 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 50w.
SC, DIFF, Direct Coupled. A little surprised to find this is the exact same amp as the AG-7000 if the transformer has a lower voltage & the Tuner differs on the metal box part. An AG-3000 is a 36w version too. This one has the proper metal top lid & base, the AG-7000 we had was with a wood case if no top lid that we found a little unconvincing as we picture on our Solds page, maybe it wasn't official? The User Manual pictures this as ours is here & the AG-7000 flyer again no wood case. We do like these early TEAC & all seem to be the same basic power amp, if a very decent one & early for it to have differentials & semi-complimentary with no output capacitor as most only first used those in 1971. Now this being a typical later design we've tried to better other later amps to try to match the pre 1971 typical design, but they don't quite come close. Will this be the one to change the opinion? Another Teac AS-100 we rated very highly so perhaps this can upgrade more than the 1973-75 ones we've tried. All in the interests of perfecting upgrading. First play of it as arrived just to see what it's like, the precise clean sound few amps have all-original, strong clean treble & midrange if bass appears a bit lacking, if a known bassy track reveals the clean midrange hides it unlike some amps with a more recessed midrange. It still has the pre 1971 magic sound that we've failed to find in any post 1971 differential amp, suspecting there was the weakness, but as often it's down to the design. Some tracks reveal volume needs to go halfway for a decent sound on headphones. The sound is like the Sansui 5000X (F6013) for a level of tight precision if a more refined sound. Knowing these Teac recapped & upgraded, it could be said it sounds a bit cold for the precise midrange as original, but the sound opened up with upgrades fills in the bass better. The 4 ohm resistor on the speaker outputs is only for connecting more than one speaker pair and is not always in circuit. Costing on these early Teac is clearly well considered with no need to cheap out: no ceramics in the audio stages just best quality silvered mica & polystyrene caps. The only minus here is the speaker connectors are the ones best known as 1971 Marantz type, here mounted upside down to hide the live metal area, but the early ones plastic goes crumbly with age so are too tatty. The circuit looks like Aux goes into Phono, but it just shows on the Phono board to not affect the signal. Recapped & upgraded we initially found it a bit disappointing, volume was not very good needing past midway, as Teac always have. but with extra gain & all the upgrades we could do it sounds very pleasing now. Of amps with Differentials on the power amp, this one still sounds flatter than the non-differential ones on the virtual size of Stereo on Headphones, if that takes a trained ear to notice. But certainly a quality one as the ratings show & of the differential amps this is perhaps the best one. It sounds very good on Tannoy Golds with strong bass, clean treble & an accurate midrange, a perfect match. REVISITED 2018. Not had one of the Teac Receivers in a few years now. At the same time we have a Teac AS-100 amplifier here too for upgrading, so to compare the two is interesting. The AS-100 power amp is basically the same as the AG-6000/AG-7000 one if the Differentials & NFB stages are slightly altered. The AG-6000 is a small cute amp with nice solid metal control knobs. The AS-100 has an IC for the Preamp-Tone with the AG-6000 having 2 transistors, but ICs were a selling point in the early 1970s. The AS-100 varies in quality for the IC & it spoils the amp. The AG-6000 sounds spot on, a very clean smooth sound with a precise midrange if not the stongest bass. If we like the amp we sit playing it as typing & the AG-6000 plays 1970s Reggae very nicely. As for the AS-100, for the IC & possibly the changes to the Power anmp, it's not as smooth & needs Bass tamed else it goes unstable. Teac certainly got it right on the AG-6000 & AG-7000. This one is in a Wood Case, with the metal fascia border standing out from the wood case looks a little awkward, if so did the AG-7000 case. Cute Amp with a Very Decent Sound & on previous tests it was great on Speakers too. BUY-RAW RATING: Good. This amplifier needs a proper 3 core mains + earth cable, see above. COOL RATING: 7 the wood case that comes with this looks a bit unconvincing, so the black gloss metal lid rates the same, the first blackout tuner design amps, use Aux & no tuner is lit making it a little plain, rating for tuner lit. (2014)
1968-69 Trio-Kenwood KA-2000 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 13w.
CC. The 1968-69 range of Trio-Kenwood are nice sounding, see the KA-6000 below for their best one, just the 13w keeps it's recommend level lower, needs the side wood cheeks to look it's best. A good starter amp findable for not much money. A nice clean sound here & the first one we bought of recent times that started these pages. See TK-150 above as it's the same amp. Again, the quality of these early Trio can't be hidden, even with a 2011 review. The KA-2000A is the same amp with an updated fascia as one on ebay showed the insides. ** See the 1971 Trio KA-2002 below for a similar amp that we upgraded 2018. BUY-RAW RATING: Good. COOL RATING: 5 average retro looks if functional & a small size amp. (2011)
1968-69 Trio-Kenwood KA-6000 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 45w.
CC. First in UK in an Oct 1969 HFN ad with the KA-4000. The first of the quality Trio-Kenwood amplifiers, very advanced for it's age & way ahead in build quality & weight of most other Trios & very musical & open like the other high rateds in this table. Very Good looking with the matching tuner. Variants on this are the earliest has a black inside floor & is 110-240v, the standard one has a silver inside floor & is 110-240v if be aware of a later 110/120v-only one that we have seen online. Needs a good servicing to sound it's best else it sounds soft & unremarkable. First mentioned in the Oct 1969 HFN if rated '58w+58w' with the TK-140X rated at '60w+60w', if both have the same power amp & put out 31v clean sine. The ratings are "each channel driven" ie use the L channel only, but that's misleading, as 45w both channels driven. For a 1969 amp, it has a rare MC phono stage & other ideas used by amps later, ie tone defeats. This is basically the same as the 1969 TK-140X receiver as the boards are just about the same, if the KA-6000 has better spec inside. A lot of work to service up though. For the 1967 receiver version of this amp, see TK-140E above. One of the classiest looking vintage amps especially with the tuner, with a fine sound. Jan 1970 Hifi News reviews this, their tests show it gave a high 70w clean output into 8 ohms before clipping. the MC phono stage showing hiss, but the preamp transistors used were clearly not so good but can be upgraded to much quieter ones, as we did on ours. Overall they rate it outstanding & of 'True Hifi Standards' yet at a modest £105 new it wasn't a big seller as not too many are around worldwide. Ours we initially kept all original & it stayed as a benchmark shaming many other amps for quite a while. This amplifier has so many new features that were used by many others: metal cages inside, MM phono stage, pink LED type lights if with bulbs, blue originally if plastic yellows so pink light now, defeatable Tone stages & a Very Good sound. Even has stepped tone controls & pre out-power in connectors, though Sony got there first on those two. This amp set the benchmark for the modern amplifier. The inside cages & other features led the scene but the KA-6000 is actually very early & quite like a valve amp still with strangely placed boards & much hardwiring. The power amp board plugs in & is quite random looking with the same circuit changes as the Trio one, it was like the TK-140E input. UA1343K power amp totals 6 transistors per channel plus 4 in total for protection. The fascia is letter-stamped neater than the Trio one & we are the first ones to open this one. But the spec for 1969 is still very high compared to some, the 65mm dia 4000µf 100v main cap & 3300µf output caps are way ahead of the Sony STR-6120. The big cap after seeing how badly the same one in the Sony TA-1120(A) is, decided to replace this. On cutting it open, actually it was still good if a bit dry, the Sony with the doubled output transistors must use it harder than the KA-6000 does. In all the amps we've seen, this is one of the Most Important Early Amplifiers (not Receivers) in the hifi story together with the more flawed Sony TA-1120(A). Multivoltage. Most are Multivoltage with the slider switch on the rear, if a few are 110v only without the switch, so if buying from USA check for this. Matching Tuner is usually the KT-5000, a nice Tuner with 2 basic ICs though our Trio & now Kenwood differ from the circuits, the Kenwood one much different. Also the unfindable earlier KT-7000 with 4 basic ICs if slightly higher spec matches. T-K tuners are decent if the de-emphasis isn't for the UK value so a little dull until altered. For the 1969 Tannoy Golds, this amp is a Perfect Match, if the TK-140X going further it's not so obvious on speakers as headphones. Deciding to recap-upgrade revealed the Power Amp needed it & the sound is very different with a solid focus. Circuit reveals this amp has the Tone before the Volume, the only ones we've ever found like this are some early Solid State Trio-Kenwoods if not the KA-8004. Having the TK-140X here & recapped it to the same level, if upgraded a few more things, the compare is interesting, the TK is the same wide rich sound if the TK. Differences in power supply notice a bit but it's still the original caps on both, the KA being higher spec. Now Recapped all but the big main cap & opens it out more. The big main cap is still high spec & the same value is still made, if 70mV ripple is not Very Good, it sounds clean still. There is a rightness to the sound that not many amps do with a very wide stereo. We've rated it for quite a while now, if never upgraded one before. As you can read, we rate this amp highly, if others copy our idead, like that ebay guide page. No-one noticed these pre 1977 amps much until we did. We heard of one that was 'upgraded' that supposedly sounded worse than the KR-4140 18w receiver below. But on seeing the awful job done, what do they expect? Respect these old amps & get it done properly & you'll hear one of the best amps ever, or get it wrong & wonder why. Quite a bit later, after the Akai AA7000 proved to be so good, the KA6000 doesn't quite reach the heights despite all upgrades done. Further research finds some odd design & after being remedied the KA6000 is without the slight fizzy bright edge it had before. Previously it brought facial expressions but now it is very clean & with the extra 45w power to the AA7000, rated upto 70w in HFN tests, the sound is certainly very rich & punchy with that razor precise clean treble that is the essence of Top Hifi. But remember ours is fully rebuilt & upgraded, the raw amp is still Very Good but there is much potential in this amp. Tone Mode switched on or off makes no difference to the sound, if may as all-original. 2016-17 slight update: We keep this amp as a reference if it doesn't get used on the speakers often, as it still has the 2-core mains & using TV only there is no real earth, but comparing to the TK-140X again it's very close in sound, see the TK-140X update for more. After trying the TK-140X on speakers, the KA-6000 got more upgrades & now it betters the Sony TA-1120 (1965) if a similar sound, the KA-6000 is fresher sounding. One of the Best 1960s amps, if ours has a lot of work done to find out how good it is. The strange input circuit that is altered on the Power Amp board on working it out, it'll have been a severe "T" bass filter much like Sansui AU-999 uses, but no need for it as it messes the sound so it never got used even on the very earliest black inner floor ones. KA 6000 + TK 140X Pre-Power swap. Using the in-out sockets to see which sounds the best. After trying all 4 combinations, the 140 is brighter on treble, if the 6000 is richer and seems better balanced-more detailed, if duller than the 140 & preamp gain slightly less, -1 on treble on the 140 matches better, if the 6000 is better on detail. The power amps differ if each is better into itself than the other, the 6000 punchy sound isn't revealed by the 140. Retry 140 pre & 6000 power with -1 treble shows the 6000 is the superior, if in reality both are top quality. But we're not happy with that so upgrade our KA-6000 further to sound the same. Early Trio-Kenwood Amplifier Adjustments. The circuit manual which is findable now says set VR3/4 to mid point voltage. Bias is VR5/6. Protection is VR1/2. Other early ones will be similar. The 'Test Plug' routine is not one we'd use, they suggest you unplug it & use a variac to bring the voltage to test, sounds a bad idea to us as even they warn of current surges. Compare an Upgraded 1972 KA-6004 to a much upgraded KA-6000. See the KA-6004 review. 2020 Update. We've Upgraded Our KA-6000 a lot. It never quite got to the Quality that other Amps did, plus the Filter Switches are Dangerous if Upgraded more, they are After the Volume Control so Full Thud from the Filters on the Power Amp is not good. We later found the Hot Resistor from the Single HT voltage, not the 2 Transformer Windings the KA-6004 has, this affects the sound, if really this is only noticed the more you upgrade. However, redo things & that expected quality returns so all is not Lost. Ours with Doubled Outputs is still a Keeper. To get that far is a bit Extreme though. Extreme? Our 2021 version now has the KR-6160 power amp which is the same as the TK-140X later one, the UA1384J board. The filters & tone changed too, with a KR-5200 tone which sounds even better plus lose all the filters to stop bad noises in use & turn on. The Best of 3 amps into one, experimenting is cool, if the hours to do this is far too much for a job to price. To rebuild a customer's amp we'd do a saner version that still sounds good & operates without noises. BUY-RAW RATING: Beware some are 110-120v only, see our Gallery to show the multivoltage ones with the rear voltage switch. Good though needs a good Service if working, note the amp needs the rear Pre Out-In links to work. Big Job to recap & upgrade, just look inside. COOL RATING: 9 very classy looking amp, needs the wood side cheeks, has pink lights sometimes & way cool too with the matching tuner. (2013-2021)
1970 Akai AA-8500 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Excellent. 65w.
CC, PARA. This is an unusual looking "85w music power" receiver amp in the 1972 Hifi Year Book for £230. Actually 65w into 8 ohms rated power. A bigger size amp than you'd expect, 488mm wide, 370mm deep & 184mm high, this is top quality build for 1970 just before amps went semi-complimentary & the cost cutting started. None of that here. The tuner display is an internal drum that is backlit if that part looks like our 1932 Pye G/GR gram, nothing is new. Sliders for Tone & balance if the rest is rotaries or buttons. 65w for 1970 is unusual & it uses doubled output transistors to get the extra wattage, originally the transistors were only 50w ones & the only other pre semi-complimentary amp we've had with doubled outputs is the Sony TA-1120(A) from 1965-67 & it does add an extra confidence to the sound. Ours is aged & tired sounding but as with these early amps, we just about rebuild them & they do very well as this page shows, but to do it properly is still a huge job that most don't consider first & the circuit needs learning to do that right. Has two speaker pairs for outputs, but one is via 6.3mm jacks which may be useful in a DJ set up of old, but could be a problem if not understood. A Remote Control socket is on the rear, but all it actually does via the 2 pins is mute the output as does the front button, not RC as we know it. This is a hard amp to find, we've seen a couple before but missing fascia parts & even playing ours serviced if original the sound seems to be another one of those hidden great amps if volume goes way past half so it needs a rebuild, but certainly is worth it. On our 'Other Amps' page we're not too keen on later Akai who became a budget brand very quickly, but this AA-8500 is their top one & others 1966-70 are high quality. The 1970 brochure on HFE shows a very high end brand with very early Video & Tape gear as well as the 8500. To clean & upgrade isn't all it needs, the tuner & meter lights can need rebuilding with available bulbs. Another issue is the sliders, explaining why they are often missing, they have a spring loosely fitted easy to lose. The Mains Switch has a live mains point on the exposed edge so easy to touch with the lid off so we have to add safety here too. The relay near the tuner inside is for the Audio Mute stage. The midrange accuracy on this is a bit special, rivaling the early Germanium amps for clarity. Deep clean bass, fast grain-free treble with impressive dynamics & transient response to give it a certain kick that pleases. Now all upgraded, the sound is certainly one of the cleanest amps we've had, very precise, not the most bassy or powerful & volume needs turning past midway on headphones if we'll try it on speakers next to see how loud it plays as the headphone needed altering which we did. Top quality amp for sure & this for the quality does better quite a few & is certainly on the higher end of 'Excellent' as we have it. for those who like to use Monster Receiver, this certainly is one of the first, it's about the size of the Pioneer SX-950. Having done the max clean sine test, for 65w it only puts out 28v like a 50w amp, so it has extra current for the doubled output transistors which does give more confidence on heavy transients if in a more musical way than later amps. Overall a great amp & surprising early Akai are this good, the build quality is up there with Sony & the others, nothing midprice here. REVISIT 2018: See the Jul-Aug 2018 blogs for more, this is the Best Akai amplifier, but not as Original. After liking the Akai AA-5800 amplifier for the design if not the midprice casework, fate has it we get another of these. Unlike the last one which needed a lot to tidy it, this one is a one-owner crisp grade one that looks New underneath, no aging at all & just typical dust in the top & never opened. Electrically it works fine if transistor hiss on one channel as typical. The Parallel Outputs with a set of 8 transistors is one of the few amps before 1975 to have this. Brings extra current & the amp sounds more weighty on speakers. It really does please to get a high grade amp after knowing a more used one. Wood case lets dust in so the tuner drum gets dusty. As unserviced the usual noisy controls & vagueness in use. For the hissy transistors, this may not please a buyer expecting Plug & Play, but reality hits as it's 48 years old & amps like this are best for us as we can sort these issues. Great looking amp too, we even rated the previous one highly despite the condition. Size is unusually large, the first of the Monster receivers as bigger than the Sony STR-6120. The Power amp gets a bizarre typo saying "0.77mV" if it's a 0.77v input, much like the standard 1v input. The Sound as Original actually isn't going to impress you, Volume needs setting midway & the quality really isn't here at all, but we look at it as an Upgrade Challenge. For it to get 'Excellent' means the Good sound is in here, but the amp is dumbed down too much as original, as are other 1970-72 amps. Circuit Errors on the Power amp on R 219 is 270R not 10R & R220 is 10R not 270R are careless, the board has it right & it matches the AA-5800 design. Recapped With Upgrades. How does it compare after the 2 Marantz amps in Aug 2018? With knowing the AA-5800 to look at this one more than we did on the last one, to redo the Preamp differently brings out the quality sound in this Amp. The Doubled Outputs give an extra weight to Bass & it sounds Fresh, Lively, Fast & Punchy with wide Stereo to easily match the AA-5800, if both are so hidden by dumbing down of circuits as original. Pleased with it, Treble is as precise as the Marantz 4070 & an amp without the Midrange Dip that loses Focus. Rock Guitar is convincing with good weight yet still the detail which many amps can't do so well. Interestingly the first amp got the opinion of "not as Bassy" which was for not getting the sneaky limiters sorted, takes work this advanced upgrading if not expecting it, to since find other amps like this. Now Sounds as good as it Looks, which is why we revisit amps we think could be better. Quite a job to redo it & lose the hissy transistors. The 7 Push Buttons & 3 Sliders Covers will confuse, they have a loose spring bit inside so careful when taking them off not to lose it, but how do you fit it back? Note the wider groove part for the switch post & the spring bit fits in the narrower bit, but the open end of the spring with the slanted end is what the switch pole grips onto, not the other way & it doesn't go in the middle of the open bit. Also the three smaller rotary controls have the shorter bit facing up, one of those amps that isn't quite as obvious & why the buttons are sometimes missing. On Speakers it reveals the Parallel Output-Doubled Transistors, a rich punchy sound which is not often heard with amplifiers. Matches well to the 1968 Tannoys, if to remember the Spring Connectors that are fine to keep, we'd not replace those, to select Speakers B as the A set is the non-standard 6.3mm Mono Jack socket. Looks very smart sat on wood furniture, one of the Best Looking Receivers. But Another Time Perhaps... The thing with getting amps we like & telling we have one is that they want it, so we couldn't spend 6 months trying to perfect the amp as was the intention after finding the AA-5800 so good. The design is too heavy on NFB in two places if to unravel that is one for another time. Too much gain to use High NFB doesn't give the best sound, it's not a Sweet Sound like some amps can bring & on speakers it sounded good but a flatter sound for the NFB. Not an easy amp to find as ebay shows. On the 2019 one we redesigned the Preamp to lose the heavy NFB that flattened the sound. This made a slight difference to the sound & on other amps we'd go further with similar on the Power Amp if they are very hard to work on unless fully unsoldered & as not to alter the looks too much, we decide to sell. Did later upgrade the Preamp with a lpt of redesign to get a Very Nice Sound. But to Decide to sell again in 2020 as to not need to Max Out every amp, it compares well with the current version of our 1970 Sony Pair. BUY-RAW RATING: Powerful amps get partied hearty & our first one needed a lot rebuilt, one sometimes found missing the slider buttons. A 2018 revisit found a high grade one if transistor hiss means it needs work. Care needed as the Mains Switch has exposed wires right on the left side with the lid off. REBUILD RATING: Advanced as it needs a proper Upgrade to bring out it's best or you'll not think it's much good. COOL RATING: 9 a big impressive classy amp with a nice tuner style if the sliders on Tone & Balance may just make it a little less easy to use. Uprated from '8' on seeing a higher grade example. (2015-2020)
1970 Goodmans Module 80 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED (slightly): Very Good-Excellent. 25w.
CC. UK made midprice amp, £95 in 1973 was a keen buy, but with a good honest sound that is above it's price range. It appears to be the most upgradeable of the pre Differential era UK made amplifiers. Read on. It'll always need recapping as the same poor black plastic caps as the Leak Delta 75 has, but it's an easier amp than the LD75. Lots of potential to upgrade up it's clean if slightly raw typical British sound if you fancy a challenge & know what to upgrade, ie most of it. We recapped one recently as we had one years ago, just to see what it was like. Only minus is DIN connectors for all. again it stood out as a good amp in 2012, we have considered getting one to upgrade even more, but it's just an amp that sells cheaply today & even sounding Excellent it'd be a hard sell. REVISITED 2016: It seems the First Amps we ever used were all 1970 ones, Hacker & Philco-Ford & the sound we thought was decent in it's day. The Goodmans Module 80 is actually a 1970 one too as the rare Operating Instructions book shows "10/70" as a date. This includes the Circuit Diagram & for the usual buyer of this 35w into 4 ohms £95 item the booklets were long since gone, but the non-worker we got was in top grade, barely aged which is nice. The Specs are 35w into 4 ohms for 1% distortion 35w, for 0.1% distortion 30w. For 8 ohms the rating is 25w & 15 ohm it's 15w. Damping Factor of 40-80-150 for 4-8-15 ohm. Bulbs are Scale 6.5v 300mA & Stereo 14v 40mA. Seeing the circuit diagram shows a different one to the 1972 E&E trader one & Germaniums are in the Tuner: 2 transistors & 4 Diodes. Phono x2 transistors, Preamp x2, Buffer stage for Loudness is x1, Passive Tone plus 1 transistor as gain. Power amp is 6 transistors of good basic design if a Diode on a driver emitter is strange. Capacitor coupled outputs are the ones on the left side. HT is +56v. There are obvious limiters in the amp plus a lack of "tuning" in the circuit, so it did sound basically 'clean' on recapping the one in 2012 but there was roughness to the sound as no finesse in the circuit. The strange 'box' shaped resistors are a unique version of a carbon composition resistor that only Goodmans used, they save space & avoid on-end resistor wires touching, but once knocked the legs come loose & need replacing, many here aren't even soldered in straight. The two power capacitors are both "C88" doubling the value as size limitations in 1970 & oddly it runs on a negative voltage. In basic terms, no less of an amp than Japanese ones, if their flair adding 'finesse' as well as better spec goes by the wayside on UK amps. Would it be possible to make this Budget amp into one of the Top Range spec of better amps of the era? Yes it would... Having gone through the design Phono to Output, the design is basically very good, but limiters & especially on bass, with some noticeable dumbing down to make it sound less than the decent circuit it could be if perfected. The Mullard stripy film caps & the odd resistors are good to keep, if ceramics have no place in audio stages. The Sony STR6850 below was a similar sized amp but despite the sound being very decent there were poor design issues. The Goodmans is a better design in many ways. Having recapped it to hear it for the first time & for all the Japan & USA amps we've had, this amp does surprisingly well for the fresh clean sound. Bass is much limited if the design is a good one as suspected. It's tempting to fully rebuild the odd resistors etc but it doesn't really need it & this one is barely used. We've upped the ratings as it is equal of any Japanese amp & betters some, if once recapped, as original it's too aged on the capacitors to risk trying it raw, some you see sold as 'serviced' are on the bad original TV grade caps so will fail as in go 'bang'. Playing it as we type, a very musical amp & once upgraded-recapped it's a bit of a sleeper for the sound quality. On Rock it copes well giving a solid weighty sound that not many under 40w amps can. Bass is limited in the design if it sounds decent without sounding lumpy, to upgrade further into 'our spec' risks getting caught by the 25w. The Quality Of Sound is way ahead of the Leak 2000 we had recently, it was nowhere as 'hi-fi' sounding as this. The Module 90 wasn't so well made but sounded good, if the styling was ghastly & the later Goodmans 110, 120 & 150 aren't so great & sadly are of later 'differential' designs. Ours has a low 3500 series serial, others seen with 16000 & 20500 serial, it could be the earlier one has the best sound as often UK manufacturers altered designs as the E&ET circuit shows, The early one hasn't got R121-122, has single tapped volume, R206 is 15 ohm not 47 ohm & C71 as 1000pf, all unimporrtant so all will rate similarly. The small output transistors are of 115w spec. On checking the output readings, clipping was uneven & at best 18v clean sine which seems low for 25w. Is it worth a rebuild with much upgrading? Of the 'CC' era UK amps, we've found this amp to be The Only One worthy to 'max out' upgrade. All others Leak, Rogers, Radford & Sugden use annoying Axial caps so what else is there before the less-good differential era begins? Armstrong are rubbish, Ferrograph too basic, Leak Delta 75 is too unreliable, if the one pictured was a success, others failed so that's it. BUT IT CAN'T BE MAXED OUT... For all our experimental upgrading, putting good ideas onto this, the amp sadly is no better than it ought to be: it is Budget Crap. Upgrades that make Japanese & USA amps sing turned this junk into an unstable joke. We can't sell this with issues that are laughable, never had an amp upgrade to reveal how bad the design is. We thought it looked good on paper, the Tuner & Preamp are decent, but the Power Amp is OK amid it's own spec, it plays music fine but is ridiculously noisy & unstable with what should sound fine. Even putting much back to as original spec it was still hopeless. All we can try we tried. it reveals too many weaknesses & it's why it has such low spec to hide the badness. We try these to see what can be upgraded & not. Upgrade this with recapping & some improvements, but to go to max it out levels has it play music nicely until you try to use it more. This is a big Nail in the British Hifi Coffin for us, if it succeeded maybe we'd try a Leak or Rogers, but sadly Budget gear is Budget made & we'll reuse the new parts elsewhere. The Moral is if it's Budget Junk, that's all it'll ever be. British Hifi is designed to be far less upgradeable than Japanese & USA which really do well for our upgrades. BUY-RAW RATING: The black capacitors & the one on the TX must be replaced as they are always bad or failing, so buy with care, else it'll go bang. The main caps may be bad too, if not always. COOL RATING: 6 only very basic looks with no real style but not ugly. But a Top Grade one always looks much nicer than aged worn ones. (2012-16)
1970-74 Hacker GAR500, GAR550 receiver-gram ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Very Good. 10-14w.
CC. The 10w Centurion 500 series was introduced in 1970 with a silver fascia & teak lid, a tunerless 500 version at the same time as the GAR 500 with the Garrard SP25 Mk III turntable & also the Tribune GAR1000A with 10w class A in a double width unit with a Goldring Lenco turntable. Later ones had a black fascia & the GAR 550 was an updated 14w version if still basically the same if later ones had a superior SP25 Mk IV without the Mk III's rumble. Usually seen with the teak lid, the smoked perspex version one we preferred on seeing the teak lid one. A basic but pretty acceptable UK made receiver of 10-14w with a turntable & FM only tuner, so a record player system really. It deserves it's rating if used with good speakers, not the basic supplied Hacker ones. We recapped our GAR 550 to the max as we had one in 1986, but the odd Line level it worked on based on old DIN socket tape spec meant it just wasn't capable without redesign. The DIN tape socket suited 1970s tape recorders with a DIN lead but by the 1980s DIN was generally long gone so the volume on recording to tape was too low. Recapped & improved it rates towards a Very Good for the sort of item it is: a nice compact record player system. As with most music centre type units, the better ones will have the Retro Sound but are only a starter unit or a second hifi. We tested this on the M20 headphones, the original Hacker Speakers plus Tannoy Sixes, for it's 14w rating it's not quite 'Very Good' as original but worthy of 'Very Good' as upgraded. The speakers with earlier ones were Hacker LS1500 as 8 or 15 ohm & the later ones usually with the perspex lid had LS550 speakers, these had a contoured foam front but will have crumbled to dust by now leaving just the frame as ebay listings show. There was a GAR 600 still using the same basic design in the last few years before Hacker closed. Hacker better known for their Portable Radios & 1964 era record players with an add-on Stereo speaker. The only problem with Hacker tuners is they only go to 101 on the FM dial, not the full 87.5-108 MHz losing the local FM stations added since the 1990s. BUY-RAW RATING: Good. Turntable may need oiling as often seized. COOL RATING: 7 looks best with the smoky perspex lid, the teak lid dips it to 6, a confident looking unit. (2012)
1970 KLH Model Fifty Two 52 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 30w.
SC, CC. Another KLH after the 27 from 1966 we review above & the 52 follows the 51 which we've not had. USA design made in Japan if still looks kooky like the KLH 27 does. The service manual says 1972 but this has to be 1970 for Capacitor Coupling & has the same output transistors as the Nikko TRM-1200 below. The wood top lid is a typical vinyl wrap with screening tape inside which few amps have with non metal lids. UK-EU 220v model, not multivoltage & must be for some EU countries so for the USA models not selling well, the 220v one is a bit of a rarity, as are 1960s 220v Fisher amps. Still has the quality build for 1970 with kooky things like the main diodes have an inductive loop in them and as many as 9 separate PCBs. The maker's check label has 'aging test' probably many hours running in. A smart fascia with attention to detail. The back has all Phono inputs & those annoying screw connectors only good for fork connectors crimped to cable, if the Remote speaker pair is via Phono plugs. A known problem with this amp is the weak volume-mounted power switch which we need to deal with too, as is found with vintage hifi, ours was owned by a moron which takes more work to deal with. As with the Nikko below, a later amp between the second & third hifi generation but with pleasing attention to detail that we do like to see. A quick play to see if it works reveals a typical 'long asleep' sound but clearly a fresh sounding amp with a fuller bass than some amps. the original power switch is a feeble thing ALPS 'Snap Switch H76' says one source & seeing pictures it's probably pretty useless & how it even works isn't clear. The only option is to put a switch on the rear & do it properly, unlike the suicidal previous owner... Trying it again after the USA Fisher amps, the sound after waking it up before, is actually not so far off the Fisher 440-T if a better bass & more detail with a wide stereo image, if the typical USA headphone L+R swap. On Rock it has a clean solid sound on guitar riffs if not quite the bass weight we can upgrade. The service manual is very detailed revealing good design if still a kooky built amp like the KLH 27 above. The power amp board is only 4" x 3" with the bigger resistors hard wired by the transistors, the Phono stage is under the left rear cover in the top & the Tone is right at the front underneath & must be the first one with a FET predating the Sony TA-1130. On Tannoy Golds for an all-original amp this certainly impressed, being a good compare with the 1966 Akai AA-7000 & 1970 Nikko TRM-1200 below. To use Speakers, leave the buttons out, if push in to turn off rather than on. As upgraded, it has a clean accurate sound that is deserving of the rating playing with good volume for 30w on speakers. BUY-RAW RATING: The weak Power switch is a known failure else good. COOL RATING: 6.5 a mix of classy control knobs if the vinyl wrap lid loses appeal. (2015)
1970 Nikko TRM-1200 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 40w.
SC, Transformer Coupled, Direct Coupled. We're always interested in amps we've not tried & to try a Nikko again from how decent the other TRM-500 was. Seems to be an updated version of the 1967 Nikko TRM-120. Very cute amp, very smart looking with the delightful fussy Japanese attention to detail that set the pace in the Hifi race. "Nikko 1200 Module Stereo Pre-Amp Power Amplifier" it proudly says, to us it's an integrated amp. Similar lever switches to the 1969 Trio-Kenwood KA-6000 & VU level meters. Separate L+R tone controls & Tone Flat switch show the quality on the front. The rear has their odd mains holding device, if it's not the tighest fit. On the back ample inputs & 2 speaker pairs. This needs Pre-Out to Main-In connectors are the short Phono plugs like the Sony TA-1120 uses. 260W (260VA) rated if the mains transformer seems small & it's multivoltage. The Mains plug & socket is not good as the plug one was, puts a high AC potential on the case [as no Ground] like other amps, so we fitted a 3-core mains cable to make a better amp for use today. Circuit breakers similar to on the JVC MCA 104E is unusual. Inside a fussy delight too with the Input selector & Phono board caged & one around the Output Transistors. The Service Manual is very detailed if whoever scanned it missed the chance to enhance the dark images. Interestingly for a 1970 amp this is Transformer Coupled like the 1965-67 amps above, a toroidal 'doughnut' inside next to the relay. The design has hot resistors under the output transistors cage upto 80°C in open air. Certainly a cute amp if it sounds clean as the early circuits are. No bias pots on these 1966 style designs as the Akai AA7000 is similar. The design is minimalist like the 1966 amps, Phono is custom IC, looks more like a 250v film capacitor 'Nikko HB18005' which is 2 transistors, 6 resistors & a small pf value capacitor if what the values are inside isn't shown. If yours doesn't work a Nikko bulletin was issued stating how to make it out of transistors & seems we'll have to: we built ours in the IC holes, the board they suggest is too big, works fine now. Pre-Tone x3 transistors, Power amp is x3 if 2 are buffers & the push-pull pair after the transformer. A relay of non-standard type, the transformer coupling & certain parts look more 1967. 3300µf 35v Elna main caps. Some with white-yellowy meters & others with blue, it seems respected online as we found with our other Nikko a few years back. Looking at the circuit, the 'TTF' is a nasty deep bass filter that has no place with us, explaining the bass-light sound. Seen this in the Sansui AU-999 & NAD 160a, sadly to sell good amps to those with rumbly turntables, the bane of Hifi & what our upgrades always undo & no buyer of our amps has complained of too much bass. 2SC889 are 50w rated. Unusual to be transformer coupled as do 1970 Nikko STA-501S with 18w has transformers as does 14w Nikko TRM40B from 1966. The BBC3 "10cc Story" showed this amp in their studio. A strange feature is "Speaker Compensator" which isn't quite what it seems as it's in the preamp not the output like the Sony STR6120 is. The 'Tone Flat' bypasses the Tone stage totally & the increase in fidelity in our upgraded version is noticeable if subtle. Our rating shows this amp has low spec & limitations to hide the excellence of this design. Once upgraded, on headphones it's more a detailed amp than a rich bassy one, very clean & precise. Trying it on the Tannoy Golds, the sound is very impressive. All upgraded-recapped except the two main caps, on headphones it's very clean if a little lean aka neutral, but on speakers the tight deep bass really comes alive & unsurprisingly is very similar to the Akai AA7000. Getting this finished at the same time as the KLH 52 above, the amps for our spec are similar in some ways, if the Nikko is far more Neutral than the KLH which is more bassy, the Nikko has neutral precision on the midrange giving more detail. It reminds us of the 1984 Sansui AU-G90X & trying it there are similarities in the sound if the 90X has a different bass, so to play it a bit & compare back & beyond the 40w to 130w power rating, the Nikko is exceedingly good. But comparing amps as with the KLH 52 above, the Nikko doesn't quite have enough volume for 40w. The pointless Bass Boost switch on the back together with the cynical Bass Cut circuit shows Nikko are dumbing this amp down, so we will remove extraneous circuitry & if means no rear switch, who needs it. We've already got rid of their lousy mains plug. Some amps we know should be better than they are & have the nerve to go further & often get excellent results. Original if bad is fair game to replace & do properly if subtle. Some redesign later the volume is far better. Bass is tight here but goes very deep as the Sansui AU-G90X does which is why we try more. On reading through the HFN mags by year, a Nikko TRM-120 exists from 1967 that appears very similar to this, for the transformer coupling it likely is an earlier version of this, if the TRM-1200 is different on the outside, but no manual of the 120 to see. Saw one on ebay 2021, main board looks the same if other parts more crudely done, £130 sale on it, if we didn't fancy trying it for tatty looks & alterations. BUY-RAW RATING: Good if check the Phono works as the IC was obsolete by 1976. COOL RATING: 7 classy fascia if no wood case loses a higher rating. (2015-2021)
1970 Philco-Ford M1550 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Not Worthy. 12w.
CC. The Roots of select45rpm Hifi: The First Amp we ever used as it was the parents one for several years & the sound is actually with many qualities of amps rated higher with a fresh open sound. It's only a budget amp though it looks nice though is quite small & like things you knew as a kid, surprising how small it is to adult you. Ceramics upgraded tidies the sound & a punchy sound is here. As only 12w it's appeal will be limited & you'll never find one, but it's worthy of including as it has a good sound. Minuses are DIN connectors & only 12w that gives harmonics & hum a bit too easily on treble, this is actually the low spec power supply. Also the power switch is awful as it fails & to awkwardly fit a different type is the only option, our family one was away for ages getting a new one & the first we got back had the same issue. REVISITED: We got another one of these in wanting to see what the Phono stage was like, good power switch at last. It was the first Hifi we ever used & using a Garrard SP25 Mk III & Goldring G800 was the deal. As this is over 45 years old now, age becometh & to find someone replaced the 1A left fuse at the back, the other near the mains cable is just 250mA, the wires were just twisted, not soldered. That's not very good. As we had to 'part' the other one got the original fuse to refit. Early on, we used to type the horrors we found with amps, here we've found another in the Plug, E wire cut, L + N swapped, 13A fuse fitted. In need of a service but working, it's not exactly Hifi yet but far from junk either ignoring inputs only working R channel on Tuner & L channel only on Tape, the sound is pleasing. The Service Manual is buyable & seeing the circuit,. small as it is, has quality to it, why not see why it sounded good to teenaged us. To hear how it sounds on the Tannoys too, good to revisit good things of the past, however modest they were. Once serviced with a little extra work the sound in Stereo is noticeably fizzy for the ceramics in the amp if hearing beyond that the sound is otherwise clean. The design isn't bad but the spec is low & a bit of a low hum. Hearing the open & rich sound of this, if far from having the fidelity we require, it really does show this little 12w amp did please the teen typist playing it for hours long ago. Don't forget your Roots, this amp is ours & it still sounds good. Sadly no service manual, the one online is an error they said. But the design on going to recap-upgrade is still a "proper" Hifi amp with Tone & Push-Pull outputs, capacitor coupled. The main cap is only 2000µf if JVC still used this value on their early ones. To see the design would be interesting, if the whole Preamp, Power Amp & Power Supply is on one 277mm x 63mm board, it says "Made in Taiwan" so it's not the usual UK low powered junk quality, so well worth giving the full recap-upgrade treatment. Unfortunately with no Circuit it's hard to tell the circuit, on recap-upgrade it reveals a very imbalanced sound, bass is good in a 'retro' way, midrange sounds recessed as treble is excessive. Not so much the fault of the power amp which looked good for us to try to upgrade, but sadly the inputs-preamp stage is rubbish, signal goes through a high value resistor & is then messed with via the Phono EQ circuit that all inputs share. The circuit is useless as there is no direct input, it was matched to other Philco gear which is why the speakers sounded clear, as excess treble in the amp. Explains why it got hum problems on loud treble, it must be over 10dB inbalanced at about 5KHz. Unless the lousy input circuit can be bypassed direct to a selector button, this amp isn't even sellable for the awful incorrect sound. We dare to try on budget gear & it lets us down. Sadly this amp is only good enough to use "as is" on budget speakers, after all it's what it is, made to sound good amid it's own components, a trick modern brands of undeserved repute still do. Once upgraded it reveals how awful the inputs board is, as well as that not working right for the inputs are unreliable, not worth putting a bypassed input as there's no money in the amp & the new parts we added best used elsewhere. They don't all turn out Winners, but it's worth a try, but crappy is usually only crappy. This also shows why having the circuits is important as we'd not have bothered otherwise. BUY-RAW RATING: Good once serviced if the power switch is ok. COOL RATING: 6 tiny budget amp still with a nice teak case & tidy layout, it appealed to us as a teen. (2013-16)
1970 Pioneer SX-990 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 28w.
CC. This is part of the new 1969-70 numbering with SX-440, SX-770 & the SX-990 is the highest number so must be 1970 not 1969 if a '69' code on the tuner. £194 in 1971. The SX-1500TD from 1969 noted above is 45w & seeing this one has changed our views, as we have with Pioneer since getting the SA-9500. This is rated 35w but a confusing 'per channel' but 28w into 8 ohms for Stereo which the Jan 1971 HFN/RR review confirms & shows it was £193 to buy new which is high for a 28w receiver. Inside it looks very like the SX-1500TD to the point of exactly the same apart from the power supply board not caged & a bit smaller as well as lower HT voltage. Has a proper Mono switch. The thing with these pre 1972 Pioneers is to get ones that have not had the power amp repaired even if faulty as the board gets messy as we've found with some we've had, hard to work on too. We've not had one in over 2 years, so can look at it with upgrading eyes, as the 1500 one on the Solds page wasn't. Power amp is just 6 transistors which means it should upgrade very well. The output caps on the board like the SX-1500TD are awkward but can be bettered with care. Compared to the SX-1500TD: the Preamp exactly the same, Phono & Power Supply just 2 minor resistor changes. Power Amp basically the same if several value changes. Our view on this after not being so keen on the 1500 for bad repairs twice is we mostly like it, nicely made smaller size receiver that should upgrade well. At 28w this is the lowest power amp we've decided to fully recap, just to see how it does as well as get a taste of the SX-1500TD as it's so similar. Only recapped the Power amp board & still has the original spec elsewhere to see nearly all original sound. First try after being unused in over 40 years by the unused look inside under the dust, it sounds decent but a little raggedy if not at all rough or unlistenable as we'd expect. A very decent accurate sound if very bass light after it's long sleep though it improves on trying it a few hours later after waking it up. Sound is punchy for it's 28w & goes loud enough before flattening off, sounding as lively as similar 45-50w receivers. For this reason well worth upgrading to find out what it can do... Recapped & upgraded the lot, for the hell of trying & the fact the SX-990 is so like the SX-1500TD. Done the audio boards first mostly & it was OK but not too exciting. Later with the rest done putting some high spec into a 28w amp like it was the 45w one, it paid off. Took a little running in to waken it up & the sound was well worth the effort. For the 28w it sounds as clean & good as any 45w-50w amp with a good punchy volume if ultimately not having the higher power, the amp is certainly no compromise like later lower power ones. It could upgrade further to lose the slightly 'retro' tubby upper bass. A Very Good match to the Tannoy Golds, they are the same year after all. With the SX-838 here too the SX-990 has the fresher sound, as is typical of late 1960s transistor amps. BUY-RAW RATING: Good if power amp hasn't been badly repaired before. COOL RATING: 7 new styling to the earlier ones & the SX-1500TD if not quite the looks for higher rating. (2014)
1970 Sansui AU-101 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 15w.
CC. This was the first amp we ever repaired many moons ago. At the time we had a Leak Delta 30 & thought it sounded better, but beyond that we've not had one since though they are on ebay often. Read more on the Other Amps as we looked deeper into the amp. Nice simple design with low Transistor counts: Phono x2, tone just One & Power Amp x6. For 15w the circuit will be very limited to stop it clipping too soon & based on the AU-999 it probably was quite thin sounding unlike the bassy Leak. At 15w not really worth upgrading. BUY-RAW RATING: Good. COOL RATING: 7 all black basic but looks smart. (1993)
1970 Sansui AU-999 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Very Good-Excellent. 50w.
SC, DIFF, Direct Coupled. *Beware* This Amp is Very Overrated & because of the "999" number it gets offered & supposedly gets high bids based on this hype. We only rate it "Recommended" it's not Very Good as Original, it has a nasty 'T' Bass filter that ruins bass similar to other AU xxx series plus it has loads of obsolete transistors that can go hissy. The amp needs a big rebuild. Then it sounded good but not the best, if to our 2012 ideas on the one we last had, but for a huge amount of work to bring it up to our standard there are far better amps. Some circuitry is not so good as a 2020 look reveals. Early on in our Hifi exploits, we rated as one of the cleanest sounding amps we had before getting more, but long since bettered. Could do with more bass as sound is very thin & it has a nasty Bass filter stage to limit it even more. But once upgraded losing much of the lousy spoilers a good amp with high quality sound & worth upgrading further, but for musical pleasure the Sony TA-1120A easily beat it even recapped & upgraded, getting the AU-999 sold on. It was still thin after many upgrades we done a while back on one & if we had another we may go further with it. Phono isn't as good as the earlier amps & the all-black looks a bit awkward unless the room is bright, though a wood case improves looks as does the matching tuner. For 50w the volume wasn't very high & our Power Ratings page shows the 25v clean sine output is low for the power. The AU-555 & AU-777 are earlier ones in the range if power is less. Nice amps but as we found out with ours, even upgraded, the AU-999 leaves a lot to be desired for the thin sound. Of the Sansui ones we've had the 3000A & 5000X noted above are way ahead of this one. Beware overpricing on this amp, it's a high model number but 50w (not 80w as some state) & not a very loud 50w either with issues as noted. The Sansui 3000A is way better. This is one still in it's 2012 review, prices are way too high to try it again & at the time the TA-1120A outdone it quite easily as the AU-999 still sounded thin. Some oddly old style transistors in here make it a lot to upgrade too. This has some poor components that are unusual to be using in a 1970 amp, the black dome transistors are as early as 1966. The low volume for 50w was surprising & the lack of bass. It has a lot of front panel controls that need good servicing & lots of bulbs for the input display. It's a decent amp, but there is far better out there. See the AU-666 below for similar amp & comments related to this also. If we had this in 2017 like the AU-666 no doubt it'd upgrade to 'Excellent' but we're only rating on what we thought at the time. Looking in 2018. This amp is way overpriced at £900-£1200 on ebay as of Sep 2018, ones supposedly worked on if no-one ever shows photos so to be wary of cheap parts & an an amateur job. It's a not-very-loud 50w amp from 1970 but the "999" number gets the hype. It's one that needs a huge amount done to bring it up to standard. Bass is limited through the amp & plenty of obsolete transistors in this amp make it a huge job to update as we found in 2012, so say this for the third time. Early to have a Differential, the Preamp for all the controls is complex & overdesigned for features you'd never use. TO66 pre-drivers on the amp floor are like the 1969 Trio KA-6000. Undeniably still an interesting amp & for our 2018 ideas we'd get a far better sound upgrading it, but the thing is we've been there & done that before & with the silly prices it's an amp that should be around £200-300 to buy as "raw", but as with quite a few amps others hype, they aren't really very good as original & need a huge job to bring up to our standards. So we'll not be too bothered to leave it be, especially seeing 'Sold' ones at £600+, who is hyping this amp? BUY-RAW RATING: Good, beware severe overpricing on this amp, it's not all that great really, as original you'll not be pleased with all the limitations & excessive controls that are little use now & then. REBUILD RATING: Needs so much redone & some redesign needed to be it's best which is a big job. COOL RATING: 8 needs the rare wood case else it looks awkward at a 6, with the case it looks very smart if all black fascia not so useful for night use & can look messy unless top grade. (2012-2018)
1970 Sansui AU-666 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Excellent. 35w.
SC, DIFF, Direct Coupled. See below for why the lower 'As-Orig' rating. The good thing about doing Upgrades is you get to work on & try amps that aren't usually found. The AU-666 is a 1970 Semi Complimentary amp, a version of the 1970 AU-999. Comparing our few pics of the AU-999 both have the same power amp board F-1159. The AU-666 has a nicer fascia, the AU-999 is too busy. Solid black anodised fascia with gold lettering & nicer control knobs than the AU-999. Midrange control & muting are early features on this & the 999. The power light is a bulb assembly if it looks like a neon. The AU-666 with it's walnut lid all in high grade visuallly is a very attractive amp. Inside is well made like the Trio KA-6000 with metal casing & shielding plates around the front preamp, the power amp boards & the rear inputs. The rear is a simplified version of the AU-999 if the AU-666 has the pre out-main in links. Sansui amps are much harder to find than the receivers, only the 15w AU-101 is findable. 220v sticker on the case suggests it was sold in the EU somewhere, the voltage adjuster is the rectangle box on the rear right outside. Here it was still set to 220v & how to alter it requires the user manual. 240v is 'red' so set the left plug to 220-240v & then set the sub plug to 'red' so 240v not 220v. Underneath has some of the same boards as the AU-999 & the groups of capacitors underneath are the harsh bass filters. Check the fuses, but a softly blown main fuse with a bit of fuse wire wrapped around it & one output fuse softly blown too. Unserviced amp probably untouched in decades as the strange dead bug cases that came out of the underneath. Old gear needs a proper check before using. This arrived the same day as the 16w Yamaha CR-400, so how does this sound? Does play but in need of a service as rough on the controls. The owner says bass is lacking, the bass filter & design suggest bass will be light, if it has a rich sound there is that sort of limited retro bass rather than the deeper bass the 16w Yamaha played, but despite the limiting it doesn't sound thin on headphones. It does have a punchy fresh neutral sound if it is a bit lacking in focus & confidence. The receivers Sansui 4000 & Sansui 5000X have poor Aux inputs, 100k & 150k resistors to Phono then gain increased again, a lazy idea that spoils those amps, if you can use Tape In. The AU-666 does Aux correctly, bypassing Phono & straight to the Preamp-Tone. The sound as original is still decent, it copes with Rock well if it's a 35w amp the sound is 'contained' to cope, if not sound too exciting or weighty. It's certainly a great amp & the 4000/5000 receivers were enjoyed if the amp in this case is the better item. Some brands are better on receivers, some on amps. At 35w it has potential to upgrade to something more confident, if keeping it within itself, volume past 5 as on the AU-999 does start to flatten off. On our 15" Tannoys it sounds clean, but the false limited bass really lets it down, a thick unnatural 'ringing' as bass-limiting brings makes it not a nice listen, didn't Sansui play it after they dumbed it down? We've found this with other bass-limited amps, but once upgraded they sound sweet & naturally extended bass, losing that awful 'retro bass' honky sound. Playing the 16w CR-400 again after to compare the sound, the Yamaha has a more dynamic sound & deeper bass, the AU-666 is more polite in it's sound, the CR-400 is much wider on Stereo also if not as smooth as the AU-666. Neither are serviced yet. The AU-999 we had 5 years before, it was in need of a lot to tidy it up, we found the Sony TA-1120A better at the time. Great looking amp with high upgrade potential. The similar Sansui AU-555, 25w AU-555A version of this gets a review in the May 1972 HFN/RR, if the wrong photo/wrong model number shown. A pretty hopeless review if ever, which one do they 'review' if they do seem to be harsh on Japanese amps in ones we've read reviews of & know too. AU-555 is 20w RMS, if the review gets that wrong & criticises as they read 21w. They must have the earlier AU-555 then, huh? Not a good Aux design on the AU-555 with the large resistors to cut to Phono stage & boost up again. The AU 555A is different. Some limiting design to sigh at on both if none of the harsh T-filter that makes the AU-666 have poor honky bass on speakers, the AU-999 has this too. Looking at the AU-666 amp to upgrade, it seems odd to see 'silver line' 10% tolerance resistors & those 1966 style early transistors we've seen in other earlier amps, the black dome XA 495G & CDC-8002 & CDC-9002 type you'll not find any info on. The Sansui 4000 & 5000 power amps similarly strange compared to other brands. The 2SC281 on the heatsink is a c1967 very early TO1 silicon, many in the TO1 size are Germanium. Sansui clearly using old stock transistors on the AU-666 & AU-999. The first stage of the power amp is a Differential. The preamp stage is amusing, undo 2 screws & unplug a 9 pin valve type connector & it's free. A reliable way to connect a board instead of lots of soldered wires. On upgrading, the circuit sadly is very dumbed down, a pity as it's so well made. But that's what we're here for, to bring it alive. Power amps & Tone-Pre done the sound is far more what we want from amps, the volume & focus is way improved & it has a fresh swagger to the sound that was a little unexpected for the vagueness heard before & seeing differentials as well as knowing the AU-999. Still not done anything else so more improvement to come, if the main changes done bring a solid precise sound. We've not had a 1969-71 era Sansui for a few years & hearing the quality here. The AU-666 series was replaced by 1974 with the AU-7500 & 9500 series, the Sansui amplifiers are harder to find than the Receivers, if the brand did end up in the Discount shops by 1972 so we've yet to try those if know how cost-cut the 160w G-8700 1979 receiver was. Now upgraded, this certainly has a quality sound, a solid weighty sound with detailed crisp treble & a rich bass if not going too far with it as 35w, but a sound not usually in below 40w amps. The owner says he plays a lot of Reggae, well so do we to test amps. The solid precise dynamic sound with good bass weight & ability to resolve muddy tracks well is what makes the best amps & so does this AU-666, but only once upgraded. To resolve dense Ska tracks well is beyond many amps, this does it very well if the power limitations keep it back a little, if at 35w you're not going to get it all. On Rock it has the clarity to deliver Hard Guitar riffs with confidence. The only trouble with the amp sounding this good is you'll crank it up too loud as it sounds great & get into distortion unless you have high sensitivity 95dB 15" speakers. Now to test it on Loudspeakers... we'd just been watching TV with a 70w upgraded amp so this had a slightly cruel compare as it's a 35w one. But no worries on that count. The big problem as original was the dismal lumpy bass, gone now upgraded with redesign it sounds great, a natural deep bass with good weight if none of the fake bass retro sound. Stereo was wide & the amp sounded good. Treble tone gain was a bit lacking on headphones & speakers as designed, the specs say a huge ±15dB which clearly isn't what we heard, more like ±6dB. But the clean natural & neutral sound played flat is the strength of this amp, pity Sansui didn't do a higher power version than the 50w AU-999, the 1974 Sansui range had the AU-9500 at 80w, see the Blog page. The owner receiving back his upgraded amp had a great few days rediscovering his Record Collection. What you are missing in sound by not upgrading amps... BUY-RAW RATING: Good if thick lumpy bass as-designed will disappoint. COOL RATING: 8 black fascia with gold lettering & not as busy as the AU-999 makes it a Classic styled amp. (2017)
1970 Sansui 350A receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 20w.
CC. Sansui made several versions of a 20w-ish receiver. First was the 1965 TR-707A at 25w, then the 1967 '400' at 20w, then the 1969 '800' at 20w, also the 1968 '350' at 18w & then this 1970 '350A' at 20w. Strange they issue one receiver 1967-70 per year, if at this time Tuner tech changed a lot. The 350 looks quite different to the 350A. These small Sansui receivers upgrade very well, TR-707A & '400' seemed to sound better than the big '3000' & '3000A'. So what is the 350A? Wood case is standard as no inner metal lid, quite a small amp if roughly the same size as the '400'. Looks more 1971 than the '5000X' receiver as it has lever switches & a more subtle look. Nearest version is the '1000x' of a similar look, 25w RMS, if 28w/28w, if not the Valves '1000' model. A bit different, has High Filter, NFB Tone not the Passive Tone of this, works on 58v HT otherwise not so unlike this if more towards the '4000' & '5000X' type. 350A Rear has the Red-Black spring connectors, Phono, Aux, Tape pair, AC outlet, no Pre Out-Main In. As usual the 2 Core Single Insulated Cable, no Earth. Aux on these Sansui apart from the '400' & '3000(A)' goes into a 100k resistor then into Phono, hardly Hifi, but to use Tape In to bypass limiting. Why Sansui used this on several models is 'of the era' when the rest is so Good. Aux is done well if sounds a little compressed actually making Rough Sources sound better as we found with the '4000'. Just a little bit more narrow 1cm & 2cm less deep than the '400', Design. Aux to Phono stage with 2 Transistors per channel if really only Top Hifi sources & speakers reveal it's slighly compressed. Preamp is One Transistor with the Passive Tone stage much like the '400', passive Tone, then another transistor for gain. Passive Tone if done right does sound more lively than the Baxandall NFB type. Adjust Pot for 'Bias', see below & Power Supply is 1x 2200 75v main cap on 2 Diodes so half-wave rectifier as the '400' has, if HT is 47v, 75v one used as too near 50v. At last away from the '400' or '3000(A)' unreliable protection circuit. '350A' is an updated version of the '350', extra Transistor in Tone & the Regulator on the Power Amp board. Power Supply for Preamp & tuner uses the same winding if a Regulator with a Zener to pull the Voltage down, if probably better than all the drop resistors of the '400'. No Filter stages is a good thing so no lossy circuitry, even the '400' had a very basic 'Noise Filter'. Compared to the Sansui AU-999 with it's extremely fussy overdesigned preamp with some lousy circuitry & heavy bass filter, you can see why these smaller models are overall better circuit-wise without excess stages. Multivoltage on this is extreme, gives 100v, 110v, 117v, 127v, 220v, 230v, 240v & 250v by two plug combinations, a bit too confusing without seeing the Service Manual. What's Inside? Pleased with this from the Outside & The Circuit. Case has 4 bolts underneath & 4 side screws. 240v sticker. Never opened before as dust carpet from open grille in lid. Looks like it sat ignored over 40 years, one of those Hoarder type houses as no Damp Rust from Attic, just lots of dust fluff. Sold as Aged but Basically Working, ancient plug wih 13A fuse & 'N' pin screw very loose, probably abandoned for that? Rotary controls aged & tight adds to unused in decades. Grey Base cover shows the design is tidier than the '400'. We got a Trio-Kenwood KR-8340 just recently & mentioned it had the Selector for Inputs on a long Rod at the rear, if the 1969 Sansui '4000' does as does this '350A' which gets rid of lots of wiring, short unshielded wire runs improve over the '400' which had quite a few long runs. Considering the '350A' is the 1970 version of the 1965 'TR-707A' this may better the '400' if upgraded. Power Amp has 2 Capacitor set holes, the original idea seems to put the Output Capacitors on the Board if it looks the design was bettered to use panel mounted ones if still a low 1000µf 35v. The transistor on the heatsink looking like an old TO1 Germanium is the Bias Transistor in Silicon, as seen in other Sansui. The black domed 8002/9002 are so obsolete no data found. Build is like the Sony STR-6050 in how neat it's done & still heavy for the size & power. Phono stage as with the '4000' is built onto the selector board if this has the rotaries on it too. Seems a quality amp, in days when 20w was still fairly high power as 50w was top power on most. A 1980 20w Sansui wouldn't please us but this has as much appeal as the '400' did on getting it. First Try after a part Service. Plays Stereo fine, background 'windy' noise quite noticeable on Headphones on both channels & will show on Speakers even sat 2m away, too noisy to use. Typical Aged Amp issues & as expected, as seller half-tells of issues & the transistors known to be like this. Music plays well enough, typical Grainy sound on first play with L+R balance not true, bass is the limited Retro Bass. Played at a modest level it sounds good enough if played just a bit louder it's messy. Knackered Old Amp needs a Full Rebuild is the Calm Reality of it, it's too old to trust on speakers hearing the issues. But to us, we knew it'd probably be like that so bought it wanting to Rebuild it. For the faults told, unlikely a general buyer would go for it, this needs a lot of work to be it's Best again. These smaller models seem more interesting than the '4000' or '5000X' we've had on looking at their photos. Upgrading. We can make this as good as the '400' if the amount of work to get that good usually outprices it for selling a 20w receiver. So to decide what to do, we sold the '400' as having the TR-707A & the '3000'. Looks good in the wood case, which is why we tried it. A Look in 2020. Preparing to Upgrade it, not looked at it in a while now. Just got other amps that were of more power. An older amp here, 1970 if it looks more 1973. Looked at the 1973 Rotel RX-400A just before & this is a nice heavy amp in quality the RX-400A lacked. Re-reading the above, Mix of '400' with '4000' receiver model styles. Inside shows this is no Budget Model, Quality 20w amp. Low NFB design, works on 47v HT which is Capacitor Coupled on Speakers. Sansui AU999 is their 50w amp, with those same obsolete 8002-9002 Medium Power Drivers, to compare both amps by circuit. Not so keen on the AU-999, it gets way overpriced for the '999' number, it's got a lot of overdesign plus hard limiting too, see the Review on this page. '350A' no Filters or overcomplex power supply, it's zener is to 'reference' the Regulator. Play It Again as Raw. This time through 'Tape In'. Clearly 'woken up' aged capacitors since, if try once. Red Meter & Green Tuner Dial lights. Sounds decent played average volume if up just a bit louder it gets shouty if unusually loud before even halfway, if does wake up more, shows the caps are past it. But not much of a 'windy' noise this time. Reggae sounds nice, if Rock is a Punchy Sound far from what's expected & with other amps we've tried at this power. This is way ahead of the '400' as or original, if we did lots with ours. Actually didn't think it'd be this good, if upgraded this will be good. Of a few 20w amps we have to compare, this '350A' stands out as original. Unusual to be useable at this age, get one session from it & next time ropey is the reality, so we'll Rebuild. Underrated Today. Looking on ebay, ones selling very cheap, wait until you hear it even as original. A good seller in 1970 & a Real Sleeper in 2020. Sounds better than the 1969-70 ones based on original. We Like 1960s Sansui. The 1966-70 era are their best. Got the TR-707A much rebuilt, the first '3000' we still have. The '400' an earlier version of this we got a great sound from & this sounds very decent as original. The Receivers 4000 & 5000(X) we've not had in a while now, they show a different sort of design to the early ones. The 350A is before those two in design progress, if their 20w range uses older designs with updating, the complex '400' power supply. The 'Aux through Phono' design is on the TR-707A if to use 'Tape In' bypasses the Compression there. Power Supply is modest after the complex '400' one. 47v main capoacitor, 2SC1061 Regulator on 24v for preamp & 12v for the Tuner which is just one fairly small board for FM & another for AM if both with no ICs, no Muting or Auto Stereo, just the Basics. Recapping & Upgrading. Preamp-Tone first as to look at it undone. Gets rid of the Hiss & a very quiet background too. Using 'Tape Mon' to avoid the Aux into Phono idea. Not done anything else yet it sounds great, Better up louder if still shows the Age & Limits elsewhere. We got this in hope of the 1967 '400' to be bettered & so far the Preamp is better than the '400' which needed a little redesign. Not got the Bass we like yet if well on the way. Unusually Good for only the Pre redone. Interesting to compare this to the 1967 'TR-707A' when done. Now Recapped. Done this to a High Upgrade aware of How great the 1967 Sansui 400 could be. This an Exceptional Amp, as Original & the Upgrades just take it further. LEDs in the Tuner window give a subtle glow, the Meter & FM Stereo are Bayonet bulbs. Biasing Isn't Needed as it's Autobias, the manual doesn't tell, two pots on the earlier '350', only one here. The Adjust Pot is Midpoint Voltage, ours reads 46.4v on Output Transistor TR2 in the line so adjust to half that on TR1, similar with the R channel. This improves it further being balanced. Some Trio-Kenwood like the UA 1383 board in later KR-140X & KR-6160 have similar. Makes the 350A an even better amp. Upgraded on Loudspeakers. See our Opinion as Original, to see this amp was a bit special. 20w model with a Sound to surprise, so we've upgraded this one a lot more as it had potential. On Speakers, It's a Keeper, Searching for That Sound in many amps. That Sound is an open precision on Midrange with Bass & Treble to Surprise Us after all these Amps. The No Filters, Passive Tone & Simple but Advanced design gives this sound. The old 10% Resistors give quite varied Voltages if it works fine, if ours needed a Redesign as the '400' did in the exact same way' if that's for upgrading only. Looking on ebay, since July 2020 quite a few have sold. Have we helped sell them? Yes. Now try find one. The Lack of Fussy Circuitry makes this a Real Winner. Playing Aux as the 'Tape Mon' input circuit to avoid the Aux into Phono after 100k resistor strange idea, it adds compression for lesser input sources. 50 years later. To find an amp like this, a modest 20w amp with the Sound Quality it's Hard to find at Any Power is nice. Why Is It So Good? Who'd know. It's a medium power amp of the time, probably around £130 new which is still a reasonable price. But it'd have been Partnered with Cheap Speakers so it'd never give the real sound away. Sansui 350A & Tannoy 15" Lancaster is an unlikely combo. 20w on Speakers here plays Deep Bass surprisingly well, clean Midrange & Extended Crisp Treble. 15" Tannoys with 95dB suits these fine to bring the Sound out. Quiet Background here is nice as some can be a little noisy at 2am TV listening. What's Not To Like? BUY-RAW RATING: Expect some Old Transistor Hiss, these Sansui usually work if not to just use it as often too old now, if ours was useable to try. Rebuild Needed if will give Great Results done properly with Upgrades & then a Silent Background on Big speakers. COOL RATING: 7 modest if smart in the wood case. Small Size receiver with a Sound to Please. (2019-2020)
1970 Scan-Dyna 3000 receiver ↑
AS-ORIGINAL (Once Serviced): Average-Hopeless. UPGRADED: n/a. 30w.
Dynaco related EU crap sadly, first seen advertised late 1969. Looked interesting, but an amp we hated by the end of it, crappy cheap construction, almost impossible to get to the power amp board even to clean, crappy cheap controls, volume worn out, sound was hard to tell as made so badly & not working right. Unworkable on as so badly designed. We wrote it sounded rough too when we wrote of it originally. So don't bother buying is our opinion. We rated this as junk for the awful construction, it might do better if a high grade one, but it's an amp to be wary of still. For the Dynaco related name it just wasn't very good. BUY-RAW RATING: Risky if volume control isn't good, else should be ok. COOL RATING: 6 we got this as it looked rather decent, but the rest of the review shows it's not worth bothering with. (2012)
1970 Sony STR-6850 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Very Good-Excellent. 40w (not 30w).
CC. This is basically the 45w 1969 STR-6050 receiver updated, not that the STR-6050 will compare directly, so see above as we have one to try. The 6850 has Aux direct, unlike the 6050. But the build quality here is not so good as the STR-6050, the power supply being mixed with the switch board is just not very good, if the preamp & power amp are basically the same as the STR-6050, the Phono is on the Tuner board. This has all DIN inputs & speaker outs as per the EU scene if these are adequate if not so popular. One of the sometimes rare 1970-71 exotic range that included the big TA-2000F & TA-3120 pre-power amps, the tiny TA-88 amp & ST-80F tuner that did sell as well as amps for multichannel & the B&W made Sony SS-7000 huge speaker that's only 25w, but most of these were sales failures as by 1973 Sony cheaped out for the mass market as well as making more general audio goods. The June 1970 Hifi News shows there was a Sony shop in London, yet the pre 1972 Sony aren't easy to find. The STR-6850 is a very rare receiver you'll find very little online. It's a EU style receiver with FM, MW, LW & SW even that's 61cm wide & clearly of the quality of other better 1970-71 Sony also the Tuner has no ICs. The styling of this is unique for a Sony & it's so retro cool it hurts, having a metal fascia with perspex window. Amps like this should be in design museums as just so of their era. All DIN connectors as it was styled 'The Europe' on one flyer but it looks a bit too well made & pricy to compete with other EU type receivers. The last Sony capacitor coupled so a 1970 design with 2SD316 transistors that are 63w rated so no cheaping out here. It already sounds more refined than the 40w TA-1140 if 30w seems a modest rating for the volume & improves quite noticeably after servicing. Still has the STR-6120 quality with the mica capacitors not ceramics, expectedly limited on deeper bass if not thin, biasing tightens the sound further & once run in sounds quite like the STR-6120 does as raw. 84v & 48v HT is very high for a supposed 30w as well as clean sine going to almost 28v the same as the 40w TA-1140. Sony were deliberately underselling this higher spec amp to match the 30w B+O Beomaster 3000 as the service manual still states 30w & looking at the circuit reveals what they done to limit it to 30w not the 40w it should be. Also suggests 50mV bias as with the TA-1140 this is way too high & blurs the sound. This amp is so rare you'll never find it sadly, but the STR-6055 preamp is quite similar if the power amps is semi-complimentary. The STR-6065 is less similar. As upgraded it delivers a quality sound way beyond what it was designed to be sold as. Music is cleaner than the STR-6120, based on both being original, if the 6120 upgrades further. The STR-6050 power amp is exactly the same except C707 if updated with later transistors. The Preamps match too if the Phono stage & Power supply are different. Talk about recycling, though the STR-6050 still strangely rates it 30w. Not to be confused with the flap-fronted STR-6060FW. BUY-RAW RATING: Good if unfindable as it's the rarest Sony receiver. COOL RATING: 7 big EU receiver size looks very retro, very stylish if not classy enough to score higher. (2014)
1971 Hitachi IA-1000 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 55w.
CC. We certainly liked the Hitachi SR-1100 receiver below & to try the slightly earlier amplifier version has been a requirement for a while. Hard to find these amps, sales must have been very low if the quality is high. A 1971 45w amp with the service manual is findable. We found a Hitachi flyer in the May 1973 HFN/RR & it shows the IA-1000 is 45w & the SR-1100 is 55w, see the SR-1100 below for year dating. 2x very basic ICs is the same as the SR-1100 we had with the IC in the Phono (Equaliser) stage though it has a MC Phono stage pre the MM stage with transistors, the Tone & Preamp is all Transistors: Tone x4, Power Amp x9. Still a Capacitor Coupled design though ignoring the Phono it should still be a good sounding amp. Pity they couldn't add the transistors not the IC. IC is FA-6001T totally unfindable, though the SR-1100 shows the circuit equivalent & you can see the transistors inside it even. They call Capacitor Coupled "Sub Complimentary" as it's 2x NPN transistors, we'll still use Capacitor Coupled as it's clearer what it means. A lower powered 27w IA-600 exists too with similar looks to the receiver we had in this range. It has an odd amount of resistors on the Aux input like the SR-1100 did, though it can be altered to be as good as it too & it has output meters which is unusual on an amp this early. On getting a nice one, it's a heavy amp if the lid counts for an amount of that. Decent Phono sockets & Marantz type spring sockets, Big blanking plate covers 3x USA flat plug mains outlets & the small box with the serial number has the voltage changer. Nicely laid out front with Green-Blue meters which is very unusual this early, only McIntosh had meters on their power amps. We have the Pioneer SA-9100 here from 1973 & you can see it copies this quite a lot. Style is very like the SR-1100 if no Hitachi circle logo & dark wood veneer sides. Inside the same plug in amp boards as the SR-1100 has if the heatsink is inside as more space if both units are the same size, the tone-pre board is a plugin, the receiver looks very cramped on seeing this, if the main power caps is just one at 2200µf 100v, the other 2 are the speaker output caps. As this has MM & MC phono, again unusual for 1971, it's under a can lid with a MC board into the MM one which has the FA6001 ICs, but so basic you can see the shape of the transistor inside plus 7 resistors of precise values for their design, not some bought-in op-amp of today. There are a few issues we found, the very hissy transistors, but the amount of limiting resistors in the signal path clearly is hiding a high quality amp by dumbing it down, sorting it out reveals a sound that is very 'there' and accurate, probably too much for most but for detail freaks as we are this has a precision unlike the hard Yamaha CR-1000 sound. Biasing is difficult as the current runs away getting hot heatsinks though it can be adjusted differently to be stable. Spec was actually low despite it sounding Very Good on it. Familiar 1950s & 60s mono tracks sound better resolved with a focus that is a delight, especially on early Jamaican R&B and Calypso 45s revealing the studio acoustic as so well focussed with the vocals so clear it can surprise, those old Bluebeat 45s sound so clean here. Upgrading is not so easy on this one, a few odd issues, but the result puts it in to the Best Ever Amps with the 1965-69 ones. There is a matching tuner FT 600, unsurprisingly it looks like the SR-1000 with less controls & one less meter. We decided to upgrade this one further as the Pro Sound was interesting & now with a recapped-upgraded Phono stage it is a very impressive amp, beats the Pioneer SA-9100 we had recently. BUY-RAW RATING: Beyond hissy transistors ours was good as not much used. Biasing is difficult. COOL RATING: 8 green meters add to the looks, good looking unit as is the receiver. (2015)
1971-72 Hitachi SR-1100 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Excellent. 45w.
CC. An excellent well made amp we rate highly. We put 1971 on this, if it first appears in HFN ads Sept 1974 & gets a review in Aug 1974. But the 1972 HFYB announces a Hitachi range yet none appear until the 1974 book & there don't appear to be any earlier Hitachi amps or receivers. To see it's a 1971 Amp that only got UK distribution by mid 1974. 45w is the correct RMS power, "55w+55w" is a vague rating to say 55w per channel if only one channel played. Phono stage with ICs if Hitachi custom made basic ones. Headphone socket resistor is too loud & a few foolish spoilers in here as Hitachi made an amp way too good & had to dumb it down, or as we note later with the IA-1000 above. It needs a few alterations to get the best from it though, so we'll rate it a little more cautiously, though it upgrades very well. This amp is still remarkable with a few upgrades & has a deep solid fast bass that most amps shy away from, if not a bloomy sort of slow bass this may suggest. An easy amp to work on as just so nicely made. 90v HT on the capacitor coupled output stage suggests maybe a 1970 model. This impressed us straight away after having had most of the other 2013 amps here, so to impress us means it is a bit special. A solid detailed sound with strong separation in stereo. Deep potential to deliver a very detailed smooth sound with the right upgrades. An amp we got later in our researching & we were pleased with how good it was after recapping, a wide stereo soundstage with fine detail is in this amp. Hitachi are a hidden secret on their early few amps, the later 1970s ranges seem much more typical. The German box & manuals have "Lo-D" logo on instead of the Hitachi if the amp is the same. REVISITED 2020. Pleased to get a NOS Boxed one of these for a Customer & have Blogged about it on the January 2020 blog. One we have never found to Revisit as these sold more In Europe. The NOS one seems to be used once & has Transistor hiss, so 'forgotten about' for 38 years until it belatedly found it's niche in life. We wanted to find one, so to have one to work on with 2020 ideas over 6 years since the last one is interesting. We found the similar Hitachi SR-800 as Reviewed below. The SR-1100 was liked if it was too loud after upgrades if now we can deal with that far more sophisticatedly than before. Beyond Loud, the Sound was as told highlighted just above, if realising it still could do more, the reason why the 1972 Realistic STA-220 & STA-150 made by Hitachi appealed. Circuits. Phono & Mic inputs have ICs, these may hiss as the notorious 2SC458 shape shows inside. Preamp has 4 transistors per channel, 1 is a Buffer, if all discrete components so here the hissy transistors to replace if the SR-800 oddly has no Hiss. Preamp is complex for High & Low Filter. Some odd design here that the SR-800 doesnt have so it plays Bass more as expected. Power Supply is modest & the 3 main capactors are all 2200µf if the Speaker output ones work on 37v & the main cap 82v. Sound As Original. More on the SR-1100 blog. The Treble & Midrange clean if a little tame. Bass is poor on this, why they designed the SR-1100 to be so weak on Bass is a mystery & the later SR-800 is very different. If you compared this in a Shop, you'd choose another amp, a shame as it's well made, great looker & from our 2013 version, we got a Quality Sound from it. As Upgrading 2020 style, high hopes on this one. As Original & Serviced, to now rate as 'Recommended' for the weak bass, if for the Clean sound Mid & Treble it's a 'Very Good'. Upgrade potential is Excellent to us. Once Recapped with Upgrades. An issue on this amp, unlike any other is that 'Aux' & 'Tape In' have a Resistor on the Input. The Tuner & Phono play a certain level if Aux & Tape are too loud. To try to up the gain on Tuner & Phono doesn't seem possible, once hearing Aux is so much louder, spending ages getting Aux right then finding Tuner & Phono don't match as in half the volume, the SR-800 earlier model as below has none of this Inputs Volume difference. Even as Raw & rough the SR-800 has a proper Bass, the SR-1100 is quite feeble. we never found a SR-1100 since our 2013 one if have Revisited many amps. This with the Upgrades that Make Other amps sound great leaves it less than 'Excellent' on first try. To give revised opinions keeps Opinions fair, we knocked it down to VG-EX. Bass is weak, the sound Overall is clean, if the SR-1100 needs more done, which is Our Interest as well, not having had one since 2013 & the Opinions have moved on. Phono plays without Hiss as it uses those 2SC458 in the package, depends on the batch. More Upgrades were needed to get an 'Excellent'. We try on Headphones first & after deep circuit gazing to find odd design, we question everything. On Speakers you'd not hear the lesser sound, if we've not adjusted & checked it for speakers yet. What does 'Excellent' mean? Simply we'd be happy playing it, this brought up Doubt so to go Searching after Upgrading more. SR-800 as below has No Limiting Aux-Tape Resistors & not the odd circuit. Finally Pleased with the Amp to our 2020 Ideals, we put it back to 'Excellent'. Final Opinion. Now sorted plus some extras, the Amp is actually decent with the Input Resistor. Played other amps since as hearing this by itself needed to get Reference Amps to listen again. the 1973 JVC 4VN990 we played quite a bit & just before this. Hitachi is nice, Bassy Sound now, Crisp Treble. BUY-RAW RATING: Good if not Hissy. COOL RATING: 8 nice looking amp with wood side cheeks, after 7 years of more amps, this clean styling is appealing. (2013-2020)
1971-72 Hitachi SR-800 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 35w.
CC. The Second Model to the SR-1100 above. As hard to find also, if these did sell more in EU as the 2020 SR-1100 we had came from Germany. This SR-800 we got as the SR-1100 is a good looking amp & also the chance it's simplified compared to the SR-1100 which has some strange overdesign that we need to sort fo the Customers one. This SR-800 is the same size, the rear panel the same & the fascia only slightly different with thin lever switches & the Headphone socket moved to the left. Inside it's different, it actually has the same Power Amp board as the 1972 Realistic STA-150. The 3 main capacitors are fitted side on Phono board with those FA6001 ICs that have 2SC458 inside than often go hissy. Much strangely so similar if less Busy with the Preamp-Tone board with 4 transistors unlike the 6 of the SR-1100. Less wiring on the selector as no FM Mute. But we wanted to try this as the 1971-72 Hitachi range were liked & built well. Multivoltage block under a cover underneath. No Service Manuals on this & at the time in 2013 the SR-1100 we had to scan the circuit. Blind buy here, it could have had ICs on the Preamp if doesn't. The simplified Preamp on a first try shows the thin Bass of the SR-1100 isn't a problem here, even tested Raw with noisy controls to hear it sounds fresher than the SR-1100 does on that NOS one, if no Hiss on the SR-800. Power Rating not so clear as with the SR-1100, here the HT is 64v. Bearing in mind the Realistic STA-150 similarity, 35w RMS is probably right, 40w/40w elsewhere is that pointless "one channel playing" rating. The FA6001 is detailed in the HFE scan uploaded since we had one first time. It's visibly the 2SC458 x2 plus 8 resistors including NFB stages. all but one value is shown, to rebuild if the IC was bad will be tricky. We have seen a lot of amps since 2013, to see the rare SR-1100 again to be reminded of the Quality beyond the Phono ICs, we have got to try this one. The later Hitachi SR-802 has an IC on the Power Amp inputs, a 1975 model. No trace of any Service Manual as a .pdf if to find an original printed one on ebay from USA, not cheap, but added with the Amp buy price it's worthwhile. Visual Comparing. Familiar with the SR-1100 now, the SR-800 is quite different in some ways. Noticeably the Tuner, the Boards are all different & the Tuning Front End Rotary parts are more updated as One Block, not two. Power amp on one horizontal board with the Power Supply, familiar from the Realistic STA-150. Underneath more space for smaller Tuner unit, Phono-Mic the same. No board by Headphones. Transformer similar if 1cm shorter. A small Resistor board needs the Manual to see what it does. The Days when models in the range could be very different. Rear Wattage (VA) rating 185w if the SR-1100 is 190w, Fuse Rating is 1A/1.5A which seems modest. Other Fuse pair is 2.5A/3A for the Power Amp stage. No Relay as Capacitor Coupled. Which is Earlier? SR-800 has no silly circuitry the SR-1100 does. Transformer 2217401 & 2217451. Main Amp 251839 & 251873 means SR-1100 is earlier than SR-800. Could be 2 designers, the SR-800 seeing the "goofs" in the SR-1100. See very close Board Numbers on the Realistic STA-150 review, both have a similar Power Amp board, STA 150 is 251942. Manual. There isn't a .pdf one yet if we got the Printed One. Look at the Circuits. The SR-800 is the Better Design for Sure. No Limiting on Aux & Tape Inputs. ICs with 2SC458 inside for Phono & Mic. Rest is Transistors. Some Limiting in Circuit as are nearly all Amps. No Bass Filter in the SR-800, the SR-1100 was too complex with 'T' Filters that can still react even switched out, didn't like that. Here only a High Filter, Tone-Pre is 2 Transistors with NFB Tone, the SR-1100 was 4 including a Buffer. Power Amps much Different also, SR-800 just 6 Transistors, the SR-1100 has 9. Realistic STA-150 is very like the SR-800 power amp 251942 number. On having both STA-220 & STA-150, the 'lesser' model was liked a bit more for the sound. Both Realistic with Transistor Phono, not basic ICs. Power Supply is interesting, 2 windings, One for Bulbs & One for the Rest. 65v HT dropped via Regulator to 45v for Pre-Tone & Phono, another for the Tuner stages. Dropped on Zener Diodes as became more common later on. Looking Technical here as Design interests if maybe reading a little random, how we wrote it. Verdict Before Upgrading. Will be a Great Sounding Amp Upgraded as were the Realistic ones & the SR-1100 got there beyond the Input resistors. With others here being worked on, this may be a 'Seller', so to do to a Price, not one of the 'Experimental' ones, if it can change. Waking It Up. Rough from Decades ignored, if why. Not used much, bit dirty, recent PAT test passed it if missed a nick in the cable, not live, but double insulation hole. Servicing it up, nice amp & noted as 'Nice Sound' so try upgrading the more tricky ones first as problems are normal. Cleans up very nice, the base lid on these always corrodes around the rubber feet, even the NOS SR-1100 had a bit. Playing Serviced As Original. Betters the SR-1100 for Overall Sound if on Headphones we've got Volume to '5' which is usually no more than '3' on other amps, gain is a bit lacking for 35w, if on servicing to see it only has a 1A fuse is telling. The Realistic receivers by Hitachi were better overall, we sold both a few years back if like both STA-150 & STA-220. Sound shows Promise for Upgrading, many do if the 1970s Buyer will have wanted more Volume. Compare SR-800 Raw to SR-1100 Upgraded. To want to compare these two before the 1100 goes back. SR-800 Volume low if it has a Fresh Sound. SR-1100 sat on top of the SR-800, Treble Detail is a bit lacking if Volume by '2' is a good Volume. The Duller Sound apart, they both have a Pleasing Sound. SR-1100 Display is brighter than the SR-800. Sane Design. What the SR-800 is about needs our Manual scanned to look closer, design is very different to the SR-1100. No Limiting Input Resistor, here Aux goes straight to the Pre-Tone with a Buffer Stage first Transistor. NFB Tone around the second one, onto the High Filter which is just Capacitors switched in or not. Pre Out-Main In connector after Volume & Balance to the Power Amp with one gain transistor, then Bias, P-P Drivers then Outputs. No Relay, No Protection Circuits, just Fuses on the HT line for each channel if Capacitor Coupled. Power Supply around 56v then a Regulator with Zeners to get the 43v for the Phono & Pre-Tone then 15v for the Tuner, all from One Secondary winding plus a Bulbs one. Expecting this to be a good one bettering the SR-1100 & IA-1000 for no limiting & probably the Realistic-Hitachi two, for lack of manuals when we had those. Partly Done Opinion. Bits to order but enough done to hear what it's about, Another Low NFB winner, to get a Fresh sound that several amps now play to us, if it's In The Upgrade. Bit of Bass EQ on the Soundcard as still on Main Cap & Output Caps plus the old corroded Driver Transistors. Playing it now, very nice Sound. This is based on the Realistic STA-150 as Hitachi built, the Power amp here 35w much the same as the STA-150 32.5w if the SR-800 preamp is without the extra STA-150 features on the preamp. Our SR-800 well used, had a Tuner MPX repair on 2 capacitors & the Top Amp regulator. Volume Control is not good, too noisy & pulls in & out so already uses for the Two Parted Amp ones, try buying a Splined 100K Loudness Volume Control. This is a Sane Design for Sure, already plays Rock with the sort of Confident Sound the 1970 Sansui 350a 20w amp does, far from the weedy Rotel 400A sound. Plays 'Start' by The Jam well with very good focus & weight. So different to the SR-1100 which got a nice sound but without this Fast Punchy Sound. Back On Planet Earth. That Review we've just re-read, it tells differences between the Hitachi & Realistic-Hitachi, if that's our interest. The SR-800 is a less fussy version of the SR-1100. Recaps & Upgrades well. Given it More Gain to get a Better Volume. Now Finished, it sounds very decent with a better gain. Upgrades to always be 'Excellent' this certainly is with Decent Bass, Crisp Treble & Clean Midrange. One we'd keep longer if got a few others that are not so well behaved. Of the SR-1100 & SR-800, this the Best one as a better design. BUY-RAW RATING: Risk of Hissy Transistors & usual aging. Well made amp. COOL RATING: 7 nice smart looks. (2020)
1971 JVC 5521(L) receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 22w.
SC, not Diff, Direct Coupled, Relay (of sorts). Yet another of those amps left in the attic for 40 years & a home for optimistic spiders, but why it got dumped is a mystery as ever. It sounds great even unserviced & louder than 22w suggests. We've championed this brand with their excellent 1960s amps & this is no lesser beast. Styling a little updated from the 60s ones & a semi-complimentary design. The main caps are only 2200µf 35v like 1960s spec still. The user manual is dated '373' but we found the JVC VR-5525L was dated "7311" inside so the 5521 is the 1971 model. We're playing it as typing still unserviced & it's got a clean open sound with wide stereo if only deepest bass is a bit shy but still there & does improve with use. Build inside is updated if still the phono, pre & power amp on the long board & very well labelled. The front sticker says "4 Channel Ready" if how they consider this is a mystery as it's fully stereo only with no extras like some Sony amps have to control 4 channel. Only a FM Det out for the Tuner suggests 4 Channel FM could be used if it never existed. The SEA graphic equaliser puts buyers off these if they are very clean & you'd only use the 40Hz & 15kHz ones like a tone control & it's defeatable, see below for more detail. As most semi complimentary amps by 1971 are with Differentials, doesn't appear there is here, explaining the cleaner sound. All transistors in the Audio stages unlike the later JVC 5535L which has one in the preamp, if shows no differentials in the 5535 either. Not that differentials are bad but circuits often are very compromised as the differential gives better specs for less quality. A VR5541 is a higher model if it still says 150w (VA rating) & rated 34w RMS. The 5521L works on ±28.5v HT. It's got enough kick to make Rock sound convincing too even at 22w, more the volume & confidence of a 45w amp. The sound here betters any other 1973 amp with ease if power is going to be less & may not suit cheap speakers so the unaware who barely used it missed out on the accurate clean sound. Heavy wood case if only vinyl wrap but smart. As this sounds so good & needs upgrading, a service manual is buyable. Reveals it's semi-complimentary if without the Differential & the power amp is just 6 transistors explaining the fresh sound. Phono x2 & Pre-SEA is x2 transistors. The Power Amp design is still like the earlier designs, none of the low spec the Differential ones get & old-style values, making this probably the only brand to not use Differentials with SC output since the few 1965-67 ones above. We like that. For a 22w amp the circuit is as good as any 45w one, no obvious limiters & sensible design. Early JVC are the hidden gems in Vintage Hifi, though what their bland silver box era are like we've not tried, if the JVC JAS11 has a STK output block, the big 80w JVC JAS71 looks more typical of a 1977 amp if all transistors. Recapped it now & there's the quality of the earlier JVCs. For 22w it has good volume & a solid bassline without getting into problems. As it lacks the differentials which often flatten the sound in some amps if not well designed, this is open & fresh still like the pre 1970 amps. This little 22-watter has all the quality of our best 1960s amps. REVISITED 2019: We get the VR-5521 version, the above was the UK VR-5521L with LW band, the 5521 is FM/MW only. Again a long abandoned amp, perhaps the looks seemed old fashioned compared to the rather samey-gaudy 1977 Silver look, so this amp unwisely get shelved. Owner used this dusty gem for a Month so it's working one. Sounds fine as a raw grade amp. Worth a Blog on how it sounds as Original so see the Aug 2019 Blog section, it's not too impressive as original if these upgrade well. Relay. 2023 putting more terms remembers this as Relay but on always unless a fault? Upgrading. The customer wants us to get the Best out of this amp. The basic design is good as JVC always are, if good opportunity to hear how a 1973 Gerneration JVC upgrades. The manual shows Power Amp section with strange "TS301" and "TS302" as mid power drivers, ours has more regular 2SC875E and 2SA532 as our 2015 one had also. The main board with Phono, Pre-Tone & Power Amp looks logical if less easy underneath. Clearly forgot how fiddly this amp is to redo, tiny board sections with wires in the way underneath. Phono, Preamp, unused stage, Power Amp & Relay circuit all on the centre board & not a board you can take out as everything wired to it. In interests of keeping the amp alive, Transistor X706 has 'B' & 'E' swapped on the board print if the manual is right. Now Done. Runs Cool on the Outputs. It's a 22w amp if on Headphones Volume is decent. Upgrades have made this a smoother amp. For what it is, a 22w midprice receiver, it sounds good enough to scrape an Excellent, but it does lack a more sophisticated sound that the recent JVC 5040U brought. The customer wanted attention on the Phono, so playing a 45 the sound is well focussed and listenable, but we needed the SEA EQ quite heavily altered from Flat to be "Our Sound", as an example the Sliders going L to R are +4, -8, -8, +3 and +12. RIAA in amps is never to what we like & odds are most users wouldn't cut the 250Hz & 1kHz as much as we have. To us, their design with our upgrades on Phono sounded too Boxy & Limited, our extreme SEA settings gave it a quite decent sound, if that's for our upgrades. We generally Don't Like RIAA Phono Transistor stages, if overall with the EQ set, this is very well focussed now. Loudspeakers. Try it on Speakers with TV sound. The Amp only has Bias Adjust, so the DC offset isn't ideal, 150mV with no Load & only slightly better at 110mV with a Speaker on it. Should be nearer to 0mV but the early direct coupled amps often test similarly if it's Safe to use, only over 1v DC offset is less good. We're trying on our speakers as we know it's Safe. with our Tannoy Golds, this is where the JVCs impress. Very decent precise sound, matches perfectly. We're using amps like 1965 Sansui TR-707A, Akai AA-8500 & Marantz 2385 as of writing, the JVC with 22w does not let itself down. Wide Stereo, good detail. Bass at 22w is there if not big sounding as you'd expect, no thick Retro Bass. Midrange is spot on. Needs SEA gain for us, +8, 0, 0, +4 and +12, this matches settings we use on Tone Controls for TV listening level. The Customer will be pleased with the Sound on Speakers. BUY-RAW RATING: Good. COOL RATING: 6 the early black fascia JVC are a little functional looking if neatly done if in a Retro Pad sort of way that has guy appeal if a little stark for all. (2015-2019)
1971 Leak Delta 30 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 15w.
CC. Always popular as stylish, sounds are a Very Good intro to vintage hifi, like the Trios in this section. Sound is clean & very rich, but ultimately limited by basic designs & power. Treat it modestly and it'll please though. The Leak range are all good starter amps, if at 15w on this one. Based on the Stereo 30 Plus if with the Stereo 70 type plug in boards. The Delta '30' is basically the 1968-69 '30 Plus' in a new case. See the 1971 Leak Delta 70 below as we ponder upgrading one. BUY-RAW RATING: Good. COOL RATING: 8 the Delta range is very appealing after the crude Stereo range, flush fitting thick fascia onto teak case with the back grille. In high grade these do look so cute. (2013)
1971 Leak Delta 70 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 30w.
CC. Always popular as stylish, sounds are a Very Good intro to vintage hifi, like the Trios in this section. Sound is clean & very rich, but ultimately limited by basic designs & power. The Stereo 70 is basically the same amp in an earlier design case, the early Stereo 30 & 30 plus is different. Note the can-type board transistors used are all obsolete & no guides offer substitutes, but he who understands transistors will find there are endless 'better-than' equivalents, so don't give up on a non-worker. The Delta range '70' is basically the 1968 '70' in a new case & looks better for it. The front plastic part with spring inside will need regluing to stop the controls wobbling else it's about all that you have to do with these. The back top of case thin aluminium strip don't unpick it if part loose as it'll get dents & look ugly. Beware amateurs saying it has a MC input, it's a MICrophone input. Pity there wasn't a 60w amp in this range. WORTH UPGRADING ONE? We've known the Leak Delta since getting one in the early 1990s & at a time did buy these but with the work of servicing, we outpriced ourselves as they are still a good budget buy. But the Leak Delta amps we have a fondness for, as one of the first Vintage amps we had. The Stereo 30+/70 are the same amp in an more 1960s earlier case design. The Delta 30/70 have a nice look if are not of any real excellence, but they are enjoyable & we'd recommend a Leak 30 or 70 as a perfect starter amp into Vintage. But to upgrade? Firstly the transistors in these are often poor, the Mullard BC147 type, & long ago putting in better ones sorted out the rough sound, of which the Stereo 30/70 suffer worst. The amp with the 4 plug-in boards is easy to get to though the axial caps limit things as only general quality ones are buyable. The trouble straight away is the Input circuit, it's Phono MM or Ceramic plus 2 Tuner with high-low switches. The best input is Tuner 1 as it has no resistor but we remember it being too loud as the circuit isn't a standard one. This sort of kills any upgrade-ability really, though the circuit gain could be altered & the Delta 75 has none of this. But looking further reminds us of the Tape Out having the Tone stage in it, not Flat which is annoying we remember from long ago if you record tracks from it. The power amp is not bad, it's just the preamp gain & inputs issue that holds it back. To fully upgrade one with redesign would take time & the results would be better but a risk of just too much of the amp would need redoing & for us selling upgraded hifi, we feel we'd outprice the amp as we did before on servicing them as they are easily bought & reliable. Getting axial caps is difficult as limited ranges & they need to fit the spaces. BUY-RAW RATING: Good. COOL RATING: 8 the Delta range is very appealing after the crude Stereo range, flush fitting thich fascia onto teak case with the back grille. In high grade these do look so cute. (2013)
1971 Leak Delta 75 receiver ↑
AS-ORIGINAL (Once Serviced): **This Will Fail = Too High Risky** Very sadly it's such a lousy design, remarkably poorly made. UPGRADED: Very Good. 35w.
CC. Unlike the reliable Delta 30 & Delta 70 amps, this is perhaps the Worst Non-Budget Amplifier Ever Made, despite a decent sound. This was sold as a Quality Item, but so badly made & designed it's a Stinker. They must have failed after a couple of years or much less if used more as these are always found in 'attic' grade as the owner paid a hefty £160 for it in 1971-73, similar price as the 40w Sony STR-6055 & Teac AG-6000 with 50w. Not good value was it? The one on our 'Solds' page we recapped fully & it liked a few years ago & kept it for a while as it was then reliable. The construction is still like bits of other amp thrown together is a fair description of how it's made, it takes the Leak Tuner boards & fits the rest around it. The design got many changes over the production run, adding in a ferrite AM tuner rod inside as well as adding extra resistors to supposedly better the spec but spoils the sound instead. The earliest ones don't have the red warning box on the back & no antenna inside. The phono stage sounded decent. Nov 1971 HFN/RR shows the debut of this & describes it as "based on the Wharfedale 100.1 but styled in the Leak Delta series and includes the old Leak Electronics". This shows it's a post Harold Leak era cobbled together design using old Leak parts. It is a disaster of an amp, which is a pity as it is a great looking amp, but so cheaply & badly made. REVISITED. We thought we'd give it one last try a few years later than the last ones. First opinion was 'it's just so badly made'. But no good. It's just got too many bad problems, terrible build quality & TV grade parts. It's disappointing as we did get a decent sound from it part upgraded but it was too unreliable so in the bin went a third one, it burnt resistors, cooked capacitors but gave 15 mins play time four times before repairing got it too messy for the weak track just comes away so easily. Out of 4 we had, only the later run one on the 'Solds' page was safe & reliable, more miracle than luck, we used it often for a few months before selling it. But all others since have failed, failed & failed again. Enough. Very sad, but Harold Leak insulted buyers with this just before he sold out the company, the guy who was the first to use, not invent, NFB had a sick joke on the public with this awful amp. Many bad faults from bad capacitors, ultra thin board track, inadequate shielding & grounding. BUY-RAW RATING: Do Not Buy This Amp. Guaranteed Risk of failure due to bad capacitors & rubbish construction & design. If one is sold as working but original it'll not last very long as it must be recapped. We've had 4 & only one survived & if we give up on it, so will you. This amp makes the awful 500 series Armstrong seem like quality, it's that bad. COOL RATING: 8 the Delta range is very appealing after the crude Stereo range, flush fitting thick fascia onto teak case with the back grille. In high grade these do look so cute. The receiver looks Very Good too, pity it's so unreliable to the point of too risky. (2011-14)
1971 Marantz 2270 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 70w.
SC, DIFF, Direct Coupled, Relay. One we've tried for, if to get one as a Customer's Amp. It's an Unusual amp we have here, it's a 'New Old Stock' one which for being unused for decades can bring issues. Whoever found it put a New Black powder-coated fascia on & a glossy piano black case. See these on ebay, they seem quite recent parts. They are very well made, if not for Purists, it'll keep one with fascia damage alive. All the rest is original, to see the insides like new actually is real here, usually Marantz have been used since new without seeing 'The Attic' as other brands did. FM Tuner has an IC only in the last stage, 8 ceramic filters betters the 1971 Sony STR-6065 we thought was very decent, to compare. Phono (P700) is 3 transistors per channel. Tone-Preamp (P400) is the typical Marantz design with Midrange. Power Amp with a Differential with 3 different adjust pots amid the slightly unusual design. Relay on the Output, Power Supply on two windings with 6800µf 55v main caps. Circuitwise it looks good, the excess of Ceramics the 2245 below had, to be discovered. Got It Working Now. New Old Stock Hifi that's now 50 years old certainly had a few issues to solve. It's like Recommissioning a car left unused for Decades, things age & just selling it as 'it works' is a bad deal for the buyer, had two NOS amps now. Relay clicks on even. The Sound As Original. The 2245 had a soft sound & to wonder how this compared. No Fear on this 2270, it has a very decent fresh sound, if not quite as crisp as other Marantz. The Retro Bass shows a bit if the 2270 is right up there with the Best Sounding Marantz we've had to date, the 4ch Marantz 4230. A Blog where we tested 5 Amps as Original had this rate highly, if the JVC one just has a more open sound for design differences, the 2270 being a little lacking in finesse with a 'shoutiness' that could be aging related as not a typical sound. Recap & Upgrade next. Circuits. All Marantz seem to have a different design on the higher models, some more successful than others. The Receivers are better designs overall, as the 1122DC & 1152DC tell. Phono (P700) is 3 transistors per channel, before the Class B designs so is a good design, why it needs a Diode on the signal between TR 2&3 is one of the quirks of design that Marantz often do. Tone (P400 + P450) is the usual Marantz one, 4 transistors & Treble-Mid-Bass triple controls. Power Amp is one for L+R that sit as far apart in the case, not seen it done like this with Marantz. Differential input, Driver then into Push-Pull stages with R782-3 as adjusters for the Protection. The 2 larger rotary pots R762 nearer the front is DC offset. R763 nearer the back is the Bias. There must be further changes as R794-5 isn't shown if no R782-3. Power Supply & Relay is P800 with the Mains Voltage change block under a cover by the two 6800µf 55v Main Capacitors. Ours dated 1974 has 55v 9000µf Elnas as original, so improved & better than the Marantz 2385 got. To cut them open interestingly shows they are still damp, not crusty & still would be useable, if in reality many other Elnas have showed dry & bad, which depends on how stored & how much used. Main Amp ASO adjustment. To work out what this does via the circuits says why the 2385 doesn't have this. If nothing has been replaced to affect it, leave it be. If it has, then it's for a tech to sort. Verdict Before Upgrading. A very decent amp, physically well made, designs mainly good. But it is rather Modest for a big 70w amp for 1971. The Retro Bass is a lazy idea & one that will not please modern users with it's Peaky Bass ringing effect, ridiculous peak at 50Hz & not flat until over 300Hz, see a future blog. It's surprising that a Top of the Range model is like this, perhaps why it's a harder one to find. Heavy amp, packed with lots of boards for the Tuner. Surprisingly the Tone board is half cheap ceramics which is not Hifi to us, the 2245 was similar. Beware board changes giving one hole two items plus some boards & the diagrams don't show the capacitor '+' marking. Now Upgraded. No more thick Retro Bass, the Bass is Natural like other Marantz are once we upgrade them. Smooth sound, no Shouty rough sound now & it plays fast Dynamics as designed into it's 70w to give a punchy sound. It plays Rock with a confident weight that is not in too many amps. The Sound is Quality, a Rich Friendly Domestic Sound with highest treble rolled off which the 1966 amps do better once much upgraded. On the Soundcard EQ to add +3dB at 8kHz brings a crisper sound, Treble tone adds similar. Wide Stereo here. The slight Treble roll-off & resulting tiny lack of focus is a fussy opinion, but the 2270 is certainly a great amp. To run in & adjust Bias as just slightly warm on the Heatsinks. Tested & Done. Clean 33v Sinewave output clips evenly, reasonable for 70w if Yamaha CR-1020 can do 38v. On Speakers a small click as the relay turns on & the sound has the Marantz signature, if the Treble not as crisp as the later 2235B can do. Alter the Tone controls, a bit less on Midrange gives a good sound. Proper Bass without the Retro Bass sound. Marantz & other brands do vary in their overall sound, the 1971 range are good sounding without the Retro Bass, a step towards the crisper sound of the 1973-75 ranges. BUY-RAW RATING: Getting too old to be useable daily especially if well used. COOL RATING: 8 typical smart looks, great in the brown wood case. Our one with the repro black fascia & high gloss black cabinet was smart but not a true Vintage look. (2021-2022)
1971 Marantz 2245 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 45w.
SC, DIFF, Direct Coupled, Relay. Early classic era Marantz, pre the hex nuts fascia, with a sweet but clean & focussed sound you can upgrade the deliberate-cynical limitations out to bring it away from the soft blurry bass-light sound it is as-made, which keeps the rating lower. Well built amp that has a proper metal lamps assembly, not the plastic one of later models. Beware missing pre-power jumpers on the back which are needed for the amp to work. Beware the fuses on the board on the right heatsink fitted to some regions has 240v mains on it but the fuses are left open & easy to touch. Also to work on the power amps & bulbs is tricky. Hides it's potential with a surprising excess of cheap ceramics in the tone stage, but you may like that cosy soft sound. We upgraded ours & it came alive towards Excellent territory, if the 2265B here at the same time was preferred. So treble is soft, deep bass is light if thick on upper bass, this amp does sound overall nice, but it's severely hiding it's potential compared to fresher sounding amps. A nice amp though if one that sold quickly before we had time to think to upgrade it further as can happen. BUY-RAW RATING: Good. COOL RATING: 9 in the wood case, a bit plain without it. Earlier looks without the cute hex nuts but Marantz stuck with this design for so long as it is just so right. (2013)
1971 National-Panasonic SA-5800 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 23w.
SC, DIFF, Direct Coupled. This brand aka Technics since 1978-ish. Firstly ignore the 23w rating, it plays like a 40w amp. Cute looking & very well made 11kg amp it goes in well with other high rated ones here. A most appealing neutral & sweet sound with good volume if not the most bass. A little bargain that deserves our lofty ranking, our serviced & part recapped one sold in less than one day. One for the collector too, it's cute. The brochure is just a bit trippy in it's sell with "let the SA-5800 be your Magic Carpet. It's Vibrant Power will set a crowd swinging to the throbbing beat, or gently soothe the mediative individual", and "The Well Bred Child of close knit Family of Electronic Wizards", far out, man. For liking this amp, we got the 1967 SA-65 receiver above... Revisited 2020. Long time to get another of these, the Customer wanting a Rebuild got it in Germany. Cute amp for sure. 410mm wide, 310mm deep not inc fittings & 130mm high. Heavier than the size suggestsVery smart cleanly designed fascia, lights up a strange colour. This one has different bare wire screw connectors, better with 4mm sockets still. 27w/27w rated if the German info says 23w per channel into 8 ohms, it sounds louder than 23w we thought before. High Quality Build for a 'Midprice' 23w amp. Rear has Phono as Phono Sockets & DIN as more a German selling amp. 1x Aux, Tape as both. Neat Pre Out-Main In plugs & AC outlets. 3A Speaker Fuses for 23w & the label says '230w' both which suggest a higher power. But 2x 2200µf 35v main Capacitors suggest it has more Current Capability, we'll find out on our Tannoys once done. Speaker Sockets. Our First One & the one in thge User Manual has the Thin Screw Barrel ttpe ones as does the 4ch SA-6400X. This second one has bizarre 10mm Nut type pieces, the hole won't grip any wire if the only way is to use 5mm Spade "Y" type connectors. Awful connector, it'd be wrapped with Bare Wire touching on the painted grounded case. Must be on the very first run. If you try to change the Sockets by removing, you'll find something unexpected. Circuit. Power amps on 2SD218, 60w 7A outputs for 23w gives away a secret as does the 50w size Transformer. Top Power supply board with Overheating Resistors surprising. Underneath tidy, shows the thicker gauge steel for the Era. Main Capacitors in a sort of Box wth the Clamps, size may be limited. Phono x2 Transistors per channel, NFB Tone with x2 Transistors. Differential Power amp. Circuits look good, Nat Pan said "We Sound Better" in Adverts, they use a well crafted amount of 'Sound Shaping' that gives a pleasing sound. Bass is very light on the Amp & it Sounds Rather Small as in not too Dynamic. Certainly a Quality Sound in the Amp, if this is where Upgrades can do well, we haven't done a Full Upgrade on this amp yet. What's Inside? Build quality here is very nice on Fascia, Inputs & the Metalwork. The Circuits are actually rather Cost Cut on a deeper look. Couldn't find this one Ourselves, so to Upgrade it like it's Ours is good for both. Speaker Connectors here are Bizarre, a Spike that a metal sleeve tightens onto, with the spike still sowing. The later 'tighten onto a cone' one as we had & the SA-6400X has a better idea, if 4mm sockets more useful. Preamp HT is strangely Minus Voltage with PNP transistors on -40v, an old Germanium idea. 2200µf 35v main caps typical spec for the era if tiny things. Top Power Supply is in the 'NAD' style with overheating resistors which is surprisingly 'not good'. Upgrades it needs quite a lot. See the similar 1972 SA-6400X for more & a compare. Verdict as Upggraded. Nat-Pan early amps are a bit special, not the Highest Power but a Quality Build & Quality Sound. The difficulty with the insane Speaker Connectors to only be able to fit connectors with shoert wire & 4mm socket. Impossible to drill the holes plus a long 'sausage' of wires far too close. Once sorted, the SA-5800 is one of the Best Built for the 23w Power with a sound to match. BUY-RAW RATING: Good. COOL RATING: 8 very nice fascia if vinyl wrap loses it a point, purposeful & cute looking. (2013-2020)
1971 Radford HD-250 amplifier ↑
AS-ORIGINAL (Once Serviced): Average. UPGRADED: n/a. 50w.
CC. **Updated** We first had this in 2012 before getting to try amps on our Tannoy Speakers & before offering Upgrades. We didn't like it as the 2012 opinion says, a 2023 update explains why we didn't like it, but it reads less well these days so to have a new look in 2018, if we've not got one since. Radford are a respected brand for their Valve Pre & Power amps that were from the era of Building In to a cabinet. The HD-250 is not going to impress on looks, a thin plastic coated aluminium lid with tape inside to stop it bending to touch the main capacitors, open frame transformer that hummed until isolating it better. Axial Capacitors are less easy to upgrade. The Fascia is like Lab Kit, as plain as can be & one we saw later shows the fascia was a purple anodised colour that fades, unless you leave it for decades & the purple is behind the sliders. The design was a bit poor, early ones have no Headphone & to get out of Tape you had to press both buttons together to cancel, did they even try it out before selling? We used our Headphone box on the Speaker outputs to try it. The Solds Gallery shows our one from 2012, mismatched adjust pots on the Power Amp boards looks sloppy too. It had a strange 'Channel Gain' volume slider plus the actual Volume Slider. This even set to 0dB was way too loud & it upset hearing on headphones on playing other amps, the Leak Delta 75 here at the same time was preferred for sound. "Overloud & Shouty" was our opinion at the time. Output Transistors on the back should have the clip-on TO3 covers, again bad design as once these fall off 35v-70v is Live on the rear. Ours nearly caught fire as the Mains Switch capacitor was found smoking heavily one time. Safety is not the deal here, if not hard to correct it. Still used Imperial thread screws, we later saw the amp was based on a 1968 SCA-30 amp of theirs. It never seemed like a 50w amp for how easy it got into distortion if this was rated 50w in a 1977 HFN ad & described as "High Definition", hmm. Rated 50w, Max power 90w but distortion 0.006% at 25w is a bit foolish as it sounded awful. On spec & not altered so why so awful? Rated very low as it has the cheek to call itself a "Reference Series" amp. Construction looked like a cheap kit amp, not Heathkit quality, with long unshielded signal cables L+R twisted together, so much for crosstalk which was lousy making stereo tracks a blurry mess. The phono stage was overdesigned & sounded very boring despite their db ratings. The Radford SCA-30 is the earlier version, see Other Amps page for that & more Radford. We have thought to try this again around 2016 as our rating is a little harsh, but left it that time. It's a Rare amp & our 2012 opinion may not be what we'd think now, so have a look at the Circuit Diagrams. Phono is a bit confusing as well as lo-res, it's got a Tape Buffer stage on the right, if the Phono part has that Class B push-pull design needing 5 transistor actually a circuit others copied by the later 1970s, if it sounded lifeless. Tone again a hard one to unravel if high NFB on the first stage, an odd mid section & then another high NFB stage. Power Amp seems a good design except for very high NFB yet again. Horrible design & build throughout & no wonder it sounded so lousy, our 2012 opinion makes sense now. A very flattened alien sound we can see in the circuit & having learned what is a good circuit with upgrading, the Radford HD-250 is the truly wors. t amp there is, one that claims to be 'High Definition' not just the average 7w budget audio gear. A 2023 Problem Noticed. Later getting better Circuit Diagrams, to see the Headphone Resistor is way wrong, far too Loud as we found, this will certainly be why we didn't like it & never tried it on Speakers. But all the Unshielded Twisted Audio Cable gave awful Crosstalk. This amp may improve with some changes, the buyer of it must have used it on Speakers to find it better. BUY-RAW RATING: Good if likely Dangerous. COOL RATING: 1 this is one ugly swine of an amp, it looks like cheap lab kit & with none of the pro looks lab kit can have. The ugliest amp ever matching a Sugden as on the Other Amps page. (2012-2018-2023)
1971 Revox A78 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: n/a. 40w.
CC. At Last we get a Revox. We looked at these in around 2013 on the "Other Amps" page if the difficulty is to find a Nice Grade complete one & at the right price. A Swiss brand by Willi Studer & the name Studer-Revox is much rated for their Open Reel Tape Machines. 1971 dated Schematic. We'll do this review as an 'Unboxing' as we've not opened it yet & what you'll read will be our first opinions. a tall amp 157mm high if not a deep unit at 228mm if fittings add more. 412mm wide so assume it's this size to stand a Revox Tape Machine on top. Top sprung flap is often broken, this one is good & it has Level Adjusts for the Inputs, Speaker buttons for 2 pairs & a fuse, keeps little used controls out of the way. A line of 5 push buttons below the flap on the neutral Grey Fascia give it a late 1960s look if the bright Teak veneer case livens it up. Old Cooker type rotary controls often missing cap ends have double use as Mode & Volume, Selector & Balance plus Tone as L+R keep the fascia tidy. Also 2 6.3mm Headphone Sockets & a 6.3mm Tape Output socket probably meaning a source to record from & power switch with light. The rear Panel has a 2-pin mains cable, we'd prefer 3 core mains for today's needs, DIN sockets for Speakers not great as 40w should use bigger cable. Inputs are Phono sockets for Tape, Tuner, Mic & MM Phono if DIN sockets for Aux & Ceramic Phono if the switch chooses either not both. Cast Iron Heatsinks like the Heathkit AR-1500 above with "+" shaped transistor covers plus a Multivoltage 110-240v adjuster. All neat if we'd prefer 3-core mains & 4mm Speaker sockets. Underneath has 2 sledge type feet quite like Ferrograph who copied a similar look or inspired it as F307 & earlier A60 both 1968. Four untouched screws undo & the amp pushes out the front of the cabinet. First opinion of the inside is it's better made than expected, rather neatly done with lots of Screened Cables. Tantalums & Axial Capacitors with the end cable trailing down the side of the capacitor instead of the more typical Japan capacitors with wires on one end. Power amps on opaque Fibreglass boards like Rogers amps use & those push on wires onto tabs as is a typical build style. Solidly built with boards with push on edge connector means a lot to service in this so it will probably sound quite tired. 4 large capacitors are Elko 4700µf 50v as the Power Amp L+R have a Transformer tap per channel which is unusual, plus a third power supply for the preamp. Direct Coupled Outputs so no Coupling Capacitor if the A50 is fairly similar & is a 40w amp also. To see what the differences are & didn't realise both A50 & A78 are 40w, both appear much the same on a quick diagram compare. Getting it ready to plug in as sold as Working, the controls are a little lacking in confidence with the Preset ones under the flap a bit flimsy. Mains Cable wired insanely, Blue & Black wires old stylem Black is Live & a typical 13A fuse as in the 1970s you could only get 13A plugs & most were unaware an amp drawing 200w needs a 3A fuse not a 3kW 13A one. Great or Junk? The Swiss build quality is different from USA-Japan amps but it's Top Quality. The more we look to see quality in the construction makes UK amps like Ferrograph seem like Junk, the fear of the grainy Ferrograph sound really put us off buying these sort of Amps. To look at B&O gear & think "crap" at how badly it's made, look at the Beomaster 3000 inputs board for what we mean, if not seeing any of that here. First Play. It'll be tired as looks little used in decades, but here goes... Gentle bomp on turn on, using Tuner for Input. Sounds decent as good as any Japan amp from the same 1969-71 era. 'Loudn-Low' works like the Yamaha Loudness by reducing the volume leaving only the Bass which is a bit odd. Presence boosts the Upper Midrange about 2kHz slightly. Needs a Service if as Raw it's better than expected, a little background noise & the odd crackle. On Stereo tracks it has that odd L+R swap on Headphones like some USA amps do so the inputs need swapping. The amp has a pleasant sound & the Dual Power Supplies do give good Stereo width. Differences 1968 A50 to 1971 A78. Very little by the looks of it. Flap hides Speaker switches so 2 speaker pairs on A78. First 1.078.110 board is identical save a 50/47µf update. Second 1.078.069 is 1.178.069 on A78 adding the 'Presence' button plus the extra Transistor that the A50 doesn't have. Third 1.078.076 board is identical. Power Amp 1.078.114 is 1.178.114 on A78 is identical beyond updated 22/25/220/250µf, two low value capacitor additions, minor change to the protection & 2 transistor number changes. Probably updated based on Hifi Mag reviews, it's basically no different to the A50. Both have a 2.2 ohm resistor on the Speaker output so you could put the DIN with the round pin in one way for 4 ohm & the other for 8 ohm speakers if ours has that looking inside if there's a White Disc to rotate to match, arrow to the left for 8ohm, arrow to the right for 4 ohm adding in the resistor is probably not realised. Diode & Pot Issues. The power amp boards have one screw & then it pulls out with a wiggle. But they don't tell you there are 2 tiny diodes tightly fitted on the back of the board into the groove of the round metal bit the screw goes into, oops a click & broken diode. 1N4448 ones easily found. Pull board away & straight up to not break should be told. Diodes got, but then to see the 4 adjust pots are very weak as deteriorated with no grip means they need replacing or the amp will get damaged. The curse of EU amps returns, probably explains why Revox are parted out a lot on ebay. We got the Grundig SV80M as partly reviewed & saw similar difficulties with it to not fancy trying another, similar issues with B&O got us tired with them. But the diodes are slimmer than modern ones to push into the block, so if you break one swap the one above the hole (D503) to keep the size. These sort of diode & pot issues are what makes us not like EU amps, if sorted now & to tell to keep these alive. Taking It Apart. Thin spindly front connectors on the plastic knob parts look easy to break, if ours are good. 3 screws on the top plastic strip, flap hold down, undo 2 long bolts. the lower part is on pointed rods that just push in, so to pull apart. Not obvious at all. It's quite fragile in places, care needed to get to the adjust pots. Leaves the 4 rotary controls loose & wobbly as designed, the clear plastic dial acts to make them solid, very EU build quality. One to be careful of buying, we've seen rough ones & passed on trying this amp several times. The EU type of amp we've known from Radiograms plus Bang & Olufsen, to see the Grundig SV-80 was a difficult amp, this is less difficult if whether to upgrade & recap as it's not that like the USA & Japanese amps that upgrade well, some UK amps we know don't take to upgrading, so to decide. After Servicing. It actually sounds very decent, it's a quality sound if not as sweet or open as some amps. Wide Stereo, Treble sounds a little softened at the extremes & Rock Guitar shows it's not as detailed as a recap-upgraded amp, if as-original amps never are. Compared to some Serviced but Original amps, this certainly is a strong 'Very Good'. Shall We Recap? To look closer at the Circuits. Using 'Tuner' as the Aux input to use Phono plugs, signal goes direct to the Filter Amp Board without even a buffer which is unusual. The 'Prescence' stage is unusual in how they Boost the Upper Midrange, leaves a slight Retro Bass sound to it. The rest of the preamp looks good, not so keen on the fuss of the Presence control that doesn't do that much, the A50 will be better without it. Next the Tone Board with Balance strangely in the first half of the circuit. Stepped Tone Controls use components, not potentiometers. Power Amp has the 2.5k adjust pot for Balancing the Audio (AC bias) & the 100R one for (DC) Bias. Circuits are good here, as good as any Japanese amp with some EU quirks. Difficulties in recapping are the 4 main caps have a screw on the end of the capacitor like huge ones in washing machines do. The spacing of the 3 plug-in boards on the left is very tight, to use typical capacitors the height needs care & for the fact boards are so close on the aging foam part, the tops could touch the underside of the other board. Space & Quirks here make us decide to sell as "Serviced" & a buyer has it from our 'Coming Soon' section. Interesting to see one of the Big Names with a Quality amplifier, if it still keeps our ideas to be wary of the UK-EU amps as this one showed. There is a reason why later EU-UK amps are Made In Japan, the build is far better as the 1978 Leak showed. BUY-RAW RATING: Hard to find nice, plus other tricky issues as noted above. COOL RATING: 6 It's a Revox which is a famous brand for tapes, looks nice in high grade. (2018)
1971 Sansui 5000X receiver (F6013 version) ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 60w.
CC. 5000 version is 1968-69, 5000A is 1969-70, the 5000X is 1971-72. The 5000x with the new design F-6013 power amp is the best version of this one, the F-1040 boards on the earliest 'X' & the 'A' versions have heat sensing diodes that are fine if the amp is adjusted right, but the F-6013 is a better design. Like the 4000 has the Aux through a big resistor to Phono level & into the Phono board to be amplified up again which loses fidelity. But use Tape In to bypass that instead. A very lively sounding amp that upgrades better than the Sansui 4000 that was a bit unstable if upgrades were tried & overall is just a better amp. One of the last capacitor coupled amps but that is no loss to the sound which is the best of the Sansui to use as-is & still hear a Very Good sound. Comes in either a metal case lid or a full wood case but no metal lid. Proves that an amp with the least amount of transistors & least stages of NFB sounds the best, this has 3 on the tone & the power amp stage is just 7 transistors. Still worth trying the Sansui 7000 & Sansui Eight of the early ranges, though the 5000X is certainly a winner and showed the 3000A up as a little lacking even needing altering. Seems the 5000X is much more wanted in the USA than the 5000A, appears to have sold well & be recognised for what a Very Good amp it is. The 3000A can do well too but needs a huge amount of work to upgrade, the 5000X isn't too much to do in comparison. BAD DIODES? There was a bit of scaremongering on this amp at one time on Forums, if it suddenly vanished as it's misinformation. The black diodes on the Driver board if damaged would go open circuit & damage the Output Transistors says one 2010 post. If it gets damaged it goes wrong, fancy that. The problem is quite like the Sansui 3000 & 3000A where 0.5A or 1A diodes are used, the 1971 update on the 3000A recommends 1.5A diodes. These same feeble diodes Teac AS-100 uses for it's main power supply. BUY-RAW RATING: Good. COOL RATING: 6 looks very like the 1969 Teac if just lacking style for function. (2014)
1971 Sherwood S-7200 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
SC, DIFF. Sherwood is a USA brand not often seen in the UK, we've seen low grade 1963 era Valve amps by them, but not got one yet. Sherwood were a smaller company not trying to compete with the big sellers like Sansui & Pioneer says an ad of the era, they were rated 4th. $360 to buy new at the time, the UK HFYB wrongly lists it in 1975 as 50w if no prices. Sherwood from Chicago USA if made in Japan much like Marantz did. Attractive amp with that early 1970s look, wood veneer case & some less typical front layout. There appears to be no Volume, if it's oddly marked 'Loudness' on the top right & has the mains switch on it. Push buttons & rotary switches have it looking a bit like the Harman-Kardon 930 we've had. The back is all Phono inputs, no DIN for tape unusually & 2 sets of Speaker outputs via typical screws. The back cover has the 2SC 1111 output transistors behind & it's rated 20-200W as in max VA power. The amp itself is a 40w one, if the specs show Bass is typically limited explaining only 32w at 20Hz-20kHz which we don't take note of for upgrading, 40w amp here. Lid off and it looks like the NAD 160 from 1972, the same custom makers clearly if nothing looks exactly the same, the layout is similar as are the case fitting bolts underneath. The NAD 160 is a strictly midprice amp for build quality, the Sherwood here looks more 1971 build with more care in the case construction as are the Realistic 1972 receivers, such as silvered Mica small value capacitors. A label behind the fascia has '7220' showing a 1972 built amp. The S-7200 is actually multivoltage as a switch inside says 117v AC - 234v AC explaining the 220-240v label on the back if "prewired for 220-240v" hides the fact. Like the NAD 160, it has the poor power supply board with hot resistors right next to small capacitors, the Akai AA8080 from 1972 has this too. The circuit is almost the same design as the NAD 160 if the Tone stage on NAD adds a extra transistor to make a version of a 'Complimentary Cascade Pair' stage & a few minor Power Amp differences. The Sherwood circuit suggests it's a superior 1970 design using the same early black-dome CDC8002 transistors as the 1970 Sansui AU-666 has, if the amp here uses more typical later ones. We'd be more inclined to call this a 1971 design, if online it shows 1973-76 era, too much here suggests 1971 as the fascia code shows. The main power caps are only 3300µf if the later NAD has 8000µf, together with the screw connectors are far more 1971. First try & it sounds too bassy as the Loudness button is pressed 'in' to cancel, not the usual way. The looks of the amp are interesting, square looks in a 'Space Age' way with a black-out Tuner until it's used so all you see is Aux 1 lit to show the amp is on. The Sound as original & just about unserviced is pleasant if a bit aged with good stereo width if the start of the volume due to the power switch means 'off' needs it pointing to 6 o'clock to seem right & match the '-60' on the fascia once it's on, else it doesn't seem loud enough for where the pointer is. The L+R on the headphone is the wrong way around for modern headphones, found this a few times on the USA KLH & Heathkit & the headphone circuit could be improved as it still can go midway & not seem loud enough, easy to correct. Testing Rock with the usual Joan Jett tracks shows the amp has a good neutral sound as it fills in the guitar well, if is still a bit polite, far better than some amps that can't deal with Rock. 46 year old amp potentially, needs Servicing, adjusting & a Recap. But knowing the NAD 160 version of this, it does upgrade nicely. so it'll get it. The logo on the boards is a Δ with arrow ends & 'EYPS', the same Δ is on the main caps too. The main amp boards had alterations if L+R are slightly different versions with one corrected more than the other. It's an interesting amp, but as so close to the NAD 160, one to recap-upgrade to sell. This amp clearly needs recapping as found in later comparing, if basically it has that decent NAD 160 sound. On getting to upgrade this, compare to the NAD 160, the HT is very similar at ±37v if the NAD 160 is ±39.5v to rate it slightly higher at 45w. Sherwood has nice looks, a bit retro quirky which add to the appeal & nicely made. Proof the S-7200 predates the NAD 160 are the power amp board numbers, '6015' on the S-7200 & '6077' on the NAD. Quite heavy compared to the NAD & the tuner glass inside actually is glass not perspex as the outer window is. As a USA brand. A Differential design if no Relay it sounds fresher, if without the odd design that held the Akai AA8080 from being more upgraded. It does well if not to upgrade too much as we can predict the results & to keep the price realistic to sell, sounds great now all recapped & upgraded it's worthy of an Excellent & does better the NAD 160 for detail. One we found interesting as the write up reveals. Matches well to Tannoy Golds. BUY-RAW RATING: Good if ours needed some recapping as poor sounding as 1971. COOL RATING: 7 kooky Retro looks are unlike typical Japan built amps, but well made looks smart. (2017)
1971 Sony TA-2000F pre-amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent.
FETs, Preamp. These 2000F & 3200F seem under-appreciated for modest prices even with the wood cases. These are aiming to be Top Quality Seperates, if sadly the Preamp is very heavily Tamed, to get the best out of it has taken us over 5 years. Sony seem Scared of these amps & as Original they're far from their best. As with our other amp reviews we look at things deeper & with upgrading in mind. The 1972 version of the 1968 TA-2000 preamp to be used with the 1968 half size TA-3120 which was more or less the TA-1120A with extra features. The 1971 TA-2000F & TA-3200F below are the height of advanced Hifi made at a time just before Discount shops reshaped the market. The early TA-2000 has the smooth control knobs and 5 of the 6.3mm jack sockets on the front, the TA-2000F has two & adds Filter & Mic Level controls. The meters have a bigger frame round them without the 'Test' button that the TA-2000F has a Meter Level adjust control, else they look pretty much the same. TA-2000 was sold 1968-71 & the TA-2000F was sold 1971-76. By 1975 the V-FET range replaced these so by 1975-76 unsold stock was still around. Both pre & power are the standard Sony TA-1120/1120A/1130/1140 size. The build quality is very high, no bare metal to corrode as it's painted black. Multivoltages ones with the adjust block just under the lid at the back. Inside is a lid covering the front controls with one filter-tape out board in there too. A shielded box contains 4 plug-in boards, another fixed to the Phono inputs plus Transformer & Power Supply capacitors. All very classy, if the foam that holds the plug-in boards is a bit cheap & it's falling apart now so a better idea that doesn't leave a gooey mess to be found. A very pleasing item with lots of controls if in reality you'll never use some. No Loudness is a good thing to see. Compared to the TA-2000 which is heavily based on the TA-1120A, here it's all different, a brand new design & layout, if the back panel is much the same. The TA-2000F can easily be seen as the better, if we aren't sure how good FETs are, which is why we are trying the pre-power pair, as the TA-1130 wasn't too exciting sounding. TA-2000 circuit again much like the TA-1120A if the TA-2000F is radically different & it really does use 150v Regulated Power Supply for some of the Phono stage. The TA-2000F adds a Buffer stage on the output showing how advanced this preamp is, a buffer stops the impedance of a Tape Recorder affecting the Preamp response. In using the preamp, we just set all Inputs to Max and the Output to 1v which suited the Power Amp & doesn't reduce the Audio Signal needlessly. If it's set differently, you may think the amp sounds a bit weak, to learn your amplifier & ours was here 2 days before we typed anything as it needs learning in & out. The Headphone socket on the first TA-2000 is hopeless as is the TA-1120A one, the 1965 TA-1120 has none. But the TA-2000F is advanced as it has a small power amplifier to drive headphones in the way you'd expect Headphones to play & in effect you don't need a Power Amp or Speakers if Headphones will do. The preamp for all the good ideas is an awesome unit of a quality never made before or since. But it is made in 1972-74 so it'll need servicing to sound good, ours as unserviced if we took it apart to check it, it does sound a bit dull with that unfortunate 'Retro Bass' from the circuit design that gives so much but then limits bass? Why do that? Ours has the single-insulated 2 core mains that was outlawed by 1976, if the blade plug can be plugged into the Power Amp to not have 2 plugs & risk Earth Loops. But either pre or power should really be wired with 3 core mains for UK safety, the Power Amp we'll put 3 core on. One mean feature is 'security screws' that scrape the metal to show if it's been tampered with, 1975 Pioneer SA-9500 uses similar. Removing the aged foam that holds the boards still we didn't like the idea so just removed it to clean and a repaint needed as glue ruins paint. The preamp via the amplified Headphone Socket as it arrived sounded very dull with a weak vagueness to the sound & the Retro Bass being noticeable. Now Serviced, it sounds totally different. Treble is restored, midrange weak focus gone. A fast sound if still the limited bass & not much weight or kick to the sound, if what a Difference a Proper Service makes. What to do next, to recap & upgrade? What's it Lacking beyond a proper deep bass? Actually not too much compared to some, but we've heard far better from upgrades, if it generally shows how great this Preamp is, or at least can be with our upgrades. A little more Air on the Treble is needed as currently it's still quite mannered, needs more fluidity to the sound to open the soundstage up further. Stereo is wide but the sound seems restrained meaning not effortless, and a proper Bass is much needed. It plays a Retro Bass that may please the unaware, but it's that "flat" sort of one-note bass that's restricted sounding. Deep Bass is generally never in amplifiers. Therefore it has potential but it doesn't sound 'Natural' or 'Realistic' to our trained ears, if will seem wonderful to most. High Upgrade Potential if the design is rather limited if we can hear a quality in it to do a proper upgrade on. Once Upgraded. There is a great lively sound lost deep in this amp, but it's so dumbed down, for 1972-74 it's a bit surprising. The preamp has 'T' bass filters & bass is limited everywhere as is overall spec, very strange design designed to perfection, based on how ours upgraded, but dumbed down like Sony were terrified of it. There is a 150v HT supply which beyond the Power Supply there is only 69v-80v used in circuit so to use 100v caps which makes it easier. We recapped the 2 main caps, a fuse is fitted underneath the casing & the 250v cap was showing minor traces of growing crustiness & a little sour, but the 70v one was very crusty, as in the eletrolyte turns to dust that fell out which was not expected for the preamp design. Bulbs are the typical 30mm fuse type 8v 0.3A & a LED bulb works fine if AC flicker can show with some amps as bulb circuits are often AC, this with LEDs was too flickery. The '1T243 1147' Diode the AK forum says it's 7.5v Zener Diode which matches the 7.5v/7.4v on the cicruit. Diode looking like a Transistor. Phono Stage is MM & MC so gets tested with the Goldring G-850 (see the Blog page for why) and it has a rare precision in a Phono stage that we've only heard with Sony in the TA-1120 & STR-6120. Higher treble is detailed with a crisp precision if the rest still sounds like it needs +2 on the Treble tone, which is more us for knowing how Valve Phonos sound. It is cohesive if lacks the depth & Stereo detail using the valve phono with treble tone set to match the sound balance. But it certainly is one of the Best Phono Stages with Transistors we've heard, perhaps it is the best one. Output Level Matching? The preamp has 1v or 300mV output levels which will suit just about all Power Amps. Pre-Power Comparing. To use the Akai AA-5800 which has similar pre-power levels to tell which is better. The TA-2000F sounds great with extra wide stereo & correct full bass, the TA-3200F shows it has a clean sound but Bass isn't as good for the odd design compared to other Sony. That Volume Control. The very slow Taper to get a decent volume is very offputting on the amp. It makes it seem like it doesn't have much Volume as it needs to be halfway almost to get the right sound & then quickly gets very loud. It's not got Loudness so easy to upgrade it, if then Gain comes too early & too loudly so needs some redesign, which we've done with ours. What a messed up design in what should be perfection. BUY-RAW RATING: Good once serviced else it will sound dull. 2022 Opinion. Not looked at these since changing the Volume Control. Finding the Tame sound of the Preamp frustrating when the 100w Power Amp is so good. To the point of selling them, but all the work in these already, why just give it away? There actually is a Crisp Bassy sound in this preamp, it's chronically suffocated by weak design which like the rest of the Preamp is how it's made. Taking 5 years to get to the point of Heavy Handed ideas as a Last Resort pay off, sounds great on Speakers. Good Listening on speakers & headphones to tweak it further next day. Probably The Most Tamed Amp we've heard. Top Sound is in there for the taking, if so well hidden. To hear the sound it should be elsewhere is the hard bit to put in it. COOL RATING: 9 in the wood case these are the Pinnacle of Cool, 7.5 without the wood case. (2017-2018-2022-2023)
1971 Sony TA-3200F power amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 100w.
DIFF, SC, Direct Coupled, Power Amp. These 2000F & 3200F seem underappreciated for modest prices even with the wood cases. As with our other amp reviews we look at things deeper & with upgrading in mind. No FETs in this despite the "F" naming. There are at least two versions of this, which is a bit confusing by the manuals. Date range is 1970-76 say some if we'll keep it as 1971 for the UK market. The first version has 2 black driver heatsinks like the STR-6120 uses plus a board next to the main amp board with a Speaker Protection circuit on. The second has 4 of the same size driver transistor plus extra circuitry in the middle of the power amp board that contains the Speaker protection board, so that older board is no longer included as it was improved on c.1973. The power supply Diodes board changes from the STR-6120 type diode rectifier block to separate diodes. Some guesswork by others reckons there are 3 versions but the description here says there won't be 2 speaker protection circuits. For a 1971 amp 100w is very high power, it uses just one transistor, not doubled like the TA-1120(A) does & that TX-183S transistor is only rated 100w. A semi complimentary design with around ±62v as the main voltage. We have the better later one. The amp has a 'Power Limiter' which is in the Protection Circuit & just sets Protection to limit the power, simple circuit involved if why buy a 100w amp to use at half-50w or quarter-25w is a mystery. The power amp is a heavy one, the huge transformer is 140mm x 120mm x 100mm, containing a potted regular transformer. 2 main power caps, the later ones use black cased Nippon Chemicon 8000µf 80v which is extremely high value for a 1972 design compared to the similar 50mm diameter values of today. Heatsink sections at the back as the TA-1130 used, so the TA-3200F was designed before the TA-1130 which was a scaled down version of both pre & power, plus power supply diodes board on the right. Front has the power Limiter, speakers, Function-Inputs 1&2 plus more Level adjusts for L+R, if as with the Preamp we set them to max once hearing it played fine. Multivoltage block inside next to the heatsinks. Speaker Connectors give the age away. Same push button spring connectors that are with under 3mm holes. On a 100w amp you can only use thinner cable & today it's known that thicker cable especially on longer runs is required, if to use good basic cable, not expensive hyped stuff. Ours has the single-insulated 2 core mains that was outlawed by 1976, if the blade plug can be plugged into the Pre Amp to not have 2 plugs & risk Earth Loops. But either pre or power should really be wired with 3 core mains for UK safety. The rear panel says "Test" on a small slide switch. This is not clear what it does, if it's actually a Bass Limiting "Low Filter" switch on the inputs. "Normal" means Low Filter in use, "Test" is without the Low Filter. Be sure everyone owning this amp keeps it on "Normal" so is using the Low Filter Switch without realising & losing deep bass. A graph of it's use shows 'Normal' rolls bass off below 100Hz which is hopeless, why is a 100w amp so scared of deep Bass? The fascia has 2 subtle versions, the Power Limiter is either marked "Full, 1/2, 1/4" or "Off 100w/50w/25w" on earlier ones as the brochures show. On looking at Google images & ebay the non 'Full' one is a rarity, 1 in 25+, possibly Japan-only version. The spare fascia we have has the non 'Full' one but is better grade. Specs on hifi-studio.de say Slew Rate is supposedly a huge 150v/µsec, if the HT is only ±62v, so to assume it reaches full 'slew' in under half a µsec? Damping Factor of 170 quoted too, probably tests in a review. This has some unfindable transistors a Driver 'SPS 885' & the 'TX-183S' outputs. Ours was filthy inside & needed a deep clean, also the heatsink paint comes off so a respray needed, it's not anodised black like some do. After Servicing playing the Power amp from the Soundcard direct with the level controls. On the positive side it sounds neutral with wide Stereo. But the Retro One-Note Bass gets tiring & on some dancey tracks it sounds awful, if you know how it should sound, instead you get a thick tuneless Bass. The sound is a bit soft on high treble as is the preamp, leaving it sound lacking immediacy if it is fast sounding, it's really not got the detail. 60s Ska is just a blurred sound that isn't musical enough for us. Midrange lacks a confident focus leaving it a bit "wanting to turn it off" as it doesn't excite. Using punchy tracks it responds well with a punchy sound if it has no balls or attitude with those weaknesses. Severely in need of recap & upgrade, aka big subtle redesign, to awaken this rather tame sound as it'll sound decent on speakers to most but it does lack the quality of how the 1968 Sony STR-6120 upgraded only just recently. After Recapping Fully it now sounds like an amp should & there is still more to do. Playing this direct from the Soundcard via the front volume controls like a passive preamp, the sound is hugely better with clear focus the biggest difference. We did recap the 2 main ones, they are 44 years after all if the black Nichicon ones look like current ones. Inside both cut open they were still good, no crustiness if a bit on the dry side, if probably still good for use if the amp wasn't heavily used, unlike the preamp ones. Bulb for this is a 2.2v torch bulb, the one in ours had failed so bougght more online as still made, if they fail after a few on-off cycles so to put a LED type bulb gives only a dim light as 12v rated bulbs. Odd choice of voltage. Output Level Matching? The specs show 1.4v is needed for full output power, so a different preamp with a lower 400mV output will not be loud enough for the TA-3200F. We found the Preamp has the right output level, but the power amp is lacking on gain on the 1v preamp output setting & doesn't sound like a 100w amp for the level. Pre-Power Comparing. To use the Akai AA-5800 which has similar pre-power levels to tell which is better. The TA-2000F sounds great with extra wide stereo & correct full bass, the TA-3200F shows it has a clean sound but Bass isn't as good for the odd design compared to other Sony. BUY-RAW RATING: For 100w power either you'll get a good one that will improve once serviced, if online reveals many are used hard, altered & problem amps. one to buy carefully. COOL RATING: 9 used with the preamp in wood cases. quite plain but 'serious kit' look. (2017-18)
1971 Sony TA-1130 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 65w.
SC, DIFF, Direct Coupled, FET preamp. The most accessible of the earlier Sony amplifiers, if it was still available into 1976. A tight accurate sound with FETs in the preamp. A quality cleaner, leaner, tighter & more natural sound is in here and this ranks it high, but not as rich bass or upfront as the STR-6120 on a compare with it as original, though it can upgrade into a more full sound if still being neutral with wide Stereo imaging. The early Sony amps have an excellent midrange that is spot on for vocals & the 1130 is the cleanest sounding one after the 1965 TA-1120. We got the exact same amp back again, since then we've been using the valve receivers more & oddly prefer it's more natural sound to the big Yamaha CR-1000. This amp has a lot of spoilers especially in the preamp & once sorted the previous tidy polite sound is now more confident with a better natural bass that sounds very different with a neutral treble not as bright as some. A smart looking amp in the big walnut case as is the TA-1120A. The next step in Sony are the TA-3200F & TA-2000F pre & power 100w combo, one day perhaps. Semi complimentary power amp design, the first year Sony done this if not quite matching how good their earlier capacitor coupled design was, though we'd like to try one yet again. Getting this amp back yet again, needed a repair, the sound once right again was still in line with the Sony STR-6120 sound, if only with our upgrades. But still not as loud as 65w would suggest & we did find the FETs are a fixed design. After knowing the early 1965 Sony TA-1120 this still compares well, but only after some of the earlier sound is put back in, otherwise it still is quite thin & grainy sounding. THE WOOD CASES for the 1970s amps are a three part clip together teak with a grooved top, sizes will be similar to the TA-1120 noted above. To find these later ones in nice grade is difficult. 2023-2024 Update. To try one again, first got a TA-1130 in about 2009. The last of the Original Sony amps in the TA-1120(A) style, aiming higher in Quality than the later TA-1140 & TA-1150. Not heard one since 2017 on getting that same one back to repair, traded repair for the solid-made wood case we got with a TA-1140 all for £40, those were the days. A 2023 Blog tells more. The TA-1130 is a particularly great amp as Original & 52 years old. Trying to sort which of the STR-6065, STR 6055 & Sony Pair TA-2000F/3200F, the TA-1130 leaves us wondering 'Why Couldn't The Sony Pair be this good as Original'. The TA-1130 has a nicer design than the others, before the overdesign & limiting took over. The Build looks earlier than the other 1971 ones, there doesn't seem to be any other FET preamp beyond the TA-2000F & this seems to be an earlier Differential Power Amp before the others. First Efforts are usually the Best. To not have noticed how great this amp is using the Same Headphones is the problem of comparing too many amps, the Neutral ones get lost for the less precise ones. Still keeping this Original to Compare to other Original amps, the TA-1130 betters the 1972 Akai AA-8080 with a more precise sound. This precise sound is What We Crave, yet others who had our first TA-1130 & we saw it back a few times, don't seem to understand such a clean accurate sound. Does make you wonder what Speakers they are using not to hear what we hear. Fuses. The UK version like the UK Version of the Sony STR-6055 has a board of Fuses. we put Plastic Clip-On covers so not to touch the Voltages. The TA-1130 has 1A, 315mA, 6.3A, 6.3A & 3.15A. Based on the STR-6055 the 3.15A is a 240v AC Mains Fuse shown as 'F1 5A' on the circuit. 6.3A are two 'F2+3' 36v AC Fuses to the Main Rectifier. 315mA is 43v AC to D918 for the 'C' preamp stage, and 1A is 2v for fhe Power On bulb. Preamp Voltage Adjust is via the Adjust Pot on the Left inner board via the First & Third side pins, set to 40v, Manual is not too clear. Mostly Recapped With Upgrades. Not done the Two Large Capacitors yet. They are working fine & 6000µf despite the age is decent spec. To redo those would add buy-in costs on the large caps plus fitting, is it worth it? Having been playing earlier 1965-66 amps with a Crisper Treble, the TA-1130 needs +4 on Treble to match 'our sound' & not compensate in Hearing which can upset by being less Trebly. It needs a Run In as mostly new caps & sounds a little rough, which isn't unusual. The Sound Once Run In is much better, a Crisp Clean Treble, a more Bassy full sound than before. TA-1130 is a 65w amplifier, the Sony way with the Slow Tapered Volume is it goes Midway for a better volume. It could be much upgraded to give a louder Volume & other Upgrade-Design things. To not need another Amplifier means we'll get it ready to sell.
BUY-RAW RATING: Good. COOL RATING: 8 looks like the TA-1120(A) with the later crinkly control knobs, but still cool in the wood case which was usually the less smart 3 part teak one by now, depending on seller stock perhaps. Without the case dips a point. (2011-2015-2023-2024)
1971 Sony TA-1140 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
SC, DIFF, Direct Coupled. **Updated** One in the same range as the complex FETs TA-1130, we first got this amp early on in our Amplifier Testing before anyone took notice, one in a wood case for £40. In 2018 we belatedly got another one, as prices are now often unrealistic for Raw Unserviced Amps. Still one of the Good Sonys despite the build inside being far from the TA-1120(A) & TA-1130. Semi-complimentary design. One known problem is messy solder which causes problems, the one on the Gallery page needed a lot tidied as the mess gave problems. It's still a Very Good amp with Good potential to upgrade here, this is more or less the Amp version of the STR-6055. See the Oct 2018 blog for comparing the TA-1140 to the STR-6055 designs. The TA-1140 we've never recapped & upgraded before or even tried on the Tannoys, so an interesting revisit here. Lid off, there's not much inside compared to the TA-1120 & TA-1130. The Preamp & Tone are on the front two boards with resistors on ends to take less space. Still all Transistors, the TA-1150 had the preamp IC. As good as early Sony are, they are always shy on bass with low coupling capacitors if they upgrade well. The Service Manual for this amp is poor quality which is probably why we've not upgraded one & even now that Photocopy blurry one is all there is, the 1140 sold well so why is it rare? The TA-3140 small power amp has the same power amp with only one minor diference on C504 so that helps. The Circuit Breaker Glass Tube item is a bit of a mystery, the Service Manual says if the heat caused by excess current trips it, the bulb lights, to assume it resets once the fault is removed. The Circuit we compare on the Oct 2018 blog if high NFB in the Preamp isn't idead to us if overall it;s actually a good design, streamlined & pared in construction. Potentially for a less fussy design as the TA-1120(A) & TA-1130 are, to try upgrading it more just to see how good it can be, after all we did sell the others. This amp does benefit from a good Service to awaken the rather dull sound that we noticed early on, the unusual 50mV Bias is a quirk of the design & doesn't affect the sound or get warm. As Serviced the Sound is far more precise than unserviced, again see the Oct 2018 blog for more. Rating as Serviced now updated. Looking at the last two we sold, the serial number inside on the current one is midway of the last two, so to wonder why the last two we only rated 'Recommended'. The 2018 one has neat solder on the preamps is one idea. It's why we revisit them. Board Layouts with 2 stages on one board suggest compromise has been made, but seeing Power Amp has the Power Amp Power Supply, Preamp-Tone has the Preamp Power Supply & the Mode switch board has the Phono stage, it's at least thought out to reduce all the wiring that makes the early Sony so busy. To realise this puts the TA-1140 into a different league after looking at the circuits to upgrade, it's not a Budget amp like the TA-1150 is. £110 new in 1973 when the TA-1130 was £155 shows costs have been reduced if the design shows it'll upgrade well. Blurry manual shows NEP & GEP models, if ours is the UK AEP one as stamped under the fascia which is a mix of the other versions. Recap & Upgrading is what we'll do to this to see how good it can be. Verdict after recapping, the bigger size main caps are more expensive on this amp, but worth doing to see how good it is. Redesigning the Preamp brings the 11140 into a much higher league, we thought these amps were g0ood but nothing special in 2012 & only revisited for looking deep into the circuits to see potential. Upgrades well giving a decent Bass, clean Midrange & crisp Treble. Still a Classic Sony & a good one to revisit. Comparing to the TA-1140. We have both 1140 & 1150 at the same time, the 1150 preamp despite the IC sounds better than the 1140 if the 1140 power amp is superior to the 1150 one. The 1140 preamp has a bad bit of design if this can be changed to give a much fresher sound if redesign takes ages to get right. The TA-1140 otherwise is a good design with certain design features that not many amplifiers have, so to try more with it. THE WOOD CASES for the 1972-73 amps are a three part clip together teak with a grooved top, sizes will be similar to the TA-1120 noted above. To find these later ones in nice grade is difficult. We got our first TAC-1 the earlier solid box version with one of these which was the right one for the 1971 ones. BUY-RAW RATING: Good if risk of poor soldering. COOL RATING: 7 looks like the TA-1120(A) if with the later crinkly control knobs taking a bit of class away, but still cool in the TAC-1 earlier wood case where it'd be an '8'. (2011-2019)
1971 Sony STR-6036 receiver ↑
AS-ORIGINAL (Once Serviced): Average. UPGRADED: Has Potential. 14w.
Direct Coupled. Sony were trying to appeal to all buyers from Budget TA-1010 to the STR-6120 or STR-6200F top amps by 1971 & this was one of their low models, if not the lowest. Laughably budget made 16w thing, hardly worth the effort to make surely as power & volume is pathetic, unlike the Trio low power ones which had some volume. One for grannies to replace a cheap gram with only must be the reason it existed & Sony were very budget conscious disregarding quality at this time. This is actually a 1971 model as in a 1971 brochure with the STR-6055, STR-6046, STR-6200F & STR-6850, showing Sony started into budget gear earlier than we thought. We initially didn't like this for the Low Volume, but read on, more to it. 2020 Update. A reader asked about this, our Review is 8 years old & at the time No Manual. Says 14w at 1kHz, so not 16w. But it looks nice as the similar STR-6046 does & it got rated better, so let's have a better look. 2012 review is early & before we tried on our Tannoys. No STK output block, this is all Transistors. Still the Sony quality like TA-1140, wiring a bit messy as boards on the top base, not fitted underneath like STR-6120 etc. Manual circuit not scanned neatly, if it looks typical 1971 Sony quality still. Phono x2 transistors per channel, Tone x2 plus NFB Tone. Power amp is as good as any Sony, we see TA-3200F ideas in here, if some limiters here for sure plus low value output Capacitor. HT is about 40v on 63v 2200µf main capacitor. Also has a Regulator stage that is surprisingly decent. 16w actually seems rather low, if 40v isn't ±40v it's actually ±20v. As we've found with 15-16w Yamaha CR-200 & CR-400 there is a good 15w amp & a feeble one. The Headphone circuit is fine, so to just consider it tamed too much at 16w. Is it Possible to Better Amps like this? Read how good the 1967 Sansui 400 receiver was. 20w but what a great 20w as the Buyer found, if that was an Experimental amp of ours. The STR-6036 as-is can only really be as we rated it, but it's not a Junky amp & we can see it could upgrade nicely, but 16w on 20v HT equivalent won't be much more power if can add a lot of quality. We actually have two 20w Receivers here as of typing, JVC & Sansui, just to try how much better they can go, picking good amps there, based on how well the Sansui 400 did at 20w. BUY-RAW RATING: Good COOL RATING: 7 looks smart & very 1971 midprice style with the wood veneer case, but hides a decent amp tamed to be a more mediocre amp. (2012-2020)
1971 Sony STR-6046A receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 25w.
Direct Coupled. A modest power later Sony with pleasing retro looks. It's actually got STK blocks for the power amp but at 25w it stays modest & still has the retro sound in a modest way so we reckon it deserves including as it's certainly above average in sound quality & good starter into Vintage. It actually has many qualities of amps but power is finite & the sound is limited to fit. Strange that a STK block amp sounded still good enough to recommend after the feeble 16w one above. BUY-RAW RATING: Good. COOL RATING: 7 much the same as the 1971 STR-6036 very of it's era. (2012)
1971 Sony STR-6055 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
SC, DIFF, Direct Coupled. This & the rarer 70w STR-6065, see below, are basically the receiver version of the TA-1140 if sounding a little more like the TA-1130. By the manual codes, the STR-6055 is just earlier. A generally more friendly richer sound with the receivers than the amp if UK buyers still didn't buy Sony as much until the 1973 more basic ranges. Fresh & open sound if deep bass is a bit lacking though as typical, but at 40w it's acceptable as original. 2021 Opinion & Update. This is a Sleeper amp, it & the TA-1140 are still Quality Sony, the STR-6055 a better version of the STR-6050 that lacked fuses. the UK one has 5 fuses, the EU one has one fuse under the power supply board. It's a well made amp still, the fascia thinner & layout less STR-6120 quality, no solid aluminium control knobs. But the STR-6120 was £387 in 1969, this STR-6055 was £160 yet still offered 40w with perhaps a more streamlined design. Passive Tone here betters the TA-1140 which we had to redesign to get the 'right sound', this one looks fine. Loudness button must be pressed in to cancel is an oddity. One of the first with the 'kettle plug socket' as kettles were pre about 1995, no captive mains if it sticks out further. Play It As Original. Aux 1 is on the lever switch not like other Sony. Crisp sound on the Brighter side as Lower Midrange & Bass isn't so strong. It does tell it's a bit low spec if overall a clean sound. Not one to play too much as the thinner sound can upset the hearing balance as your brain compensates for unbalanced frequencies as we put on the site & blog. Tuner works on FM, Sony tuners are reliable. The STR-6055 Circuit is a nice sane design if very shy of bass. Differential Power Amp is quite different to the TA-3200F if the Protection stage is similar. Pre- Tone is partly passive, different to Sansui & Trio-Kenwood designs. Phono is a tiny board tucked at the rear corner underneath, two transistors if not so unlike the STR-6120 one. High Filter is basic. Muting is FM too. Power Amp is differentials with AC bias-balance adjust on those. Lots of Diodes are for a Protection Circuit. Power Supply in two parts, the board at the top plus the lower half of the power amp board. Sone TA-3200F power amp ideas in here, takes it ahead of the STR-6050. Sleeping Dogs Awoken. We had one sold in 2020 if hadn't played it in a while. The TA-1140 came & went over a year before with upgrades to get a pleasing sound, deciding to upgrade it firstly, if STR-6055 was seen as better, things get forgotten. Only on checking it before packing to hear how Good It Sounded. Similar with the Yamaha CR-800, we had these early on not realising after 200+ amps that they were better amps compred to others. The STR-70xx series have ICs as per the TA-1150 & a drop in quality as a 1974-75 range into the 'Comet' era. STR-6055 a 40w amp to us, the 20Hz-20kHz ratings show bass roll off if upgraded it'll be over 40w. Big Improvement From Original To Upgraded. We had two of these at once, getting another one with the full wood case, the Original version, knowing the Upgraded version, is adequate if ordinary having little to inspire. Not much Bass & Treble soft, if the 'Sony Sound' hidden, as with the TA-1140 & TA-1150 too. The Sold one was Recapped with Upgrades, if not further upgraded as that takes a lot of time & we do that to Experiment. UK-EU Variants. NEP UK version, GEP Germany 'FTZ' version. 5 Fuses on NEP adds secondary voltages, bulbs & speaker outputs, GEP only has the Primary Fuse. Tuner changes, the '100' & '1000' either close or not on the glass. Dark or Light boards no difference. Power Supply 5B4 rectifier or 4 Diodes. 2SC633A or 2SC1364 no difference. Playing With Recap & Further Upgrades Done. The 2021 one going further with, the selling one, to see what it has. Power Supply, Preamp & Power Amp done. Bass & Treble not Soft now, sounds crisp & precise. Took a lot to get the TA-1140 to sound this good, here the Preamp is much better if a tiny board on the Tone Controls as no fussy filters. The STR-6120 wasn't this good still on the original Power Amp. Sound is more like a Trio-Kenwood than an Akai of the same era. Neutral precise sound here, treble very clean. Bass is Decent & a Sweet Sound like we got from the TA-1140. Certainly hiding it's quality this one. Suits Reggae well, Rock is clean & precise, Stereo is wide. Adding Bass Tone gets more Grunt to the Sound if the Rock Guitar sound is precise. For that Clean & Precise sound it shows this could go further, i that usually takes a year to perfect. Why Like It Now? Having tried quite a few Sonys, to know them & see-hear what's different here. Never rated it too highly or upgraded it further before, if it's well made so deserves more respect to try more with it. Only seeing what wasn't so obvious, to go more. The thin fascia compared to the heavy STR-6120 one. Differentials Amp, to compare to the Trio KA-6004. Tuner is Extra Good. The STR-6065 Tuner with 6 Ceramic Filters & No ICs is much the same here, slightly less sensitive if still pulls in lots of FM Stereo stations. Such a clean sound & beats the previous Sony Tuner design easily. Most FM stages are muddy on FM, even late 1970s ones, but not this Sony series. Compare Original to our Recap & Upgraded one. Bought another one to get the rare full size wood case & put the high grade one we were considering to go further with, in it, the selling one an Earlier EU version & sounded better as original than the 5 Fuses UK version. The redone EU version is crisp & punchy with a decent if not strong Bass. Compare the original 5 fuses one, the sound is very flat with soft treble & bass lacking, add Tone betters the Treble if Bass is still low. It's adequate as sold if far from an exciting sound it can be upgraded. Probably sold well if the sound we got on the EU one is well hidden here. This Amp is a Real Sleeper & at last we've seen it for it can be, so this 5-fuse one we'll upgrade further. We're finding quite a few amps hide a quality sound, if only revealed by the upgrading. We've done STR-6120s & the TA-2000F/TA3200F pair to now realise the STR-6055 is more worthy than considered, if 2013 the first one had in the days these were a cheap buy. The STR-70xx has ICs & lacks a quality here. The 60w STR-6065 is similar if much rarer, same size as 6055. Puts Loudness as a lever switch, the 6055 idea is a bit awkward, like they forgot it originally. Heatsinks more like the TA-1130/TA-3200F, power supply a bit different else much the same. Power Amp more like the TA-3200F 1st version with TO66/TO5 size drivers mismatch sizes. Phono x3 transistors, Tone-Pre much the same, Power Amp just 1 transistor extra if 70w RMS both channels, ignoring the 50w 20Hz-20kHz showing it's limited on Bass & treble also. Price unknown on this one, may have been outpriced by the 6055. STR-6055 Compared to Hitachi SR-800. Similar power, both quality amps & both recap-upgraded to be sellers. Both of a similar Quality. STR-6055 On Speakers. Trying the 2021 current Sales one. Upgraded to a level to sell at a fair price this gives a clean crisp sound. Bass is rich on this, if it's one that has potential to upgrade further, we got a STR-6065 for that. BUY-RAW RATING: Generally good if the power supply can be a bit rough & well hidden to not see. Sold Well, not Appreciated so a Sleeper still, a good sound in here if upgraded. COOL RATING: 7 looks very like the 1969 STR-6050 with the aluminium fascia, with the full size wood case in high grade it looks a very classy 8.5. (2013-2021)
1971 Sony STR-6065 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 70w.
SC, DIFF, Direct Coupled. Despite being much like the earlier STR-6055 above, this higher spec Receiver is much more like the STR-6200F. $429 in 1971 which is £176 then, bit of a Bargain compared to the £354 STR-6200F. Another USA ad puts 6065 at $399 & 6055 at $299. Actually it's the Updated version of the STR-6200F as it uses the 1971 Sony Tuner which wasn't in the STR-6200F as it still used the 1968 one. The Tuner & Tone are as the STR-6055, if the Power Amp & Power Supply are very different. By the manual codes, the STR-6055 is just earlier. The STR-6200F receiver is also 70w & both use the same basic Power Amp as the 100w TA-3200F if the earlier version with 2 types of transistor on the Drivers, 2x TO-66 & 2x TO-39(TO-5) on the heatsink. Proper 70w rated & reads like an 80w amp with 36v clean sine output. Why the STR-6065 & STR-6200F are similar is an odd one, 6200F uses the STR-6120 Tuner & Preamp. The STR-6055 we've found is a lot better, if only once upgraded. We had the TA-1140 amp which is similar to the 6055 so to max it out having done the 1140 already, to try the rarer STR-6065. One you don't see in UK as not in HFYB as UK 6055 needed the extra fuses, if Google images shows some. The Power Rating shows how Bass & Treble are limited, 70w at 1kHz yet only 50w 20Hz-20kHz. 1971 buyers will have seen 50w STR-6065 (70w to us) & 30w STR-6055 (40w to us). Front Panel only puts the Loudness button by the Volume as a Lever Switch, if the rear is different. The Power Amp heatsinks like the TA-3200F & a larger transformer with wires about it & the Power Caps stacked horizontally. Perhaps a little cramped but a Sony to try, first looked at it in 2013 if not to realise what it is, seeing 50w. Captive Mains seems normal, not the Kettle Plug style maybe as lack of space for it. Preamp is the same passive design as the STR-6055, the Phono is more like the STR-6120 one. Sony gone a bit bonkers on this one & the STR-6200F. Jun 1971 Manual Supplement shows Tuner changes & 1972 German Brochure shows 6200F, 6065 & 6055 together, if with confusing power ratings. Got It Here Now. There's a 5A fuse in here, hidden by the AC outlets if no other fuses. It's a packed unit inside, STR-6065 not in the HFYB so for no ability to put the UK 5 fuses board in, it's not for UK standards. The 52mm diameter main caps stacked sideways, 6300µf 63v is very high spec for 1971 if the STR-6200F ones are 80v. Power supply board near the front similar to 6200F with empty spaces. Power amp much the same as 6200F. Tuner uses the same MPX board as the 6200F & the 6055. Transformer is the same big box one as the earlier STR-6120 & the 6200F uses. Heatsinks like the 6200F & TA-3200F if here the solder boards as the 6120. Rear panel space a bit limired, only one Aux on the rear if the Aux 2 with 6.3mm front socket for use with a 3.5mm jack adaptor on modern portables, Speaker push connectors like the TA-1130 for thin bare wire. Captive mains cable. Looks better than the 6055 for 3 levers midway, Loudness off is down not up to match better, maybe Loudness considered normal? Not for us. the 6120 styled volume with balance rather than ganged L+R volume. Actually only looked deeper this as we have the wood case that fits, if to see what it actually is looking much like the 40w STR-6055. Sony hid this one a bit. Serious piece of kit & one that pleases us seeing how advanced it is & with the 1971 Tuner. Base cover is painted black & without the lip grip bits on the front edge. Rare Amp. Not so many sold as still sold as 50w as 20Hz-20kHz if 70w to us rated at 1kHz usually. Sony playing tight on the power here, 70w rated on 2SD88A which are 80w 5A if the other two showing a repair are the TX-183S ones used in the TA-3200F etc, no data sheet if maybe only 110w for the 100w amps? Cramped design putting the STR-6200F in the medium size case 50mm diameter main caps laid on the side is certainly an odd one. Sound As Original. This one needed quite a bit done to even try it, if it then worked first time. The Output transistors failed & had failed before so the 70w-80w low spec transistors need uprating for peak levels. All clean inside now it looks very different & had it turned on a few times now fitting Bulbs so it's trusted. But as Unserviced, beyond rough controls, we played it over an hour as the sound for a Sony as original betters any of the many we've had. Still the Retro Bass Sony if a very clean treble & still has the limiters the STR-6055 does if the Power amp is a very good one, the same in the STR-6200F as is the Power supply. Nothing else changed yet if a sound that isn't expected from a Raw amp, clean & precise with wide Stereo usually takes more. The STR-6065 seems an Experimental amp, they way underpriced it when new, this just $100 more than the 6055 seems more like $300 more in quality. The STR-7065 goes into ICs so the STR-6065 is the last of the Best Sony era if cramped & chaotic with the Output weakness with just one Fuse. Fascia lettering just Screen Printed on this range so Nicotine use means lettering loss. But the Sound as original, not used in Decades & Unserviced just to try it makes the 6065 probably the Biggest Sleeper in Sony's ranges. Great Tuner. The 6065 tuner is uprated to the 6055 one, we know the STR-6120 one as recapped losing the coupling ceramics, so set to UK 50µsec via the inside switch, the 6065 picks up a lot of Stations & in Stereo on FM. This is a high quality tuner, the FM with 6 ceramic filters gives a very clean sound for a 1971 receiver. Most Vintage Tuners don't do the compressed Pop FM well if here it's unusually good, pity the music of today. Sony ST-5130 tuner is only slightly higher spec. Jun 1971 Service Manual Supplement. Seems they altered this early in the run, so to see what ours has. The Tuner Front End, under the clear box, is FAF16AW on ours, the updated one is FAF20AW so a 2SK23 not the later 3SK37 dual gate MOSFET plus the IF board changed. Power Amp on ours is a replacement & has the later 2SA677 showing if the original frazzled one does too. The 10D2 diode rectifier is fitted, if different shape as the early one is & numbered 10DC. Minor changes beyond Tuner that sounds great already. Shall We Just Use This As It Works. We'd never trust a 51 year old amp for more than minutes even if it's in good grade. We take them apart to look before plugging in even if others do trust & get into problems. Here the tighly packed power supply shows corrosion on capacitors, might be as just aged, not leaking. One bad is the Switch Capacitor that is swollen up ready to burst into white smoke which looks like the amp is burning. If it reads OK on the speaker outs to trust it for a quick try on speakers, to see if it would suit us or just to sell it on, but why risk failure on a quality amp by using it longer? It's the update to the big STR-6120 & STR-6200F after all. DC offset under 5mV so safe to try. On Speakers. We've been using the Sony TA-2000F/3200F pair so another Sony will compare well. The crisp clean treble & midrange in the STR-6065 even as original, if Bass is another thing. Further depth in sound on the Pair if they sound very similar. Sony don't usually sound this good, UK buyers missed this one. Recapping & Upgrading. Doing this By Stage & have a listen, we know several other Sony plus other current plays as of Sept 2022. Preamp-Tone then the Power Amp. The Power Supply needs caps to fit neatly in the tight space, so another time. The 6000µf main caps are large enough to still be good despite the age. Tone done gave a good taste of the best Sony upgrades if to hear where it's lacking. Power Amp done takes it further but still to hear the Power Supply limitations. Beyond that, a Great Sound here, wide Stereo, Bass done properly which Sony always seem afraid of. Important now is the Treble being Crisp, Powerful & Smooth, this does this to a high degree if we've heard better, it certainly is very decent. Power Supply next, the black one on the left is an Inductoir, not a capacitor. Ours look a bit coroded & they're glued in which never pleases as it's messy & they don't exactly need gluing if soldered right. No board markings, the manual images only show detail. The STR-6065 manuals miss a few pages inc the Tone & Power Supply board layout. Tuner Glass on some Sonys is unusual, it is Blacked Out on the edge so even with LEDs it's too dark. Seems some have had the black pain cleaned off over the years & look much better brighter. Power Supply Board. This is almost the same as the STR-6200F one as is the main non-tuner parts. The spaces aren't a lesser beast, it's just the second regulator & parts as the old tuner needs 24v, the new one is different on 15v. Power Amp Board. Looking at the STR-6200F explains the empty spaces. a 'Line Out' feature of a reduced level for some use. But strangely they don't put the RF Output Filter in the STR-6065 that is a requirement in amps usually, R741 & C712 plus the R channel ones. See our Pioneer SX-950 a message on the back about FCC Rules about RF issues, Part 15 compliance that is still current. Seems this is a USA issue, you see these filters in most later amps just to have it a Standard, UK & EU amps seem not to require this. BUY-RAW RATING: Higher Power Sony age more as used more, rebuild needed. COOL RATING: 7 always better in the wood case. (2021-2023)
1971 Teac AS-100 amplifier ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 40w.
SC, DIFF, Direct Coupled. In our earlier amp testing this was one of the first clean fresh sounding amp we got after the Trio KA-4002 & was a benchmark for some time outdoing the Sansui AU-999 with ease. Very clean, open sounding yet still musical. Surprisingly it has ICs in the preamp, on the first amp we had we noted one is a 'Teac 42708', the other a 'Sanyo LD3130', not that they are findable to buy or research. It appears these ICs are a bit fragile, OK in use but if knocked or the amp dropped the IC legs get loose so problems arise. This amp upgrades up very highly. Got us trying the Teac AG-7000 which beats the AS-100 for the higher power & no ICs. Oddly the later production ones are bass limited in the preamp but can be altered. Does have a bit of a 'boop' on turn on which again can be sorted, but both are design matters. Has stepped tone controls. Looks nice with the matching tuner & the stark industial look is timeless & certainly one of the more memorable amps. See 1969 Teac AG-6000 above for our latest verdict on these Teac gems. Still being sold in 1976 as shop ads show. REVISITED 2016: Had one of these in 2016 to upgrade & the stainless steel & black look is very cool. £107 new in 1973 it was priced well with other midprice 40w amps. Even after many amps & a lot of upgrading, this still sounded very decent on first play as original. Now recapped improved further if it still has odd noises on turning on with headphones, we'll try it on speakers when finished. The AG-6000 & AG-7000 receivers from 1969 reviewed above are the same basic amp circuit & the basic IC isn't a problem. One issue with this one revealed the volume control wasn't well matched being 10% different so the L channel was a little lower if the electronics tested fine. Unfortunately to get a loudness volume control with the long post is impossible, so the only option is to add a resistor to balance or leave it be, customer will need to decide. A known weakness in the AS-100 are the regulator diodes, we've seen these replaced before & were here, so we needed to sort that out better. The metal lid has extra threaded holes for rack mounting, there doesn't seem to be any wood side cheeks on this. To find the AS-100 still sounds great with all our progress since shows it certainly is a very decent amp & we'd say it betters the receivers once upgraded. So this is the fourth one of this amp we've had, shows we like it. But issues with this particular one are more to do with previous use & luckily the owner had a spares amp as one IC was faulty & the volume control was out of spec too. Now they have a great reliable amp again, worthy of an 'excellent' if other earlier amps upgrade to give further precision, this is still a worthy amp for it'd era. REVISITED 2018: Stylish amp always worth a revisit & we get one to upgrade that we just missed buying ourselves. Long stored in a damp attic, if a UK model with blanked out AC outlets that aren't fitted & Trio-Kenwood KA-4002a style screw connectors for speakers so it's an early one. Doesn't look much used if needs a good clean. These usually fail on the feeble power supply so to see the original AC diodes is unusual, just 1A ones. Has the Teac 42708 ICs in the preamp, these are probably 2 transistors plus a few resistors, much like the Nikko TRM-1200 Phono stage one used that we had to rebuild in components. Modest looking amp inside, but the same basic Power amp as other Teac of the era use in the 1969 receivers we've had. The amp does appear to vary over it's run, it's a bit lacking in spec on the early ones & does sometimes have an instability on turn on after a few seconds. Teac receivers are reliable, if the AS-100 appears hard to find as several design weaknesses got it thrown out long ago. 1973 price was only £107 when the 1968 AS-200 was £170. This is an early one with screws for Speakers not the later square push blocks. Early Version. The Preamp IC appears to be better spec on the later ones, but the early ones it can go very unstable after use even with no real fault & blow fuses, even once rebuilt with lots of upgrades. Early is TEAC 42708 X, a later with 3X appears better spec. Boards otherwise are identical. Still sounds 'Excellent' but Bass is limited as well as Treble not quite as clean so 'Very Good-Excellent' is fair. Early ones have Screw Speaker conectors & Tan Boards, the later ones have Darker Brown Boards & upgrade better. Would be good to find the IC equivalent as Transistors, but no Data findable. BUY-RAW RATING: Good if a few issues we found in our fourth one as noted. Top lid doesn't have enough paint so usually found in low grade. COOL RATING: 8 no wood case but an appealing Bauhaus styled Industrial quality classy look here with black & aluminium fascia & mirror control knobs, on some versions. (2013-16-18)
1971 Trio-Kenwood KA-2002 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: Very Good-Excellent. 13w.
CC. Not had one of the 13w Trio amplifiers since we started into trying out Vintage amplifiers in 2011. The TK-150 & KA-2000(A) are earlier versions if this is restyled more into the 1971 range such as KA-6004. Short-lived 1971 KA-2002 version as 1972 saw the KA-2002a with updated styling, see the 1972 18w KA-4002a review also as we had both here at the same time to compare. 330mm wide, 238mm deep & 115mm high smaller size amp. Wood, or formica, side panels would be an optional extra as most don't have these. After servicing, the Sound on this is pretty decent, Bass is lacking & a bit thin accentuating the midrange with upper bass a little tubby, but Upgrading will bring out a more natural sound. Treble & upper midrange as with early Trio is still very decent & it'll upgrade well amid itself as it's a little dull compared to reference amps. We never upgraded the KA-2000/TK-150 before to hear how this sounds will be interesting. This will have been a Budget Buy in 1971-73 at around £45, but far from cheap junk like a lot at this price level like the UK & EU stuff often was. The back panel still has high quality connectors like the higher models. Modest size transformer & only 2200µf main capacitor & typical 1960s value of speaker coupling capacitor, with no Differentials. The later KA-2002A from 1972 appears much the same if with Silver control knobs, not mostly black. How does the Circuit differ from the KA-2002? Transistor count is only 6, input, driver, PP drivers & PP outputs, the rest is not exactly the same but not so far different. Output transistors are TO220 15w 2SC1060s which are commonly found in other circuit sections. The HT voltage on this is 42v, not the same as ± HT on semi complimentary which is equivalent of 21v. It's an amp that will upgrade to sound more natural, if for the 13w it'll never be a powerhouse & not one worth upgrading excessively as the power is limited. For general use 13w should be fine, it'll bring a sweet detailed sound with proper bass if not too much, so we'll try it on our 15" Tannoys once it's recapped. Once Recapped except the 3 main ones the dull sound is gone. It sounds a lot more lively with a smooth detailed sound. Stereo isn't as wide as some amps. On Rock Guitar it plays it surprisingly convincingly even at 13w. After the main caps done & Biased right, the amp does sound very decent, if rather small & modest in dynamics compared to the 18w KA-4002a, still has the typical pre 1972 Trio sound, as based on the bigger KA-6004 being less of the earlier sound. Adding soundcard EQ to give a fuller sound, the amp can cope on Headphones & sounds very decent, but with the whole 13w design on Loudspeakers, it'd likely get into clipping. To rate it cautiously as above for the lack of a fuller bass & punchier sound, but you can use an EQ if the Tone Bass doesn't quite do the same thing as per the 13w design & not wanting it to overload. Clean Sine output of 14v is decent for 13w rated, if it shows to Upgrade further to get more out of this will just go into clipping. That upgrading rated it "Very Good". After comparing to the very similar KA-4002a, it is possible to upgrade the rather small sound of this amp into the punchier 4002 sound, if to be aware it still is 13w which gets it rated "VG-EX". An interesting "revisit" of the 1968-69 Trio-Kenwood TK-150/KA-2000. See the 1972 Trio-Kenwood KA-4002a for a comparision. BUY-RAW RATING: Good. COOL RATING: 5 Modest but quality amp looks smart & sound is better than you'd think. (2018)
1971 Trio-Kenwood KR-4140 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 18w.
CC. A later design, still clean but a bit soft in treble detail but still a good budget buy as a clean sound is here. Several in the ranges numbered similarly, if the less exciting sound than just the year before on a similar lower powered receiver. One to use if not upgrade, most components are on the one board as is the 5150 below. The rating is actually 18w on seeing the specs on the user manual, 18w into 8 ohms both channels driven. Not to put the amp down, it's a decent one for what it is, but the way this was sold in USA as 95w 'Power Output' into 4 ohms, which is Peak Power for 1 second before it destroys. This must have been one of the last to use the dishonest ratings before it was outlawed, the USA manual hypes it very unfairly. Also amps used to put Power Output Continuous per channel, so this rates 24w per channel, meaning you play one channel only, you get 24w. To play it Stereo into 8 ohms, 18w is the rating. But the USA flyer makes no mention of 18w both channels used. Also the power bandwidth is 30Hz-30kHz but no mention of how rolled off it is, from how it sounded it could be -20dB at 15kHz & for an 18w amp 30Hz will be even lower. Bandwidth needs a qualifier in dB of where it's limits are. Did try the similar 5150 below to get a later opinion, but not so impressed with the later receivers & we've not tried any Trio later than 1972 as the quality dips off & ICs become Trio's way to stop us being interesred, see all the Trio amps we've looked at on the 'Other Amps' page in search of a later one. UPDATE: This appears to be the Receiver version of the KA-4002a, if the sound quality is very different, the KR-4140 we thought sounded dull & ordinary to give it the rating here, the KA-4002a you can see we thought was far more lively. Even the KR-5150 below was rated similarly. The bigger KR-6160 appears to be based on the TK-140X Mk II. BUY-RAW RATING: Good. COOL RATING: 7 after seeing the KR-6160 with similar looks, it makes sense, 4140 is still budget grade inside that affected opinion. (2011)
1971 Trio-Kenwood KR-5150 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended. UPGRADED: n/a. 33w.
CC. A modest power T-K with pleasing retro looks. All transistors, no ICs in the audio stages & plays a decent sound & represents a good buy then & now. Pleasing sound if not the extremes of the better amps, but you'd not expect it either. A good starter amp into Vintage, if without the dynamics of an amp 40w or higher. 33w is the Continuous power into 8 ohms with both channels driven rating, the manual shows various confusing ratings. Not much else to say really, the sort of amp that was good enough without anything particularly quality like earlier Trio. {Ouch}. 2018 update: We got the bigger KR-6160 as below & thought it a much better amp if the looks front back & lid are actually the same as the 5150 but better insides, it appears more a 7 to 8. Quality inside affected the earlier rating. The KR-5150 we didn't upgrade in 2013 & it seems from upgrading other Trio since that our rating of it is a bit low & now estimate a 'Very Good-Excellent' if upgraded. Probably it was just aged inside & didn't seem very impressive, the KR-6160 sounds aged on first try. This is why we upgrade not to miss the good ones as it looks like we did here. 2022 update: This is very similar to the KR 6170 Jumbo, look at the Power Amp-Phono board. After having the KR-6170, the Power Amp is decent if can go much further, but that's redesign territory. BUY-RAW RATING: Good. COOL RATING: 7 as with the KR-4140, only seeing the lower models with midprice insides hid what is still high quality build, so our '5' is now more fairly a '7'. (2013-2018-2023)
1971 Trio-Kenwood KR-6160 receiver ↑
AS-ORIGINAL (Once Serviced): Very Good. UPGRADED: Excellent. 55w.
CC. A bit of a hidden good amp here & for knowing the KR-4140 & KR-5150 from the same series, surprising we noticed it really, as they were thought not so great, but that was 2011-2013 opinions before recap-upgrading reveals the full story. £195 new in 1972. Clearly the 1971 receiver range was underrated even by us. The KR-6160 is actually the same power amp board as the Trio TK-140X II with the UA1384J which is an updated version of the Trio KA-6000 amplifier. Later ones may have X07-0018-10 which is exactly the same if transistor changes. We thought the 140X II a great amp if ugly looks & a dead tuner despite it upgrading to sound wonderful & bettering the KA-6000 at the time. The looks of the 6160 are nearly the same as the 5150, surprised we rated it quite low based more on the inside quality. Very 1971 looking, the Sony STR-6046A receiver is quite similar, the white "teeth" soft push buttons maybe look a little odd as does the orange border to the Power switch if the weight of this amp at 10.8kg impresses, the other ones were quite lightweight. 6160 adds Stereo Mic & a Midrange Tone Control like the Realistic STA-150/220 does. The 4140-5150-6160 range is now seen to still be the quality of the 1969-70 Trio with wood cases & a good rear panel, the more we see the better we can rate. KR-6160 is the top of the range one if the KR-6170 'Jumbo' 33w one has an Organ type signal generator for some reason. Rear panel on 6160 with 2x Phono, 2x Aux which is needed for TV & DVD player, 1x Tape with DIN duplication, 3x Speaker pairs as the same screws on the KA-4002A. Pre Out-Main In with a switch instead of connectors that get misplaced, AC outlets & rated 320w which from knowing the KA-6000 is probably a modest rating as it has a 4A main fuse which means 960w. Underneath like the 5150 is still the half hardwired construction, if the 6160 is very busy underneath. Features that show this range is still good is the text looks like screen printing, which often wears off, but it's paint in etched engraving so won't wear. Push Button mains a first for Trio-Kenwood this year, if unlike the KA-4002A we had recently, still has the old skinny 2-core mains which was outlawed a few years as not Double Insulated. A good improvement on the TK-140X II is the amp is a bigger size so not so cramped up now & for the 4140 & 5150 tuners working, this should too & does in Stereo. KR-6160 in Context. This appears to be the best "early era" Trio-Kenwood receivers, if looking at our List of Receivers page the 18kg KR-7070 at 65w seems the higher model if seems an earlier number, the manual shows it's likely the same 1971 year as we briefly looked at on 'Other Amps' page, if perhaps designed more for the USA market as so huge. The KR-7070 fussy 'boost amp' doesn't seem such a good idea as likely not bypassable & likely the KR-6160 is the better sounding from knowing the TK-140X II. Main HT on the 6160 is 86v & 7070 is 100v, both still 'capacitor coupled speaker output' designs, the 55w 1972 Trio-Kenwood KR-7200 is the now the Differential-Direct Coupled design if still of quality as no ICs. One year models at this time keep them hard to find. This fills in gaps as later 1974 Trio-Kenwood KR-7400 starts to lose quality with ICs in the Preamp. KR-6160. Back to the amp, one smoker owner likely just left unused in a room for decades, not tested by seller as no plug is good for a change as it works fine, at least plays music adequately. Checked over & a quick service first, we'd never just plug any vintage amp in. Much in need of a service as noisy controls if the sound is lively if crispy & a bit weak sounding as likely not used in 30+ years as the bulbs all work showing low use, it's a Granny amp mostly used for Phono as the inputs are cleaner. We can hear the TK-140X II sound in this & construction, if not having stepped tone, is improved over the 1969 model with preamp Regulators so this should upgrade very nicely. After Servicing the sound is much improved losing the vague "Warm Vintage" sound that some think is good. Does still sound like an original 1971 amp that's not had much use, maybe it got 2 years' use with the Mic level control showing finger use the 'One Careful Lady Owner' likely sang along to the Radio, pity those hearing it. From memory, the KR-6160 here as all original sounds a lot better as it's cleaner & more precise sounding than the KA-6000 & TK-140X did on their first use, only 2-3 years difference. Deep Bass & even Upper Bass is lacking here though, perhaps from the decades unused that hours running in is known to help sometimes. Rock despite bass being light sounds decent with good focus & presence that few amps can do as Original. Also Stereo is very wide on this which again is unusual. One of the Best early Trio amps plus the 1971 Tuner is reliable in the 3 of this range we've had. BUY-RAW RATING: One that sounded good even raw & unserviced, reliable 1971 range. COOL RATING: 7 Points for 1971 Retro looks that are pleasing plus a walnut veneer top lid, not vinyl wrap. (2018)
1971 Trio-Kenwood KR-6170 'Jumbo' receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: Excellent. 33w.
CC. The 'Big' Trio-Kenwood Receiver, 'Monster Receiver' for sure. 1971 as the Brochure year code shows. Pro Gear too, sounds like it, 33w is misleading. The KR-6170 the 'Jumbo' bit added on the Brochure & User Manual, HFE has this to describe what it does. Seen this in the HFYB if never seen a UK one to buy, if a boxed USA one would cost £1200 if it pleases. It's an amp for 'Button Pressers'. It's a 33w receiver with a Spring Reverb unit, 'Electronic Rhythm Composer' like Hammond Organs used, a 'Beatbox' to later years with Synths etc, no ICs to do this in 1971. It just plays a simple back beat to which you add Guitar etc. You can use 4 speaker sets at once it seems, this must be limited somehow for Ohms needs. Has a timer to switch off, be sure it's set 'reset' or the amp won't power up. A very Kooky amp, but 33w RMS only, the 180w is 'Music Power' into 4 ohms, both channels at 8 ohm is 33w RMS. Based on the KR-5150 as the Power Amp-Phono boards are similar. Use as a normal Receiver with Tone & Standard inputs. This has to be the First amp with "Mood EQ" like 1990s Music Centres had with several variants plus 'defeat' & normal tone. Our one a 'Kenwood', can't imagine UK sold many & these would be 'Special Order' £279.00 in 1973 if ours has 1971 dates inside & part of the KR-6160 series. Same price as the Marantz 2245 so aiming for a certain buyer. Ours not much used, 2-3 years before Quadraphonic came along as the Next Toy. This seems a Gimmicky Amp, if is of 'Pro' quality for Musicians or Studios. The Reverb unit is a Spring Unit you can use with any input. The 'Lock' Device would have had Foam to keep it from rattling, foam long to dust. To buy this just to see what it's about. If we had this as a Job, to get all working, if possible, would be a Huge Job as so much to do, to leave certain parts alone, ours All Works after a Service, good on Aux, FM & AM. But it's certainly got Table appeal for all the Controls & with the 1971 Trio looks it has appeal. Timer needs keeping at 'Reset', the Tone to set at 'Tone' to use normally, or Jazz, Vocal & Mood modes plus Defeat which disable Bass & Treble controls. Read the User Manual as it's not so obvious. Guitar as L+R is odd, guitars are Mono, if use 'R' to play dual Mono, 'L' is L channel only. Rear Panel has 2x Phono, 2x Aux, 2x Tape In-Out with one duplicated on DIN. 4 sets of Speaker outs. Pre Out-Main In sockets with a switch, no connectors to lose, AC outlets, 3A fuse & an old skinny mains wire of the single insulated type, plus an Antenna rod. Inside Top & Base. Power Amp to the side, 4 big Capacitors include Speaker Output ones. Middle Amp board, right Tuner board plus others for the extras. Rear Sockets unshielded cable if the Phono ones go through Tubing. Aux goes 1ft unshielded cable to the selectors, if it played fine. The busy KR-6340 4ch amp has these shielded. Underneath to see the 'Rhythm' board with many transistors & chokes, plus other boards. Should have an 'X' brace underneath to keep the large amp solid, these show through the base cover, the top lid comes off & a wood base with Earthing Foil undoes, if it looks like a Sony STR-6120 box case. Our Rating. We've decided to rate this 'Rec-Very Good' based on how much this can improve. We see a few on Hifi Shark, it's not an understood amp & as original it's 33w isn't that loud until turned past midway which on 95dB speakers shows it needs more Gain, which made us try to sell it before upgrading more. But upgraded further it's the higher end of Excellent. Quite a few amps are hiding Their Greatness, this perhaps the most different from how it was once serviced, hints of a great sound as told below. What's Missing? An amp this complex needs care buying, ours has all the controls if lacks the right of the facia, just a plain aluminium shaped strip, the Rhythm Switch is like the KA-6004 type so easily broken if easily repaired too. The top edge to the fascia under the Tuner window seen as 'aged', ours is if the brochure shows it clealy to print a sticker perhaps. Should You Even Buy This Amp? Gambling a lot here, if inside has never been touched so no bad repairs. Just a long sleeping tired amp. will it ever all work? The Basics do on ours, if to get the rest going, Reverb Springs new to us, is a job to do if not right. LED bulbs if they don't flicker too much & cleaned up it'll look nice. An amp for Advanced Users only for the age & the extras. Had to get one, this is Our Game trying the Off-Standard ones & finding interest & a good sound too. Who'd Use This in 1971? Small Clubs used these Rhythm tracks for Backing playing Live as in Cabaret & small groups, the UK 1971 'Inshallah' pink label pop covers EP uses these rhythms. It'll have it's place if probably out of date as Tech got more Advanced. Kid's toys 'Stylophone' & 'Melodica' have a place in Pop History & these Rhythms similarly if on 45rpm, can only think of that one. Reverb Springs. For the Clamps Foam to have failed as foam does, the Insides which from seeing other Spring Reverbs could have been rattling around to not work. Metal Springs in a Long Box. Only to try... Does It Work on The Extras? Reverb was the risky part if it all works on Reverb, the Metallic Retro Springs reverb is very different to the Digital version on 'DC-Art', this is the 'Echo Chamber' sound in a Tin Box as full level. The Rhythm section works, the Options are very Retro if used with Reverb they are very Synth Drone squelchy & Dr. Who sounding. Any Rhythm played slow on full reverb is real Trance trippy stuff, play it for hours. As the Reverb Spring is Live, tap the Amp & it adds Deep Bass like an Elephantine Bass Guitar. Even more Trippy. "Bong Bong Bang Bang Choof Choof" endlessly Latin Beat, with Reverb varying it. Try It only Lightly Serviced as Original. Looks far better washed & with bulbs. LED Festoon bulbs don't light evenly as they need more than 4 if a German ebay seller has the correct 8v 0.3A ones. LED in the 3 meters can seem a little bit flickery, LEDs need DC as AC flickers. Controls still rough if since a quick use a few days before it woke it up. Sounds like the KR-6160 in the same range & sounds fine. As good as any Trio-Kenwood plus all The Toys & Output Meters. Stereo is wide, the low NFB sound with a decent bass as original. Rock sounds convincing, just as well as this is a Guitar Amp too. For the extras, they cause no bother to using just as an Amp through Aux. 33w amp of good quality to cope with 'Pro Use', the KR-4140, 5150 & 6160 receivers we've had to consider this nearer to KR-5150 if better Punchy sound as Pro Gear needs. Makes this 'Jumbo' amp more than just Gimmicky as we thought on 'Other Amps' several years ago. Playing The Damned 'New Rose' the KR-6170 gives high excitement like probably no other 1971 amp could do as Original. The Timer is a strange feature on the amp, it's not explained well & if arrived to the "Off" position it's fully Off & the Power switch does nothing, it's a countdown Timer to Power Off. But just set it to "Reset" after you leave it on up to 2 hours. The Control knob says nothing to where this point is, it can be fitted anywhere on the spline rod, so we just played it until it cut out, reset it & put the pointer there as you'd never know. Obvious it's not. Probably useful as a sleep timer or using it Live, but learn how it works or you'll think the amp was Dead. Serious Hifi or Gimmicky Guitar Amp? Depends what you use it for, it's Sound is like the other 1971 ranges if a more Punchy Sound as Original. The 'Rhythm Composer' may have Retro Synth Appeal & the Spring Reverb is going to have uses too, if use the Amp as a Receiver it's an Impressive one. Depth for the 30mm long Spring Reverb, top has Tuner, Main Amp Board, Power Supply Caps & Transformer plus the 4x TO3 Outputs Heatsink. Looking at it again the Extras add a Unique look & don't interfere, the 'RC' switch to Off to not hear it behind the music. As a Vintage Spring Reverb amp of 33w got to be worth £300 by itself, the Analog 'Beat Box' by itself maybe for Retro Synth use, not sure what else beyond Organs would use this, Roland 1980s MIDI of far more sophistication around £250, if this is a 1971 version on Germanium Transistors. So What Are The Circuits? To trace Aux to Output, not easy with the long lines. Tell it's Secrets, why does it Sound So Good as Original. A Better Schematic we found that's Clearer. Guitar goes through a low value capacitor, if you know Guitar, it with no Deep Bass Limiting with make things fall off shelves, this keeps it within reason at 33w as guitars can put out extremes. Mic has a preamp stage as does Guitar, both go to the Pre Out & can be used with Reverb, if limits on the Audio to keep them safe. It's Limiting but for PA applications, to not want untidy sounds. Reverb similarly switchable, nothing on unless selected, unlike a 1969 Pioneer Mic always on the Signal being Hissy. Aux via Selector to Tape Monitors then Filters with Source Resistors if not unlike the Sony STR-6120 type so not limiting like some Filters. Then to Muting to Volume, then the Tone -'Mood' settings which can be Defeated. Complex with Resistors in the Signal a few times. Into a 'Mixing amp' that is exactly that, you can play Guitar over other Inputs & similar. To trace Aux to Power Amp is advanced as Rotaries have several layers doing other functions. Probably easier to do on the Unit. 'Preamp' is Phono with Tuner last stage after MPX as other amps use. 'Main In' rear socket goes straight to the Power Amp. Pre Out from a Mixing Amp that has limits on both inputs. Most Designers can't get this Sort of sound, to find a 1971 with this 'Pro' Sound as Raw has to be Unique. Power Amp is Input, Driver, P-P Drivers then the Outputs, No Protection Circuits as these can trip in & no good for Stage Use. Play it up to '5' on Volume & you can see past 5 here's not much more, if Sound Quality with a Pro Sound is the deal here. Power Amp Board is first Half the [Phono-Tuner] Preamp & second half the Power Amp. Trace Aux to Pre Out. Too Complicated via circuit. Aux direct to Tape Mon 1/2, then has 18.8k resistance to Low Filter. To Volume then 6.8k then to Tone Board with Transistor gain & Passive Tone EQ modes. Then through the Tone Variable control board if set to 'Tone' else bypasses it. Tone Out to the Mixing Amp with similar on the Guitar & Mic stages, then out to the Pre Out stage & Pre In to Power Amp. The Aux Signal sees 64.6k of resistance. This gives a slight Compression effect if it well designed to still be Hifi. Boards. Underneath right is the 'Composer' Board, left is the long Reverb Board, medium one is 'Mixing' Preamp with 2 smaller boards as Mic & 10db Guitar amp. Middle wired resistors & tiny board section is 'compose board 10db gain. Top Left front is the Tone-MPC board, middle bigger board Phono & Power amp if the smaller mid board not detailed. Then Tuner right & Reverb Unit. What To Do With It. To redo the lot is a bit much, the work would be extreme. Like Tuner stages to leave the Extras as they work is fine. The Stages Phono & Aux go through plus the Power Supply to redo. Tuner, Generator, Guitar & Mic work fine. As with the TR-707A, keep it's design in Resistors as Original if Upgrade the Rest. Rare to find a Great Design that Sounds Right to Us. Try On Speakers. Rare to find a Vintage Amp we'd trust on Speakers, this one we've played on Headphones a few times & it's Capacitor Coupled so give it a try, First Raw Amp this Old we tried for 1hr Playing TV. Wide Stereo, matches very well & sounds good. Slight Hiss from the Composer if it is Germaniums, no noise otherwise. Clearly Lacking a Proper Bass, the Treble on 49 year old caps could be better if the overall Sound Balance is correct. Looks good on the table too, about the size of a Yamaha CR-2020. Plays Cool on the Heatsinks. The Amp stored in an Attic keeps them better than in a Dry House area, if others would just keep using it, to Rebuild will Better it. The Volume on the Tannoys is at just over '2' so to get a high volume will be possible. Surprisingly good amp. Interesting touch, the Rear Feet broke off so they used Two Bathplugs. Bathroom Rubber 2" Plugs. Rebuild & Upgrade. Big Piece of Hifi, a bit Overwhelming for the Extras & the size, if understand it to see it's a good one, still more to get deeper into. To just do the Power Supply, one Mix amp and Pre-Power Amp boards firstly. Recap & Upgrade on the Pre-Power Amp. the middle upper board so far, to try it. Quite a job & a workout moving it around, the fixed main board makes this an involved one. Play it with Soundcard Bass EQ to Balance & listen to 'burn in' the new caps & to do the it Power Supplies to do next. Takes about 20 mins play to not need the EQ. Very Smooth Balanced Detailed sound, a Designed sound if very well done for Pro use. Detail on 1960s Ska is very good, no muddy mush of sound here. A certain precise Focus with light Compression if then Pro tuned to give a Unique sound in a Very Special Way. Ska really reveals how good an amp is. 'Renegade' & 'Babylon' from the orig UK 45s sounding very nice, or perhaps the best we've heard them? Now Done. Interesting Sound, the Crisp Treble Detail with the Pro Amp style compression, see similar in Guitar Amps, will make Music sound better than you've heard as Ska from 45s proves. Bass is a little different with a more filled out sound, if to play it more & on Speakers to really understand it. To learn the controls to see Reverb & Rhythm is turned off unless using & the rear Pre Out Switch is set right. Compare with the Hitachi SR-800 once that's done. Puts out 32v Clean Sine (No Load) to rate it with 32w-40w amps. Try on Speakers next. As Upgraded, Deep Tight Bass & Crisp Clean Treble with Wide Stereo, typical no NFB preamp with Passive Tone, not many of these. Worth trying for longer, how does the Pro Design differ in use? Could do with a little more Gain as also found with Headphones. Sorted that now, an interesting Amp for sure. One for The Detail for Sure. Playing Rock not got the Weight of Bass some amps at this Power or Less can do, if up the Bass fills it out more. Guitar is Defined Cleanly as it is a Guitar Amp. Also a Pro Stage Amp to not be a Deep Bass Monster, but more sensible. Reverb is suited to less Busy Music as it descends into a Mush. The Rhythm Composer is a Retro Sounding Beat Box that has many variants with Reverb & Slow Speed, use it as Mood Ambient Music even. But still a Quality Amp, large size for 33w RMS. No other amp like this one out there, especially as early as 1971. Nice amp to know, Rare one. Later Opinion. It's such a different sounding amp, it needs careful comparing to hear how Great it is. The Inputs use PA ideas with Impedance Matching, on the preamp it takes a 2v signal to 0.6v. This looks rather strange on a circuit if to leave it as original & keep trying it. To get the 1973 Yamaha CA-1000 useable & on Speakers gives a different sound that compliments the KR-6170. What you get is a Sound with a fullness on the Lower Midrange & Upper Bass. It plays 'flat' on testing Sine Tones on it, goes to 30Hz with 20Hz audible too. It sounds like no 33w amp & the Power Amp is very like the KR-5150 that is 33w too. A rare amp, several on Google images isn't matching ones you find, usually in poor grade in & out. Clearly not one that gets much Cred despite how well it upgrades. We had a Trio TK-140X recently, it's not so unlike that if the Preamp Design here gives it the Unique sound. A large 55cm wide amp only 3cm wider than the Yamaha CR-2020. Use A Bigger Power Amp? Trying it via Pre Out sockets shows it's not the standard higher output, on our 1971 Sony TA-3200F 100w power amp it wasn't loud enough. A Mug's Eyeful? Buyers don't seem to like this one despite all the Features & Monster Amp Size. We put ours for Sale to Silence, which keeps it Safe until we find More Upgrades it can take & does it so well. From the Original rather Tame sound to What It Sounds Like as of June 2024 means it's Not For Sale again. 1971 amp Capacitor Coupled not the Differential Design that doesn't upgrade so much. Of Course we'd like a 9/10 grade Case & Fascia on ours, The Thing is we're not Keeping any 1970s amps as they aren't as Good Sounding, if the recent KR-6200 had a better souns it still looked Midprice. We do have a KR-8340 if finding the tiny & tightly fitted Tone Boards less easy to try more. Far from a Naff amp, 'Mug's Eyeful' on Google finds you Amstrad budget gear. it's Quality is a bit hidden, but that's for upgrading. These will have seen Pro-Stage use for the Guitar Input. But Nobody Wants It. More Fool you to be blunt, it keeps taking the Upgrades so well that we're finding that now it is perhaps the Best Sounding One. Deep Upgrades, years to research & have the nerve to try. A Huge Difference from it as Original & Serviced plus Recvap-Upgraded. A Sweet Colourful sound was an Oct 2024 opinion, will any other Receiver-Amp better it now. Nobody wanted this even trying a Low Price. Ours Hugely Upgraded & not really talked about too much, so it doesn't sell to 'Keep It On The Barbecue' for us to revisit. It's in the league of the 1965 Trio-Kenwood TK-80U Valve-Germanium early version reviewed above. BUY-RAW RATING: Reverb & Rhythm stage needs to work, ours was good once serviced. COOL RATING: 6-8 depending how you look at it, over the top or lots of buttons cool. It's grown on us. (2020-2022-2024)
1971 Yamaha CA-700 amplifier ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 60w.
SC, DIFF, Direct Coupled. One of the earliest Yamahas & a 60w Semi-Complimentary amp. This has a MM and a MC input stage for Phono & both are independent. Just a pity it's all DIN connectors unless you get the Non EU versions. Has the classic neutral Yamaha sound. Only a midprice quirkily built amp unlike the hefty later ones, but interesting. Beware the power amp plug in sockets may crack & fail, though other amps use smaller versions of this type fine & new ones can be got. But there is a lively open sound on these early 1971 CA/CR-700s that is more restrained in the later ones. We did try to upgrade this but the tone board is a strange design that isn't upgrade friendly at all. Before this 1971 range Yamaha mostly only made record player-receivers though there is an AA-70 receiver of about 25w. 2020 update: See our amp again 7 years later, only part recapped back in 2013. Needs a full recap now if back in 2013 amps were still useable to leave original, if it shows how they age. Again the DIN sockets if otherwise a worthwhile amp if a Rare one. Wonder what we didn't see as 'Upgradeable' if to understand it more now. They'd messed with it a bit losing parts you can service like the Power Amp adjust pots, puts us off a any price, Told the seller it was one of ours, to give an idea what a rebuild would cost if said they had a £100 offer on £150 item so seem to have accepted it. BUY-RAW RATING: Good if power amp board sockets are intact. COOL RATING: 8 a pretty looking amp with wood veneer case, unlike the 1973-77 Yahama style. (2013-2020)
1971 Yamaha CR-700 receiver ↑
AS-ORIGINAL (Once Serviced): Recommended-Very Good. UPGRADED: n/a. 40w.
SC, DIFF, Direct Coupled. One of the earliest Yamahas, Very Good looker, a quirky midprice amp before their higher quality later ones. It's varied in our opinions but actually is deserving of the current rating. All DIN connectors as the CA-700 is. Still has the classic neutral Yamaha sound. But there is a lively open sound on these early 1971 CA/CR-700s that is more restrained in the later ones. For the 40w here it puts out a confident enjoyable sound. On later compares to the CR-1000 & CA-800ii this receiver is no slouch even all orig spec. One criticism is the background hiss is a bit higher than some amps, due to the tone stage. There are 2 versions though, the original 4 transistor one is with correct bass (eg SN 12xx) but a later 6 transistor one (eg SN28xx) is bass light for design alterations. The sound balance of this compares well with the CR-1000 if not as loud. The start of the Yamaha golden years. Not a good match for the early era speakers like Tannoy Golds. BUY-RAW RATING: Good. COOL RATING: 8 as with the matching CA-700 amp, pretty looks functional with a friendly look unlike some harsher looks. (2014)
* See Part Two covering 1972-2007 *
*PHOTO GALLERY
We've added many pages of photos of the actual amps we had & were taken as they were sold. An unique archive of Serviced, Cleaned & sometimes Upgraded amps with many photos inside & out.
*MORE AMP REVIEWS
See the "Other Amps" page for others we looked at but didn't like or try yet for various reasons, plenty of amps there get a look.
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