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Hi-Fi Blog... Page 5 - 2021

See the MAIN PAGE for the INDEX.


January 2021 Blog


Amplifier Rebuild Kits & Where Are The Inside Photos?
These mostly from USA based sellers. Easy & Cheap Fix? We think it's just a Money Making scheme giving False Hope & Risks Ruining Good Amps. If you have Quality Hifi & only want to spend small money on it, well it's up to you. Got the Skills and Confidence as more Advanced Tech, you'd source Parts yourself. Kits are an Amateur Solution. To imagine 90% never get used as they are a 'Snake Oil' item as they know you'll never be able to tackle highly complicated & skilled work. TV shows many can't even Wire a Mains Plug yet to tackle a Vintage Amp is just a way to sell a Dream really. The Failure Rate you can imagine & then to ask someone to do it Properly, er, no thanks, don't want to undo Messes as it can be Double The Job. If you have a Quality Amp & think you as Unskilled Tech can fix it... Don't. Start working on cheap 1980s amps that you can ruin & not care, leave the Money amps alone as once these get messed try find someone to undo the mess. No Inside Photos? A few on ebay say they recapped, some show the old bits, but why will they Not Show their finished work? It takes more time to do it neatly & to show you use Quality Parts not the Rubbish No-Brand Capacitors often on ebay. This we look for but rarely see. Buyer Confidence is based on Seeing The Work Done Right. Rare to see the underside of Valve amps especially Receivers even as original as not to scare you off. There is a Long Way to go in Vintage Hifi still.

The Joy You're Missing Out On.
As 'The Repair Shop' shows, the Happiness seeing an item maybe of little monetary value but much sentimental worth restored or just to be able to use it again is obvious to see. Tug at the Heartstrings, if the TV show does it for Free if they say you Can Donate which most surely will. Your Knackered Old Amp in the corner or in a cupboard asleep in the original box, it still looks in decent condition but it's Days of Playing Music Daily faded over 10 years ago. Vintage Hifi bought pre 1980 seems to be Good for 20 years use after new, if probably not with Modern Budget gear for 'Error Mode'. You ask us for a Rebuild as It Was Your Best Amp. It's not a model we know & seeing a 1980 model to be aware of difficulties, so to give a broader estimate. Estimate confirmed if seen, but the Lower Estimate may suit if the Higher one not. The point of an Estimate, if not to 'Do It Cheaper To A Price' as it's more work to Cut Corners than Just Do It Right. The Message from one who's Read Forums & says the general type of comments that shows they, er, Read Forums. Think that'd be some Incentive to Get "Old Crackly" up & going, but not so. Their Amp will just sit Non-Working until life changes in whatever way, maybe it'll end up thrown in a Recycling Yard. It happens, ask our Marantz 1090. A more Dynamic way is to decide to sell other hifi on ebay to at least have the Higher Estimate, if it may be quoted at the Lower Estimate. We had the 1984 Sansui AU-G90X here from one who wanted it looked at but then didn't want to pay even the lower estimate. Not good dealings there. But that's Hifi we see & buy, it's been kept as "One Day..." type of thinking if 40 years later it's cleared out of a Damp Shed & put on ebay cheap. Missed Opportunities are in All Walks of Life, Hifi & Cars both get this a lot as they are 'Living' items needing Maintenance & Work to be Revived. Being Optimistic is Good, if Ideas do fade. Wired a Neighbour's Radiogram so they could use it if it never got used again. It's How Much Your Heart Is In It, the one who decided not to get their Pioneer rebuilt maybe wouldn't use it again. If one we've just done for a Customer of an Age to have Bought It New will be delighted to get their Marantz back all working nice & better than new. They kept Optimism for it as well as The Box & Books & will certainly enjoy playing this amp again. Enjoying Music is Good For You.

Onkyo Brand From 1968 To Date.
Difficult brand to understand. No real UK Distribution with ony scant info in a 1974 HFYB but then nothing. Their 1972 Onkyo Integra 732 a 59w stated now, an amp on our March 2019 blog if much unknown then. Recently we've heard of other 1970s ones if where to start really is only the HFE site if these are only listed by Model Number & no Year shown. Onkyo TX-666 seemed one we'd get if their Seller messed around. The Designs look good, styling much of the 1973-74 era. Sold more in EU. Not a reason to bypass early Onkyo, USA's McIntosh barely got sold in UK, only One Shop imported these it seems. But What Is There In Onkyo? To ignore the Modern Brand as will nearly all brands, we're looking at 1970s ones. Actually the 1968 Dokorder Amp & Tuner we've had to review & sold is of Denki-Onkyo origin as the rear panel says. Onkyo a Japan company since 1946, are they the same? Their Listings on the HFE site, a lot of Amplifiers, Integra ones earlier including a 100w Onkyo A-929, but what year is it? 1980s-1990s possibly? The flyer in Japanese shows CD input & may just be for Japan only. Only the 725 at 22w, 732 at 59w, & A-755 at 26w look 1970s. Amplifier A-7055 looks mid 70s, more in the Silver era 1979-83, black era lots more into 1990s, many models. HFE reviews give the idea they're liked, if to consider who reviews, a 1995 amp "the best they've heard" is a newbie review. Seems Onkyo a good brand in the Pioneer Sony type of quality. The brand known to us for rubbishy modern 'systems' clearely has more to it, if there are so many samey-samey amps past 1981. Receivers has a large amount too. 'Dynamic Four 800' looks 1960s if must be about 12w. 'Integra' ones here are very recent. A 'RU-D1' 1990s one like the JVC SU-Z1 for the names game, if it looks like a Fax machine. 'Model 225' looks early 70s at 22w. TX-220, TX-330, TX-440 with STK output blocks, TX-555, TX-560, TX-666, TX-670, TX-7000 more 1980 & TX-8500 a 110w one. Should be something there for varied Vintage Interests, if the 1969 Dokorder 800A or X 55w receiver seems their only 1960s receiver, so likely an earlier company to Onkyo, details unknown. For us or a customer to carefully Buy & Try one will get us reviewing one

Sanyo Do Have Vintage Hi-Fi Credibility: 1966 DC-60 & 1968 DC-66

As a Hifi Brand to those around in the 1980s-1990s, Sanyo are sadly on par with Alba & Amstrad for cheap portable gear. But that Image stops their early efforts as those two receivers being noticed. The 1966 Sanyo DC-60 & 1968-69 Sanyo DC-66 are interesting amps, great wood cases & nice looks. Top Quality Gear priced above midprice. The DC-66 with the Black & Grey fascia looks 1990s almost. But these are Rare, no Online Info apart from Photos. No pics of the insides so what are they? We actually have Both in Dec 2020, DC-60 is ours & the DC-66 a customers. They got the DC-66 so why not try the DC-60. Trouble is No Manuals are out there, no .pdf's & useless P2P sites that never have anything. See the 1966 & 1968 reviews for more. The DC-60 is based on no other design if uses Germaniums, Transformer Coupling, Direct Coupled output with the +/- HT, like 1966 Sansui 3000 & others. The DC-66 is a more sophisticated deign, Sanyo having seen other Transistor amps, if here still the +/- HT & no Coupling Capacitors. No Hot Resistors in this one, if no Manual to see Circuits. DC-60, we actually got the Printed Manual. DC-66 for how ancient & unknown it looks inside sounds suprisingly quiet on background with a Bassy sound if typically old sounding, but maybe to trust on speakers? DC-60 is quite crude in places & not tried it yet for reasons. Sanyo also did the 1973-era receivers like the Sanyo DCX-8000K which missed the HFYB but will have sold a few, if the lower models in the series turn up quite often. These 1973 ones are more Budget-Midprice if still worthy, if based on knowing the 8000 only. Looking on HFE, the Sanyo page is much fuller now, these as with Onkyo must be Exported far more than for UK sales. More potential good ones pre 1974 & even pre 1980. But Sanyo is budget priced portables & systems. Time to look at the Older Items, as a Brand making the 1980 Sanyo Plus 130 receiver at 130w has to be dong something right. Sanyo best known for Components, the early ranges didn't get promoted enough if EU countries bought Hifi more in 1971-74 than UK did. But a Brand Name once tainted for being cheap junk, time to look deeper. There are very Pioneer-looking later 1970s models like Sanyo JCX2600K & Sanyo JCX2900K of higher power that get decent bids in USA. Sanyo really hid their best stuff from the UK, if it's how Trade was in the 1970s, UK maybe had enough Brands to not take another brand offering Pioneer styles. Further Research shows Sanyo DC-60A the first, DC-60E updated tuner most likely & adds Multivoltage. A new find by the DC-66 owner shows the DC-70 seems a little later if much like the DC-66 with various differences & the DC-66 adding 2 Speaker pairs the last one. DC-70 on an extra-poor circuit basically shows it differs on the power amp. Any more?... "Because it is a used item, please refrain from purchasing if you are nervous."

Unswitched & Switched AC Outlets On Amplifiers.

We saw a 1967 Pioneer SX-1500TDF where the "expert" rebuilder actually Cut These Out to put in a 3 pin'Kettle' plug socket. Kettles used these into the early 1990s if long since abandoned, if the name sticks. Butchering amp Cases to put in a clumsy Plug is awful, captive mains cables are fine once rewired to 3 core with earth, as we do on all amps. The Pioneer one showed what they replaced, getting it only a small amount done to how we do. Those USA type 2 blade AC connectors are still useful. We kept the 2 pin plug on the 1970 Sony TA-2000F to plug into the TA-3200F switched outlet so you only need turn off the Amplifier, rather than switch two items. One Mains-earth connector to the Power Amp & the Preamp Output to Power Amp input has the Ground-Earth to both items without Ground Loop Hum as would putting Earth onto both units via 2 plugs. Some Earth Loops interract better than others, if we still use the Ground Loop Isolator on Our 3-Core Mains wired amps to lose the Earth noise which can be a 'Flaky' noise or hum too. To use 2-Core mains or 3-core explained before, a 2-core mains leaves a Ground Potential of 50v-100v+ that can cause problems. An Amplifier can use the matching Tuner via the Outlets, a Turntable etc similarly. Removes the risk of Ground Loop Hum & noise. AC outlets are useful, if long not part of UK Electrical rulings as amps had these blanked out or even removed for UK sale, because of non-standard connectors & the thought you would do things wrong. 4mm Speaker Sockets. UK even on the 1984 Sansui AU-G90X had 4mm looking speaker plugs, but they actually weren't useable as plugs as no innards to grip on, only to tighten wire around. Only by the early 1990s did the Great Idea of fitting 4mm sockets for 'banana' plugs become the Normal. So easy to use, but often you see Gold Plated large ones retro-fitted to amps that are a huge risk of shorting as too close. On 1990s amps with the Golds, they were spaced well apart. We use the Plastic 'VOSO' ones as they are smart & look Retro.

Big Desk Lamps On 'The Repair Shop'.

Getting tired of our Anglepoise lamp, the shadows & amount of times the shade gets dinged. these the 2002 'type 3' ones we got rebuilt a while back. Good lamps with Enercy saving twisty Fluorescent bulbs, but the old filmament bulbs are too hot & ruin the weak holders. Last looked at LED desk lamps but found the LED bulb isn't replaceable, not pleased at what was around so never bothered again. But Steve the Clocks guy uses a big wide Desk Lamp. Gimme Gimme, but what Is It? No name on it. Screws onto the desk edge & he uses it under his chin as sitting up higher than we do at our Victorian Estate Desk. Trying to find the lamp is not so easy, what is it? Turns out it's a 'T5' bulb Fluorescent Lamp with 3 Bulbs & made by Velleman. Ebay only has a seller in France. Put the listing name, not showing Velleman & ebay shows the Brand Name so instead of messing about with Glass from France, we want it before Xmas ideally & guess who has it at the same price. Amazon. So we buy one. Goody Goody, the work to find these specialist items & know what they are & what they use is a battle. "Velleman Working Desk 14 Watt Compact Fluorescent Lamps, T15(T5 actually), W, White" is what it is. VTLAMP6. One said 'T5' if these are possibly 'T15' LED bulbs like Cars use & easily found. But 'T15' is the LED cluster type bulb in modern cars lights, not really Fluorescent. Seems Amazon had these since 2013. It's not too clear which bulb, T5 or T15 & still isn't. A video by a reviewer shows 3 long bulbs in the head which is what we wanted. I's the 'T5' long glass bulbs like Shop Lights etc. The LED type bulbs wouldn't give the full area of light. Be careful what you read these days, it's often Incorrect & Confusing. Amazon Ways. We bought this on Amazon before 1am Sat 19 Dec, Amazon try the tricks to say Thu 24 Dec delivery, don't want Prime even for free as they'll charge you next month. But by Sun 20 Dec 6pm it's here via their rude "slave" who wants to leave it outside & claim it's delivered? No you don't. Email shows delivered minutes later. The Light Itself. Do we really need a big light to show more truth of life today? But it's for lovely 1960s & 1970s Hifi so we sure do. To fix it on the desk edge & figure it out soon brings a very white Light, not dazzlingly bright, just right. Makes the LCD monitor look a little yellow so to adjust it's colours. Frees up the Anglepoise base space which was often annoying as right in the way. Got it over the 1966 Sansui 3000 receiver & as a much bigger light source no more shadows & forever moving the Anglepoise head to light it right. 'The Repair Shop' helps us again, they will have worked for Companies to know the right tools. To see next how it is in use. Comes with a 2 pin EU type plug which isn't strictly right to sell in UK, some Companies add a 3 pin plug block the 2 pin clips fully in, if this round type plug would be too bulky. Fits in a 2pin-3pin Shaver type socket adaptor. Should make Selling Photos look better too. Still reaches well on our 6ft wide desk, if to fit back as far on the edge as to fit in front of us is where the Monitor is. To be able to push it away to not be 'oppressive' right on top of you is good. Judging by Compliant Life today, not many will understand that. A bit like one we visited & their electric clock was noisily vibrating on the cabinet. Person sat right by it probably for months, but we move it to settle it evenly so quiet. Used It A Bit. Could do with the Desk Fitting part nearer, the light pulled nearer is bright if maybe could do with Brighter Bulbs. The light as a Large Area is good, shows the Grade of Records much better as not needing to rotate into the light as the light is all there. Move It & Brighter Bulbs.

February 2021 Blog

Radford Valve Power Amps: MA 15, MA 25, STA 15 & STA 25 From 1961.

These have been popular for Decades, the Designs are much used in later amps. MA 15 & 25 are basically the same amp, only the last power amp stage & power supplies differ. MA/STA 15 uses a Valve Rectifier GZ34 that's a familiar one. MA/STA 25 use Diodes as Half or Full Wave rectifier. HFYB shows these first in the 1961 book... "Radford introduce STA12 12w EL34 stereo amp £38, DSM preamp £34, MA15 15w EL34 monoblock £23 each" as on our List Of Amplifiers page. 1962 brings..."Radford add MA15 Mk II 15w EL34, MA25 MK 2 monoblock amp 25w KT88, STA12 Mk 2 15w stereo amp, STA15 doubled version of MA15, all no prices". Fast with the Mk II versions, maybe adding Diodes & losting the GZ34 & other changes. These are Rare & this 2013 comment on that Amps page... "A Radford STA15 in high original grade sold for £1486 May 2013, stunning high grade is our opinion, not their hype, looked like new, 1963 dated caps. One questioner wanted it for his collection as all-original, don't people use these? Early PCB design if with the similar hardwired lined-up look" shows where the money is, if since to see ones original or rebuilt if never with inside pics, still make the prices. See the rest of our page for more, including their Transistor era which aren't as popular. So What's In Them? Classic Design here, parts of Quad II from 1953 as input & later stages like several mid 1960s ones. Sensible design & much copied to this day as are the Mullard designs. The Mk I are limited by the Valve rectifier so will be a slower sound that some will like. MA/STA 25 have Diode rectifiers which will be faster. Design is Ultra Linear which some think is great, but having found UL sound boring & changed two amps to Pentode mode, the improvement is huge. As 1961 designs the Spec is as limited as 1963 Trio WX-400U, a Spec that will become frustrating if the Cosy Sound initially appealled. Mk II? This isn't shown on the HFE manuals that put MA & STA on the same .pdf, what they changed on MA/STA 15 likely the Valve Rectifier if what on the MA/STA 25 is unknown to us, not the sort of amps we'd buy. But the Circuits are familiar from other amps, if the Spec on these will bring a Warm Sound with No real Bass & Soft Treble, but once you hear this 'Old Fashioned Hifi" sound, you'll find it very nice. We started with that 3w Sterns Anp & a prewar Tannoy PA speaker, the sound was limited but just so nice. The sort of 1920s Directly Heated Valve PX25 sort of scene, not Hifi as we know, but an Enchanting sound, much like our 1932 Pye G/RG Radiogram that's as original as possible for 88 years old. The Radfords will have that limited sound if the 0.1% THD ideal by 1961 unlike the 1932 gram. The Quad II we had in 2002 had a similar sort of Early Sound, no big dynamics, no bass, soft treble but an Appealing Sound. Quad II were good with a different preamp, the Quad & Radford ones will be awful & limited. A quick run through these, an appeal to a certain buyer as well as paying a Premium for one of the few survivors. But how often do they get used? A 1966 amp rebuilt better will show them up as "Quaint" too easily. Maybe the same Low-Spec appeal of Brass-Era Cars is the appeal here & enjoying their limits. Ultra Linear mode is in this design with the Output Valves. Most 1960s amps use Pentode mode. All Modern amps including the 1979 Luxman LX 33 use Ultra Linear. We don't like Ultra Linear after hearing ones like the 1963 Trio WX400-U as the sweet open Pentode mode is hugely better than UL. To prove this, we changed UL amps TT Genesis & LX33 to Pentode mode. Pentode takes better design as 'Ultra Linear' is just 'Extra NFB' in reality, smoothing the sound in a way that's hugely inferior to Pentode mode. Pioneer SX-800A & ER-420 plus the Fisher range are Pentode mode, Rogers HG88 III is Ultra Linear. HG88 III is designed more upfront to better the UL sound, if to us the modern UL amps sound so boring.

Trio-Kenwood KA-6000. What Do We Think Of It Now?

This together with the Sony TA-1120 we liked in 2014, it's now 2020-2021. Our Upgrades are way ahead now & for Valves the 1979 Luxman LX33 gets every idea thrown at it, the LX33 today gets regular use for Vinyl & is right up there with the Best 1966 Receivers for Sound, if the Receivers are more Bassy for delivering more Current. For Transistor Amps, we Upgrade many amps, we get ones that interest us from Bargains to USA Imports. The Trio-Kenwood KA-6000 has been the Amplifier that gets all the Upgrades tried on. Over time the KA-6000 reveals issues that emerge only from Upgrading to a much Experimental way. Don't get us wrong, the KA-6000 is a great amp & why it's got all these upgrades, recapped with upgrades to a Sensible level it plays a fine sound. Going Further reveals issues: the Filters are direct on the Power amp stage & after the Volume control. This is not good as the full 'Boop' of the switch can drive the Amp stage unstable & probably trash it one day. The KA-6000 as we'd return Recapped would stop this being an issue, if having to tame things to keep it nice in Use. Also on Power On it connects the Speakers & disconnects on Power Off. Again this brings issues, a loud Click as the Capacitor Coupled Speaker outputs suddenly connect is really not what you want to hear. Our KA-6000 ideas we put into the Trio-Kenwood KA-6004 now & on it's Relay turning on, only a small noise that's acceptable, as with Relays generally. But look inside the KA-6000 to see an extra pair of Transistor spaces going unused. This was from a time like the Sony TA-1120(A) that they used Doubled Outputs to get 50w plus Peak Headroom, By the time the KA-6000 was issued the 2SC898 which are 80w 7A TO3 outputs so no need to double up. Parallel Outputs are actually Good as it delivers extra current, so the 48w KA-6000 if given adequate resources can be a 70w+ amp now & it drives speakers well. We've liked the Trio-Kenwood TK-140X Mk II with the Black rear label & the "UA1384J" board & it seems no other Trio amp uses this, if the KR-6060 receiver does, so to get the amp board & rewire the KA-6000 to take it. Custom stuff, gets rid of the TO66 transistors so we made a Custom part to not need the KA-6000 clumsy metal case. The KA-6004 has a strange Preamp-Tone with Stepped controls & a Deffeat Tone which is the same as setting Tone to "0". Try moving that a few times, the 3.9K resistors & wires make this a mess. The Buffer Board behind the Volume is terrible also with Noises & odd issues, so yet another poor stage. It works fine "amid itself" but really the KA-6000 is best left Original with Recap & Upgrades, but it's our Experimental amp & of couse it's gone too far. KA 6004 we had sitting unsold & for it's more sane build, beyond the messy filter boards to put 'all the ideas' into the KA-6004 worked out very well, the KA-6004 is very tamed but has awesome potential. Had the KA-6004 four times now, the 3rd one we did a lot with the preamp if decided not to do more, the 'desperation' with the KA-6000 got "what the hell" attitude & just maxed it out which brought an Amp that's now on our Speakers, dislodging the Sansui TR-707A which despite a light background noise, it's been used most the last 2 years as it just sounds nice fter a mega rebuild. KA-6000 again. It's now very custom, but there are wiring errors on the diagram so the Tone refuses to work, got sick of it over a year ago so to try to rewire with standard pots & lose the pointless Tone Mode got no better. Looks no different from Outside & still works as a regular amp, but Custom. The next thing is a Trio-Kenwood KR-5200 we got very cheap purely for parts, if it does work. It has a nice Passive Tone stage with no added nonsense on the Tone board & it could be made to fit the KA-6000. "Frankenamp" one called it on first hearing the idea, not too much KA-6000 left it to Experiment brings progress. To use the tired KA-5200 via Pre Out & KA-6000 main in gives an easy way to try. KA-6000 is known as having '400mV' Pre out-Main In & later amps including the KA-6004 have a standard '1v' level, if how this is measured is vague. KR-5200 has a Pre Out if not a Main In as a 30w Amp stage would usually be wanted to go Higher Power if a Preamp will be designed for a 30w amp not a 100w one. But to upgrade & alter. KR-5200 Pre Into KA-6000 Power Amp. Cables connected. Levels match, the KR-5200 says '180mV' if it'll be the sub-1v level. Actually sounds a lot more precise than the KA-6000 pre ever did & even the TK-140X II into the UA1384J board. As hoped KR-5200 pre into TK140XII/KR-6160 makes a better amp if a more 1969 sound than the KA-6004 is with 1973, if the Doubled Outputs make the KA-6000 a bit special. KA-6000 Power Supply. This is an early design still, there is only One secondary winding so a large hot resistor drops the HT to a Preamp level. Later amps use different designs, the Hot Dropper Resistor is a Valve design. So that's what happens when you keep One Amp to try all the ideas on. The KA-6000 as a "KA-6002" protype of ours with the KR-5200 tone even as original is an improvement, with the TK140X II/KR-6160 amp board & using Doubled Outputs puts it into a different league. Three Amps Into One may seem a bit Barking Mad. But Designers used older parts in later amps, the Sony STR-6200F uses a lot of the STR-6120 for example. So why not, will it better the KA-6004? To Be Continued...

Cherish The Past: It's The Best There'll Ever Be.
In 2020-21 we can Cherry Pick the Past & realise how great it is compared to today's cynical offerings. Some things go into a place where you keep them Neatly but Ignore them 20-30 years, we collected loads of Classic TV on DVD if some you'll never watch. In the Case of Hifi these amps are being dug out 40-50 years later from a long sleep. Big work needed to Recommission old wrecks in Hifi & Cars but it's worth it on the best. The Best in Hifi is what we are discovering, some 'Bests' are severely hidden until upgraded. Our Xmas TV amp is that Trio-Kenwood KA-6004 that sat unsold for ages, so we gave it 'the lot' to reveal something very special. This is good as when you Rediscover these forgotten or abandoned things, time has had many thrown out as TV Antiques shows tell of Great Stuff found in skips which does happen. How Great they actually are is a nice thing to find, if often to be the only one realising this. We've been Discovering Great Hifi Amps & Receivers for over 10 years & our Records site is more a Hifi site to many if Records carries on. Xmas TV we record TV Shows or Films that are worth a try. 'Dad's Army' 1975 episode with Arthur Lowe, then 60, playing his Drunken Brother is TV Gold if he himself was a heavy drinker. 'Dad's Army' clearly kept the Veteran cast going by their final dates. Not watched the show since the 1990s as it was always on so we saw the later series if the early ones on DVD didn't have the charm. "Morecambe & Wise" another one long forgotten if BBC2 put their 1975 Xmas Special with two 2020 departures, Des O'Connor, then 45, & Diana Rigg, then 37. Watched all of both shows except the M&W Brenda Arnau singing. TV today offers predictable Animated Films that we tried last year if 2020 has BBC1 with a new "Zog", nicely done if a bit bland as the last one. But BBC1 HD broadcasts it with the Volume going to a glitch failure noise & then stays at 1/10th the proper level. Unwatchable if broadcast the same level, needing volume way up on the amp all the way through if still hard listening. The extra loud end swap over will have annoyed many. Huge Fail there, lazy beyond belief, nobody noticed? But we recorded it so the Catch-Up version is right. What Modern TV will there be repeated in 45 years like 'Morecambe & Wise' a strange blend of Music Hall, Old Time Comedy & Edgy stuff like beating up dry Robin Day who looks a dinosaur now. 1975 ones aged better than the 'alternative' boring 1982 type that swept them away. ITV offers 30 years of 'Ant & Dec SMTV Live' as it's gem, should we laugh? Much like CD era threw out the pre 1978 gear, the Vintage always comes back as Quality stands out. Books are sadly not as popular now even on ones once Collectable & selling well, if our Books page on Prewar Annuals still gets as many hits as our 'Solds Gallery' Hifi individual pages & the 'Beatles Contract Pressings' page. We still keep a few series if have sold quite a lot. To read a 100 year old Annual to give a taste of a Century ago is a Mellow thing, so '1921 Playbox Annual' is being read, or at least partly read as some is a bit samey after reading several. The artwork by the likes of W. Heath Robinson has a lot of appeal if some stories are set & then rushed endings in a few lines. Then read a 1923-29 era 'Felix The Cat Annual' always plenty of The Past worth a read.

The Repair Shop Xmas 2020 Episode.

This features a Radiogram of some early 1960s type, has Valves & a typical Autochanger with 78-45-33-16 speed. Brought in by a pair of Sisters who's Dad from Guyana bought it when new, an unnamed Dad who owned the 'First Black-Owned Record Shop in Brixton', Google says 'Desmonds Hip City' & plenty online about this. As another 'Desmonds' 1980s TV show had similar & us dealing amid many Radiograms as the infamous "Blue Spot" made by Blaupunkt was a wanted item around 1985 by a Guy into Shop Fitting Interior Build & Design, maybe 'Nobby' is still around, so we took interest in them. They say their Mum kept it all these years as a Sideboard until a year ago if missing legs means perhaps this story is a slightly created one, who'd keep a large broken item, if possible for how previous Generations just kept items from never moving house or flat. Closer look at the one shot of the badge seemingly "Kaiser" brand or Model range could have been used in that shop & modified, not enough info here. The big hole cut in it is very 'Garrard 4HF' sized if it's oval, not D-shaped so any sort of Record Deck could have been fitted in top, or Baby Bath. To refurb a Vintage Turntable like this is a Huge Job as the old oil & grease goes solid, to take it all apart & clean a non-precision item is a tricky one. The other stories are far too "Reality" with subjects they aren't cool forcing for an Xmas episode, we skip through those as we don't want to hear it really... New top made for the Gram, legs added & insides made working. The Very Smart matched Veneers & Piano gloss like a Russian "Rigonda" brand one from around 1962, if Google shows similar if not the actual one with Speakers 'Built In'. They play an LP on it, if sound probably added Post-Production. The odds of a Radiogram being of a Use-Daily stable quality without wiggly noises, hum, crackle & failures is very low. Repair Businesses taking in Radiograms must get so tired of them, they may look nice as this one did, but insides they can really be 'too much' to restore. This one is marginal, if could have History to it, if it fills TV shows & ticks boxes in today's way. We've tried plenty of Audio gear since the late 1980s so keep it to Amps & Receivers of a certain Era. Nothing worse trying to deal with cheap broken items, use them just to Display if pretty. We had a 'Sobell' Desk Top Gram that the Deck got too rough on so it went, if the innards are in the loft still, if why? The 'EAR Triple Four' as on the 'Solds Gallery' we still have the Grey version of this 1957 player. Big Job to Redo the Turntable, it works but It's getting crackly now. Back to the TV Show, they all seem pleased with it if just a tad overcooked on the Sentiment does make you wonder how scripted it is. "Can't Wait" childish talk is very scripted, it can indeed be a Delight to work on Interesting Old Items you've not seen before, if you can see Annoyance on Suzie & Steve sometimes. Here the Jeep really gets to Dom if he later hides it, far too much of a job there, because Annoyance is always there & part of doing a tricky job. Mild Mannered Techs they may seem, be sure they swear the roof off, just like we do, but soon forget once it's working right. Problem Solving is the skill here, attitude is required to solve. To think 'Why Bother with That Junk' if they don't get to pick their jobs being given. To never see the finished insides to see what they did on the Gram. The Results are What Makes It Worthwhile. Results that could have been a Nightmare to get to.

Monster Receivers. Owners Like The Loud, But Sound Quality & Bass?
We've Questioned the validity of Monster Receivers for Years. We've had a Few of the 1976-78 era ones to know what they are like. Some Models, like the Big Pioneers get Rave Reviews but Never do you hear of Great Bass with them. Because it's never there, it's Not For You & probably you've never heard Proper Bass in any Amp. Marantz 2385 we had for about 18 months so really got into it trying to Better the Sound from it's Original Soft & Blurry Sound to something worth comparing to the earlier amps. Very Hard to get Proper Bass in any Amp design if there are a few if of much lower power that sound way better than these 150w+ if rather limited tamed designs. Anyone else agree? Yet to find any criticisms of these, as no-one else Questions these Amps like we do. Bass is very tight with none of that THX Cinema type Rumbling Bass that is on many TV shows these days, that Deep Effortless Bass just about all Amps won't give you. Looking at a Pioneer SX-1250 a brief look on 'other amps' found it interesting, 30kg lump that it is & in one piece only, if boards do unplug. The design is 'tight' at every chance, it will be a Rather Flat sound taking No Risks. The Problem is 1976-78 is Past the 1975 Specs Wars & Past the 1974 Comet Discount pricing, the big Pioneer were sold by Comet & heavily discounted by 1979. Bassy open deep detailed sound is in Very Few amplifiers. The Ones we got that Sound from were ranging from Great as Original to Very Limited. You'd like that sound? The trouble is it takes Years to get this right, 1 months to get the Best from the 185w Marantz 2385 as we experimented on it, it was a well behaved amp at all times, unlike others of that range as in 1122DC & 1152DC. Getting a potential upgrade on the Pioneer SX-1250, to see much online with others recapping. They miss such a lot as who'd Dare to Experiment on a Monster Amp or Any amp. They say it recaps well even like-for-like but as Blogged Before, be sure the Overbright sound with No Proper Bass will disappoint. We're still with the 1969 Pioneer SX-2500 which is the First Pioneer Monster Amp for size & wattage if their design is so dumbed down it really takes a lot to reveal it's Real Sound if we're still working on it as the typical 1 year+ to get the Best on an Amps repeatedly tells. There are a lot of Bad Builds in these Monster Receivers, crappy Power Supplies are Standard, they Overheat & are poorly built. 2021 now so 1976, that Hot Summer, is 45 years ago. As with Any Amp, willing to try & upgrade if Money is the Limit as a Year to Do It Right is a job that will cost plus always the Risk of Would it be Worthwhile. Marantz 2385 cost us £1500, huge service, recap & upgrade job yet to only sell for £2200 is experimenting but ultimately selling One's Talents Cheap. The Monster Amp market is a Different Sort Of Hifi. To Keep Them Working seems more the aim than giving them Deep Bass & Sweet Treble. The Marantz 2385 we got a Nice Sound & Used it on Speakers, if ultimately to Sell as not wanting to go further. We enjoyed the 2385 though & this is where it pays. Did we learn Much From It? Not really, if ICs in Preamp aren't a problem, if a 1976 amp has lots of faults & broken bits even if the power amp was untouched. These Huge Amps have been often used since New so much fiddled with & bad repairs is the risk.

We Question All We See In Hifi & Wonder What Others See As Hifi.
We're always reading Circuit Diagrams, Opinions from the Era when the Amps were New & How Forums etc see those Amps today, 40-50 years later. You Never See Comments about Bass as these Amps aren't designed to have a Proper Deep Bass. The Bass you may get is a 'Ringing' type Bass from Limiting, this gives the One Note Lumpy Bass aka Retro Bass, or more often a Dry Limited Bass with Damping High past 1980. The 1966-79 era is The Best Sounding with Many Amps sounding very decent if rarely Bassy. We're trying amps as Original as much as we can to hear what they sound like, obviously Aged but some can be enjoyable still, this is on Headphones. We played a very tired 1966 Sanyo DC-60 for 2 hours as it sounded pleasing if far too rough to chance on Speakers. On Speakers we do try some amps if they are trusted. Here as this Blog shows, on Speakers such as our 1967 Tannoy 15" Monitor Golds, these amps are not all that is a reality, if based on hearing much Upgraded amps, you can't review any amps not hearing how a deeply Upgraded amp sounds. On Speakers to hear Original Grade Amps as Unfocused everything, feeble treble power, midrange untidy & poor bass with that Vague One-Note Bass that gets boring fast was what a 1967 Pioneer receiver gave, if Upgraded these sound Very Decent. To Judge an Amp on How It Sounds as Original if forgiving it lacking bass if looking for precision in Midrange is the starting point. There were no real Hifi books, so we wrote this Site to Educate. Still plenty out there Realising Vintage Hifi is way better than Modern, if the pre 1974 era is even better. We keep looking to find 1980s amps as good as the 1984 Sansui AU-G90X, still looking. Ten Years Ago, only the 100w+ Monster receivers got interest. Now the Sleeper Amps & Receivers from 1963-1973 are getting interest when you can see from Old Forums they were just Oddities. The Problem now is Severe Overpricing where ebay now shows loads of Unselling Overpriced Raw Amps from 40-50 years ago & even 'nothing' ones supposedly £250+, to who? See the same ones on auction selling for Real Prices, as in rarely over £200. All Vintage Hifi is a Gamble to what you'll get if in our years to see 90% survive, it doesn't mean those 90% were easy to fix, probably under 40% were Useable on Arrival, if ones to trust on our Speakers is a different thing.

"There's An Awesome Amp Hidden Inside!"

Is that actually Really Helpful to know? It shows The Potential in Amps if Doing Extreme Upgrading to find that Sound is the Only way you'll get to hear it. who'd be bothered to go looking? The 1972 Trio-Kenwood KA-6004 we've had 4 of. The Trio-Kenwood KA-6000 was the One we chose to do more with if still seeing parts of the KA-6004 were better, such as the Preamp-Tone & Power Supply with two secondary windings. It's like hearing a Person could be a Cartoon Voice artist or a Great Singer if they never chose to further those talents, they'll never be realised. KA-6004 gets an 'Excellent' if many bettered it, the KA-6004 never got upgraded further for not liking the messy filter boards. A Gain Stage & a Buffer on two untidy boards with unused spaces is not too clever & why the metal cage covers it. So why did we bother 'maxing out' our KA-6004 having first had one in 2013. The 1970 Sansui 350A we heard a quality sound with even as dirty & original, a smoker's amp with a wood case needing a refinish. See the Review, as one did & wanted to buy it. Really tried to put them off as not finished with it, but if they're that keen, sell it. It would have been the Xmas-NY amp to use as it sounded so nice with 20w having a rare design to give a sound that was a bit special. Several other amps on the go if not ready to use, Sony Pair & Sansui TR-707A recently used & hearing where they can go further, if not yet. Trio-K KA-6000 getting tired of by Nov 2020 so why not just put all the ideas that'd fit in the KA-6004? Revealed how Dumbed Down the KA-6004 as We Question Everything & the KA-6004 has a sound like the Sansui 350A does. A few issues with the KA-6004 as we've found before if it was used over Xmas as it sounds so good. Reveals the KA-6004 an 'amazing' sleeper & the Amp it was even Recapped & Upgraded to sell is way short of it's best potential. The Sound is 'In There' but to bring it out was based on 5 years with the KA-6000. It's a slow 'journey' & without the want for an Xmas amp we'd probably not have bothered.

Tests. Multi Amps. One Amp Can Sound Tonally Different One Time & Different The Next.
Humans are so easy to suggest things to, their little brains can only cope with a certain amount of "Difficult Stuff" which is why Stuffed Shirts can't understand why lockdown is so ruinous to people who see Reality in a different way. To have said similar for years on this site. To play one amp for a while & get tired of it, this usually manifests in you playing it less loud. Why Hearing does this is one never researched by Million Pound Grants. the sense of Quality remains constant as you hear better, other amps can not satisfy. But the Tonal Difference of Amplifiers, caused by Preamp, Tone & Preamp varies hugely. Take Jan 2021, had the rebuilt Trio-Kenwood KA-6004 on speakers over Xmas & found it very decent. Back into Hifi again & trying the difficult amps, the ones that sit for ages until ideas emerge. The 1966 Sanyo DC-60 as it's 55 year old self all as original was the laat one played earlier. It's playable & the sound is so pleasing. A NFB amp with Germaniums, but the Sound is quite remarkable. As the 1966 Sansui TR-707A was two years before, to upgrade it carefully & be surprised how well it upgraded if a huge huge job to do. DC-60 pleased, the KA-6004 after dinner swapped the Sony TA-200F/TA-3200F pair back. Last played those in the Summer & thought maybe they needed more if had more amps to deal with. 'Let's Try The Sonys' was the idea Mid-QI. On they go with all the connections. Found the need to alter the Tone to suit the current Amp Tonal balance. How great the Sonys sound now, thought them a bit lacking before, if listening now, why? Ideas you gather can greatly alter your audio Perception, as said quality meaning Precision & Clean sound remain constant, if now to hear the sonys with 'new ears'. Try it tomorrow too. The thought to change was for how good the 1972 Akai AS-8100S sounded if it needed more & still does. Your hearing wants a Change. Better or just Different? But... watching more TV reveals the truth, you were tricked. the QI no-audience episode was broadcast rawer without compression. This sounded way better than TV usually does sound & other familiar shows then made the Sonys again sound like more needed doing.

Early 1971 Hitachi & Sanyo ICs Can Go Hissy.
Transistors of the non standard 'D' shape can go hissy, some are notorious if in reality with all the amps we've had, it varies to the point to say some can be ok & some bad even with the same Transistor number. Easy to check, it is Too Hissy or Not. Affects amps in different ways, with use they can go from Good to Bad as the 1972 National Panasonic SA-6400X did as the preamp grew noisy with use to just redo all the offending ones in the preamp to sell a reliable product. Early ICs we've had in the 1967 JVC 5040U if these are not in all of the run for design changes. These on 3 of the amp were all fine, working with No Hiss. Hitachi in 1971-72 used an "FA 6001" strange IC looking like a big ceramic capacitor that USA Fisher & McIntosh use. This was hissy on the Hitachi IA-1000 Phono as told on seling it. The Hitachi SR-1100 we had a while ago was fine on the IC. A New Old Stock SR-1100 we had last year was a 'reject' as the preamp Transistors were hissy if the Phono & Mic ones were fine. But after more use, the Phono ICs became too noisy with a 'Seashore' Hiss which is not useable. Our Hitachi SR-800 for sale was much used so the ICs being fine will always be fine, the NOS SR-1100 hadn't been used. SR-800 we can turn up past 4 & not be bothered with hiss. The 1972 4ch Akai AS-8100S we have is an oddity, the "LD-3120" ICs are in other Akai of the era & the Akai AA-5800 sounded fine. But the Gain on the Akai was too low as designed, but once corected it brings up the same noise the Hitachi FA 6001 does, it makes it too noisy to use n speakers if the Sound quality was great. An ebay seller has the FA 6001 which we've suggested to the SR-1100 owner to replace. The LD-3120 IC render the Akai unusable, but the same seller has LD-3130 that the Teac AS-100 uses, also numbered as 'Teac 42708', as we had a Teac with this one fitted with as a mixed pair as factory made, so the same IC. The pin connections are the same & to assume the LD-3130 is the same one. Sanyo LD-3120, Sanyo LD-3130 & Teac 42708 are basically identical on pin connections. No Data sheets on these, if Manuals show them. The chances of finding the ICs as NOS is zero, but the seller has them from their dad's old hifi repairs from 40-50 years ago. These things will exist. The spares will be of later manufacture so hopefully avoid the hissy early (?) ones. The LD-3130 in Teac AS-100 has always been good if the pins can be fragile. Last one we redone the customer needed to use his spares amp to fix the ICs & a unbalanced volume control. How will these LD-3130 work in the Akai is to be found out. Hitachi FA-6001 in the SR-800 that was a later model in their range we've checked to see 'D2G' batch ones on all three on the Phono-Mic board. The hissy SR-1100 ones are 'D3B" & the seller has "D3F". Maybe the 'D3B' ones made on a very hot damp day to be not of a good standard, what was the weather like in 1971-72? Different batch could be good, still a gamble but worth trying. Akai & LD-3130. The old hissy LD-3120 are '2g' coded (small g), put one in, sounds good. Put 4 in, one is hissy shows batch numbers are random for hissy ones. Bought 8 to have options. Gambling buying NOS if the LD-3130 were £2 each, the FA-6001 at £7 each means more to spend to get a set, but in real terms to have a chance to repair hissy parts is great. To use a few hours to see they don't go hissy as NOS like the Hitachi SR-1100 was.

NOS - New Old Stock Hifi Isn't So Good After All.

The failed 1967 Pioneer SX-1000TDF looked unused beyond sticker marks on the lid. To fairly consider it was a Sales Reject now that got passed around or just forgotten in a Repair Shop until being sold. The 1971 Hitachi SR-1100, not our Gallery one but the NOS Brand New in box one came to us with loud Transistor Hiss. The Loudness wire had broken at the connection if on the metal piece as the Rivet holding metal to carbon track had failed. The thing is the Loudness control worked fine for us after resoldering & testing the amp quite a bit. But going a long journey got it shook up to loosen this Loudness so one channel was louder as the Loudness switch only gave Loudness one channel & the other was louder with no connection. Loudness lifts the Zero Ohm ground to give more gain in the loudness design, it doesn't limit the original source when loudness is off. To think it was repaired but on getting it back to find other issues so it got slammed about quite a bit. But that's Couriers, the issue here was Damage from when New & Unopened plus Transistor Hiss. NOS Valves & transistors are reliable, if a large receiver would generally have been dealt with in 50 years if it likely emerged once the warehouse owner's collection was liquidated. "We've Got A Brand New Boxed Amp - Never Used" but Reality shows it was opened when New & Rejected therefore. A Dusty Dirty Amp that still works to any degree is a survivor. It's like with Cars, dare to buy a New Car & be sure it'll have issues that need repair, if you should Reject New Goods if they are Faulty & more than just a minor issue. The SR-1100 needs a 100K Log Splined Dual Pot with standard loudness tap. Unfindable unless you find NOS spares or ones from a salvaged amp. But all is not lost, to rewire the Loudness Volume Pot to not use Loudness is a solution.

1971 Hitachi SR-1100 & Hitachi SR-800 Comparing & Via Pre Out-Main In Connectors.

Got both here together to try. We liked the SR-1100 in 2013 if design wasn't so understood then as it is now. The SR-1100 has Phono & Tuner at one level if Tape In & Aux are of a Louder level if are limited in the Design by resistors. Usually all are designed to the same level, to get the Aux level sorted to give a great sound if then Tuner & Phono were half the level means undoing good ideas, who would think it'd be like that but the SR-1100 is. The SR-800 came slightly later if is a totally different design like Hitachi used in the 1972 Realistic STA-150 as they built this for the Tandy-Radio Shack group. The NOS SR-1100 had issues if it's long journey to the owner caused more bother, so to fix it for them. Volume Control was bad, what do you do? Consider options then remember an amp you saw might be useful for that part & it was, so to get that & the SR-1100 is spot on again. Rare parts are 'priceless' until you find another option to get them where they are considered unimportant. We get messages expecting just to find rare parts easily, critical parts from 40-50 years ago usually unfindable & long obsolete , if see 2 blogs above about ICs. Even Alps pots aren't free from getting damage if it's certainly an odd one & only really will Original Parts do to keep the looks right. Playing Both. The SR-1100 & SR-800 for being both our upgrades sound very similar, it's a nice fresh sounding amp. The SR-800 is not as loud on the Volume setting & we'd already bettered it. So as both amps have Pre Out-Main In sockets, to compare & see which half of each is louder or better sounding. Cables used are 2 pairs of those 'Van Damme-Ream' cables blogged about before. Aux input using those 1967 era cables. SR-1100 pre into SR-800 main. Volume on SR-1100 at 2.5, SR-800 needs volume to 5 so the SR-800 is quieter on pre than the SR-1100 if the power amp is fine on both. Answers that mystery, if why the SR-800 preamp designed lower volume so much? Sound quality on both despite the volume difference is still much the same on Headphones. Circuit Comparing. The SR-1100 pre has 4 transistors per channel including a buffer. The SR-800 has only two: a buffer then tone with NFB around a gain transistor. Overall preamp gain is more like the 400mV level of early Trio-Kenwood than the standard 1v. SR-800 gain can be bettered if not quite as expected. Specs on SR-1000 are 800mV main in, SR-800 is only 275mV as on the manual front pages. SR-800 & SR-1100 are not compatible, SR-800 needs volume higher using pre & power so to ask 'why so different?'. Together SR-1100 pre & SR-800 power sound right.

Test To Destruction: Amps That Clip Unevenly Left To Right.
This is part of our Testing & it gives the 'Power Ratings' readings. An amp should be the almost identical Clean Sine reading both channels at the point where the Sine Wave starts to clip. Where this point comes in relation to the Volume Control marking does vary, if typically it's around Midway, the 12 o'clock level. We have tested beyond the start of clipping to see a 50w amp at 25v clean sine on the Oscilloscope an go to 30v-35v if with Hard Clipping. An amp that reads one side lower has a fault of some sort that the user may never notice, but what happens if the lower side is pushed by running it & the correct side together. Testing one amp of ours, the first channel we read seemed a bit low before clipping appeared. The other channel read about 20% higher. So what happens if you push the faulty side more, as in getting the good side to clip only mildly, not deliberately overdoing it to '10' on the volume. The answer is the output transistors & drivers are trashed, as the slightly faulty side clips a lot harder. This actually shouldn't happen, you can drive an amp well into distortion if you may fry the speakers, the amp should be fine. Unless there is a fault. To get an amp to Test Status to find this fault shows it's a tricky one.

March 2021 Blog

Amplifiers That Make A Loud Click On Turn On: Solved.
This only relates to Capacitor Coupled Amps that Connect Speakers on turn on, most keep the Speaker connected via other controls. This affects only a few amps, it's because the Output Capacitor keeps a tiny charge that just sits indefinitely as these amps. Disconnect the Speaker with the Power Switch. This sounds much too loudly on 95dB speakers, will be less noticeable on 88dB ones if still annoying. It's more noticeable once upgraded as the amp is faster & more powerful, as original you may not hear these sounds so much, if not got an amp with this Design to try. Relays in later amps solve this by letting the amp 'warm up' for 5-20 seconds so you'll hear no noise beyond a small click as the relay connects. Amps more tamed with this design or made to start up slower have none of this noise. One Solution is to use "Speakers B" & turn to that after a few seconds. The way to do this properly involves a discharge circuit, of a design not to affect the sound but not give a noise after turning on again after a 10 min wait. The Click can be as much as 8-11v we read with two amps, this is awful to hear if it'll be within your speakers rating so won't damage speakers of the correct wattage. We tried a few ideas & got a decent solution as of typing this today, solves an annoyance that should have been better designed. The Trio-Kenwood KA-6000 does this apparently, if actually the filters causes this as poor design as direct on the power amp. Once sorted the turn on is very quiet. The Hitachi SR-800 & SR-1100 do this for the capacitor charge, a 'leak circuit' can sort that if can affect the sound. Many designs use 'odd bits' that do similar, so it's not an universal fix.

Current Model Yamaha Receiver RN-803-D Compared To Upgraded 1975 Yamaha CR-400.

Recently sold the CR-400, it sounded good as do the 1973-75 range of Yamaha. The RN-803 is a £589 to buy new item. Has all the 'Connectivity' of today that younger folks may or may not find of use, getting into Hifi is for when 25 we assume, as then having the money to buy these. Getting Secondhand Used gear the thing rather than buying new. The RN-803 is typical RRP £759 for £589, the same dubious pricing as decades ago, RRP is meaningless really. DAB, Phono, DAC & more is a very packed unit, soon come the 'Error' code & it's not economical to fix, 5 years use if you're lucky & the rotary controls don't wear out. The 1975 Yamaha CR-400 is 46 years old & forever repairable unless badly damaged, RN-803 has built-in obsolescense & looks like any modern amp, this one in black, maybe silver on other models. Power Rating is back to the pre 1971 stupid ratings 'Maximum Power' & 'High Dynamic Power' if no true RMS rating. 10% THD gets 140w if no RMS or per channel. Guess what power it is, how miserable. Model recently discontinued so hard to look online too deep. The customer likes his CR-400, recapped with upgrades we got a good sound from it, 16w amp gives enough volume on higher sensitivity speakers & sounded good on our Tannoys. They get to borrow a RN-803 so can compare both. They find it lacking the CR-400 Upgraded Bass with the Newer RN-803 lacking the more open sound of the CR-400. The RN-803 reviews, if you can believe 'What Hi-Fi' who are there as paid advert reviews, the 'Warm Smooth Sound' suggests it's as dumbed down as that 2005 Marantz PM-6002 we had. It'll play music, it'll sound OK but as we've found with post 1980 Hifi it'll just sound Boring with little Excitement revealed in the Music. Have thought to Buy a Modern Amp to try on Amazon & return, if that's a bit selfish. If we found one without all the Network stuff to try to put 1960s ideas, but we already tried that with the PM-6002 which never really gave too much. Today's ideas of DAC & Remote may be useful if a £10 external DAC & leaning forward to set the volume once on turning the amp on isn't so challenging. £589 today is 'midprice', it has lots of features that will be priced to the penny, all that & supposedly 100w+ is today's pricing but the 16w CR-400 was £148 in 1975. As you'd expect, the CR-400 was preferred, nice looks & aluminium controls compared to the hard to read Black fascia with plastic controls. In 1984 the Sansui AU-G90X was all plastic controls & flimsy buttons, the PM-6002 was better made if still that generic metal casework unlike how Vintage is made.

A Very Strange Pioneer Receiver: 1969 Pioneer SX-2500 72w Rated.
The Best Pioneer Amp, if it's very hidden away. Whoever Designed this was Really Experimenting. But it was much too Wild so Pioneer really tamed it down to sell it, it's a rare amp. Look on the Pre Out-Main In connectors, it actually does put the signal through a 100K resistor to tame it. Plus many more exciting limiting design, but it's still in there. As our Review tells it sounded great as Original & Recapped but seemed to be a little restrained. Gain cut very heavily, Gain added crudely & sound Balance messed with to lose the quality a bit. To undo this is a mindblower but it's what we do, beware the loose wires. It has a FET on the preamp-tone input, if you put a regular transistor in, there goes 'that sound'. What is 'That Sound'? A very unique amp sound, on headphones it takes you into a New Stratosphere & up louder can leave you in Mild Panic as it's like the amp's in your head. Of Course it is, so try it next day & playing less loud, the sound is still there, but very unusual. On TV & Tannoys 'Meerkat Manor' has the narrator sitting 4 feet away from you if the Tonal balance needed the sweetening we tried before & on Headphones again it's a nicer listen, on Speakers it was Unsettling again as so upfront which is a bit too much. First appears in the 1972 HFYB if it's a 1969-70 design & £319 new is a competitor to the Sony STR-6120 £387 & STR-6200 at £354. The FET is a bit of an unknown in Hifi, the Sony TA-1130 & TA-2000F preamp use them if the sound is very decent it does lack bite, the SX-2500 has bite & a very smooth sound focussing the sound like no other amp, none of that soft grainy sound here, it's as solid as a wall tile, playing 1960s Reggae recorded from 45s with such focus & depth is hearing these tracks like never before. Huge problems upgrading this one make this a real challenge but eventually to get there. The Amp recapped still sounds Special if way more in it for pushing it way hard. The SX-2500 has a great Tuner with Autotune, as in Station Finding, if not the Digital Voice Enhancement, if it certainly brings an Unique sound to The UK 1960s Reggae 45s. The FET seems to the The Winner here, as trying it with a transistor it sounds more like a typical amp. A FET has High Impedance to not affect the sound balance. It seems to 'Compress' the sound slightly giving a strange sound where Music Bits that were loud aren't so loud & similarly makes other sounds sound deeper with more detail. Impedance is a real mystery as in it's not measureable if only via criteria & maths. The SX-2500 uses standard transistors elsewhere. On Headphones it makes older 45s we recorded much more Listenable, if similar 45s played on the valves Luxman LX33 we need our unique design to get that sort of sound. Playing an obscure 1954 artist 'Roy Hogsed' his tracks on USA Capitol are recorded direct with no mixing so his voice is straight in your head, if the 45s have high frequency noise that the SX-2500 focusses well. So the FET is good. MOSFETS in 1990s amps for Power Transistors may give a similar focus, if cheap design & ICs elsewhere will hide this. To find a nice no-ICs 1990s amp with Tone, that'll not be easy. Next Time. Pioneer SX2500 playing now, the strange overpowering sound now worked out, the Tone passive stage isn't done well. Playing on headphones Tone always Flat, the Tone needs -2 on Bass as 62Hz, 125Hz & 250Hz. It's not neutral, if maybe made suited the tamed version. How to get it Neutral is difficult, so -2 is best. Has the nice SX1000-1500 1967 sound now if 72w. On HPs the Bass turned up is too thick & Treble a bit thin on max. Set Flat it's great if not neutral on upper bass. On Speakers this will sound odd as Tannoys get Tone added for TV. On Soundcard EQ Tone set flat as made needs -3dB on 125, 250 & 500Hz, trying it as typing. EQ off & it muddies up again. Try that on the JVC JRS600/5040U to hear how different it can be. Shows Upgrading can be a Huge Problem especially if the amp was heavily dumbed down, but this is a Top Range 1969 amp, not a 1977 'Comet' cost cut amp.

QI Reckons Vinyl Doesn't Sound Better & Klaxon Noise For Saying It Does.
How Very Dare You. Vinyl Is Better on Music made before Digital. No Remaster Sounds as good as The Vinyl. See the YouTube Link at the top of the page for How Good Vinyl can sound. The Dynamic Range is Limited on Vinyl, 3dB difference in some Tracks not unusual to be punchy on radio back in the day. CD-Digital can have 10 times the Dynamic Range if in Reality, CDs are oftem mastered way beyond clipping as we found 20 years ago seeing the mashed waveforms on Muddy Sounding CDs, they clipped heavily on midrange even. If CD used the full 100dB+ dynamics, some would be so quiet you'd not hear it. A Record is as good as the Mastering Producer & the Amplifier used to play the 'vibrations' to the Cutting Head. Valves gave the Best Cut Records. But a lot of Vinyl is Mastered Badly so 'vvvv' shaped grooves which sound rough can be found on pre 1968 vinyl, 1968 as the Quad amplifiers took over from the Valve systems, giving a further limited dynamic range, we can hear 'Pye' records with a distortion that can only be Quad related. We as Record Folks know Vinyl is The Best as it's the Nearest to the Original recording, without Modern Ideas of what Music should sound like, ie heavily limited by compressors & other features Audio Programs have. Authentic Vinyl well mastered or not is What Sold It in the first place. Vinyl Rumble from Mechanics is a low punch, if it's why nearly All Hifi is very limited on Deep Bass. But Turntables like the Technics from 1975 as Direct Drive have no Rumble if cheap idler drive ones can do if not made like the Garrard 301. Then as other Phono Stage pages-blogs tell, the Amp itself is usually 'not all that' on Phono stage so the music isn't fully resolved.

Hifi Questions We Get. No Reply Needed.
As we offer Hifi Work, we get a lot of messages. The Autoresponder deals with most of them if some are so insane to share them is required. The Amp is a 40w 1981 one, Budget Gear of the Era, part of a Music Centre probably. "amp: Rotel RA-560 budget: I just paid £160 for it, I don't really have a budget, but I wouldn't want to spend more than 20% its current value question: I have just bought this beautiful Rotel from the 1980s, it works fine, but the balance knob doesnt + it would be great if you could give it a nice clean and make sure it doesnt overheat. It has a little hum coming from the unit not the speakers though and it gets pretty hot. Since I use it everyday and it stays on for most of the day I just want to make sure its fine." It's not one we'd recommend you pay for our work on. They think someone will service maybe repair or replace worn parts for £32 is unrealistic. One sold late January for £104 in Germany, probably not that one as described as 'nice'. We see Bad Balance Control may need replacing which is usually near-impossible, it Hums & Overheats. You've bought A Rubbish Amp, it isn't safe to use, you should talk to the seller. Again, they never even read a thing on our site & think we'll tidy up their mess, not interested. Having tried to fix these sort of problems before & still do on gear of quality, it's a difficult job sometimes relying on buying spares amps for one crucial part, so cost add up. A lot of 'Hifi' that sells on ebay is not worth rebuilding, use it & sell it on as spares once it's broken, as the Rotel buyer got landed with.

1954 Record Player on 'The Repair Shop'.
Watching the Extended versions of Series 2 & 3 on UK's 'Quest' channel, they were originally rushed 30 minute episodes if clearly they made longer versions. The shorter edits made no sense making jobs look less well done than they were. Series 1 seems to be 25 min with harsh edits. The full versions are like watching it as New again. This S3 episode has a very rough 1954 portable Record player in parts almost. Very true about early Cartridges for the stylus, you can still buy NOS stylus if the Cartridges are long gone from the 1950s style ones & requires parts units to get these. Here they had to use an early 1960s one cut to fit the headshell. But the 1954 capacitor, he said it's not swollen or leaking so considered it good still. Be sure it's Not, cut these apart & they are totally dry & full of the acid's dust plus they can crystallise badly. They may still work, but a large aluminium capacitor needs the wet electrolyte to work, you're running it dry on dust. But this is the General Lazy Opinion, use it until it blows up or catches fire, or just fades away, well it's your choice, rather than renew & preserve it. 1936 Murphy Console A30C floor standing Radio had a Capacitor block, dead & turned to Mummified Compost so no voltages, but dry so just not working. Put expected new capacitors fresh in it, radio works. Easy job on their one too, but he left it. Some of these 1950s & 1960s capacitors can be 2, 3 or even 4 capacitor stages in one can. The 1963 Trio WX-400U had ones like this working on 300v level & they were very dried & crusty inside. On trying to read voltages, some were very wrong, one actually exploded which is lucky it wasn't one pointing it's mess at you directly. You're trusting 200v-450v on 50+ year old capacitors plus later Transistor amps with 30v-50v on the output capacitors. The Sound from the Nat King Cole LP was a post production addition, no wobbly sounds & unusually clean for a rough old portable. They always fake the sound if a ropey old Cylinder Player was gloriously awful as they did play it. The amount of work to rebuild the Turntable & Motor properly is a huge job.

Clinical Sound? What Does That Mean?
This used to be an Amateur Description read on Forums if never in Hifi Mag Reviews, as they aren't allowed to Criticise when being Paid for an Advert Review. Nothing new about Paid Opinions. Our Opinions have No Sponsor so we don't need to pretend in the way of 'recent' years, as in CD era onwards. What they mean is the Sound has No Proper Bass if can be far too Sharp as the sound isn't Balanced. It can sound 'over analytical' on Treble or Midrange but without a Richness of Lower Midrange & Bass, it's Cold & Unappealing. A term first heard in the mid-late 1980s when CD sounded like this on Audio Gear & Portables of Basic quality, the Mass Market gear. Today you get loads of nonsense to 'Boost Bass' & give an unpleasant sound of a different style. The Clinical Sound we'd say the 1985 Yamaha A-720 is a prime example. Horrible Grainy Thin Sound, music more distorted than any THD rating would reveal, bad sound is audibly poor so could be 50% distortion. Yet sold as Good Hifi. We remember the Class A stage made it more listenable if the Design was so cheaply made it had no quality unlike playing a Leak Delta 30 amp did. Music is supposed to be nice to listen to, today's ridiculous Sound Bars as on a Feb 2021 'Gadget Show' sounded suspiciously like post-production sound added as those tiny but long boxes will never ever sound anywhere near a 1967 Tannoy Monitor Gold 15" Lancaster. Clinical Sound is actually a step in the right direction if needs a lot to upgrade it out of the thin overbright grainy sound. Still Is An Amateur Opinion. The HFE review of the Yamaha CA-610 said it was 'clinical'. Far from it says our review on getting one to rebuild. Who do you believe? A one-shot review or one based on 200+ Amps with Upgrading? It appears the misuse of 'Clinical' is confused with a Clean Tidy if Dynamically limited sound. They must be used to the Grainy UK Amp sound. Seens they don't expect Hifi to sound realistic, never heard live music? Similar to 'Top Gear' saying how well a Car handles & takes turns at speed, others not deeper into cars thinking 'It's Just A-B in the Dry'.

April 2021 Blog

Advice To New Hifi Restorers. Ease Up & Don't Overdo It.
It takes many years to be good with a skill, see the age of 'The Repair Shop' lot if understand the younger ones like Will are getting older ones to advise off-camera. To get a Vintage Amplifier & want to upgrade it like we do it appears Us Making It Look Easy. No it's not. To go into upgrades to be extra good at fault finding & have much design knowledge & previous amp successes to work from. We've got a few amps we'd like to sell if they still have a lot to make them sellable. To push it saying Akai AA-7000 & Yamaha CA-1000 will be for sale is more to try to get us into getting these ready. Making amps sellable can vary in difficulty, some upgrade nicely & others want to annoy you for sloppy design & cost cutting with dumbing down. To want to replace everything & have an amp looking like our Sales-Sold pics can be a lot more work than expected. An amp like the Marantz 1072 is made on one board so less involved, the Marantz 4230 4ch receiver is on several boards of much higher quality & is a huge job. Doing Like-For-Like is still a huge job if you're still a newbie, learn steadily. You'll still get issues to solve if best play safe to not try to overdo things as it's an Electrical item & it can get damaged & then you're way out of your depth. Being careless or rushing an amp will Guarantee problems, if it gets annoying, leave it a day, week, month or year. Check & Check, then Check again before plugging in. All the Best Upgrades can still sound disappointing, if changing other components can reveal the sound you want. Custom Fine Tuning an amp is a Dark Art for sure, to get the right sound needs knowing it to hear to see where changes can be made.

1998 Amp To Recommend? Proton AM-455 (Pro).
A reader recommends this modern Taiwan brand amp with JBL speakers. It's a 1998 USA made 50w amp. But on looking to see it's got 'classic' TO3 Transistor outputs, 2SD424 & 2SA554 which are similar ones as in Yamaha & Pioneer. Makes a change from MOSFETs. The Amp is modest looking inside with 4 large capacitors if not much beyond large Film Caps. Other 1970s style driver transistors too & would you believe Bass & Treble tone, if no outdated Filters, Loudness still though. Phono has an Inductor input through an IC, Preamp after some limiting into a Class B differential design, the standard 'IC' type design if in transistors, followed by NFB tone. No Pre Out-Main in, onto Power amp with typical differentials, fixed Bias then P-P drivers & Outputs. 1998 design? Looks much more mid 1970s as with the TO3s. Works on ±40v HT. Power supply on ± 18v regulators is a more modern design, a proper fixed voltage one. Two seperate power Amp HT supplies from the one TX winding. Only unusual part is the two transistors on the Balance control, if thise seems to be a sort of Buffer Stage to the pre outs for 'Tape' to stop differing connected impedances affecting the sound which can be a problem. The amp as it's mostly a 1970s design looks fine to us, what it's built & designed to be we don't know for not having heard it. For there to Be Amps like this is encouraging. No ICs beyond Phono betters the sort of typical 1990s amps, this will be repairable as no obscure parts as is often past 1980.

30w Modern Valve Amplifier: Leben CS 600
Seems to be from 2012 by reviews online. Much more info online, our opinions here. Looks like the 1958 era EMI Stereoscope if without the Oscilloscope. To see it's a modern amp worth a look as they want £3000 for it on ebay. Valve Rectifier isn't so good as it can only sound like a 1950s amp & the lack of Large Power Capacitors means it'll have the Ancient Spec ones like 47µf underneath, we can only put this value in our 1932 Pye G/RG radiogram so not much progess here. EL34 or 5881 can be 'rolled' which has switches at least to alter the circuit, tube rolling 'blind' will usually cause problems going too far from the designed ones. "Dumper tube 6CJ3 (for Colour TV use) is applied to delay a supply of high voltage (B-Voltage) to output tubes in order to protect output tubes from damages and to longer the life." to stop the turn on surge, Tube Technology Genesis used an IC to delay the HT until the heaters were optimal, both of minor value based on our years of valve use. No Tone here is no use to us, limits sellability if some do believe Tone isn't needed, believing the 'we can't be bothered to add a tone sage & valve'. A worry is "Bass Boost Switch" which means full gain is limited to give a fixed bass gain, as Valves can lack a proper Bass unless designed more like the mid 1960s receivers. Smart looking unit in all-metal casing, lots of Line Level inputs & 4mm speaker sockets. But No Phono & No Tone for £3000 is not so user friendly. Nothing on HFE at all on this company so no circuits. What it sounds like is the Unknown here, others' opinions we take little notice of as the "Clinical" nonsense above tells. Great Looks, well built if quite a bit lacking with no Phono or Tone & the limits of the Valve Rectifier. Probably a good one for those to upgrade & improve on, if not at that price.

It May Be Too Far Gone, But It Means A Lot To Them.
'The Repair Shop' again. S4 E1 has a chap in his 80s with a very worn out 1950s portable radio, likely Germaniums 1956-59 era. It's broken & missing loads. To the Repairer, to sensibly stay away from ones this bad, if to keep him happy to search online for a Nice Grade one would be better. But said Portable Radio made by GEC may be hard to track down a better one. We've still got two battery portables as mentioned on other pages, the Ultra one works if the Decca one with different Germaniums would be hard to get going, so to know what you're dealing with. The one on the show missing the Rotary tuning & Volume, the handle broken, the casing vinyl worn & bits of toothbrush for the buttons that often crack away. But on seeing it tidied up & seemingly working, he's overwhelmed saying it's like when he bought it, if far from it really. In a monetary sense it's of zero value beyond parts as so tatty, but priceless as it holds... memories. All very well being sentimental, general Audio now & then is cheaply made not to last, it's disposable. Our two radios are in good condition externally if they're for decoration only as ones we had in the 1980s. To need a parts radio for the antenna rod & handle is telling, the electronics guy has lots of issues, to hear only post-production radio sound to wonder if he got it working. In reality it could be £200-£300+ job to do what they did, is it worth it? Even if they would spend that on it, an experienced Audio-Hifi tech may run a mile, if try to find them a better one is all you can do which takes your unpaid time. To Google "GEC Portable Radio" shows a few of them, a 'Transistor Seven' which in nice grade has the 'frog eyes' of the matching controls so is a nicer one, if the 'repaired' one is miles from that. If you wanted to buy one, be sure you'd find one with some deep searching or maybe easily, there must be Junk shops with loads of these sat unselling, if to find a decent one can be buying two or three to cobble one good from. Ebay shows the exact one, must have sold well when new, £34 bought one just on Feb 2021, seller making out they can't test means non-worker if the outer would clean up as complete. Just £34... better to buy a better one & restore that.

1971 Sony TA-1120F Japan-Only Amplifier.
The manual now on HFE we're told. Rare Japan only update of the 1120-1120A with the 1971 STR-6200F & STR-6065 basic design, got our STR-6065 just the day before & been working it out. Predates the TA-1130 which was a later 1971 65w model sold worldwide. 'ISO' screws are a 1971 era update to metric screws. 2SD88 single output pair supposedly 80w if the transistor is only 5A 80W rated. The 1965 TA-1120 used 2SD45 which are 50w but used Doubled for 50w rating allowing peak headroom. 1120F uses the 6000µf 80v main caps the STR-6200F uses & is rated 70w using TX183S output transistors the TA-3200F power amp uses. TA-1120F not 80w if more than 50w if not clear in Japanese text specs. IHF 80w x2 as shown will be the Peak Power, based on 80w transistors. Power Amp is Semi Complimentary, no Differential so could be 1970 even. Phono is Differential FET input then 2 transistor Differentials amid each other, similar to Marantz 1122DC. Flat Amp inc Tone is a bit much with similar FET-Transistor differentials totalling six sets if Passive Tone amid, like the TA-3200F power amp, if it's all FETs. These overdesigned stages may impress some, if they do lose the sound leaving it too tamed. Filter Amp uses some odd limiting, like the Yamaha CA-1000 did. There has to be a reason this is Rare & Japan only, it's not going to sound as good as the earlier TA-1120 (A) & seems an earlier version of the TA-1130. Sony do go strange around 1970-71 with over complex preamp designs yet put the STR-6065 hidden in a similar STR-6055 receiver if have the Best without the clunky design in it. TA-1120F with all those differentials isn't good, based on the Yamaha CA-1010 having similar nonsense & sounding too bright with no Bass. Seeing design in other amps you'll never hear of elsewhere, we get deep into them to upgrade.

Rogers Cadet III : Now Severely Overpriced.

Big selling Budget Valve Amp 1966-67. Only 10w by valves which is a bit low for a full sound. But ones on ebay from £400 to £625 are seriously overpriced. Sold as "Not Working" often to not let you return as these are way too old & past their best. These used to be common £100 buys in the late 1990s & swiftly sold on as not quite what you hope them to be. The HG88 III is a far better buy & they rebuild well to sound great & with a modern valve quality, if that's our design. The Cadet III is always around if getting way overpriced, based on suspicious auction prices, these are a common amp, not rare. A 55 year old valve amp working on high voltages will Always have bad capacitors that are Dried Out. They may work for a quick try if these certainly aren't to be trusted for regular use. A capacitor needs to be Wet to work properly, a crusty or dry one will be too far gone. These small amps need proper recapping, the multi capacitor cans need other ways to redo & it's not got the space to do properly. A First Valve Amp for many when new & 20 years ago, we got one after the 3w Sterns one, but why a 55 year old 'Project Amp' in very aged grade is worth more than the £100 still is newbie buyers believing the dream unaware how they've aged too far. Bad Cadet IIIs get many problems beyond old fiddling, the tiny transformers burn out from power supply capacitor failure. We'd not recommend the Cadet III for the low power, the one box amp or the tricky 2 part early one with the 'umbilical cord' connector that has connection problems. The £625 one has no '0' Ground screws for speakers so they misuse it on the other connections. See our Review. As an amp to buy at the right price & to rebuild yourself it's worthwhile, but £400+ for a tired out one is just not a good idea. A few days later one for auction, outside looks better grade if insides unknown. "Not Tested" is all they say. Some may notice the Cheap Aux cables, obviously it's been tested & has issues. Sells for £360 if externally tiy if no inside pics so a blind buy on 'No Returns'. Another sold £290 a few months ago, 2 part one, again "Not Tested". What do buyers of a 55 year old amp expect? Buying Mania. This happens with certain amps quite often, prices go high, reality of them soon realised as expensive advanced jobs to rebuild & interest goes back to normal. A Cadet III is a good starter amp as we found ourselves, if nearly 30 years ago when they still were working. We've not rebuilt one in our current ideas & recommend the HG88 III instead as 15w & better space inside.

Why We Deal By Courier & Bank Transfer Only.
Dealing Online, it amazes how Trusting people can be based on previous ways such as Dropping the Amp Off At The High Street Shop & Paying Cash On Collection. Those Days are now gone & not suited to Online Dealing. You see ebay "£25 Hifi Repair Estimates" where you gullibly send your £££-or more amp to a person on ebay to check over. Estimates on standard jobs should be free, only complex damage or real unknowns need to be seen first. Send Your Amp to 'Bert in Devon', they have no Web Presence & you'll only get an Address on 'buying' the Estimate. Would you even See The Amp Back Ever again? Ebay sellers can vanish so easily once this has netted a few & ebay-Paypal wouldn't cover you buying a Service as they'd call it. To have strangers arrange to turn up, make you wait & change times is a typical timewasting thing, plus many other reasons why 'Doorstep Deals' don't work. So You'd Drop An Amp Off At A Residential Address? Where's any Proof you left it there? A Courier Tracks Delivery to Us & Return to You. Bank Transfer again adds to the "Paper Trail" a Business term meaning you have proof of delivery & payment. It gives you Proof In to us, Proof Invoice Paid, Proof Out & Delivered tidies a lot of unsure ways of the past. We do Payment before work started, or we'd end up with abandoned or forgotten gear that is still theirs. To get one fairly near, say 50 miles & they think as we're nearer they get a Doorstep Deal. Not with us as just explained. Pack it up & use a Courier like it's any address. We have given this much thought & tried the Drop Off-Collect way but Lack of Proof of Tracked Delivery needs these old ways abandoned. Run a Tight Ship on it & get no Aggro is the modern version. The only Aggro we want is with the Hifi is working on it. Set your Plan clearly, see it work fine. If they don't want to Courier it, then sadly No Deal, but no worry.

1981 Sharp-Opticona SM-7100H. Ebay Seller Says "It's The Best" They've Heard.
Good to hear such opinions as we can look deeper & see if they are right or if they are just Hyping unaware of Better. They say they've had the 1977-79 era amps to rate this better. That Era in Hifi was a mix of tiny THD spec hunting & not so great sounding compared to 1969-73 amps. The Manual easily shows IC Output Stage so you know it's hardly going to match Our Faves. 60w Integrated. Phono is Differentials & FETs plus that IC-style Class B stage. Preamp-Tone is with a Differential, NFB & surprisingly a Passive Tone Stage in 1960s style. Power amp Differential into Driver if the P-P Driver & Output are in a IC Output Block 'S-603-W' if also 'RH-IX-1128AFZZ' which is with no datasheet or findable. The Power Supply is decent if really with IC output only the Passive Tone & less fussy design of the era will give it a Fresher sound than the compared amps. IC output blocks we really don't like. The Seller says he's been told to sell it to buy a Streaming Amp stuffed with even more ICs. Men today are too passive & give her the Streaming Crap & keep your "Best" in the Man Cave. But there's little hope of that. SM-7100H is nothing special & for their £299 for a 60w IC amp that'd not be repaired if the IC went, well overpriced. Deliberately we hope so Laddo keeps it. The amps of this era we've heard, another 1980 70w Toshiba SB-66 one a record guy used & it sounded awful if they were used it. But only hearing it on their speakers may not rate it fairly, but a blurry muddy sound may have been more to mismatched speakers. Headphones always removes the Speaker Mismatch issues.

We Recently Bought An Amp, Seller Says It Works, But We're Wary To Plug It In?
Yes, we've been told this one. Who knows where they got it, they've not plugged it in so Working Status Unknown. Sellers will Always Test Gear however foolish it seems to plug it in & for you to have paid a good price for it, 1977 Sansui AU-11000A is £1400 to £3200 on ebay. 1977 110w amp, lots of Differentials if Transistor power amp. £1330 & £1720 recent EU sales, might be one of those. But Why Never Try It? Sounds a bit dodgy for sure, never played music through it they say. why buy it at all? It's Sold as Working, so it's on The Seller if it's wrongly described. To deal with an amp of this strange status will need it checking over & plugging in on the Owner's emailed agreement. If we see too many issues as with a 1960s Marantz pre, we'll just return it, to avoid high risk of problems. To wonder what their Game is here, sounds one to avoid if no status known if supposedly bought recently?

1966 Duette SA-400 Amplifier.

One on ebay with inside pics. Germaniums, 22v AC about 28v DC meaning 14v midway so about 10w with TO3 outputs 2SB474 12w 35v 2A so 10w may be slightly less if higher than 6w. Transformer Coupled, it's not a junk amp. Interesting, if we've got other Germanium ones of higher power & has an Alps pot in if the 4 pin Loudness type if they used the wrong type as goes loud too fast. An early amp to try for small money for someone if you dare. We had the SA-500W a few years back as on the Solds Gallery & reviewed it. Looking at the pics, looks early inside if the outsides updated as UK got the remainder stock of these in 1971. It Sold a day after this blog online, have fun.

Should You Trust A PAT Test On Vintage Hifi?

No. All it proves is that it powers up & doesn't go Bang (yet). The person Testing the 1966 Akai AA-5000 is a menace, but it amazingly gets through. Seller at least makes no mention of PAT test passed if it was only For Sale in their ebay shop. 2-Core single insulated cable is surely an instant fail as no Earth & not Double Insulated. But this amp got a "Pass" by some idiot 'DM' at a current website online with a long name. Vintage Hifi as we deal with is Class 1 goods, like Cookers & Fridges, 240v & Metal casing. "Passed Safety Test - Equipment is safe to use" bleats the label. Dangerous PAT Test Pass? [1]. Illegal 2 core wiring that is not suitable for Sale in shops if appears to be fine online, yet No Earthing & wires untidy into plug. [2]. It has a 13A fuse where 3A is required, 13A is for 3kW Kettles & Heaters not a 160w rated item. [3]. Neutral wire screw needs tightening up. [4]. The Plug is an early one without the black plastic bits on the Live & Neutral to stop kid's fingers electrocuting themselves. [5]. The Item is over 50 years old, it should have Failed 4 times yet it Passes. Worrying? How much Dangerous Gear gets Passed this Casually? PAT Test is Being Abused for sure. Sell it as Aged and Dodgy but just works a bit, but to give it a PAT Test Pass by a supposed 'Trained Professional' is a disgrace. Why would any non-Pro buy a 1966 raw amp? From what we hear, all amps get tried & used. 'Bargain Hunt' mentions £5 PAT tests & to cut the wire off on Vintage in Public Auctions, but online anything goes, assuming who'd buy it would be a Tech or have one to properly look, if unaware of rebuild costs? Electrical Gear over 20 years old is Too Old & needs more Safety Testing than a PAT test.

May 2021 Blog

Vintage Hifi On Ebay Early April.
Sometimes we look every day, sometimes leave it a bit to then look at a week or so of listings. 7 April, Currently three 1978 Yamaha CR-2020 at £900 to £1000, typically 'raw' amps if knowing the overheating issue, anyone buying these still? At lower prices they do, but £1000 is just greedy with little sense of reality. We bought one for £30 if owner fiddled-messed with so sold as embarrassed what they did, if we did it right to sell. Not had one for a while & they're not the most Hifi sounding of amps if 110w may impress, the sound isn't too lively & we've rebuilt a few. Interesting Harmon-Kardon Seven-Twenty with 1967 looks like NatPan SA65 & Toshiba SA-15Y but it's USA only as 110v, HK were slow to arrive in UK. Says 'not working' but shown lit up if "not tested" line, be sure it has & is with issues. £320 is a bit high unless you really liked it, 90w max rated means likely 20-25w. Depends if you fancy a nice rebuild on it which will cost. Kitsch appeal on Teleton A500 amplifier & T500 tuner with a Teleton custom cabinet for both. Must be 1979-80 style for the budget if Retro looks. 300w max suggests about 50w if DIN connectors limits it. No turntable on top, TRP 200 on a search shows they did make one. £180 buys it delivered. The sort of £30 job at a Car Boot not so long ago in reality. Sony TA-1130 without the wood case for £450 is pushing it, seen £300 ones sell. Scruffy fascia says avoid if oddly a nice fascia by itself seen just before could be yours for just £35. £450 is just greed really. More of the same at £400 on a budget Nikko TRM 40-IC, try to figure out what 'seller refurbished' means. 14w weeny amp from 1971. The IC will be at least the Phono one that seems weak & fails as our TRM-1200 had plus that awkward mains plug idea. A Realistic STA-860 has a 1979 look, maybe not the quality of the Hitachi & 1974 era, if the seller took pity on it seen as 'Not working' & got it repaired, but sells it already hoping to 'break even'. Wants Rid? Not sure about 'good as new' for a few repairs if £200 buys you a better looking later receiver. The lack of info limits interest perhaps if it looks a medium power one by the insides pics. For Amps we look at, so much is Too Expensive & still in 'Raw' grade. The Auctions are better value if there are still lots of amps £50-£100 as Buy Now if the 1979-1985 era appeals. As with any Ebay Category, always Interesting items amid lots of ordinary 'filler-cookie cutter' type Hifi. What Has Sold? Too look at Ended-Sold items sees what people are buying. A lot of Hifi does sell, if to wonder why they want that if buyers are at many different levels, 'just an amp that will do' is why much sells if priced right. Sony STR-6046 a basic 1971-ish Sony if nice looks, £139 bought it. Sales over £1000 are more for Modern gear that is likely 'well reviewed' by Hifi Press. That scene still exists & to buy based on Advert-Reviews may seem a little naive, if you need a guide through Hifi, if we found our 'New Scene' amps disappointing, never giving what Vintage can. £765 bought a Rogers HG88 II 1960-era one, some repairs to keep it going, but still the 61 year old dried out 300v+ caps that 'look good' as dried out caps don't leak. They say it needs Tech help if rather vague blaming the Courier, huh? To wonder why it was bought. £1500 for a 1950s HMV Stereoscope 556 Valve amp. Again needing so much redone & not what we'd consider going for as with the HG88 II as too early. 'Not Tested' if Scope lights a typical description, again who buys these so willingly? Other valve gear like a supposedly EMI early Stereo amp sells, £285 for maybe 5w-8w, certainly a fascination with valves out there if what you get is probably far from what you expect. Looks more like a Heathkit built into a cabinet amp & no EMI logo anywhere. Early Stereo amps were considered 'poor' by 1960 if this seems reasonable, if it'll need much work. Based on prices on other similar Brand Name ones, 1958 Stereo valves may seem a bargain to some. Leak Stereo 30+ for £100 a realistic price compared to some, no wood case if these are around, built in cabinet one. £350 for a 1971 Yamaha CR-510 receiver, quirky early Yamaha as we've had a few. £110 for an Armstrong 621 amplifier, only their 600 range is worth buying, if buy cheap. Trio-Kenwood KA-4002 no side cheeks for £160 will please the buyer for the sound, the Amp that started us on this site, shows we're being read to try a weeny 1971 amp. Plenty Under £100 and Under £50 means Modern Youth can get into Hifi at a bargain price which shows they tire of Earbuds & Tinny amplfied speakers & stepping up to a Sniff of Real Hifi like Uncle Steve has. That's how we all started into Hifi & good to see a lot of under £100 sales. What Speakers they match is another thing, most cheap amps can not sound so bad on better speakers, as in £200+ ebay ones, if the prices here are uneven for reality. A lot £150-£250 is Boring Modern Gear, nothing special & probably nowhere near as enjoyable as the KA-4002 is. Higher prices for Audiolab & Cambridge 1980s-1990s UK amps, never felt any need to try these having heard the things at the time, if perhaps better on speakers way over their usual price level. If It's Silver, Have A Look, If It's Black with 'CD' Pass It By...

UK Hifi. 1968 Leak Stereo 70: 1. Time To Update One Of These?
Not had the Leak 30/70 ones as the early 1968 version or 1971 Delta repackage in years. The attractive but lousy Delta 75 receiver we've tried as reviewed but these aren't well made & the design messed with too much after the early batch ones. Our 2012 one pictured on the Solds Gallery the only good one. The 30/70 ones we found rather crude with a nice rich sound if grainy & not the highest quality, if still recommend them as starter amps. The Stereo 70 priced right & in the correct wood case worth a try. Seller showed an inside pic & seeing differences to the Delta version, why not try it, they were liked by us. Update is the thing, the 'Line Level' input is considered too loud for CD & the switch makes it too loud or too soft, it's a aged design really, if more suited to British non standard Output levels. Attenuators are no good as they limit the fidelity as well as gain. The speaker plugs are those awkward UK big pin-small pin if the VOSO will go in there. Tape Out was from after the Tone which is not useful we found having the Delta 30 in 1991 as Our Amp. The UK small signal Mullard transistors were not so good, the blue axial capacitors used to be fine still if 2011-2013 buys, it's now 10 years later & we see that time is getting amps go bad as they are at the end of their aging cycle now, big rebuilds we do a lot these days. But this is for Our Interest & To Be Able To Offer A Proper Upgrade on these Worthwhile amps that sold well & can be bought easily, if in nice grade isn't so easy. We'll not bother with the 1963 Leak Stereo 30 with the UK Germaniums, not worth the effort, if the 30+ one is good. The last time we tried British Hifi to upgrade was with the Goodmans Module 80 that recapped well if Upgrades were too much for it. To be aware of why & what emerged will get the Stereo 70 treated more gently, unless it can take it & maybe compare with the Japanese brands. Keep The Ideas Fresh as there's no-one trying to update the Leak Transistor amps, if to assume their 'end of service' is on the way, to Keep Them Alive. Well that Was the Idea...

UK Hifi. 1968 Leak Stereo 70: 2. Looking Deeper. User & Service Manual
The first thing you see is a Warning about not connecting other Electrical items to the amp. In 1968 TVs were still Live Chassis & there were no real ways to connect a TV to an amp & even in the late 1980s we could only use the TV Headphone socket if there was one. The rest of electrical gear is foolish to scare about, if 2 core mains wired items can be connected as the Leak has Ground via 3 core.
Power Output using both channels is 35w per channel 8 ohms & 28w per channel 15 ohms. Low Damping Factor of 20 will be good for Bass on Speakers. Input Settings are awful, the Best Input for Aux/CD/Line is Tuner 2 with "Lo" Gain. This actually plays 0dB High Treble without clipping. 250mV input there. These other settings on Tuner 1 & 2 were suited to how British Hifi was at the time & the 1971 Delta range are the same. The Delta 75 Receiver is different & we got good results with the one on the Solds Gallery if trying 3 others showed how badly made it was sadly. Can The Inputs Be Made Better? We got our 2021 one to look deeper & listen afresh, if the Circuits show how they did it. "Pickup 1" aka Phono is direct, "Pickup 2" is 27K or 100K on the input. "Tuner 1" is Direct & is much too loud for Aux. Used the Phono inputs fine back on the one we used in 1991. "Tuner 2" has varied input resistor & grounding. "Replay" is Tape Input that has 47K on inut & 2.7K to ground. Only "Tuner 1" is Direct but much too loud. To alter the amp design to make "Tuner 1" correct for Today's Use when "Tuner 2" on 'Lo' matches could be altered if to consider it not really worthwhile for the amount to alter. Verdict: It Could Be Recapped with a lot else to do that would Outprice it as it's a Decent Budget amp despite one crazy seller thinking it's worth £1200, they go for £100-£150 usually. Finding a nice grade one sounding Nice instead of those usual Rough sounding ones we had before got it Rated "Very Good" as original. The World isn't ready for a £750+ one of these properly Upgraded if the Inputs not altered. The 1963 Leak Stereo 30 Power Amp, not the 30+, shows one flat base board with similar components. This 1963 design will have influenced many, not even 1964 USA Fisher had a design like this if their 1965 updates did. This Leak design for a Power Amp is ahead of Any Other for it's 1963 design. The HFN mag showed the Early Adverts for this amp, a real 'pioneer'.

Buyers Love The Fresh Open Bassy Sound Of Our Upgraded Amps.
But here we get an illogical exception. To us it's the buyer not even trying the Beautiful Sound compared to the High Damping No-Bass Amp they say they prefer. The thing is Different can be Confusing for a less experienced Hifi person. With Amps we try, some that are Too Different wil Really Mess with Your Hearing balance. When at Electronics College we used to go to the Markets looking for Records. One Shop played Music over Speakers, if they used a very mismatched Midrange Driver that was about 10dB louder than the Bass Driver. It sounded horrible, the sort of Harsh sound you get playing Music on a Mobile through the tiny speaker. Knowing no better, that shop kept it's awful sound for as long as we went there. Here a buyer goes for a very decent Neutral Sounding Amp from 1971 & one we considered keeping for it's nice sound. The buyer never asks before buying so we assume they know what they are getting by The Review. The problem is now we hear they are used to a 1979 Trio-Kenwood KA-601. The Circuit of this is typical of the tamed design of the era, we do not like these type of amps. High Damping limits Bass, Tone Control really reduces Bass in design. Loads of Differentials limit Bass. There isn't much that can be done upgrading these as poor design, plus IC Tone Stage. If we had a KA-601 asking for Upgrades, we'd tell it may not upgrade much better for the design. The buyer actually prefers this Compressed Limited Sound as it's Far from Neutral, it sounds like putting the 1kHz range up on a Graphic EQ. The thing is it will take Learning to lose the awful Trio sound idea compared to the Neutral Open Bassy Sound of ours How on Earth can they not hear it's Better? It'll take weeks to understand it yet to say after one day they don't like it is not a considered opinion. It's strange what Awful 'Hi-Fi' people listen to on Rubbish Speakers, one Psych-Prog LP collector had an awful mid 1980s amp, a 1980 Toshiba SB-66 on some random 1970s speakers that clearly didn't match. It was wallowy bass with no midrange & scratchy treble. Interestingly they recorded an LP & the sound was really bad, just like his 'Hifi'. You need true references for Sound. People Talking in the Room is an easy one plus Live Music. Of Course one person's sound may not compare with a Pro Listener like us who Designs Amps in the Upgrades to sound Better. You'd think they'd take the idea "This Is Great Sound" & understand why their other amp is mediocre & strive to get into the Sound, then go back weeks later to the nasty Trio which will be stuck on ebay soon after as it's so poor sounding. It's like an ebay scene around 2005 where New Hifi was bought & rapidly sold on "Two Hours Use", utterly crazy not even using the item a few weeks to understand it.

Vintage Hi-Fi To Vintage Cars: "Bangers And Cash" on UK Yesterday Channel.
Interesting UK TV show about a Very Knowledgeable "Mathewsons" Vintage Car Auctioneers in North Yorkshire. All the USA Car shows get a bit much, if this gem of a show reminds us of British Cars & how many there are but even 'Wheeler Dealers' didn't used to cover. A show aimed at Older Generations you may assume, but often these Pretty & Classy Cars are Sold to under 40s & Dealers who bring them to a more updated quality for more regular use, if maybe not Use Daily as we try with Hifi. UK Cars have got a bit forgotten on TV, if they certainly picked the right lot for this show. It can get a bit Cosy as can 'The Repair Shop' as it shows the elderly owners being sad to say goodbye, if to see the Love For Cars is easy to see & all the work these have done to the cars in high quality. Derek is a London guy so has the London sass about cars like Mike Brewer has, makes good TV. To see who buys it & what happens adds to the story & an unique part of the show. Into Series 4 now, to think they'd only make one series but it grew in later series. Prices on UK Cars not as high as USA Cars, if the British Style & Quality makes some of the USA Cars a bit 'trashy' as we thought those huge 1970s square Cadillacs like Land Boats & forever getting smashed up in 70s TV shows. UK Ones not built for Speed or Muscle if we're finding many that are nice. Family used to own Scimitars & a stately grey Rover if the1974 Fuel issues had to get that Sold. Audis, Escorts, a Citroen & a weighty Saab. Plus others. Daddy was a Car Mechanic so we got through lots of Cars from Austin 1100, Princess & some crappy Austin Allegro they got at an Auction in 1978. So the typist liked cars if never got much into them. To see many Home Garage tinkerers making Quality Rebuilds is encouraging. 'Wheeler Dealers' Mike features this show on his site & must see the UK needs him back as their USA era has ended. Bring back Edd, but no & Ant (Griff Rhys-Jones II) stays in USA so that 'Elvis' one is his car buddy now, not a good idea as the 'Dream Car' fail showed. The Car scene is way ahead of Vintage Hifi which has only really grown since 2011 when one Website wanted to Open The Scene beyond Monster Receivers & still does today, you're reading it now. Without sites like 'Hifi Engine' we'd not be where we are now, as even 10 years ago, Hifi Manuals were kept well hidden away as not considered worth putting online. Can't see there being a Hifi Restoration show, a Vintage Tech TV show got one series as blogged, if Hifi starts with a tired dusty dirty non-working mess that can be transformed into a great sounding great looker, if depending on finding 'scrap yard' type parts & the skill of the Tech who Upgrades it. Nobody Upgrades like us as it's Advanced & can cause big issues without understanding. Those who do recap play it safe with Like-For-Like which still keeps the Hifi useable. But to not see the rebuilt amp is still holding back progress. We've had our work photos online since 2013, anyone copying us?

June 2021 Blog

The Customer Base For Hi-Fi Upgrades Is Widening.
Hi-Fi is now aging a lot. Life brings out Hifi that's been unused for decades & the Dream to Restore often hits Reality with the Cost, or not seeing it's actually worth spending on. Usually today it goes up for sale, rather than being binned, if Recycle Yards turn up great amps that had 5 minutes of bad treatment. The last 3 Marantz receivers that were long owned & came to a tech for rebuilding, we've had in, the 4230, 2235B & 2270 were too aged to properly use, the last one the 2270 used regularly until it gave up, if we've yet to find the cause, it's at least not got a trashed power amp. Pioneer of the 1975-77 era is failing too, if oddly the 1960s ones can still be working, if still old. Yes, you can get it fixed, if just repairing is a waste of Money as other parts can go wrong shortly after. The Rebuild with Upgrades catches the eye, we're not doing cheap jobs if the Quality & Reliability we offer & use our own amps to know how regular use treats them. Many Ask, the Money aspect is not realised based on the Cheap TV Repairs of long ago, we Rebuild & Upgrade as the pages tell. Some want rebuilds on amps that really aren't worth doing, some will take these on, but we offer "Excellent" as a Rebuild level & if we can't see that in the amp, then we leave it be. To hear your beloved amp isn't a good one doesn't go down well, so to leave the Autoresponder to take that. "The Repair Shop" once again is making people wanting Hifi Repaired & working again. The Reality of Cost in Rebuilding, Restoring, Upgrading & Redesigning is what has kept many things up in the loft or rusting away in the Garage To hear the owners could never find anyone to do the job is often. "I Didn't Think It'd Cost That Much" is many just think it's a Black Box. Look inside your Amp to see How Complex it is. Some we look at & think it's a hard one to work on but on actually trying it, as with the 1966 Sanyo DC-60, it's actually even more tricky with tight wires & how to actually get in it to work. The 1969 Sanyo DC-66 was a Mindbender, if the DC-60, well it can sit, if it's got bits bought for it inside bagged up still. Another day, but it sits there a wanted item. To look at the Worth in the Amp once rebuilt, great sound, 20 years or more good use, or go buy an Amazon thing you'll soon regret.

"You Can't Restore That For The Price I Paid."
On 'Bangers & Cash' a guy who restored a Triumph Spitfire to perfection knows he'd not get back the work he put in, if got near what it cost in parts at least. Goes to buy a 1967 Rover 2000 for a modest price & that's what he said. In the Realms of Hifi to do some rebuilds we have done for our own interest, similarly you can't price 5 years work in it. But if a time came you wanted to sell, to price it to have it sell will always be an issue, the market will only go so far on pricing & to trust the Rebuilder. We done a mega rebuild on the 1971 Trio-Kenwood KA-6004 putting years of Trio KA-6000 upgrades into it. This takes the amp into a totally different realm, if we're playing the much upgraded KA-6000 now (as of April), with all it's extreme changes, if looks the same outside. KA-6004 is a 40w amp, if for those with sensitive speakers, not 87dB feeble ones, so the market is limited. The amount of quality in the KA-6004 means it's way outpriced the £750 one we sold fairly recently & the £750 one it was before it got dealt with. Should be a £2000 amp as any 'Maxed Out' Gem by us could be, once we get it right. We put it at £895, based on what it is, lucky will be the buyer. Market Decides, those two later Marantz still sit if the Trio KR-6170 has a huge amount of work in it & it sits, maybe do more as we can see what it needs if that could outprice it. Knocked the two Marantz down in price to a point they are underpriced, but they're a bit late & not higher models for us so to move on suits. But we have others that aren't listed that could move on, if always a lot done with them, if never quite finished. Sold the 1966 Akai AA-5000 but to see it's a nice ornament so bought another as reviewed that arrived 2 days after the first one left.

Bang & Olufsen System: Worth Restoring?
A message we got about the 1965 6w Beomaster 900 'Radio', Beogram 1000 turntable & Beovox 1200 speakers. Some would rebuild this, if the cost to get it to 'Use Daily' let alone upgrade it should put you off. B&O gear we'd not touch beyond the Beomaster 3000 (-2), 4000 & 4400 which we had plenty times early on. The Turntables are usually made for B&O cartridges which are all long obsolete, so no new Stylus unless you get one retipped. The build quality of one later model was very poor we saw years back, wouldn't put a record near the thing, the 1000 is more like a Garrard SP25 type. Beovox speakers often a budget type plus 4 ohm. They probably look nice as a system, but assuming late 1960s by the turntable, it's a basic set up. Would be good to see "The Repair Shop" with one, but they'd know better to run a mile, based on what they do show. To pay us to Rebuild one, not for us, but it's the sort of job an amateur should try to see how hard it can be rebuilding amps, if the Beomaster 900 is way advanced with the poor UK "AC126" type Germaniums. For 6w power, for Enthusiasts only. Best thing to do is put it all on ebay & be glad you got rid. Good Hifi is worth restoring, as "American Pickers" shows, much of early Audio as Radios etc is now Ornamental value only. As with any Vintage, to see if they have potential to rebuild as many are worthwhile. This B&O lot came to the messenger as a freebie with wires cut off, seems it's already been considered 'Bin Food'. There are Beomaster 900s on ebay, £40-£160 for non working & £150-£300 for supposedly working ones. Sold listings show one apparently 'sold' for £500 then relisted & sold again. Price fixing likely, if reality of Sales is very different. B&O may be 'Posh' gear if in reality Hifi folks stay away for the build quality & strange obsolete parts issues.

Domestic Electricals: 'Wago' Connectors Are The Normal.
Had some domestic electrics updating done & to see Modern Ideas are as Ropey as the PAT test. Look in older Mains Installations with the Fuse Box & you'll see brass screw connector strips. These once screwed tight will be good 90 years later as 1930s installations tell. Strip connectors with Screws in a plastic case you see in 1990s amps & similarly these will last a long time. But today the 'Wago' connector has replaced these Screw Connectors. It's a tiny plastic box with 2 or more levers & a Spring to bite onto the wires. It just hangs free wherever you put it, it has no way to fix it down. So a 30A wire can be connected by a 'Wago' & be "Safe"? This is a Rubbish idea to us & the sort of item to avoid. A Spring is never as strong as a well tightened screw & as our 2000s 'Anglepoise' lamp proved, a spring is weak, causes sparking on 240v & breaks down. The unsupported 'Wago' will have the ability to slightly move on the wire over time & fail. To trust these on high power 13A & 30A circuits is ridiculous to us. It'll cause failures & further jobs for the Electrician. How can such a feeble 'temporary' connector be acceptable as safe? The idea today is you update things often so the weaknesses will not be shown. We're used to very old items still being useable as well made. Would you trust a 'Wago' to be safe after 10 years? Lazy ideas of today aren't meant to last.

Hi-Fi & Modern Cars: The Crossover.
On 'Wheeler Dealers' usually the Post 1990s Cars are a bit Boring. But S16 E3 about a 2001 'Audi S4 Avant' was interesting to us. A more sedate looking 4 Door estate, very nice car if far from a Cool Car, if it is in different ways. Cars have been getting more & more Complex, this seems to be pre the Diagnostic Car ECU units that you plug in to find Error Codes, if this is more a Garage tool. To get to the Oil Leak & Replace a large gasket on these Well Filled Cars that are so tightly packed involved Ant taking the front & wheels off, then loads of parts. To get similar in Hifi so lots of Photos needed to get it back together right. If you do Photos, it's usual to have just missed getting a photo of one bit as a wire was in the way, to learn the more you do as having to trace wires on complex Amps like a 1977 Marantz 2385 can be illogical as changes to the circuit occur. The small dent in the rear wing he managed to push out which is a bit of a miracle, if skills. The Cup Holder like most plastic items sort of breaks, as in bits came loose & to get theirs fitted back more luck than anything, if parts were broken, as with Hifi, it can be impossible to get a spare or repair it properly, if to at least try. A LCD display inside the dashboard fails on these Audis, of course they fail after 20 years. After 20 years out in the open air, the metal ages on contacts & corrosion on bolts can get lots of problems. The LCD unit Mike gets a new one if replacing it is like Electronics of Today. Heat Gun to unsolder the ribbon wiring. On some like our old DVD-R these can be plug-in & click a plastic piece to hold. These are weak fixings & do that a few times & the ribbon starts to get rough. Ribbon cables in Hifi start around 1978 as the Marantz 1072 shows, ideas from the VHS world. All the TV-VCR shop guy had to do was Solder the new ribbon back on, his magnifying light with a round fluorescent bulb a light we've not seen before. The shop guy clearly been fixing TVs since the 1980s, no VCRs left if be sure he'll still see them. A wall of tech testing gear if having seen these, most are obsolete items just for show.

Great Sounding Tuners?
We always play the Tuner as to see it works & get the FM Stereo bulb showing. UK's FM isn't too much beyond BBC, Indie-Local stations & whatever Capital Radio is these days. We do play the Radio as sometimes it can be interesting if the Autotuned Pop-Dance rubbish of today is very poor. Classical in Stereo sounds nice if not our bag & the Talk Stations are rarely more than Propaganda. The first FM Tuner we thought was better sounding was the NAD 300 large receiver from 1977 if the rest of the amp wasn't so good. Valve Tuners as the rebuilt Trio WX-400U from 1963 sound so nice as do the 1966 transistional tuners with One Valve & a Nuvistor, or all Nuvistors. These Nuvistor ones do vary, if the 1966 Pioneer SX-1000TA with Valve & Nuvistor is a great sounding one. To think the 1968 era Sony tuner was good until the 1971 one on the Sony STR-6065 really set high standards. No ICs and has the New Ceramic Filters design. Picks up a lot of stations & sounds very clean, a long play of the STR-6065 showed the once highly compressed blurry FM stations sounding clean & fresh. But this seems a short lived tuner idwa, soon come ICs & a blurry muddy sound probably worse than ever. The 1977 Marantz 2385 tuner was just that muddy sound & stuffed with ICs. The 1977 Yamaha CT-1010 rated highly on Tuner sites, we didn't think it was all that, if it lacked Stereo & these sort of tuners best not fiddled with as you'll break the ferrite cores. The Yamaha CR-2020 tuner was similar sort of quality & not to think it too special either.

July 2021 Blog

Upgraded Amps All Sound Different. Have A Few To Swap Around.
Us Upgrading amps has Many Ideas that can be used in Many Amps. No one amp can upgrade the same as things like Stability need keeping reliable. To use two much Upgraded Amps may mean 'not much' to the Reader, if the Differences are worth reading of. 1969 Trio-Kenwood KA-6000 much custom with Doubled Outputs, TK-140X later Power Amp, KR-5200 Preamp Tone & much more as well as tuning in all in to match which is a tricky one. This amp soulnds ultra fast & very clean. Strong Bass if a tighter Bass. Played this a few months since updating the Preamp. It pleases for sure, if after a while, a Change is needed. You can tell when you need to swap amps as you don't play it as loud as you did before, such on TV level. Our KA-6000 version is "perfect" in many ways to have used it for months, but it is different to others. But man likes a change to not become complacent. 1966 Sansui TR-707A swapped in next. This is a reference amp much upgraded if still using the original resistor circuit, if all redone beyond the Phono board & tuner, the 1966 resistors are a bit noisy we found. TV input into 'Tape In' which is more direct. The Sansui is a remarkable amp. The Big Rich Crisp Detailed Wide Stereo sound is so smooth & precise. Very Dynamic Colourful Sound, to forget how good it is. No Germaniums now if still the S:N ratio leaves a little background noise, where the KA-6000 is very quiet, inaudible on speakers, the TR-707A has a little low hiss & hum. 1966 is the First era of Transistor amps & still in Germaniums the noise is higher. But the sound is the thing. Swapping KA-6000 to TR-707A, the KA-6000 was designed by us to be like the TR-707A but it's actually quite different. The Huge Dynamic Soundstage of the TR-707A, a richer upper bass & solid midrange. Deeper Bass than the KA-6000 if the Crisp treble is similar. The TR-707A design is unique & never revisited, it's not so unlike the early Fisher 600T we've had, if the Sansui is more refined. A standard sort of power amp, found on 1967 designs like the 1967 Pioneer, became normal by 1969. Input stage(s), driver, splitter, PP drivers & output drivers. The 1966 designs, beyond the 1965 Sony TA-1120 which introduced the standard design, were often very quirky. Transformer Coupled to not need the splitter stage with Hot Resistors to allow a Direct Coupled Speaker Output. Amps like the Sansui 3000(A), Sanyo DC-60E, National Panasonic SA-65 & others we've had are like this. The Sanyo one is different with no Bias to adjust, if to rebuild that still to see how it works.

Do Our Upgrades Increase The Power Rating?
You can see from our 'Power Ratings' page that Sine Wave Output, read as RMS on our Battery Oscilloscope do vary. A 28v output can be anything 40w to 60w. The Akai AA-8500 has Double Outputs to get it a 65w rating. Our Upgrades can increase the Current to make a Wattage Increase. We've known this but never really got into it, as to Really Increase the power rating, it takes the More Advanced Ideas. Power on Original Amps is often deliberately limited by design techniques that we upgrade. To Read Power is another thing. It requires reading voltage on just before clipping, the Velleman HPS 10 Scope can read Wattage, if the thing is, to provide a Signal that brings the best Current out, something like Hard Drumming as you find on Test CDs like the "Soundcheck" one from 1992. Don't mind running to clipping as it's a test we do to see the amp is good, to run a little beyond clipping is part of that as you turn the Volume up. To really push the Amp to Max Clipping & Trip the Relay is what we did with the 1977 NAD 300 just to try it. 44v max unclipped if about 52v hard clipping. Deliberately running way beyond clipping isn't a good idea & not wanting to trash the amp or speakers. Trying for Max Current is a "Peak" thing similarly & wil vary by frequency, so we don't test the Wattage as it'll not be too clear if it's RMS or Peak. Upgrades will increase the Current, if not the Voltage, explaing the big difference of 40w to 60w on a 28v output. The Mains Powered Oscilloscope could be used & to read Slew Rate too, if not for Bridged as you can't have a Ground Reference as Bridged works with Two Audio Signals, but no Ground. To not test Power into an 8 ohm large resistor either as no Speaker is 8 ohms flat impedance 20Hz-20kHz. Tests in the HFN/RR used to test power & found a 70w amp could be capable of 92w, such as the 1973 Yamaha CA-1000. The Yamaha CA-1010 rated 100w has the same 37v Sine output. Power Rating & Sound Level do not match Wattage as is found with how great a 13w 1967 JVC 5010U can play on speakers. Our 25w 1966 Sansui TR-707A sounds like no other 25w amp.


August 2021 Blog

The Original "Tone" Of An Amplifier.
Going back to Pre War Radios, a Table Top Wireless was sold on it's Tone. In those days a dull heavy throaty Upper Bass was liked, a very Retro sound. To get Treble crispness without a Tweeter wasn't possible so they created a certain sound. It was far from 'Flat Response' but people clearly liked the rich sound of the Bigger Models. Hifi today is all about Flat Response & No Tone Controls. Modern Hifi can sound Very Boring as it has No Idea about making a nice Vintage Sound anymore. The Post 1980 further cost cutting made this Sound accepted & CD which sounded much brighter furthered this departure. We've had & used these Old Radios & plenty of Radiograms to know all The Flavours of Audio since the 1930s. Our 1932 Pye G/RG Radiogram the earliest one & it's spooky ancient sound has an appeal. The First Transistor Amps by 1965-66 based their sound on Valve Amps. By 1969 the basic sound that lasted past 1977 was made & this Vintage Sound is still very popular if the amps are getting too old to use now. Rebuild them, ask us, it's what we do. Varied Designs created a "Retro Bass" that sounds great still as the Amp has some Richness. To upgrade a Retro Bass amp can be done if it needs a lot more Quality to sound this way & it is possible to lose "The Original Tone". A 1976 Marantz 2235B surprisingly has a 1960s idea to get a Retro Bass & it sounds very decent for it. The Deepest bass 20Hz-50Hz most speakers can't play, our Tannoy 15" Golds can play this & it's a sound we want. Most Today use Bookshelf type speakers or the smaller Floorstanding plus anything between that size. Look at the Frequency Response, the Deep Bass today is made up wth a Sub Woofer that can be adjusted to play the Bass Louder to suit the listener. Retro Bass can be Really Awful as well as Really Nice, as you'd expect it depends on Design. Some designs use a harsh "T" Bass filter to cut off Bass so there is No Bass. we tried a 1967 Pioneer SX-1000TDF with it's Filter built into the design. On Speakers as Original, Bass was lousy with the lower end a blurry mess. The 1967 Trio-Kenwood TK-140X first black label one on the earliest one as we have here, it has Two of these Filters so is very weak on Bass if the Treble & Midrange are good, Bass is non existent. Some Designs get it very wrong in other ways so you get a "One Note Bass" that is horrible. A Honky 100Hz peaky Bass that gets very tiring very fast. This effect is called "Ringing" & how the designer used it varies a lot. Having Encountered all these types of Bass as well as Upgraded many to get Real Full Bass, on the Marantz 2235B to ask the customer who's amp we're rebuilding what he thought of it when it worked better. Interestingly they replied saying they preferred the 2235B Bass over a later Marantz. We know the big 2385 160w & Bass on it was surprisingly weak, once serviced past the muddy aged sound. The Marantz 2235B will be upgraded if keeping the Original Tone if complimenting it in our way. To play it on our speakers to listen that it sounds good.

1972 JVC 4DD-10 CD-4 System Disc Demodulator.
Got one of these with the JVC 4VN-880 4ch Amplifier as reviewed. The amplifier is aged too much to need a rebuild. The Demodulator box as it's from 1972 will need a recap too. Said not to work by the owner & finding it on ebay, scant details if the old line of "untested". Never tried or heard 4ch in it's full version before. CD-4 is the 1971 JVC/Victor system but sadly no one format was decided leaving too many non-compatible versions. Read Quadraphonic sites for more. The stylus picks up a 30kHz FM type carrier frequency that has two further channels to the ones you can play on any record player. Low Capacitance cables required, not these overpriced Filter type ones we've blogged on before. Inside. This has a top power supply layer with further 4ch components. Underneath is that one big board you can find pictured online. At least 60 aluminium capacitors underneath & about 25 up top. Also pieces that aren't capacitors showing it's not for an amateur rebuild. 9 of those Tuner type adjust coils in the square cans. Do Not fiddle with these as you'll mess up the alignment & in tuners these are the last things to touch if ever, similar with the adjust pots. The top board only has 2 adjust pots. The Red blocks are FM styled sealed choke inductors. The '104' black round items are Chokes. The insides look like new, if the capacitors are nearly 50 years old. Unlike the 4VN-880 this has updated small transistors to the hissy ones the amp has. To Recap is quite a job for so many pieces, it can be done. The issue then is Does It Work? Has it been fiddled with on the FM Coils & Pots before? A job like this is to tell the Customer the issues. To recap it & not be able to test is Their Gamble. If untouched it should work like FM tuners do after some recapping, if depending on the Tuner quality. Gamble to get it recapped, or do nothing & never know. Connect It Up. Cartridge Stylus into the Phono input. 4ch Out into our JVC 4VN-990 that works. Headphone Sockets are 4ch only, not bridged, so to play 4ch using one HP socket then the other. Input on the meters to max. It plays 'sound' on all 4ch if hyper distorted. 4ch radar light on & Decoder plays sound, if the same mono signal noise on 4ch so far from working right. All we can suggest is decide if you want to Recap & take the Gamble. Verdict. Customer didn't fancy the Gamble. The thing is their other 4DD-5 is the same age & how much longer will it work. Hifi Dilemmas, often Solved by The Cost & the added Gamble here. If it was ours, to recap it if the Sell Price would make it worthwhile. But a buyer may expect it to be Fully Aligned & Perfect in use, a thing that's beyond us.



September 2021 Blog

Quadraphonic CD-4 Should Have Been A Better Success.
HFE has a few JVC 4ch Brochures. Shows JVC was the first one & proper 4-4-4 way of recording & decoding. Others use a less precise 4-2-4 which mixes 4ch to 2ch before opening out to 4ch again. The Shibata type non-truncated Stylus read up to 60kHz from a 4ch record. All well & good, if they say to use a Modern Turntable if not specifying any JVC model or any other one. Heavy playing Stylus set to the wrong weight will Wear Off the High Carrier Frequency, in a similar way a 5 ounce 78 head will wear the grooves. 4ch sound is Like the Greed today by ebay forcing payments onto their contrived system, losing the "Mad Money" aspect of a Paypal account plus the Payments from them are non UK so probably see £7.00 bank fees each time it's over £100, they cheated you on that of course. On 4ch sound, Too Many Companies offered different & non compatible 4ch of not always the 4-4-4 quality. For how well set up the system must be, it failed dismally despite much advertising as we saw in the HFN/RR. It's a Gimmick, like 3D Television-Film is a few times now. As with the JVC 4DD-10 top range demodulator, once it goes wrong, how would you fix it again? Websites about Quadraphony exist if are they offering repair & calibration? A 50 year old system of limited use. The 4ch amps that are Bridgeable still can live on, if they've usually been ignored since 1976 & usually rough by now, unlikely the Bridgeable ones were understood to make them good 2ch amps. How Reliable the CD-4 system was isn't much told, forums may tell how unreliable they are & how the records don't last as 4ch items for too long. The Brochures give the Idea that JVC's CD-4 is "Natural" but it's like 7.1 channel cinema etc, it's just a producer's mix. We prefer 2ch Stereo or Mono played on 2 speakers, the idea of weedy speakers playing 2-5+ more channels is a bit pointless. 4ch Bridgeable amps are well worth having, the Bridged Sound certainly has something special to it, Two Audio signals & no Ground gives a Dynamic sound, depending on amp & design.

Quadraphonic CD-4 Discs Cut At Half Speed.
One of the HFE
brochures on Understanding JVC 4ch tells the discs are mastered slower to be sure the Ultrasonic Carrier Signal is Recorded. Like those mid 1980s Nimbus Half Speed Masters & other Major Labels did these via Hifi Magazines. Ultra Hifi was the Rage in the Hype, if to read they had to Boost the Bass to get it to Record properly is a bit lacking. The Half Speed LPs do get Mastered very precisely, better than the Domestic LP release as HFN/RR did test articles on. Overall the Tests told the Half-Speed LPs were "Better" by having certain frequencies recorded louder, different is not better though & they found the Bass not so satisfying. These Half Speed Master LPs didn't last for long as CD arrived soon after. The Idea of 4ch with a Carrier frequency on a Disc based on early experimental TV discs that started with just still frame images in the early 1960s. These ideas all not really that great & a Disc as a medium only really became a success with Video Discs & CD. As for Quadraphonic Discs, all our years dealing records, you rarely saw any. Ebay has some Quadro LPs, ones purposely 'created' like Pink Floyd & the Sampler type ones. Optimistic pricing as always online, the Pink Floyd ones sell under £100 as a Curio never to be played fully 4ch. Imagine how awful a crackly 4ch record sounds.

To Need To Hear The Amplifier As Original.
As amps age, it's getting less often to actually Play an Amp properly even on Headphones. To Hear it's Designed Sound to know what to Upgrade. Very few we'd trust on our Tannoy Golds be they Direct Coupled or Capacitor Coupled. A 1971 Marantz 2270 we have to rebuild, it blows a Main Fuse if the Power Amp isn't damaged. To rebuild it to a degree to at least play it is required, if other Marantz were just too rough to pinpoint what stage was bad. The Marantz 2235B we did work on to try it & this gave a playable amp. To hear the 2235B has circuitry to create a Retro Bass that the customer liked could be missed. The 2235B is done very well for it to sound right on Headphones if we'd not try it on Speakers yet. Another 1973 JVC 4VN-880 is rough for the plug in boards it needs servicing more to try it, the 1973 JVC 4VN-990 we couldn't try on speakers as DC offset was faulty. To hear the 4VN-880 as original despite some transistor hiss needs knowing. 4ch Amps are always long abandoned & rough, buyers didn't understand they can be Bridged to give a powerful 2ch Stereo amp, so they get put away for decades. Many amps we can at least try, if they are very rough but to hear the original sound. 1966 Pioneer ER-420 valves was well aged if did reveal a nice sound amid the hum & crackle. 1966 Sanyo DC-60 again very noisy on the preamp if can be quiet with volume at zero meaning the power amp can at least be tried. To hear it's sound got the DC-66 later model understood better to get the early Sanyo sound. 1966 Sansui 3000 early version was too rough to use, if we've had the later 3000A to know it's sound. Two 1966 Sansui TR-707A were very aged if both working, rebuild needed to try properly. 1966 Akai AA-7000 we had three, only the third was useable if rough. 1966 Akai AA-5000S was playable if aged, the second AA-5000 we got doesn't work right so needs a rebuild to try it, fault finding bad parts isn't worthwhile when a rebuild is needed. 1966 Pioneer SX-1000-TA needs the volume control & loudness from the TD-F version we have spare, without the spare parts it'd be a problem. The TA one works fine which is typical on 1966-67 Pioneer if the 1976 era ones are failing often as are Marantz. The 1966 amps are First Generation ones that often have designs never reused, but 55 years old now. Huge jobs to rebuild.

Too Easy To Laugh At Modern Audio Gear.

The very Low End of Audio has always been Rubbish, if Marketed to the Newbie who will soon feel a Fool for having bought it. Mentioned those "400w" mega systems before. Here is a gloriously amusing Sound Bar. "High Bass Ultra Loud Bluetooth Speakers Portable Wireless Speaker Outdoor/Indoor" is it on ebay, yours for under £19.00 inc postage. No-Brand round thing looks like a German Sausage. Ad only shows Women so the customers are likely Women not aware of Crap Audio Gear yet. Lifestyle product. High Bass? Ultra Loud? It's just 5w RMS inflated to 10w as it'll be Stereo. High Bass of what Contrived Quality? Ultra Loud means 120dB, what can they mean? Frequency Response? It sounds truly aw
ful because it will be. TV, Mobile or Laptop Speaker "Upgrade" is the Idea. You'll soon throw it in the Bin & go buy something better once you get Laughed At. Or maybe 'The kids' like this stuff, today's Flakies with only opinions they are told to have. Sound Bars have been a joke on 'The Gadget Show' for years now, the thing is Mass Market Crap actually will suit many just as those Flashing Light CD Systems of 30 years ago did. More Sponsored items by the seller show more Ultra Cheap Made in China crap. Big Bass for Small Money? The Sad Thing is buyers like it & say it's good plus arrives fast. Grading Turds again. Item clearly from China as Biz details show. But it's in Middlesex they say, if it'll usually take 6-8 days to reach UK as they hold no UK stock. These sort of Products may please Teens as a first Audio item away from the Earbuds. Recycling Yards must be full of e-waste like this. This is Today's Marketplace, looking at their Sold items, most is £40 or less, quality isn't the deal. You know it's Disposable, like Phones & just go buy another. What do you expect for the Price?

We Don't Like Ceramic Capacitors.
That's not quite true, We Hate Them. Have mentioned these several times before, if seeing overuse of them in recent amp jobs, it sort of limits things. They have No Place in Any Audio Circuit yet you see tons of the crappy orange cement disc things. Ceramic Filters in FM stages are another thing as mentioned recently & don't confuse with Mica ones which are perhaps the Best for small values. Ceramics are fizzy & blurry sounding. They take up a very small space so together with How Cheap they are, they are widespread when you'd think they'd use better. The only good use for a Ceramic is a 1.4kV one over a Mains switch as these will never fail. To see dozens in a 1977 Tuner stage is bad as the Tuner stage will not be one of quality as adding all the 'fizzy' sound over all the Tuner stages just creates a poor sound. We redid all the Sony STR-6120 tuner ones & the sound way better. To not touch the Front End ones of tiny values, the rest will better the sound. The risk with recapping any tuner is it probably will usually need realigning. The latest amps to Over-Ceramic are a Yamaha, actually they use these things even on the CR-2020 power amps & why is not good for the drop in sound quality. Another Marantz, again they use far too many of them as a Phono stage that looks precisely designed if they must use 4 of them despite using quality Polystyrene ones in the EQ. To use a Ceramic on the treble gain is insulting, if not so uncommon. The tiny ceramics make it hard to do anything & space is too limited. Ceramics are still everywhere as Surface Mount ones, probably more used today from seeing more modern gear & computer boards. Designers know they are poor quality so Tame designs to fit. To upgrade out of ceramics & tame design can be a difficult one. Costs? 100pf Ceramic are £0.06 to buy one in a lot, a 100pf Film one is £0.34, a 100pf Polystyrene one is £1.60 & a 100pf Mica £1.50. Film-Poly ones are fine in use if we've used Mica where it matters, the sound difference without the slight inductance of a film one is noticeable. Ceramic to Mica is worlds apart in quality.

Is It Worth Redoing Every Ceramic Capacitor?

We state that Our Upgrades will give around 80% of the Best in An Amp. We can rate it "Excellent" if some amps need a bit more to get to that, if we can do it. This is why working on Budget or Low Quality amps we Avoid as the Results won't be good enough & Not To Waste Your Money aware the amp isn't good enough. Upgrades we do for Ourselves have tried all these Ideas We Use to know what gives the Best Result at a Realistic price level. Ceramics to better capacitors will give an improvement. On a Midprice amp like that Yamaha to bring it to a higher level could be tricky to find parts to fit. For the Cost involved, it's not really going to give enough difference to Justify it. Of Course you can 'Max Out' many amps, just like those spending huge money on Cars or Bikes, yet it doesn't add enough in value. To see we did a big rebuild on the Trio KA-6004 to price it for what it was, but then Reality hits as what it'd sell for. The Big Rebuild was for our interest to see how far it could go. To sell it, to make it look more original if playing it again, not that hugely different, if keeping the known big change ones. We Rebuild some amps way further just to see what they do, rather than hoping a High Price will be paid based on a "Standard" Upgrade. To offer Great Ideas into the Trio TK-140X early one, the Customer asked would it make much difference. It would in our thinking, if in terms of a big rebuild already, to justify to spend more is not such an easy sell. The "Standard" upgrade they know the improvements so to keep it at the price. If an amp is 80% of what it can be, how many would notice any further sweetness, detail, smoothness & kick in an amp? The more amps we do from 'Higher Up The Ladder' to see what gives the best value. The Ceramics are Only Part of what a 'Maxed Out' upgrade would get. Some may only give a few % improvement. Some we've done these Upgrades too & finding it's the Overall Design that holds back an Upgrade that was very noticeable on another Amp. To be Happy with an Amp we'd Rate "Excellent", be it just scrapes it or is a High Excellent. We Rate our own Amp Jobs, see some don't quite get there as Upgraded. Some older reviews since updated by Revisiting some, others to realise that's all they had.

Retro Bass Explained.

A Blog just a few above "To Need To Hear An Amp As Original" mentions finding amps with this Retro Bass as we call it. It comes in Many Flavours. often it's Not Done Well, from having all lower Bass removed with a "T" Bass Filter. As we found with a 1967 Pioneer SX-1500TDF this as original sounds vague & directionless on Bass as it's been spoilt. Bass In Audio Gear. The 1940s-50s Jukebox has a big Bassy Over-Rich sound as Retro Bass ideas used. Radiograms were often severely limited on Bass as the Turntable was in the same Box as the speakers, no wadding in the cabinets made Bass a problem, so lose it. Music Centres of the 1970s were also Bass limited, our 1970 Hacker GAR-500 & 550 were 10w units. The Retro Bass obvious here if it was liked. Playing certain 45s today to 'miss' the fuller bass & find a Boost around 125Hz gives the Hacker sound. This would be considered "One Note Bass" & getting a Hacker a few years back, to sell it on as not too sophisticated now. The 'Loudness' Control is a Retro Bass thing & we hear some use it as Default with the Tone also. Amp Designs are varied from the "T" Bass Filter, to No Bass under 100Hz, to the One Note Bass that gets weary quick. The Differential Era amps are often just lacking to give Bass if to see the "Retro Bass" ideas are in a few we've had. Not to be Pleased the Bass is "Created" rather than Designed Well & too much to undo their idea which can leave it sounding too thin. The "Tone" of an Amplifier like those Boomy 1940s Tabletop Radios. But as with our Hacker used 1986-90, we liked the sound & Buyers Today like the sound. Only Large Floorstanders will cover Bass under 50Hz so the Retro Bass & Loudness are still wanted. We've tried many an amp to put Full Bass in, which is Possible if can take a Quality above what the Amp has. The Fact the Marantz 2235B has this Retro Bass & sounds Great on Headphones is to be discovered on Speakers of a Class Above what it'd be used with to hear what Retro Bass done well is like. Any limiting on Bass is not for 15" Tannoys, if smaller speakers may suit it better.

1975 Sony V-FET Series of Amplifiers.
These look a decent range of amps, on the low THD 0.005% spec which usually means a rather flat sound. We had the Non-V-FET TA-3650 that showed promise if not in sellable grade. The V-FET is long obsolete & to just avoid the range as if a V-FET fails, what do you do? Someone may redesign one as the V-FET output isn't too unusual, if knowing the Specs. The Bias Diodes may cause problems too we hear, if the ones used are in other Sony that are usually fine, if the V-FET was a new idea maybe not perfected in circuit. The TA-4650 has 2SJ18 & 2SK60 outputs. Looking at the Bulletins, the V-FETs have those awkward Rating Numbers as do Smaller FETs, to do with Gain. Says to replace the Full Set to keep the 'Rank' the same but only to use certain ones. A Third Bulletin, not In English then says to Change Resistors as their Design wasn't good so it'll be dumbed down. Once you're at this point, to realise the amp is best avoided, sell it on ebay as they do still sell if Working right still, if at Recap point for the Age. Datasheets on both V-FETs available, if perhaps "Why Bother?". The design of the 4650 is still like the 1971 Sony style design beyond the V-FETs. It is possible to Swap a FET for a Transistor & get it to work, we tried it on one amp's Preamp FET, the Pioneer SX-2500 from 1969. It worked if the sound wasn't so precise as other factors to alter, but shows it can be done. The Problem with Long Obsolete Parts like V-FETs & IC Power Amp Blocks is there aren't any substitutions or redesigns to keep the amps going. A V-FET amp is like driving around with a Bomb on the Back Seat. One Day you'll not be so lucky. Interestingly the 2SK60 is on ebay a few times, a set from China for Fools to trust. The 2SJ18 only one has. Like Old Valves from the 1930s & Germanium Transistors, there around from New Lots Found if soon gone.