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Hi-Fi Blog... Page 3

See the MAIN PAGE for the previous Blogs plus INDEX.

June 2018 Blog

Hi-Fi in 1963: A Digest.
Jan 1963
shows there is already steady progress, as 1962 details, towards more familiar items, the HMV Stereoscope amps first seen in 1962 were a step towards Hifi & make good prices if as with most 1956-64 Valve gear we do wonder why for the circuits are still very basic. Sony with Tape Machines & other brands like Gevaert (pre Agfa merge) & Ampex show the non UK brands. Goldring turntables look far more modern, if these are armless ones you'd add an SME to, Revox Model 40 amp, 10w valves, is an early EU import with UK branch even, KEF Celeste, Tandberg, Sherwood S-5500II integrated amplifier is one of the first USA amps to get UK distribution. Pioneer SM-Q300B Stereo Receiver another first. Pickering 380A & Shure M33-5 cartridge from the USA. Progress by Jan 1963 indeed all show how trade restrictions that were recently lifted brought in the Best Of Worldwide to the UK & soon many UK brands couldn't compete on price or quality, as their gear it has to be said was old fashioned, crude, ugly & still without much progress since 1958. But here the Valve Amp was still King, if to a standard now that the Rogers Cadet & HG88 III from 1965 would progress on, the earlier Rogers were still crude & all British slow progress.
Feb 1963 still has a huge amount of ads relating to Tape machines & blank tape, despite it being a small market, the machines were 3 times the price of an amplifier on average, so competition was fierce. World Record Club ad highlights Tapes over LPs any 3 for 30/- introductory offer, if WRC was always tame on what it had, a Platters R&B LP being the most interesting on their selection. Goodmans report their new 12" Axiom 301 was popular, probably used by many Beat Groups if 20w via a PA amp will still be loud. Purchase Tax was reported to be reduced on many items, not Amplifiers but Records, all to help The Beat Era along, how kind. BBC Stereo broadcasts were expanding to Snday Mornings, if the amount with Stereo MPX Tuners will have been tiny. A London shop called 'Politechna' must have confused several or more to read 'Polite China'. Goldring 88 turntable is another new no-arm one if it's not one of the more wanted ones today. The Decca Separates speaker mentioned above gets a review to say how smooth it sounds with 6 tweeter units, large surface area of the 6 x 4" cones, if sadly it's 15w and 15 ohm rating keep it away from being much wanted beyond early Valve Amp users. Rogers Cadet II gets a review, one rarely seen, it's a small sized preamp with just 6w rated power amp, for building into cabinets, the earlier Cadet III was a 2 part unit if most you see are the later one piece unit. Mar 1963 have Lowther with the top-handle PM4 speaker & the Acousta enclosure, 'famous' they say yet no specs or price shown. Lowther made very few items & as the List Of Amps page shows, they still had unsold ones into 1970. Not much new in this issue if the Sherwood S-8000 II receiver rated 30w which is likely 15w per channel for £138, never seen one for sale, as with the early Trio & Pioneer receivers few will have sold in the UK. Apr 1963 has a bizarre front cover with Louis Armstrong trapped in a huge valve amid circuit diagrams, some night that must have been. Audio Show edition means a thicker issue if later 1963 ones match it for size. Hotel Russell in Russell Square London WC1 was used for several years until interest grew. Largs is another of the big London WC1 shops sellin g Hifi & Cabinets. Sherwood announce the First Public Demo of Stereo Multiplex, the BBC will have broadcast more Stereo to make this possible. Sherwood XP-1 a "200w fully transistorised receiver of the future" also shown, if 200w is likely 50w RMS, but nothing on Google shows it was only a prototype, if someone has it still, maybe, it's pictured on p773, a long slimline unit with coupling transformers first seen at the 'New York Audio Fair last Autumn' they say. The article on the fair says Radford have transistor gear with SC5 preamp with 5M, 6 & 6M versuions if the power amp isn't named or on our List of amps page. A SC4-20 transistor integrated 20w amp expected by May. Tannoy York & GRF are newly out as standard box versions instead of the corner units as previously. Just to show the lack of progress by UK makers, a 1958 looking box Derritron (Chapman) 306 8w amp is unlikely to have impressed many compared to the 'new stuff' of the last year or so. The 'Paraline' DIY kit speaker is first mentioned & must have been popular as it's heard of for a few years with updated versions, if to us it's not so good with a speaker driver at 45° facing up towards a wall to reflect sound, Stereo imaging will have been limited, if it was made as a budget price speaker, the double version is nearly 7ft long at 82" total, a space waster too. Again the USA amps are way ahead, the H.H. Scott 299C at 136gns (£143) if we assume a wood case was available too. Also shown for many years are the Cecil Watts products, the infamous Dust Bug today is useless & leaves marks on Garrard 301 plinths, if at the time pre perspex lids, you left the disc to collect dust & the Bug picked it up. The Disc Preener velvet tube was popular too, if in reality it just dragged dust over the record more than remove it. May 1963 shows the 1963 Hifi Year Book was out earlier in the year, if later the difficulties of making a book with new Audio Fair items in April meant the book could be out of date, so later it came out in the Autumn. Mullard Control Unit pre amp by Stern Radio as a new product still looks so old fashioned, yet the ads show this strange mix of outdated UK gear & flashy USA amps & EU tape recorders of more sophistication. The UK stuff just looks tired & through the 1960s many UK brands deservedly fade away for not updaing their looks or circuits. The HMV Model 655 10w Integrated Amplifier has better looks & is available as the 657 power amp & 656 preamp, if it's still valves, the HFN reviewer says it's a good looker, if in reality still way short of Sherwood, Pioneer & Trio. Jun 1963 has the Audio Fair report, but the inside cover has a big USA Fisher X-100 amp looking so classy, £59 17s buys the non cased version for a 20w USA rated Amp, likely 10w if the X-100-B is 15w. We have the slightly later X-100-B looking similar to upgrade as of typing. The UK Rogers HG88 II for £40 on a following page with 12w just looks so basic in comparison. £40 in 1963 is £800 in 2018, would buyers today spend £400 extra to get quality? The Sherwood Stereo test is revealed as them playing a Stereo Record & using their own local transmitter of low power, no BBC help yet. In this era, "Readers' Hi-Fi Installations" pictured the gear people actuaslly used, most was UK gear built into ugly cabinets & the amount of Quad gear pictured shows that the Hi-Fi Press had sold the brand very well to the Public. The Naim-Linn type of Press Hype was years before with Quad. The fact that a Hifi Mag tells you how to build a 'Transcription Pickup Arm' seems impossible, but here one is, if you'll need an advanced metalwork shop to make one, unlikely many bothered to try if we've seen some laughable home-made arms that came with our cream Garrard 301, bits of wood & crudely shaped metal. Pioneer SM-500 is a 25w valve amp we'll blog on below as we have the circuit diagram. Jul 1963 has the Eagle advert as seen a few months before, but no info on what they are, amps, tuners & an early double tuner Receiver by the looks of it, the early way to get Stereo FM so obsolete by now for Multiplex. Aug 1963 Wharfedale get on the Compact Speakers "with Clean Bass" they say, if 23in high is a lot bigger than the tiny 11" Goodmans Maxim out in the previous year. Sherwood are advertising every month of recent issues, if how many they sold doesn't match with the ads for what you see trying to find one as they are rare. Probably booked a year's ads in hope of big sales that didn't come. Sep 1963 has Eagle again if finally realised they needed info on the ads. the double tuner rec eiver with 2 Magic Eye tuner 'meters' is the SM.Q141 with '14 watts' which may be 7w RMS per channel or only 5w. The tuners are one per channel it reveals to get the obsolete FM Stereo that was half on FM, half on AM. Eagle SA.150 says "15w" but on looking at their valve amps on our 'List Of Amps' page for 1964 probably 7w RMS per channel. Ortofon SPU-G/T-E Moving Coil Cartridge is reviewed, Not quite the later MC type as 2mV output & it's a headshell unit of the Technics type connector used today still, not just a cartridge £29 or £26 without the transformer. Oddly they reviewed the SPU-G/T only in Nov 1962 so the E is Elliptical of 0.9 thou major x 0.31 thou minor & must be the First Elliptical Stylus if the sizes seem to be Mono Compatible as the review tells & tracks fine at 2g. H.H. Scott 299C amplifier at a hefty £142 new (£2800 2018 equivalent) gets a review, a 40w amp if it's still got a Valve Rectifier which is a pity.Oct 1963 has a Trio (Kenwood) advert, the first one of theirs in the UK has the Trio W-41U amplifier we've had, if no Trio WX-400U yet, also has the Trio W40J 10w RMS receiver, Trio W38 7w RMS, Trio WE24 5w RMS integrated, Trio W45A 9w integrated, Trio WE8S which is about 4w RMS & Trio W10-10.S unrated receiver, a lot of similar powered models a few turn up as Trio were still trying to sell these in 1967 when they were long out of date in looks if great retro looks now. The UK brand 'Jason' shouts on a full page of Expansion, if are still selling 1962 amps & soon faded away. UK Hifi manufacturers really did fail to keep up with the USA & EU progress at the time, the newly imported Japanese amps kept the USA quality seeing how good some of the best gear was. "Transistors In Audio" is a comprehensive 14 page section, not including ad pages, that we'll blog separately on. More Pioneer amps with the obsolete Eagle idea of Double Tuners, some crafy salesmen flogging obsolete gear, the Pioneer SM-G204E & Pioneer SM-Q300E likely 8-10w RMS by the 14w-17w max power ratings. Fisher X-100 gets a review, GZ34 valve rectifier as we noticed on looking at the X-100-B when we helped a customer buy a Fisher valve amp. HFN like the styling if don't say anything about the sound as typical, if hearing the X-100-B as original, the buyer of this will have stepped up several flights in quality based on more average UK gear. Nov 1963 shows a typical way the adverts are now, here for expected Xmas sales a big run of the main dealers & brands is interesting. Imhofs has a double spread as the first pages showing a range of the best items if probably only for the richer buyer, Imhofs show they are the Best Hifi Shop in the UK for importing Fisher & the range they stock. Cecil Watts with the Dust Bug, Parastat & Disc Preener all out of date by the end of the 1960s. Revox, Largs, Goldring, Stern-Clyne amalgamate for their Kit amps, Dulci (Lee Products) & their 1958 looking UK gear looks so old fashioned now, Goodmans Axiom 10 gets a page ad if only 10w, Modern Electrics of London W1 are one of the first to do those densely worded ads covering many products, Garrard, Tele-Radio of Edgware Road W2, Eagle, Heathkit by Daystrom more kits on a double page, Brenell with their 1950s looking tape machines, Clarke & Smith with the 655, 656 & 657 the same as the HMV ones from earlier if rebranded, Decca Anti Rumble Pick Up Arm sounds a bad idea as the arm must lose energy in soft construction to lose bass & more than the bass, C. C. Goodwin another densely worded ad, Sony distributed by Tellux of Essex & of course Quad get the page facing the Editorial. Further in Driitron-Chapman announce a "New Range Of Elegance" if it's far from the USa & Japan styling, still using 1950s white bakelite knobs with gold inserts is still looking no later than 1960 to us. Armstrong by this time look better, we did buy the Armstrong 221 hoping it'd be a good one based on these looks, if the circuitry was mediocre as we reviewed, looking at the prices shows they are much cheaper than competing UK brands. H.H. Scott 299C ad "here comes... and there goes 136 gns... and worth every penny of it". Aimed at those who must have the best, if how it compares to the Fisher of a lower price we'd like to know if USA ebay doesn't really have any & the age will mean so much to rebuild. The amount of Teak Hifi Cabinets that are Radiogram shaped interests, a big market in these as build-in amps like Quad needed them, but after 50-60 years how many got thrown out unaware of the good stuff inside. Explains the rarity of early gear if usually ones kept behind doors & lids are in high grade as the Quad II system we had in 2002 was from an unseen cabinet with 2x Garrard cream 301s. Nagra III tape recorder is the first UK showing of this premium Swiss made professional machine, price £339 is £6600 today. The review says it's world class & probably for an open reel machine today it'll have many wanting it in a similar way to the best cameras, if ebay shows £300-500 is an expected price today. Dec 1963 adverts add Stentorian-Whitely speakers ad that's an occasional regular, Philips Tape "it's ready packed in colourful Christmas wrappers", Telefunken tape recorders, Vortexion with their high power pro gear, Kodak with blank tape, Agfa pre the merger. Leak gets their ad after the editorial "lowest prices highest quality" which means we sell decent midprice gear, a cabinet with the Point-One stereo preamp £21, Stereo 20 power amp £30 & Trough-Line II FM tuner £29. Why they call it 'Troughline' is so ebay sellers spell it wrongly. Trio has the Trio WX-400U if a typo as '4004' hides it, 99gns to you nearly double the price of most of theirs expect the 79gns W38. Scotch even have an ad, 3M as their long Minnesota Mining & Manufacting Co Ltd & they too have colourful xmas packing ion their blank tapes if they use an outdated 3-letter word to describe it, if looking at the 4th Santa maybe it's the right word, yeah like anyone'll see the ad to understand that. Ferrograph don't advertise much "The Incomparable Ferrograph" is a weak slogan. A 2 part article on the USA Audio Scene will get a blog below. The Hampstead High Fidelity cabinet is a big teak, walnut or mahogany cabinet. Well laid out with a Turntable & Tape Machine under a wood lid, no perspex yet, but the problem of where the Tuner & Preamp, at this time the Quad or Leak would be fitted is given a pull out section that tilts forward to show the fascias to use. a good idea, but the trouble is everytime you open - bump - everytime you close - bump - is what the Hifi gets as it's a full width section masybe with 10kg weight. Bumps mean Hifi fails & for valves to be shook up, it'll have had repairs often if likely the shop offered repairs unaware their design caused it. A Bizarre Mains Plug idea "Universal Mains Plug" to use older round pin plugs that we saw around in the 1980s if they should have been upgraded long before plus the modern square pin plug that's rectangular. The idea is the pins carrying mains retract, but again the problem is after a few uses they'll wear & could start sparking causing heat. Pre British Safety Standard Kite Mark days. Braun CSV 13, a smart all-white amplifier is a 12w valve amp for £75, likely these are rare & expensive, if ebay reveals not too much as £250-£350 will buy one, a German sold one shows it's very plain looking made just of bent metal panels, DIN connectors on the back & the insides do have that "European Radiogram" quality to them if it does have Bias adjust pots & no valve rectifier. One supposedly restored by a pro tech only made £250 & seeing their poor effort it explains the price. The Braun L60 speaker for £50 is futuristic-minimal looking, a white box on chrome leg square hoops like chairs. Then to see a Bryan Model 400 amp 12w for 60gns looking old fashioned back to the dated reality of UK amps. Trio W-38 receiver gets a review, 7w is all it is for the nice looks, ECL82s with 221v, Double Tuners AM/SW & AM/FM. the reviewer notices the 220 ohm 'stabilizing resistor' unaware it's in the WX-400U to keep headphone use safe, if thw W-38 has no headphone explaining why it wasn't understood. The 0.005mfd coupling caps were considered very low & they pick up on issues that the WX-400U had when we were trying to get the best from it, MM Phono lacked bass as did the WX-400U. The looks impress, worth buying for the looks alone even. Another shop that grew over the 1960s-1970 gets an early ad, R.E.W (Earlsfield) as they called themselves for years in Upper Tooting Road, London SW17. Telesonic end the issue with one of those densely packed ads if with photos too & with Monthly Payment terms being the first time if the Sept 1963 ad is similar. Buy Hifi on HP starting the Buy On Credit world. Overview of 1963: A long blog section here shows actually more things of interest than we'd expected, a big increase on 1962. But again for the Modern 2018 user there's not really much you'd want to use. There are interesting amps but they are 55 years old & not to be trusted for more than brief use. 1963 Speakers & Turntables that are useable are still limited to just a few.

The First All-Transistor Amplifiers Of Higher Power Were By Fisher.
Jan 1965 HFN shows a review of the 35w Fisher TX-300 amplifier. This was only imported by the big 'Imhofs' London shop & a $329 amp cost the UK buyer £169. This will have been the first Transistor Fisher to get to the UK if the earlier Valve ones Imhofs imported. 35w power for 1964-65 is very high, most other Transistor Amps going back to 1962 were usually 10w Germanium ones mostly of UK manufacture & not ones we'd consider trying for the low power. This clearly predates the Sony TA-1120 which arrived Nov 1965 if UK didn't get it until 1967 by the time the 1120A version was out if there will have been some earlier models. To know the USA Hi-Fi Scene better to find when McIntosh, HH Scott, Marantz, Trio-Kenwood & Sherwood first had early higher power transistors if sites showing this info take some searching. McIntosh first Transistor Power amp MC 2100 105w & MC 2505 50w in 1967. The MA 230 integrated amp in 1963 was transistor preamp & valve output hybrid & MA5100 45w from 1966 was all transistors. Marantz first transistor Power Amp is the "15" 60w from 1968 & the "18" 40w receiver.

1969 Sony TA-1166 & TA-1144 Rare Non UK Sony Amplifiers.
A reader in Sri Lanka recommended the TA-1166, if we didn't know of it as being in the UK, this "missing link" of the Sony Amplifier Range strangely didn't get imported if Google finds info & pictures. We consider it a Missing Link between the 1967 TA-1120A & the 1971 TA-1130. There are similarities to both & this amp is a Semi Complimentary one without the output coupling capacitor having ±40v HT supply. The styling on both is very different to the 1120-1130-1140-1150 design, looking quite like the early 1970s Marantz amplifiers with sliders & a black middle panel on a silver fascia together with some UK looks in other ways, not one you'd instantly see as a Sony. Back panel looks more like the Sony STR-6050 with pre out-main in connectors & a switch, not connecting cables as the TA-1120(A) had. As with the European styled Sony STR-6850 we had, the experimenting in styles by Sony around this time shows in the Brochures of the era, if clearly only certain countries got the TA-1166 & TA-1144 as an 'Export Model' has DIN sockets duplicating the Tape Connections. A Japanese brochure found online shows a Sony ST-5300 tuner in the same styling. The TA-1144 manual we have & it's a 30w one, the TA-1166 assumed to be 45w-50w. There is also a similar looking Sony TA-1000 that is likely 15w. Inside images on the blurry manual show it's all on one level as the 1120(A) & 1130 are. The TA-1144 will be a midprice amp, what the TA-1166 is like is unknown as no photos found. The circuits will be quite similar if build inside could be different. Still built on several PCBs & the Tone Sliders are unusually stepped sliders, not just a continual slider, assume it must be notched in use to be precise. Phono stage is more basic than the TA-1120(A) or STR-6120 with 2 transistors, Tone is 2 transistors & quite like the STR-6120, Power Amp is 7 transistors, no Differential. Regulated Power Supply with 4700µf is decent for the era. Overall it'll probably sound like the Sony STR-6050 which is an earlier 1969 design, a clean sound if limited deep bass & spec quite modest. One that would likely upgrade well.

Germanium Amps: Are They Any Good?
As all original, a Germanium amp has a soft pleasing sound, if not exactly fast & the circuit will be limited to keep it within it's limits, as well as being generally aged & a recap needed. The 30w KLH 27 receiver from 1967 is all Silicon except the Power Amp Drivers which we found were "not capable" for a 30w amp with a typical upgrade, so put Silicons in instead, plus the TO3 outputs were found to be Silicon too, so now the whole amp is. The Fisher 600-T & Fisher 440-T are nearly all Germaniums including the Output Transistors. An interesting design that sounds very pleasing with it's detailed if slightly retro sound. Tailored to fit the Germaniums spec is an unusual design, if very well created, it's not so honest. Another Germaniums amp was the Duette SA-500W which was a 1966 Japanese amp imported into the UK to be sold off cheap in the early 1970s. It was a strange one, nice sound if some crudeness in the design, but no circuits to see where. We recapped it, found some oddities & as the driver Germanium was hissy we put in different ones. The Germaniums did hiss a bit, the S:N ratio is not so good if the Fisher again was cleverly tailored to get the best from them. The buyer found it a wild amp on their speakers for the scary bass they said, if on our Tannoys it was fine, clearly it needs well damped speakers. The 1966 JVC MCA-104E was a better Germanium design than the Duette & it had a pleasing sound if again a slight hiss. The current Germanium amp the 1966 Rotel 100AMP appeared to have bad PNP Germanium outputs despite being the same number as the JVC MCA 104E 2SB 407s. We bought some NOS ones that were reading bad C-E as our old ones. To change the amp to NPN Silicons was a bit extreme if the Rotel 110A manual helped. The sound difference just for changing PNP Germanium to NPN Silicon took a rather blurry aged amp, even with the pre-power recapped, to sounding a lot better & we're playing it as we type. The softness & hiss of the Germaniums is noticeable & on playing bassy Reggae the amp with the Germaniums & still the original power supply can't cope occasionally. The Rotel pre & power amp has Germanium on all except the Driver which is a Silicon as is the Phono stage. 15w amp here & usually a Germanium amp of the Japanese design, which the USA Fisher 600-T & 440-T are very different, are usually at 10w for a reason, so they can cope. Higher power is a Silicon design which is why the KLH 27 was so poor until we rebuilt it. But the Germanium sounds softer if still detailed which may help hide rough sounds on less good inputs & edgy speakers. For the fact the Rotel 100AMP is much improved for Silicon outputs & with the tuner it's cute in the wood cases, as well as a rare one, to initially consider to upgrade it all from Germaniums just to see how good the design which is much like the Rotel 110A can be, but we wanted to have a Germaniums amp. The real progress in Hifi came once Germaniums were abandoned is the reality, if the Retro Sound is nice, it's a small & wallowy sound on the Japanese amps. UK-EU ones with known bad Germaniums we'd not bother with. The Rotel 100AMP gets the whole lot of the resistors on the tiny pre-power board replaced just for the hell of seeing what happens as there was a fault that wouldn't reveal without too much unsoldering. It solves the strange Balance Control issue so turned to L the R silences as the design suggests. The Rotel 110A is only similar on the Power Amp, the 100AMP has an extra transistor in the preamp likely as a Buffer. Sounds more stable with new resistors if still has the 5 Germaniums per channel to see what they sound like. The problem with Germanium is the S:N ratio is poor which is why they are so tailored in the Fisher 440-T/600T. The background hiss sounds like a seaside with a bit of a mainsy hum too. Wouldn't call it small & wallowy now with new resistors & new caps on that board too, if the rest is not recapped, the thick Retro bass is obvious if not excessive as part recapped. Is there a way to live with the Germaniums, the JVC must have been quite tamed to not be hissy. JVC MCA 104E is tamed quite a lot, the Germaniums sound being smooth is from tailoring of the design to give the best sound & least Hiss. The truth of Germaniums is out. But the Rotel 100AMP on the pre-power board Germaniums is a pleasing Retro sound, a bit crappy before Power Supply Recapping with limits but maybe that's the "warm vintage sound" others like & our upgrading to give a more precise sound isn't everyone's taste, but once you hear the upgraded as we'll put in the 100AMP, the cuddly Retro Sound will be forgotten about. But to try the amp with the hiss, hum & leaky stereo on speakers first. Hum is more noticeable than Hiss, if the amp itself sounds nice & there is a clean sound in the amp beyond the Hiss & Hum. It needs more work, but is it worth keeping? See a Sept 2018 blog conclusion.

But You Said... "Retro Bass & Germaniums Sounded Nice".
This is based on a Germaniums amp on the Pre & Power Stages if Silicon Outputs were needed. Recapped only partly on the larger caps as ones to order in. Beyond the Hiss & Hum it does sound nice like the sound you heard on lesser Audio Gear when you first took notice of Music, old Valve or European Transistor Radiograms rather than Portables. One Note Honky Bass with no Deep Bass but not thin sounding, a surreal sort of swishy sound & a bit rolled off on high treble. The Bass is bearable on some music if annoying on others. Playing 1960s Ska it has that 'Dancehall' flavour to it a bit like an overplayed valve amp & sounds rather Authentic. Here the Rotel 100AMP has new resistors & capacitors on the pre-power plus Silicon outputs & now a new main capacitor, if still the Pre-Power board is still Germaniums & will stay that way. Look on the better Audio Restoration programs like DC7 & they have a Virtual Valve enhancer to give the Harmonics that music Digitally Recorded when made has, to give it some character, in the same false way Crystalliser & Bass Enhance does on Soundcards. They need to add a Retro Bass & Germaniums limiter to DC7. The Fisher 600-T had this sort of sound, precision with the Retro sound that was an interesting one to hear on speakers, if not as honest circuit-wise to get the best from the Germaniums, but you could just hear how The Beatles 'Revolver' & other classic LPs of it's 1964-66 era would have sounded. The Rotel has that sort of sound too & we could upgrade it to Silicon but it'd lose the Retro Sound & just be like a 15w version of other amps. So if it's still noisy once other work is done, why not get the same Germaniums the JVC MCA 104E had? 2SB22 & 2SD30 are still buyable for the drivers, as are the originals. The Rotel is better without the TO3 outputs as Germanium, as the Sanyo ones are aged to almost short on C-E. The 100AMP has ceramics on the power amp still that will add to the Retro sound, on Tone the Treble gain they sound lousy, if on Silicon ceramics always sound gritty. After sorting a bizarre problem that stopped us playing Stereo tracks, we now can. This does reveal the limitations of Germanium more as louder 1980s treble can get caught out by the design & it still sounds softer than Silicon transistors can. Stereo tracks do make the amp sound inadequate, but on 1960s Mono tracks it suited better. Heavy Bass on the 470µf outputs doesn't come through too well & some ends up as the thick Retro Bass which is hard listening. But more to do still. Once the Capacitors all redone, interestingly some of the "Smooth Germaniums Sound" is more for aged capacitors as it's a lot crisper now. But 'thankfully' it still sounds Retro, the Ska is punchier but the dynamics a lot smaller than an upgraded Silcon amp we tried just earlier on the same tracks. No more lumpy bass either. Trying it on more demanding 1980s Stereo tracks, again the smaller dynamics if still a nice sound & doesn't embarrass itself now. It's a 15w amp & still has some background 'Sea Noise' hiss & slight hum, after all it is a modest 1966 design. It could be upgraded with all Silicons, but the idea was to have a Germaniums amp, if the Outputs didn't work out, the rest still has enough of the Retro sound. As nice as it sounds, the Rotel 100AMP won't please a buyer for the hiss & limited sound so to resell them to go All Silicon will give a better product.

Hi-Fi Sounds Best... With Clean Ears.
As people get older, past 40 or 50, their ears get bunged up with wax & debris. This creates a plug of dust, fluff & hair that you can still hear the full range past in lesser cases, but it's like "putting a sock in it" on an old Horn Gramophone as it reduces sensitivity, or you may be quite lacking in your hearing range but over time not realise. They put it down to aging so ignore it & say "aye?" all the time annoyingly as they can't hear you clearly. We've heard of those who can't stand Bass as it makes their Ears Buzz, no, it makes your earwax lump buzz, ugh. Another doesn't like to get their ears wet as it causes problems, actually it soaks the earwax blob to temporarily block your hearing canal. All rather nasty if unnecessary to suffer it. Use Cotton Wool Buds some say, no it just pushes the debris further up yor ears to block the eardrum & create the plug. To see those big metal Ear syringes & thought they just sucked your ear clean so avoid them, but no, it shoots warm water into your ear canal to clean it which is less traumatic than thinking your brains will be sucked out. To use Otex to soak the debris leaving a fizzy sound or just to spend an hour with warm soapy water syringing to soak & loosen the build up leaving it to soak a few times if the effect doesn't feel right yet & then see what's causing you bother in the sink to know you're done. But you remember as a kid you never needed this as you had a bath & soaked your earholes to clean them. So keep your lugholes clean, syringe wash them regularly, never use cotton buds & hear how sweet your Hifi sounds, or how rough it sounds perhaps.

Flatscreen LCD TV Problems: They Get Old.
We got our LG one in 2013 & it got upgrades to keep hot areas cooler by adding heatsinks, the plastic behind the rows of log thin Fluorescent tubes smelt bad after a year so we Wallpapered the inside with A4 sized paper stickers. Sorted. Not looked inside since 2015 say our dates inside. But now the Freeview Tuner doesn't work at all, not that we use it with TiVo but on BST arriving it still says GMT time on turning on. Also it's developed a slightly dark shadowy part that is obvious on bright scenes, but as Unserviced Hifi Users know you learn to put up with it as you're busy. So today we take the thing apart which despite 3 years since last doing it's remembered if needs careful handling of the big LCD unit, on the bed is best. LCD off, looks fine, two thinner plastic layers are fine too if them the darker areas are seen, it's on the thick plastic diffuser that's facing the long Bulbs. It has the typical Charged Dust issue & a wash cleans it off, surprising how dust gets in, we'll try to seal it more on putting back together. But a problem with that thicker sheet is, like most plastics, it browns with age & heat, which is noticeable against a white surface & the edges are lighter. It'll just keep getting darker if probably will last another 5 years, you'll need to adjust the TV settings which we can do to make it look like a big money TV beyond the Blacks not being quite Black, it's good enough. Another issue is the thin flat ribbon cables that drive the LCD, if these get loose you'll get Vertical Lines & for the amount of times we took ours apart to solve the smelly plastic liner issue, ours got slightly loose. Don't glue it as you'll lose Electrical Connection, we just taped a bit of thick card over it to hold it down so it's worked fine for 3 years. Many would just throw a 5 year old TV out & buy a New One as the World Wants You To, but us being resourceful will fix an item forever to get use out of it. The Boards look fine, no burst capacitors or popped ICs, to service it & put it back together is all we can do & see if that solves the Tuner issue. The tube lights gather that 'fine black electrical dust' slightly, like old CRT TVs used to insides & on the screen until the grounded flat screens arrived. No dust on the rear of the LCD panel, if the Power Supply panel is where the dark patch is & appears even with the plastic sheet backing it to be an issue that all will likely get. Plugged in, the picture without the dark shadow patch now, no lines shows our bit of card fix holds solid. Freeview now shows a picture, if only 6 channels instead of the full range, TV Forums say as Digital TV channels are together in 'multiplexes' as in grouped on the old Analog ones, the few we got only appeared late on in the Tuning suggesting some are weaker than others. UHF CH 35 has 6 channels, no Radio. Manual Tuning says 'No Signal' on going through each other one 21-69. More searching says the TV Channels altered & possibly the aerial is misaligned now, but the Freeview page says not despite the channel change noted. 18 March 2018 said to be a DTV changeover date & to do a Factory Reset which we have. Ch 61-68 now not DTV ones & Ch 31-37 & 49-60 are highlighted as the main ones. But "No Signal". Answer is likely the Aerial for the block is out of date & no-one else uses Freeview so no-one bothers complain. Leave it be as TV not damaged, if servicing the TV, resetting & using the same settings we devised in 2015 the picture appears brighter & clearer which will be partly the fine dust it collects inside. A LCD TV improves after being last serviced 3 years ago.

1966 Kenwood KW-1100 Valve Receiver.
One on ebay interests. "37w per channel" says HFE & it has 490v HT as 7591 valves can put out 43w in Push Pull as the Valve Museum site states Sylvania & these were used in a Hammond Organ amplifier. But these are shorter versions of the EL34 & others state 19w per valve maximum. 37w we assume is "Music Power" & a pair of EL34s in our Luxman LX33 is only rated 30w, probably a 20w-25w RMS amp by the size of the Output Transformers, probably nearer 20w. You need to research these early amps as the Power Ratings were misleading then as are now & people just blindly quote without putting a reality on things or seeing transformer size tells the power. The amp is tired looking & some new caps underneath if generally original. Receiver as was our Trio WX400U & the underneath is chaos as is typical. Phono stage has 2 valves & appears a little uprated to the WX400U one, lots more stages to the Power Supply reveal it's 3 years later but very complex. Has an extra valve for better gain as the WX400U seemed lacking if it was only 10w. ECC82, ECC83, 6AN8 triode-pentode for the Power amp first stage-splitter & 7591 push-pull pair. The 6AN8 is only available as NOS or used Vintage so it's obsolete. DC heaters on Phono & the Preamp. A plainer looking amp for 1966, looks more like a Sansui if the lid type is like the WX400U. The mix of valves in it is messy, they put 2x EL34s by the looks which aren't fully compatible. Simplified Tuner compared to the busy WX400U one. Grade of the insides shows bad storage so it'll never be a pretty one. If we'd not had the WX400U to know what a huge rebuild these are, it'd be one we'd try, but the reality is these amps don't get rebuilt, they just get patched up, sound too aged & mediocre so they aren't coveted. The results after a huge rebuild of amp & tuner including recap, upgrade & redesign will give a great receiver, but to do it properly to be use daily would be a very expensive job a way into into 4-figures. Would anyone dare to pay for an extreme upgrade like that? Unlikely, the amp will sell for £200-ish & the buyer will likely not do anything to it beyond a clean up & just add it to the collection to try once a year. The reality of the 1962-67 Receiver-Amps like this is the Rebuilt is just too much, a Valve Amp by itself to rebuild is more affordable if still an expensive job. Sells for £233 which on the face of it for a 20w valve amp is a good buy. To see amps like this first time will overwhelm at how messy & complicated it looks, only by taking time to learn the sections does it make sense & then is quite logical, but there are no manuals pointing out the parts in the unit. Advanced stuff, but rewarding if you can do the job right.

Comparing Two Mostly Upgraded Amps: 1970 Trio Kenwood vs 1972 Akai.
We compare Amplifiers a lot to decide which to upgrade further & keep around longer. This comparison session is with the 1970 Trio-Kenwood KR-6160 a 55w amplifier that uses the same UA1384 power amp board as the 1969 TK-140X II, the receiver version of the Trio-Kenwood KA-6000. The Akai AA-5800 appears to be their best 45w Amplifier from 1972 based on the 1970 Akai AA-8500 receiver. Both 6160 & 5800 have the same sized transformers if 55w vs 45w, the Trio we have found underrated in power for how welll they upgrade. KR-6160 & AA5800 upgraded to the same level, if still need big caps to order. KR-6160 differs from the KA-6000 circuit quite a lot as 2 lots of low NFB instead of one larger, the only amp design that does this. AA-5800 has a buffer on the input stage that no other amp has, at least of the 1965-80 era. Comparing back a few times with Bob Marley ‘Is This Love’ a much used test track as wide stereo & also his "Jamming" both recorded from the UK 1970s 45s. Both very close if the Akai is just slightly fresher & more open losing the slight blur of the Trio, if Trio does still have 1970 output capacitors which are likely the difference, Akai is direct coupled. KA-6000 in comparison beats both if more upgraded, if it's nearer the Akai sound. The hardest amp test is resolving 60s Mono Ska & it is better focussed on the Akai. KR-6160 upgraded more could match KA-6000, if the Akai is more unknown if could better KA-6000 & after KA-6000 the Akai still sounds good. KR-6160 we’ll finish & sell, if not upgrade more, still a great amp & betters the TK-140X in several ways including looks. A test on Speakers tells a different story though. The AA-5800 has wider Stereo if not quite the Drive of the speakers on Bass that the KR-6160 does if that lacks the crisper detail to give the more detailed Stereo imaging. Both AA-5800 & KR-6160 as upgraded still sound great on speakers & both sold quickly as at the price level that Buyers are comfortable with.

Comparing Amps Via Pre Out & Power In Sockets.
Continuing from the above tests if worth a new header, as we've not compared pre/power stages for a while. Tests between pre & power need Blanking Plugs on the unused part to avoid difficulties as well as caution in putting the volume to zero on both to allow for level mismatches, as well as plugging things in right. The Akai AA-5800 pre-power level similar to Sony TA-2000F/3200F so why not compare pre of one on power of the other & vice-versa. Sony pre on Akai power shows Akai power is good & perhaps better than the Akai pre, if the Sony pre is a bit lower output as later found. Akai pre on Sony power is louder than the Akai fully as the volume control is set lower if the Sony pre sounds best. The Trio-Kenwood KR-6160 has a very different pre-power level so as blogged above it won't compare well, if does tell the Akai Preamp is weaker than the Power amp stage. Designs being designs the Akai pre maybe won't upgrade anymore than we have done already. But we can swap around the KR-6160 & KA-6000 pre-power amps so to try that. 6000 pre on 6160 power amp is good, if 6160 pre on 6000 power a bit limited if we know the circuit. So as 6160 & 6000 power amps differ in design as per TK-140X versions, try the 6000 power then the 6160 less upgraded power to see. 6160 still on original power & output caps yet it's crisper for the different amp board matching the Sony STR-6120 & Sony pair type detail. KR-6160 is the TK-140X II amp board & even not fully upgraded it sounds fresher than the KA-6000. The Trio-Kenwood KA-5002 looks like it may have the KR-6160 board but it's a later Fully Complimentary 1972 design. This test also tells the Sony TA-2000F is great, if the TA-3200F isn't as bassy as it could be. With these further tests, the Akai shows the preamp as with limits & the Trio-Kenwood preamp similarly. Which one to upgrade more?

We're Selling our Garrard 301 & SME IV Arm.
As Record Dealers we wanted the Best Vintage Turntable & from 1998 with a Silver-Grease Garrard 301 bought for £30 in an ugly cabinet with Dynaco Pre, Tuner & Amp, there it started. 301 was a NOS early one first used probably around 1968 & in high grade for being in that cabinet. To read the 1998 Hi-Fi News Vintage Supplements got us the Maxplank plinth that was the best one out then, beyond using the cold slate ones. The 301 came with an SME 3009 Series II that we thought was a bit lousy for the feeble Headshell that was like a Soup Strainer & lost too much energy in the 'soft' design, plus the awkward loose knife bearings. Put a more modern Headshell which improved it to a degree. We had a Garrard 4HF that was first out in 1959 some years before, the one with the steel platter & speed control that always burns out, if the Arm we thought was worth getting as the Garrard TPA arm & we got a nice boxed one & fitted it to the Maxplank plinth. It was a big improvement over the SME for being strongly made & rigid. But it was based on a 1959 design & weight adjusting & fitting a modern cartridge wasn't good enough so that got sold, the 3009 came back if still dissatisfied. So for reasons obscure we bought a SME IV in silver to match the 301. Lovely solid item, takes a bit of setting up if sounds were great if oddly not far off the old TPA arm. Soon a Cream-Oil 301 pair come along in 2002 with the Quad II Pre-Tuners & Amp system, the Oil Bearing is far better sounding than the overdamped Grease which slows the music. 301s apart fully to service as you'd expect from us. But since moving to where we are now, the 301 was only getting used to record new records stock, we'd tried a Hacker GAR 550 for the want of having a different record player by the Desk & this led to getting the Trio-Kenwood KA-4002A in 2011 that started our Hifi Pages. The blog shows our testing of the Technics SL-1500 with it being serviced & several upgrades, plus trying the Valve Phono on Goldring G800 & G850. The sound from the SL-1500 & G-850 despite them being buyable under £200 showed the 301 & SME to not be that far off, even using the Roksan Corus which has the original Corus stylus, not a Goldring 10-series one. We'd been watching Prices for years, if the prices on ebay for 301 & SME appear to be based on Fake Bidding, where a unscrupulous seller "sells" gear to themselves to try to create a price on gear that otherwise isn't making those prices. The sort of sellers that see our price on a Rebuilt & Serviced High Grade Sony STR-6120 & think their raw tatty one is worth the same, work & parts doesn't figure to be of value apparently. The 301, SME & Plinth look very classy, but from using the SL-1500 again, we had one we got from a Charity Shop in 1993 to know it was one of the better Vintage Turntables, the 301 & SME started to lose appeal. The 301 relies on the rather clunky lever switches, to turn the motor off to change speed isn't so bad, but to cue a record by hand, you have to rest on the pointed end of the lever. Other problems are the Strobe Platter relies on an Incandescent external flickery bulb to work, none built in like the 401, but the modern ESL Fluorescent or LED ones don't work the same so the strobe doesn't work. A more tricky one was even when freshly serviced, the 301 in colder weather runs slow until it gradually warms up over an hour, so if recording tracks to watch the Strobe. The 301 first came out in 1954 with the Silver finish & Grease Bearing, the Oil Bearing is on some later Silver & the Cream one arrived by about 1958-60 with either Silver or Black finger panels & was replaced by the Garrard 401 in 1965 if supposedly a better unit, the looks & plinth shape at the rear corners keeps it less expensive. The SME arm doesn't have as much travel as the SL-1500 one & the fixed headshell instead of the SME detachable one isn't so user friendly either. The SME arm cable that plugs underneath is actually a bit poor quality for the high price we found, if maybe the later ones improved, one cable broke at the feeble Phono plug & the wire was a type you can't solder neatly, so we made one from a Reel of Shielded Cable we had & found it sounded better as lower capacitance than the SME one, why bother getting a £200 new one? Cheaper if still good quality cables aren't designed with LCR features to filter the sound & this we've blogged on before. So the 'record player' parts are to be sold, if we'll keep the Roksan Corus Black as we have several custom stylus sizes as made for us by Expert Stylus Co. The SL-1500 is 33 & 45rpm only, but we devised a 78rpm setting on the pre 1998 one & did one for a customer fitting a subtle switch on the lower plastic plinth which worked well, so ours will 'go 78' too. Now why do people buy expensive 'High End' turntables & arms when we've proven what can match it? The truth is our Valve Phono stage is our design unlike any other for the detail & focus it has. The typical Transistor or IC Phono stage, as on the Turntables page, we've shown a few can be good, if most including ones with MM are blurry poorly focussed messes. The extra precision of the SME-301 will give a better signal to the blurry Phono stage, but our Phono stage is of a different quality that the differences 301 vs SL-1500 are so close. We've not said we had an SME IV before as our site is not a 'High End' site, aiming for a more aware audience than just throwing big money at items, so to not confuse by mentioning it, if mentioning the more affordable Technics system ones. But now we have proven as blogged that we don't need them now, to tell our experiences with both. As you can see, a Quality Direct Drive turntable with a metal plinth & a decent bearing can actually be as good as the 301 with some subtle changes & upgrades, but easier to use & more stable, once serviced naturally.

Upgrade A Decent Turntable Into One Much Better.
Is it possible to make the Technics SL-1500 towards the Quality of the 301 + SME? You'll actually be able to do quite a lot for following a few simple rules. The technique of Damping means softness or lack of rigidity that the vibrations from the Record Groove as travel to the Cartridge get lost in poor design, construction as well as poor designs like knife edge bearings like the SME 3009, non-rigid headshells as the SME 3009 'soup strainer' one is. Some others have rubber mounts in various ways supposedly to dampen vibrations & reduce Turntable Rumble, but these are going to lose a lot more than the deepest bass that can be on some records, the slightest damping of Stylus to Cartridge to Arm to Bearings to Plinth & how the arm is fitted will lose quality. The Cartridge fitting can be fiddly to set up & only really those with bolt holes to fit are easier, the ones with lugs often don't tighten as good, if never use the plastic washers as it's damping. The Hex nuts are better than the Round Notched ones as more surface are to grip solidly. The idea of springs to decouple a turntable now seems laughable if one Record Guy with Expensive Rock LPs used the most wobbly turntable we've ever seen, the dealer sold him a bad unit that didn't have the foam spring damping. But they wouldn't hear our advice neither would one who put feeble foam rings around the 301 platter to damp it, we said they were rubbish as they did nothing & took them off, but they returned next time we saw as people will believe 'Experts' not Free Thinkers. No Springs, No Rubber parts. As of typing we still keep the thin rubber ring on the Technics headshell we notice so remove it & surprisingly it's better sounding without it, just that tiny area of damping does matter. Even a spacer made of plastic will damp the arm softening the sound. Unfortunately a lot of Turntables & Arms are of Plastic, Composite or Wood based manufacture. An arm with rubber or plastic bearing parts is never going to be the best. The Technics SL-1500 arm is all metal where it matters & once serviced it's probably better than the SME 3009 II that many use with these, for the rigidity is superior, if no SME owner will believe it until they hear it. SL-1500 is Direct Drive with all-Transistors driver board, unlike the later IC ones & once recapped is very reliable. The bearing on the SL-1500 is a quality piece, a much thinner one than the 301 if still decent once serviced. The rounded end runs on a plastic piece that we noticed ours was with an indent from use, so perhaps this 'pressure pad' could be bettered to reduce the surface area, if to look at the 301 bearing end, it's a 1cm plate "Thrust Pad" with flat to flat with the oil to float on. A Turntable & Arm needs to be as Hard & Solid as it can be, if the SL-1500 base cover is only thin plastic, this isn't important as not coupled to the arm & platter, merely covering the underneath so no need to alter that, if perhaps a little more solidness would help. The arm has rubber decoupling on the rear plastic weight post, the weight of this piece is crucial so not to mess with it. The weight itself rattles as the plastic tab with the tooth to grip has flattened to lose grip. The Technics feet are hopeless, either spring ones or a rubber cup type. To fit big rubber feet, add a Sorbothane layer & a Felt pad over that is what we've done, or you can buy Gold Plated efforts if we prefer our custom way as those Gold type ones are expensive & often not as good as you hope. For Cables we fitted Phono Sockets if kept the captive Mains & Grounding lead. Why spend more? The Harder & More Solid the Record Player construction is, the finer the sound & adds more solidness to Bass as less energy is lost throughout the frequency range. Playing Records not played for a few weeks, they are sounding a lot 'tighter' in sound than before. The Mat, as we've said before, is a piece of Cotton Velvet over the Original mat, the old 78rpm players used a Velvet mat so it's what we chose many years ago. The idea to try with no mats direct on the metal platter makes no real difference, to disprove those bad designs that suspend the record in mid air, but a higher or lower mat does alter the VTA-Vertical Tracking Angle which does make a difference to sound if ours with both mats rides the cartridge flat to the mat with no tilt. There is a Garrard turntable, possibly the Lab 80 that was first out in 1965 that had a lever to raise the arm bearing end to 'Track Better' which by taking the rubber mat away does alter the height & angle slightly. One to play around with but we'll stay with the 2 mats. So there's the inspiration to "improve your turntable", but as with any Vintage gear, if it'll look messy, don't do it, sell it on & go buy one of the Technics Direct Drive players. There are very likely other name brands with good Record Player units that could upgrade, if with some you may see it's all metal to find a hidden plastic bit that spoils the idea.

Hifi in 1964: A Digest.
We're going to do these for at least to 1969, as it does condense each year in Hi-Fi nicely, the Year Books & reading a year of magazines does dilute the interesting developments & the 1963 one above was much longer than expected. So to Jan 1964. Imhofs of New Oxford Street do seem to be the Biggest Hi-Fi shop at the time if there were plenty more smaller Hifi shops around the country. The Chapman Derritron company gets a full page ad where they are trying to update styling towards the USA looks if not quite getting there with an 8w amplifier not in the league. The Kit scene with Heathkit & Stern-Clyne must be thriving the 3w Mullard 3-3RC Mono basic integrated amplifier despite the low power gives a taste of valve sound as we had one in the early 1990s. A surprising article is how to make a Unipivot Pickup arm if you'd need a machine shop & skills so unlikely many were made. Eagle SA.150 amplier gets reviewed, 15w says the hype if 3w is the tested power & oddly the amp is discontinued as a footnote adds saying "it does not match the standards of their other products". Substandard Japanese product is the idea here & a little embarrassing, if Eagle Audio gear never lived up to the brand name, strictly budget. The scene as we saw for late 1963 is actually more advanced & steady for the Overseas influence if making the UK brands seem rather old fashioned in comparison. Feb 1964 starts with Imhofs sale & the Decca pickup arm. Nice Sony ad for the Sony TC.500 tape machine with Stereo speakers, 106gns (£111) complete with 2 mikes, if still a very expensive item when a typical amp or Garrard 301 was in the £30-£40 range. "New Heights in Hifi" say Armstrong with the Armstrong 227 Tuner-Amp 10w, at £48 it was still in the budget price range though & probably their usual quality. Leak with the new design 'Varislope Stereo' predates the Stereo 30 transistor amp that arrives shortly, for UK 1964 gear it has the right look. A Transistor Amp Circuits shows the Design of this time, All Germanium with Transformer in circuit for the Splitter stage to the Output Transistors, quite like the Akai AA-7000 design from 1966 did in Silicons & if done right can sound very nice. Pye HFS 30 TC Stereo Transistor amp gets a review, 12w RMS is the real rating & uses obscure transistors NKT226 & NKT401. Opinion is it is liked, well made but poor on high frequencies as the 10kHz Square wave looks like a Sine showing difficulties in design & Transistor quality as was known. Interesting but stay with the valves is what we see here. Mar 1964 again Imfofs but Armstrong the second ad shows they are doing well, perhaps their early stuff was comparable at the time if medicre in comparison by 1966 standards? Another flashy Sony ad for a Sony TC200 tape machine & speakers, this is clearly where Sony made their start with good looking gear if always tape machines the 'suitcase' type design. Goodmans Maxim tiny loudspeaker 10.5 x 5.5 x 7.25 inches at 8w was a Groundbreaking Mini speaker if of limited use today, 45Hz to 20kHz is impressive but it'll still sound what it is compared to a 15" Tannoy driver. Test gear at this time like Heathkit MM1U meter & AVO Model 8 are very basic, the AVO one in cast bakelite still looks like 1930s kit, if today they'd look nice as Retro shelf fillers. A rather odd Thorens TD224 turntable newly out, it's an autochanger that plays records individually picking from a stack next to the turntable section. How this works is vague if mentioned a few times, only one stack so where does the played one go, but we just remember the 'Tom & Jerry' cartoon where an animated Radiogram does similar & throws the records off. actually gets a review too, records picked up by the centre hole for LP hole or USA 45 holes with a rising adapter if required. To use you Select Speed, Start it, a disc is picked up swinging it onto the turntable which then feels for the disc size before it hits the mat. Once played it picks the disc up & puts it onto a lower shelf rather than just chuck it across the room. Likely it would need regular maintenance to work right & still piles up dusty discs to scratch together. A nice automated idea, but not one you'd want & 3.5g playing weight is required. Pioneer SM-83 amplifier looks interesting, all valves, says its 27w RMS per channel which may be 20w RMS both channels. Apr 1964 is a bigger issue as the Hifi show Preview issue, this time Imhofs & Sony are the first two ads, if the rest are the usual lot as since 1963, not too much new in 1964 so far except Beatlemania & Ska. Saying that, Teddy Bear-Faced Harold Leak introduces the Leak Stereo 30 Transistor amplifier & be sure the Audio Fair had much interest in it. The early Stereo 30, not the '30 Plus' is a one-board All-Germaniums unit, for 1964 it will have been like no other UK or USA offering a 15w Transistor Amp for £49 10s. Unfortumately by 2018 the poor EU Germaniums have faded away & despite some making good prices as Mint & Boxed on ebay, the amp will have deteriorated. But this amp is a Milestone in Hifi for it's progress & affordability compared to the USA Transistor amps at much higher prices. Harold Leak introduced 0.1% Distortion in Amps & now this Transistor amp, neither totally his fresh idea, but he's the one who brought these ideas to the public. Another interesting early Pioneer SM-G205 receiver for 85gns (£89) quickly replaces the outdayted Double Tuner ones, 12w per channel if not saying Peak or RMS, we'd expect it's a 8w RMS one for the price. Then to see ancient Tripletone & Chapman tuners brings back how out of touch the UK manufacturers beyond Leak were. Rogers didn't go Transistor until the 1967 Ravensbrook-Ravenswood average efforts in comparison, the Pye one didn't sell & various other UK brands with budget looking 5w-10w efforts that don't compare. Danish B&O 609 Stereo amplifier we've seen online before & thought it was just too crude, a hybrid amp & being asked to upgrade one to see it's just not worth it for the low power & cranky build, if the case styling & 'movable line' is perhaps the interest in it. Around 15w output if the 10kHz squarewave is poor revealing the circuit still isn't the quality of amps that were around by 1966. Eagle SA.80 is the replacement one advertised to try to get away from the awful review & withdrawing of the SA.150 in January, if a mere £9 10s buys you an 8w Stereo Amp, it will have met a need but HFN are taking an ad for non Hifi gear here surely? May 1964 has Shure as the second page ad, to match Shure & Garrard turntables appears to give Garrard a free ad, but it helps the buyer know which cartridge suits. The Shure "studio Stereo Dynatic Integrated Pickup" arm just looks like a stick with a post through it, not very sophisticated or not selling it well. We've never seen Shure brand gear until on later 1970s gear. Still the old fashioned 1950s looking Tape Machines, not the modern lookimng Sony by Brenell who by their ads were a big brand at the time if quietly faded away not too soon after like a lot of UK makers. Truvox TSA 100 amplifier announced, "an important amplifier" they say if the Leak one deserves that. Truvox on ones we've seen online were just budget 10w Germanium efforts if looking contemporary for 1964, not worth bothering with today, in 1964 for 49gns you'd buy the superior Leak at the same price. Ferguson "makes for happy families" is as bad a tag line as is the early Philips one mentioned earlier, but perhaps it is, 33gns (£35) for a basic 4 track tape recorder is good value when others are 3x the price, if the quality of the Frequency Response isn't mentioned. Audio Fair Report hits with a Grundig SV50 amplifier that looks interesting, if pics online show it's a hardboard backed DIN socket & typical EU build if apparently 20w, not really for UK buyers with the DIN is the problem. Leak Stereo 30 was compared pre-show to Leak valves we assume & proven to be what it claimed, without the USA type 'transistor sound' hype. Shure M44-5 Cartridge is reviewed, one of the first Modern Style ones with the removable stylus assembly for around £14, if the 1963 Shure M-33-5 was an earlier similar version if not with the 15° angle as was now standard, so the M44-5 can be seen as the First Modern Cartridge, if the response curve on midrange & treble rolled off over 1kHz to a 'slight' dip of -5dB around 7kHz if peaked up to the level of 1kHz with a peak around 14kHz. A dull sounding cartridge with 68k ohm loading, but progress 7 probably ground-breaking for 1964. June 1964 has Revox as the second page ad, another expensive tape player. The amount of ads for these things chasing the few will have needed or bought them. Whiteley have a "new range" of amps & tuners, looking years out of date, preamp & two power amps that was clearly still selling for Quad but people wanted Modern if they could afford it, not this 1959 looking gear, who designs such aged looking gear for a 1964 range... a company that soon closes for not keeping up with the times. Facing page is futuristic Goldring-Lenco GL 70 turntable to show the big differences. Quad still have the ad page facing the Editorial by Miles Henslow if he's gone within the year. Trio still with the W-38 receiver, the same ad likely booked in advance as it never changes. Dual 1009 transcription turntable with Autochanger, if not the arm-across 1950s type. We've had Dual turntables & found them clunky awkward things, if like much Vintage some swear by them, we swore at the one we had to service as bits were found broken needing more repair than expected. A bizarre 5w Transistor Amp Kit, fixed Bias if design looks familiar to many later amps good value for Home Construction perhaps, if 5w transistor power is limited. Goodmans Maxim Loudspeaker gets a review, low sensitivity & only 8w handling is only for background music, you'd be fooling yourself it was room-filling as the hype about tiny speakers suggests. To say 'speech sounds natural' from such a tiny speaker is misleading similarly, if HFN do. Pioneer with yet another new model, the Pioneer SX-82 begins the long-running "SX" series, likely 20w valves for the "80 watt" hype, if looks interesting, an earlier designb to the ER-420 is likely as we looked at on 'Other Amps' page. Jul 1964 has an anechoic room on the front cover from Shure in Chicago. Mullard gets the second ad for Transistors "The Sound Of A New Era" if sadly the Mullard Germaniums are useless today as they age badly, AD 140 was the power transistor. Another First is Philips with a Cassette that is Loathed or Hated as a music format if loved by Hipsters for decoration. Cartridge Loading Philips EL3300 battery portable machine is yours for 25gns (£26). Decca ffss Mark III arm looks good for 1964 with the square block cartridge-stylus, probably a good match for the SME of the era. Armstrong 222 amplifier gets a review, 10w for £27 is budget priced, 10kHz square is reasonable for the era at the price & value for money is the opinion. Aug 1964 has a selection of Hifi Furniture based on the Radiogram shape still for building in the UK Quad gear, if the free-standing USA & Japan gear has no use for these, if you could still take the lids off & cut a template hole out & let the amp age without it's metal lid. Armstrong gets the second ad page, Imhofs always the first, the Armstrong gear strictly budget if the bigger pics show it's freestanding gear that is plain but functional with perspex fascias. metal lids & wood side cheeks. Report on the Los Angeles Hifi show show USA tastes differ, building a Fisher receiver into a lower drawer on a desk, KLH portable gear, KLH Model 16 amplifier, (Trio-)Kenwood KW-70 receiver, KW-100 tuner & KW-200A amplifier showing Trio made quite a few similar receivers if not many amps or tuners. An insane Fisher-Lincoln 70 autochanger like the Thorens but a lot more Steampunk styled. KEF Duette speaker was advertised often in 1964 & gets a review, if at 15w of limited use today & wood grille will only limit the sound if this design was much used. Akai M7 is one of the first Upright Standing Tape Machines, like the famous Revox type the hipsters like, if at £139 this is one of the most expensive items beyond the Fisher & HH Scott amps, if there will always be a market for Prestige Goods. Sep 1964 has ADC turntables, arms & cartridges distributed by KEF as the second ad. Double spread on Shure M44 cartridge range "excitingly beautiful sound". Dynaco new with Kit or Ready-Made SCA-35 amp, PAS-2 & PAS-3 preamps, ST-35 & ST-70 power amps, the amps especially much noted online, appear to be all Valves. Philips with a budget 24gns (£25) tape recorder EL3552 break from the rexine covered wood to plastic case, did the earlier Cassette one not sell? Scotch get the ad facing the Editorial with 3/4 the ad a huge baby face. Is that you, you're 54 now. BBC FM Radio first on 2 May 1955 if over 30 by 1964 & 25+ planned for the Future. A silly idea by Pye "Stereo Projection System" is just a desktop record player with side speakers & flaps to reflect the sound plus a Loudness control on the Volume. Oct 1964 has City & Essex Tape Recorder Centres as the second ad, "over 300 models from 15gns to 243 gns". Imhofs on the first page has a Fisher range ad, Fisher XP-5 Free Piston Speaker System with 8" bass, Fisher X-100-B "20w" £59 from the updated fascia, Fisher TX-300 "36w" £159 transistor amp, Fisher X-101-C "27w" £99 & Fisher X-202-B "35w" £137. But where are they? The higher priced ones you can only find in the USA suggesting UK sales very low. Armstrong with a Double page spread on their "200 range" with the 226 tuner-amplifier at £61 being the top model. Radford have a half page ad with just text in telling of the STA 15 & STA 25 range plus the mono versions trying to convince that Valve is Beast still & say they recently introduced the ISTA 30 & ISTA 60 'Reference Standard' range. To find out more you had to write for leaflets. Early Mordaunt (pre Short) speaker Arundel Mk II for 29gns looks quite like a smaller Tannoy case. "Look what's Here From Denmark" yells a TO-R S-15 advert for a tuner-amp, looking a bit Legoland as was the typical EU design, but to say "The Finest Tuner-Amplifier On This Or any Other Market" for a 6w thing is going too far, bugger off back to Denmark you liars thinks us, but we won't type that here. "A Touch Of The Ultimate" is an interesting article by a Cambridge Hifi enthusiast who imported a Harman-Kardon Citation A + B fully transistorised unit built into a 1930s pillar cabinet with a turntable atop. 40w power RMS is impressive for 1964. Turntable is a Thorens with Ortofon cartridge & Dynatron tuner. Turning on gives silence for 20 seconds, similar to the 1965 Sony TA-1120 as it lets voltages settle before use, the sound on Tannoy 12" & 15" is described as "very smooth, well-balanced & tightly controlled" if this is 1964 & compared to later years may not be quite so impressive, but for 1964 it's State Of The Art as the closing line agrees. New out is the Garrard 401 that divides opinions if has improvements & weaknesses as later HFN reveal. ADC Point-Four & 660 cartridges continue the Shure ideas of the more modern cartridge. American Letter by John Berridge is about 'British Equipment On The American Market'. Wharfedale & Goodmans speakers sell well if surprisingly Tannoy are lesser known, the Quad ESL isn't popular as Bass is too weak for the USA ears as well as being $350, Leak Sandwich sells well. Only Quad & Leak amps are popular, the rest doesn't figure as they say & Quad is getting overtaken by Leak for progress in Transistors. The Quad system of many units seemingly old-fashioned as is a lot of the UK gear by now compared to USA & Japan gear. Garrard sells tons of autochangers. Garrard 301 & Connoisseur turntables sell well as do SME arms. Looks like USA cherry picks the best if tastes are finding the traditional British gear isn't keeping up with better styling elsewhere. Nov 1964 the usual adverts if "This Man Saba" attemps to be James Bond yet sells cheesy Radiogram Innards as Hifi, we don't think so with Saba Stereo Studio 1 a feeble 9w for 89gns & Saba Freiburg Studio looking like a 1950s table top radio for 135gns, if it uses external speakers. An article about the USA 'Console Stereo' scene is a late arrival, the USA with big consoles by Fisher, HH Scott & others was a cornerstone of the USA Audio Market as these were no mere Radiograms, but proper seperates quality if with huge wide cabinets with built-in speakers & usually a gap to store 30 LPs as a Radiogram offers. The Console never made it to the UK beyond ones imported personally, the cheaper Radiogram as with Budget Stereos being more the UK scene. Koss SP-3X Stereo Headphones show what was around in 1964 as Amplifiers by 1963 usually had a Headphone socket that is compatible with Modern Headphones. Still looking like the WW2 era Headsets with a thick padded band. The sound is reasonable if rolled off & with some coloration, which suggests the Headphone wasn't yet used for serious use, the Koss one here is fed from the Output Transformer direct, so not quite the match of today's 40-100 ohm type ones. Dec 1964 all the usual ads, impressive overall for 1964 if still plenty of old styled gear including Jason with a late effort to shift their stuff, you'd think with a West end Showroom in Tottenham Court Road they'd bring out some more modern gear, but they don't & fade away, yet Leak & Rogers kept fresh ideas & carried on into the 1970s. Rogers Cadet Mark Three introduced, 10w valves for £32, initially a two-piece unit if one piece fairly soon after is the most common 1960s amplifier around still as it sounded good & sold well, priced cheaper than the Leak Stereo 30 transistors that many would have been uncertain about. "Transfiguartion of a Quality Amplifier" is apparently a first about Upgrading Amps, 'obtaining a modern performance from an old circuit' is the claim & doing similar is our game. Here they look at a 1944 design with PX4 valves, directly heated Triode for 15w, pre the Williamson design, if 6w is the actual power. But if you've read any books on Repairs, there is nothing said of what they do, a circuit diagram shows extra gain & NFB have been added, but to us it's not really doing very much.

July 2018 Blog

Original Capacitors Condition on a 1960s Valve Amplifier
We're rebuilding the 1965 Fisher X-100-B valve amp for a customer. It has 6 capacitors in 3 cans. Here is the Photo of the Decayed Insides, if some of the muck inside fell out. To redo this requires redesign & problem solving, it takes ages to get right. So on a high grade little used amp there is still going to be 53 years of aging & high voltage or high current caps age badly. These are Never Suitable for regular use & one try away from failure. Light Use or Heavy Use, any sort of Use will age High Voltage Capacitors.
The three in the Fisher are C1 with the card outer as the case is live, it hadn't leaked but was dried out with crusty earth inside which is dried out electrolyte fluid that oxidises. It smells sharp as it's stale & is useless, if will work to a degree but without seeing inside by cutting open, you're just gambling. C2 is a double capacitor in one can. To take it out showed how easily the pin broke off & it's even drier inside with crusty deposits if not as smelly as drier & no trace of leaking. C3 is a triple capacitor, it had leaked & traces of cleaning the chassis done by a previous owner as it leaked quite a bit. On opening lots of stuff came out, it looks like garden earth, barely smells & is just about mummified. Explains the rustling sound on the stage it supplied & it might last 1 day or 1 year with these severely decayed capacitors, the risk of Trashing The Transformers is the Gamble for not getting them replaced. The reality is 50 year old 200v-400v capacitors are ALWAYS VERY DECAYED inside, we've cut open all we've had. Any HT capacitor be it 16v or 450v if it is pre 1969 will be Gambling as they always are in bad grade. On some 1969 era Transistor Amps they may still be OK inside, as in wet with no crusty build up, but more often than not they are well past their best.

Damping Factor In Amplifiers.
This is mentioned variously on the site, if not as a section, so worth telling more on. For what Damping Factor is, see Wikipedia as the learned-booksmart types keep technical pages accurate & well written. We go beyond that to say what we see with Damping Factor. Firstly it's related to Output Impedance of an Amplifier that is not a Factor measurable with a Multimeter, how you find what the Damping Factor is by looking at the Amplifier's Data Sheets & Specifications. Damping Factor of say 250 is in Modern amplifiers. "Good For Controlling Loudspeakers" say some, but not us. High Damping is Restricting the Amplifier, like the Design in a Strait Jacket. If you use cheap Flappy Cone speakers then a High Damping Amp will tame them, but you're taming poor quality speakers. The accepted idea of Flappy Bass Drivers from seeing the same on 1980s-1990s Music Centres or Ghetto Blaster Cassette Machines that made it clear the Cone Flapped if oddly you never heard much Bass. Cone Flapping is usually in the 10Hz-30Hz region of the Speaker Resonance. What a 250 Damping Factor Amp sounds like on Quality Speakers is So Controlled & Damped it doesn't have much life & therefore sounds boring as be sure the rest of the amp is cost cut now they don't have to bother much about Deep Bass. Cynical but true. Going back into the later 1970s you find some Amps with a DF of 70, these sound more lively with "The Rich Vintage Sound" that once you hear, you'll not care about Modern Amps again. This is still a fairly high Number & Bass will be controlled but enough life in it to please. In the early 1970s values vary around 40 to 70 & again a little less restriction livens up the Bass which may not suit your cheap Flappy Bass Driver speakers, but on the right speakers, to hear a more open sound. The Earliest Transistor Amps from 1965-69 quote DF values from 15 to 30, if the Sony TA-1120 quotes "more than 70" & the 1967 Sony TA-1120A quotes "180 at 8 ohms". The DF of 15-50 requires good quality speakers or as one buyer told us about the Duette Amp with it's low DF sound that it was a bit wild on some speakers. But DF of 15-30 has that rich full bass, limited by original design, but these upgrade to sound wonderful on 15" Tannoys. Some level of Damping Factor can be apparently upgraded to give the lower DF richer sound, based on knowing the sound of a DF 30 amp to a DF 70 one, if without measuring it to know for sure, it likely is no different. To choose a DF value to match Speakers depeds on how much the Speaker Cones move, the 15" Tannoys barely move in an Infinite Baffle Sealed Cabinet, if our previous 15" Fane ones with a rear port shifted a lot of Air if never really gave the deep bass. Low DF to Highly Damped speakers & High DF to Low Damped Flappy Cone speakers is the obvious choice if Amps Mid DF 70-120 would best be suited to Speakers that move a little if not much. Never a Precise Science in Matching Amps to Speakers if based on the Many Amps we've tried on our 15" Tannoys, generally the Low DF ones 15-50 suit better. 1977 Yamaha CR-2020 with a DF of 40 sounded good if the 1973 Yamaha CR-1000 at 70 didn't match so well. The 1984 Sansui AU-G90X doesn't match our Tannoys if no DF given, by the sound we'd estimate it was at least 150-250 DF. Based on upgrading that amp, it's not possible to upgrade to alter the DF if you can alter the sound, the Mismatch would require more redesign.

1963 Transistors In Audio.
Oct 1963 Hi-Fi News has a large 14 page section on Transistor progress, 14 pages of info not including the Ad pages is unusual to put all in one issue instead of a 4 parter. The overview is in the Portable Radio market, Transistors have taken over. From what we see here & from knowing early Transistor amps, the limiting factor to stop Hi-Fi amplifiers was the Germaniums & the odd idea of using PNP transistors with Minus Voltage HT. we've blogged on Germaniums just above & the problems & pleasures with them. Difficulties in getting Good Frequency Response was mentioned often in this era of HFN & some ingenious if not so honest 'Sound Shaping' circuits could make use of Transistors that had High Frequency Roll Off. High Power Transistors were Expensive too so only really a few Transistor amps of 10-15w were made by this time. Hybrid amps with Transistor Tuner & Preamp but Valve Output were the usual item at this time beyond the 10w or less amplifiers like the Bryan 304 integrated, Pye HFS 30TC, Hart, Vectron, Henry's Radio & Radon R600S seem to be the only ones going into Power Amps with Transistors. B&O 608 is a hybrid , EMG DCU5S & Lowther SS2 transistor preamps. a few Tuners & Tape Machines as all transistor. The USA scene shows a lot more advances with decent looking Acoustech 1 if the real only competitor is the Harman-Kardon Citation A-1000-T "70w" Stereo amplifier. Interest in this in 1963 will have felt like a New World, if in reality only the 1965 Sony TA-1120 & the Fisher 600-T & Fisher 440-T seem to have sold by 1965-67, the HK one will be a rarity today.

USA Hi-Fi Scene in Dec 1963 into the Later 1960s.
HFN in Dec 1963 sums up how the USA market is. You'd need to get into the USA Hifi Mag scene to see further about these early years. Interestingly UK Leak restyled their cranky looking Troughline tuner & Point-One preamp for the USA market by getting more appealing fascias, aware of comments on how drab, amateurish & old fashioned the UK brands looked. The big difference really is the Styling, USA made the products look very 1960s Bachelor Pad with Big Loudspeakers, Hifi Consoles that are a big step up from the Cheap UK Radiogram. USA homes larger than UK so bigger items with bigger power were needed. This exact scene with Fisher, Marantz, KLH, HH Scott & Lafayette is what The Japanese saw & soon took over to dominate the Hifi Scene, giving modern looks & better quality at prices that saw Japan start to dominate by the late 1960s with premium brands like Sansui, Pioneer, Akai & Sony leading the way. They gave the buyers what they wanted, if at the time their customer service & backup was revealed to be poor until they got UK agents to manage the brands. At the time the USA wage & cost of living was higher, if more free money to buy these goods, the UK at the time wasn't buying the amount compared to other countries, often the Best 1960s Vintage stuff you have to buy today from USA, Canada or Germany as it sold there if really didn't sell in the UK, Fisher were advertised by the Big London Shops & got imported a lot apparently, on Special Order is likely the truth, yet you only see the USA voltage ones saying big ads don't make sales. The UK readership of HFN isn't revealled until the early 1970s, there may be just 1000-2000 who buy HFN or the Yearbooks, but how many bought the best stuff? In our HFN archive, some are marked with items the reader wanted to buy & usually it's the cheapest items. The thing with Blogging is you start to realise you've said similar in other sections already. To look at HFN articles from 1963 & expect there to be more to write about & find the article didn't really say much after all. The Pages Of Waffle in some HFN articles hides the fact "ain't much happening".

Quadraphonic & Amplifier Bridging plus Parallel Outputs.
4 channel "Quadradial" as Marantz calls it is part of the 1971-76 attempt to get Multichannel audio into peoples homes. The Reality was it Failed Dismally as many had barely got out of Mono or cheap Radiograms. The amount of 4 channel formats on Records was a mess so the Public stayed away. Amplifier Bridging is a strange concept where the 4 channels can be Bridged into 2 channel Stereo, certain 1990s era Power Amplifiers are bridgable as apparently is the 1973 Leak 2000 receiver, if we never tried the Leak as the circuit description sounded lousy, read on. So as we always say "Avoid Quadraphonic" or "Avoid Bridging Amps" to get a fresh opinion & get a 1973 Marantz 4070 Amplifier, a 2x 35w or 4x 15w one. More on the 4070 on the reviews page & in further blogs as it reveals it sounds far better than expected. So to read Wikipedia about 'Bridged And Paralleled Amplifiers' to understand what that does & we realise the Sansui AU-G90X is quite like this with it's Balanced Design & having a 'Floating Ground' as described, the 90X doesn't like mains grounded test gear & the HT on the Capacitors is unexpectedly low for 130w. The Paralleled Amplifier section doesn't relate to this amplifier, if does relate to Doubled Output Transistors that some amplifiers use & these do control speakers so well with a better bass than any Single Push-Pull Output pair does, the Double Push-Pull Output pair we put into our Trio-Kenwood KA-6000 as it had extra spaces & the 1965-67 Sony TA-1120(A) has these fitted, more to cope with 50w as the early Sony transistors were only rated 50w not giving much headroom for peaks. Usually a 200w+ amplifier has these Parallel outputs so has more Current available if usually they don't go that much louder, as in voltage gain, for the Power rating. What a Bridged Amplifier does is it phases the second of the Amp pairs the opposite way to the first one with the speaker connected to the Positive Connectors only, if you introduce Ground into the Speaker Circuit you'll get problems. But the Leak 2000 with it's "High Power" mode isn't all it seems... the Service Manual says "In the High Power mode, the Output of the Right Channel main amplifier is connected to the Input of the Left Channel Main Amplifier and the signal is fed into the Right Channel Input socket. Hence with a Speaker connected across the Outputs the System operates in a High Power Mono Mode" meaning to use only the "+" connections & the resistor from R out to L in is 820k ohm. This actually doesn't appear to match Bridging as the Wikipedia page shows with in phase & out of phase signals into two amps with the Speaker on the "+" running through 2 power amps equally. The problem with Bridging is it requires both Amps to be on Spec & equally matched which from having tested many amps for Output Power, the Amps are never usually identical, if within Tolerance. This inaccuracy causes one half of the output to not match the other so creates the soft blurry sound. We still say that Bridging unless critically adjusted will not be so good, but adjusted right after recapping then to hear the Marantz 4070 to see what it does.
In theory if upgraded & adjusted right, the Bridged Output should be as good as a 2ch amplifier & with halving the Damping Factor, it may actually be pretty good. Once the 4070 is done we'll blog more about it. Risk Of Electrostatics on Bridged Amps as the ES speaker or headphone may have a ground reference & as there is no True Ground once bridged, the Amp "won't like it" as we found testing the Sansui AU-G90X which is actually a bridged design and the new Mains Oscilloscope has a ground reference. To uisde the Battery Handheld Oscilloscope is the only way to test a Bridged Amp.

Repair Shop Label On Quality 1970s Amp Says "Too Far Gone" But Is It?
As we are Amplifier Specialists doing stuff that no-one else is doing as in Upgrades & Redesign, we look at amps in a different way. Sadly a lot of 1980s-Modern gear is not repairable as we blogged before, but 1970s Hifi if of Quality we don't give up on easily, if nasty ones like the 1971 Leak Delta 75 receiver are just so badly made that we only ever got one working right. We may be just Gambling, but as with anything, the more challenges you get, the better you get. So the Marantz 4070 quadraphonic Amplifier mentioned above we see it has a Repair shop sticker on & after reading it upside down it says "Too Far Gone". Now this shop is still trading, they are the TV Repair Guy quality as is obvious, today they'd just swap boards or tell you.. "It's Too Far Gone" because they are Not Specialists, but TV repair guys trading for 35 years. The 4070 review we've already put it could head into 'unrepairable' territory for how difficult it is to work on, but we've checked it over, it's all there, no damages, no burns, fuses still all good. It'll get more serviced before plugging in as the seller who was probably glad to offload it did say it worked. If it had damage to transistors then it would head into the difficult territory of being Uneconomical to Repair which means if you wanted to chuck money at it until it's fixed, likely it'll be fine but it'll probably outprice it, a clean one part serviced-recap they say if no crumbly speaker connectors is £300 with 2 sold for similar if one higher as with the wood case. Here the Repair shop looked at it & gave up, too much a job to fix the crumbled speaker connectors & too stuffed with parts to even attempt it which is lazy. Did that shop even plug it in? They didn't check the cheapo UK made 'Legrand' one Plug as Live & Neutral were swapped, the plug bulged midway as the fuse barely touched the pin as misaligned plus a 13A fuse. Worst plug we've seen in a while, to cut it off & fit another. Of course it's repairable, not the easiest, but plan it right & there it can be, if we have done many amp recaps. But as first try of it revealed the L channel with severe low frequency pumping if music could be heard in a choppy way & the R channel silent, there is no way to just do bits of it to see if it's any better. So it gets new Speaker Connectors, the Power Amps, Preamp, Matrix-Buffer-Power Supply board & Phono all done before it sees Mains again. First try redone the R channel is fine if the L is distorted so needs fault finding. Too Far Gone? To most... yes it appears a wreck electrically, but we see the potential & for it being a 1973 Marantz, work into it will make a good amp worth the effort to fully recap. It takes many amps to be able to do complex jobs like this plus much checking, there is no 'hope it works' in Hifi. The faults will be found, we'll try it out & probably sell it on sooner or later. It's not What It Used To Be... It's What It Is Today. To fully recap & replace all the preamp transistors is the job & an advanced 'repair' that would probably outprice a restoration to a customer, but for us to try what's involved. See the Marantz 4070 review for more, as well as more Blogs below.

We Are Looking To Buy A Top Quality Amplifier To Upgrade.
This is what we're doing having sold the 1984 Sansui AUG90X. To get a mid-late 1970s amp of around 100w is the idea. The market in Amplifiers, as opposed to Receivers is one of unreality & lofty expectations based on none selling. Receivers with the Tuner are nice Retro looking if we have no need for a Tuner so to just look at Amplifiers, Integrated not Pre-Power ones. The Sansui for all the work & research into it didn't make much in reality for the buy-in price plus all the work done, disappointing really, but one to move on to try others. Our Research amps get a lot done yet it shows the Market doesn't know the amp or really understand the Upgrading work. So to look what's on ebay. For getting the 1973 Marantz 4070 4ch amp, the Marantz range is severely overpriced for the highest model the Marantz 1300DC at £3500 in a repro wood case, we saw one sell for £1800 a few years back & though the buyer who bought several of our B&O amps was insane paying that much. We had the Marantz 1152DC before & found it difficult in several ways if now we'd look at it very differently. A Marantz 1150 with a badly resprayed lid for £450 compared to overpriced £900 ones elsewhere is the best out there, no wood cases. Sansui AU 9900A for £1800 with those awkward side connectors is only an 80w one from 1977-79, all Transistors but the design by now with so many Differentials does leave that rather dry sound as the AUG90X had that needs so much upgraded. Other Sansui AU-999, AU-888 are severely overpriced for the power & need of rebuilding, the sellers just copy other overpriced non selling ones. Pioneer we've done well with the Pioneer SA-9500 Mk I to know what they are about, good but not the greatest again needing so much upgraded. Harman-Kardon only has more modern amps as only the receivers of the 1970s had better power. Sony we've done deeply if there are STR-6120 & STR-6200s at very high prices for raw gear, we've sold two in recent months to know the real prices for rebuilt ones. Rotel has the usual late 1970s high power ones if looking at a RX-1203 recently, the build quality is a bit midprice which we found a bit disappointing plus those naff rack mount handles. None of the 'Michi' series ones from the 1990s when Rotel went 'High End'. Trio-Kenwood we are wary of for the amount of ICs & the 'Other Amps' page has looked at these enough. Trio with the early valve receivers at £400 are dreaming, they need a full rebuild & redesign. Yamaha we've done very well already, in the days these were cheap & unwanted, like many brands we get them, say they are good & then can't buy into them now. Technics (Panasonic, National) only really got into Pre-Power Amps into the early 1980s, we'd really not want to get into 1980s amps for the risk of ICs & overdesign. The integrated amps are just depressing plain tin box type ones. How about UK & EU brands you say? We've looked at many, the UK stuff we just don't like as it's not of the quality, EU brands similarly with the best being Tandberg TR 2075 that we didn't like for the bitty construction. Overview. The amps we like are now too overpriced if Auctions are where more realistic prices are, Buy It Nows are mostly dreamers. The difficulty also is we've had the Best Stuff already, there are Monster Receivers that we've not tried but having had a taste of those, such as the 1979 Sansui G-8700DB there are difficulties in these that perhaps are not worth upgrading to see how good they are as we can see the limits.

Got Money To Spend & Want To Spend It?
We're Record Dealers & at one time Collectors, into Coins, Hifi, Furniture, Signs etc. The thing is if you have ££££ to spend usually what you want won't instantly be there. Gimme Gimme but beware you'll waste money if not buying carefully. We'd like a better Computer, to start from Scratch to get a High Spec one. So we look at the High Spec Gaming Computers, not that we game beyond Spider Solitaire (W7 versions) & Angry Birds. As an example £850 buys you a refurbed Dell computer, but we want the specs of what they offer. Today the Intel i7 is the current processor range, Wikipedia tells of dozens of variations from 1.5MHz to 3MHz+, how do you know what to choose? Our computer is limited by RAM to 3.75GB which is useless for Windows 10 even using the 'Blackbird' program to stop all the spying crap. We compare specs, our 7 year old i3 2120 at 3.3GHz is actually faster than the i7 6700 in the £850 Dell one. The Dell has Hard Drives, RAM, Display & Sound Cards better than ours if it's not such a good deal really. In the end current computer spec isn't much better beyond RAM, so why bother buying new, leave it another year. **Computer Update: after looking for years for why RAM is limited, the fact is your 32 bit Windows is ancient 1995 tech, you need the 64 bit version, so we downloaded it to do a clean install from a DVD-ISO you can get as the x64 version. The 2011 motherboard & i3 processor can cope & 64 bit processors can run most 32 bit programs. Free upgrade to get the full 8GB of RAM fitted now. Why is this info So Hard To Find? As for Hi-Fi as above, you want to buy something good, it's not there or it's overpriced. The Specs disappoint as did the i7 processor, you realise you'd be paying £850 for a 2015 year processor & likely the Display & Sound Cards are a few years old & for the 'progress' today, they stop issuing updates, our Display one is only a few years old but no updates now. We use our 2002 Macromedia Dreamweaver MX, 2003 Office Outlook for emails & don't like the newer versions. A 64bit Windows 10 installation likely wouldn't suit those & a lot more, so more money to go buy newer versions you don't like. It's very hard to Buy Hi-Fi if for us we look for diamonds in the rough and unknowns & bring the quality back, but outside cases must be in good order for the work we'll put in. No point having a great amp with ugly damage unless you can buy the parts as spares as some sellers break up amps. So the idea was to buy an amplifier a little different as the AUG90X was to try out more upgrading ideas. So What Do We Buy? Nothing (as of typing), but Time to buy more carefully & get what we really want. To chuck a £50 gamble on that Marantz 4ch is worth a try, but to put £499 into a painted lid one is not a good buy as it'd need a full rebuild & still not get the overpriced prices others hope for. A firm grip of the Reality of Buying & Selling is needed. Solid State Hard Drives. Progress in Laptops & Portable Gear means a Solid State HDD is now worhwhile getting. It's no different to a huge SD card & when Digital Cameras first came out the pre-SD card was only about 100MB, if now a 256GB SS HD is buyable for about £40. Bigger Hard Drives are still multi-disk items & the speed of them isn't any better. To put the Computer OS on the SS HD & keep the Drives for Storage makes sense. The price of a DVD Burner in 2006 was £70, the 100MB SD type card was bought about 2002 if Amazon doesn't show details as obsolete, in those days it will probably have been £40.

Awful Restoration Ideas: Restuffing Capacitors.
This idea is really bad, the amateur can't work out circuits to properly upgrade Valve amps, so what they do is cut open the original 1950s-1960s capacitor, take the crusty insides out & fit in modern ones of the same value, seal the can with tape inside the capacitor clip & soldering to pins somehow so think that's a good idea. It's a very bad idea for several reasons beyond being unprofessional. You'll never see if the capacitors leak, get hot from miswiring plus the idea is redundant as you can actually buy the old value capacitors as Guitar amps use them, probably NOS ones from the 1970s or new ones even. To use the original pins means awkward soldering as the bits inside the cap are aluminium & don't solder. Strictly amateur job & don't forget, they are selling it as they don't think it's very good sounding. Seen on a Sansui 1000A valve receiver with a "professionally powder coated" lid is poor as they didn't strip the old paint leaving dents in the paint from missing patches. Their recap is mediocre just replacing like for like as again these early Valve Amps need a full rebuild & redesign, we've just done a 1965 Fisher X-100-B & it takes a lot of work & planning to do right to then look deceptively simple. Done right the results elevate the Valve amp to a standard of today for daily use. We'd not buy a Valve Receiver again, the amount to redo one as the 1963 Trio WX400U got is extreme, the results especially on the Tuner are great if limited by the power rating. The Sansui 1000(A) valve receiver we looked at on 'Other Amps' & for knowing how bad the Sansui 500A was, to keep away, but nice to see inside pics to confirm to stay away. There is a price limit on Hifi we've found & their hopeless like-for-like recap for £825 is not good value. The idea of it may appeal, but once you hear it sounds aged & mediocre, you'll want rid quickly too. Vintage Valve Amps are not a good buy unless you plan to get one rebuilt to a more modern spec to bring the best out. We've done two valve amps like this now for customers & results are certainly worthwhile. But to buy a raw one, like many Rogers Cadet III for £300+ you see as these sold well in the 1966-68 era, they are just too aged to be what you hope they are.

Very Overpriced: 1970 Sansui AU-999 Amplifier.
Seeing this amp at ridiculous prices just for the High Model Number we find a difficult one to understand. Ones £900-£1200 on ebay July 2018, there they'll stay too. We got one in 2012 so know it & there are a few pics in our Gallery. Firstly it's a 50w amp from 1970. It has a lot of switches & controls that you'll never use. Compared to a Sony TA-1120A at the time we had both, the Sony had a higher Sinewave Output as the AU-999 was a bit low for the power. 50w it output 25v sine before clipping if the TA-1120(A) does 30v which is quite a difference. The Sony easily sounded better was the opinion in comparing both. We got ours for £175 at the time & felt it was overpriced for the grade & power of it & the amount that needed redoing even for us in 2012 just a year after starting these pages. Lots of outdated crappy hissy transistors was a big problem. The back panel with those Spring Connectors for Speakers we had difficulty with as the things break off, ours was still minus one cover if useable. We partly recapped it, if now we'd go a lot further, but the reality is the Sony TA-1120(A) & Trio-Kenwood KA-6000 better this amp easily. It's a Semi Complimentary amp, ie no Output Capacitors which is unusual for 1970. Looks wise if in top grade it looks nice, if more used it looks a bit tatty. To have in high grade with the rare wood cases & the matching Tuner is a nice item, but Way Overpriced. For a 50w amp that needs a lot done to us we'd not pay more than £200 on one to be sure to cover upgrade costs on resale as a lot needs doing. These £900-£1200 prices are insane & in reality even rebuilt, it's not 'worth' that much as we found on selling ours in 2013, if prices for our website interest & others have upped the prices, buyers are not confident to pay the prices on Hifi & the risk of outpricing needs careful thought in choosing amps to upgrade. The Sansui AU-666 as the AU-999 is capable of a great sound, if read our Review on the AU-666 to see problems there too. Only when these greedy sellers see there are No Sales will prices be lowered, but ebay is stuffed with way overpriced amps, look at Yamaha CA-1000 as another foolishly overpriced one, we have had that to Review also.

Buying Vintage Hi-Fi Online: The Cynical Reality.
You see how we sell Hifi, pictures with detail inside & out, all faults noted & there you know exactly what you're getting. Buying on ebay where we & others who send us amps to upgrade reveals that often you are Gambling. At one time Sellers packed amps badly & they still do, if overall they've learnt the hard way to pack better if some arrive safely by luck more than good packing. Descriptions are usually painting the item in a better light, some of it is outright lying, the Marantz 4070 was said to be partly working & they tried it on speakers, total lies as it would have trashed speakers if the broken connectors even worked. As a "For Parts or Not Working" amp we just took that it generally worked, saw the photos & for the £50 price plus their overcharging £20 for UPS courier, to gamble, if £70 could still be wasted in reality. Further up the ladder pricewise, ones said to be working yet wires loose & dangerous to plug in are just insulting. Ones said to have "been repaired" but badly patched up leaving loose wires & loud hiss & hum we've had a few times. Ones said to be "Serviced" yet no sign of it in the dirt inside. Ones said to be "Repaired" by putting wrong spec transistors in that cause instability or stop Power amp Bias. Ones said to be "Recapped" using cheap rubbish Made In China capacitors that we'd not trust & using severely wrong values & voltages. Mains plugs miswired with 13A fuses or the Fuse removed & soldered over as an early 'Cash Converters' buy by us found. Beyond the quality of the Amplifier you are buying, quite often you end up with an item substantially less than you expected. Of course you can get bargains in lovely condition that don't really need anything more than Servicing, if that is rare. The Sansui AU-G90X we bought from a EU country, it didn't work on first trying it. At the time ebay didn't do the Returns like they did & try to get anything from the dodgy seller was impossible. If you bought that, you'd have got a 'dead' amp as it wouldn't click the relay on. The 'fault' was one that was likely intermittent but shook up by the Courier this stopped it working. To get that repaired by you lumbered with an expensive 'dead' amp might have cost you at least £200-£300 to get it working as it had other aging issues too. It's like the world of Buying Used Cars, you can often end up with a dud. One car we got from a "reputable" trader had the battery compartment badly rusted out from battery leakage if sneakily hidden plus the alloy wheels they just put regular nuts on if later said we should get some proper alloy ones that have the washer parts on. Water always leaked in if that could never be found. We scrapped it in the end once the heater fan failed as not worth putting more ££ into for the next MOT. You only learn what can be bad in any used gear by getting stung by shysters. Unawareness of the item must make people overpay millions.

Trio-Kenwood Supreme 1: Is It Really Worth €9999?
Quick Answer: No, Hell No. But what is it? It's an early one first seen in the 1968/69 Hifi yearbook, "Supreme I 33w bass - 23w midrange - 15w treble crazy multiamp system ignoring ideas of phase-shift £280" as on our List Of Amplifiers page. What it is shows here it's a Tri-Amping idea of 1968. It's not a good idea to Multiamp if Hifi Mags used to hype this... to get you to buy more amps. The Power Amps in the Amplifier are 3 separate ones with Bandwidth limiting to suit Bass, Treble & Midrange. On amps with Output Meters, such as the Yamaha 1977 ranges, the meters show that Bass can jump the meters very high but Treble can actually hit higher Peaks, so to put Treble power as less than half the Bass wattage is wrong for a start. The ideas of Phase Shift with 3 amplifiers driving 3 drivers in a 3-way speaker are again ignored, the timing of going through different circuitry can create Phase Shift & minute Timing errors giving a blurred sound. We've actually blogged on this before in Feb 2017 here looking further into the amp. We know & like the early Trio-Kenwood amps, the KA-6000 & TK-140X Version 2 are their best ones once upgraded. But as original they are quite a way back from what they can be upgraded to. The Supreme 1 is a rare item of limited use. One we linked to before made £400 in 2017 which is probably it's value as a Collector Piece if not one you'd really use on realising it's not very good. The €10k price is a seller severely taking the mick & trying to hype something in that sinister cynical way. There's a lot of it out there as just blogged above.

Beware Vintage Amplifier Circuit Diagrams Have Errors.
You'd think you could trust Circuit diagrams aka Schematics, but there are occasionally Errors as in Misprints that can trip you up. There are also updated versions of boards with similar numbers but alterations to navigate through. Misnumbered components we've seen most, why are there two lots of R702 sort of thing, marked on boards or diagrams, which one is the real R702? what is the wrongly numbered one then? Capacitor +/- connectors on one Luxman amp was wrong on the Circuit, Marked Wrong on the PCB if the original capacitor was fitted the other way round making it correct if not corresponding to any data. On one of the Yamaha amps the power supply PCB is marked +/- wrongly on one capacitor if the Manual is correct. Another Yamaha circuit completely misses one Power Supply line to join 2 sections on the Diagram. To blog this now on seeing the Marantz 4070 amp has errors. The H809-810 transistors are PNP if it's marked a NPN code. H711-714 are NPN-PNP pairs if all 4 are marked as NPN ones. Be sure there will be more errors out there, so the rule is understand circuits & question what doesn't seem right. How can a beginner make sense of these big errors that will cause problems? How would anyone fault find them from misprinted data?

1970 Pioneer SA-900 Amplifier.
Smart looking 50w Pioneer amp, aiming for the Trio-Kenwood KA-6000 market with an amplifier version of the SX-1500TD amplifier, if 50w compared to 45w for the receiver. Two on ebay currently, one got bids to the same price as the Buy-Now one, shows they're not aware of the other one. But it is 48 years old & needs more than a Service to be it's best, if usually capacitors in Pioneer amps last better than some brands. SA-900 the first better quality Pioneer Amp in the SA-500 13w £54, SA-700 34w £91 range in the 1970 HFYB & the SA-900, misrated at 60w if 50w+50w both channels in the manual, for £133 belatedly in the 1972 HFYB. Photos online show it's much like the SX-1500TD if the Power Amp board is better without the several problems the Receiver version has. Still a very small power amp board half hidden. SA-900 adds MC Phono as does the KA-6000 if usually too hissy on the transistors even from tests at the time. No wood cases on either look a bit plain with just black metal, only with small side wood pieces on the fascia. It'll sound nice as do the Receivers if Pioneer at this time don't upgrade as good as Sony or Trio-Kenwood. We'd like to try one but we know what it'll be like so to rebuild & recap it'll still only be a certain price with no wood case, so ebay prices don't leave enough in it for us which is often the problem. The buyer of these will get a nice amp, for the age it'll sound a bit soft & lacking in life as other early Pioneer do as original. Most early amps sound soft as original but upgrade to be a lot better. A worthy amp though, a good one to get to then get upgraded & it led to the bigger Pioneer SA-1000 of the next generation by 1972. The only minus with early Pioneer until 1972-73 are those awful speaker plugs that are only for thin bell wire, use anything heavier & they fall out. We've yet to devise a better speaker connecting way as our 1968 Pioneer SX-1000TDF isn't working yet, but it'll be worked out then.

McIntosh MC275 Valve Amplifier On "How It's Made".
Series 23, Episode 9 has this 75w Power Amp being made. The show can often be as mindnumbing as it's overwhelming in how fast they chuck info at you, if there are often interesting sections amid the same-old predictable ones. "How Is It Made?"... Much Like You'd Expect. The UK Voiceover guy Tony Hirst a Coronation Street actor with his cheery bland puns gets very saccharine sometimes & the generic Musak backing can be annoying in it's blandness. The MC275 shown here is the modern version based on the 1961-73 original, if the Mk VI is the current one with modern connectors. They show the top case being cut out & bent. The Transformer making is interesting, the plastic bobbin part is wound with wire & then the thin metal "E" shaped laminations are put in from both sides to create that metal outer part. Then the transformer is put in a case & sealed with pitch much like ones made many decades ago, if for Audio the idea probably started Post WWII. The circuitry standard is as you'd expect these days, on a PCB which for high power valves is less good than Hard Wiring, as long track instead of short if often untidy old-style construction is far better for reliability. The Valve heat on PCB joints is not as reliable. The Main Capacitors are 4 fairly small ones for the size, possibly 330µf which seems low spec to us. All very easy to manufacture compared to the better quality of earlier construction. Be sure the 'VI' version has more adjustables & ICs to monitor things, if manuals on HFE appear for 1980s ones at latest, McIntosh aren't giving their designs away as it typical of modern Valve amps. Looking at the underside of the PCB, there are 3x ICs for control & likely bias settings, autobias perhaps plus other modern type plug-in cables & a small transformer which may be a Choke or a secondary TX for other uses, bit vague with no circuits. They use the typical red Wima & yellow Vishay type coupling capacitors if these appear small meaning still using low values as per the early designs, instead of realising how much further these old designs can be bettered, if they don't want you having that. It looks a compromise in design & space too limited to upgrade to 'our standards'. It uses the big KT 88s x 4 plus a line of ECC83 type valves if with a green LED underneath? A closer view of the "Rev E" board shows loads of surface mount resistors, transistors & as 5 pins some sort of IC. This is a valve amp with 'lots of modern crap' sadly. Because of the PCB, the transformer leads are pushed onto the PCB pins. It actually looks "unrepairable" beyond valves, bigger resistors & film or electrolytic capacitors, if the 'control' parts fail you're stuffed. 7x smaller valves are 12AT7 & 12AX7 are ECC81 & ECC83. The severely naff Green LED under the smaller valves to show they are working, but not a good look. Today's user wants these things though, we think they are cheesy on what's supposed to be a Top Quality product. We're Not Impressed with the current McIntosh MC275 as you can see, unlikely the sound is as good as the early ones for the dumbing down will be in the circuits to get the "CE" label.

1966 Bang & Olufsen Beomaster 1000 Tuner-Amplifier.
This is the first of the B&O Transistorised Receivers, previously the B&O 608 was a valve-transistor hybrid. We've had quite a lot of the 1969-1977 Beomaster 3000, 3000-2, 4000 & 4400 & we are tired of them as construction is poor, components are poor & sound really is not much better than average as well as these are not worth upgrading like many Japan-USA amps are. To bypass ones at a good price that we should buy at tells we don't want B&O gear & all that again. £82.19s buys you a 15w output amp, no clue of RMS, Peak or Ohms, if later the tests show 13w into 8 ohms. As with B&O the looks please, the performance is considered good, but you can't help but notice their harsh closing comment is "... had not the electronics be rather better, we would have returned the Beomaster to it's importers - unreviewed". Scatching comments done politely hit harder than any negative terms, but what don't they like? The FM tuner is a good one, it tests fine on Power Tests if Square Waves "were rather poor" meaning low spec & feeble design, just as their later gear suffers. Phono doesn't match RIAA with response steadily rising from 400Hz to a +6dB peak at over 10kHz if a dip below 100Hz. But the construction gets this comment "From the handling and mechanics angle, the Beomaster 1000 is among the worst we have had in our laboratory for review". Ouch to that, EU amplifiers we tend to avoid as this is found true when the Japan-USA gear is so much better made. But... to tell the review is by A.W. Wayne of 'Shirley Laboratories Ltd.' who made their own amplifiers, a UK company that didn't keep up so failed as a comment on our 'List Of Amplifiers' page for 1970 says... "For Shirley to still offer the 1960 looking Jupiter in 1970 will have looked so out of place, it's a build in a box type amp, but only £23 for a 12w amp." to fairly wonder on impartiality as the same person's reviews on amps we know are good are often of a similar 'jealous' tone. The facts here are they suspect damage in shipment as the Buttons don't stay down & the tuning pointer has issues. B&O were popular, they sounded good for the money & looks were ahead of many & for the fact B&O are still going with their "Lifestyle" products that may not please Hi-Fi users or us as Techs to upgrade them, they please many & you get the idea the review is unfair for blaming for damage as the row of buttons if knocked out of true, as with the Beomaster 3000, need adjusting back on screw fittings to work right again. Our verdict, Amp is a good one for 1966, reviewer with a slightly damaged one is using the review to again unfairly put down non-UK manufacturers.

The Aged Sound Of The 1977-1978 Monster Receivers.
We first heard the huge Pioneer SX-1980 with a Reggae guy in about 2002 who used it with mid 1970s Tannoys. The Tannoys sound impressed so we got the Tannoy Monitor Gold 15" Lancasters & the guy swapped amps to show what a McIntosh 2505 power amp sounded like that we bought plus whatever else more modern he used as a preamp. The SX-1980 sat on the floor like an abandoned coffin with huge 560 x 211 x 497mm size with 35kg weight. The Sound of it we were not impressed, it was heavy, slow & dull sounding with little character or detail to the sound unlike the other amps tried. The SX-1980 power supply is very poor for the 270w power output via the triple-paralleled outputs. But several of the mid 1970s receivers have similar overheating such as the Yamaha CR-2020 that we've devised a cool running upgrade to. We've not really had the chance to try any similar "Monster Receiver" until the 1979 Sansui G-8700DB that we found a bit disappointing as the cost cutting from the 1977 ranges to 1979 was obvious. The Biggest Monster Receiver is the 1978 Sansui G-33000 with 300w, 45kg & 636 x 227 x 553mm which is beyond insane really as is the Power amp with 5 differential pairs per channel & quadruple paralleled outputs. So to try the huge 1977 Marantz 2385 receiver, 185w with triple paralleled outputs & 26kg, what does it sound like to us as All-Original & Unserviced after all the amps we've upgraded. Interestingly the same sort of sound as the SX-1980, rich weighty sound, treble lacking with slight grain, deep bass lacking & a lack of depth & not much Stereo width. It sounds slow, tubby & after a while the rather flat soundstage got a bit tiring, if we can hear it would service, recap & upgrade well. This is playing with Tone set to Off, with Tone switched On the quality noticeably lessens, as the Tone is a poor design & led to the false marketing idea that 'Source Direct' was better when the Tone is made with sodding ICs. The thing is these huge amps are 40 years old, one on HFE with the Marantz 2600 proudly tells "it's in repair every 2 years" showing it's aged & their lazy tech just repairs it rather than suggesting a rebuild. These Huge Monster Receivers really are living on borrowed time for the age they are. "A Rich Warm Vintage Sound" Sales Hype as seen often actually is a tired out unserviced amp to us, detail is lacking, it runs a bit warm as not biased since new. The thing is with amps so huge is they need a correspondingly huge amount of work, for us to redo the Marantz 2385 would tell how many hours are needed to clean, service, recap, upgrade plus working out all the circuits & design. The cost to do that to our standards would likely be about what one would cost to buy as raw, are there buyers out there for one once rebuilt?

Turntables: Technics SL-1500 vs Technics SL-120 + SME.
Currently the SL-1500 sells as used for more than the SL-120 when it has no arm included. Both the 1975-76 versions. It's just because we've said the SL-1500 is a great turntable in comparison to the Garrard 301 & SME IV. But to try the Technics SL-120 the armless version of the SL-1200. The SL-1200 Mk I was first out in 1972, the SL-120 & SL-1200 Mk I are more Domestic turntables, if since the SL-1200 Mk II it's become a DJ's favourite that's at Mk VI & spawned the similar SL-1210. The Turntable used for early Hip-Hop scratching as high torque compared to feeble belt drives. Direct comparing of SL-120/SME & SL-1500 using the same velvet mat, the same Goldring G-850 conical stylus, with the Straight wire 'Blue' Cables on the SL-1500 & the original SME cable on the SME 3009 II Improved Version arm. We add the Ferrites on the Phono lead as it does make a very noticeable difference to perfecting the Focus as blogged before. We'll compare the decks more later, but first the sound. The SL-1500 with our several upgrades playing a 1967 UK Psych 45 by 'July', it's a loud & dynamic recording, plays "very nicely" with good detail & musical pleasure to the sound. We've played the G-850/SL-1500 combo for a while now & it's pleasing enough to play 4 hours vinyl sessions on Headphones until the Headphones get tiring physically on the ears. The next 45 we've chosen is a 'Stan Kenton' Mambo-Jazz vocal 45 from 1955, very cleanly recorded with strong dynamics & a female vocal. Again it just sounds right. Some of the louder parts are not as focussed as the 301-SME can do on similar tracks which shows there is still better, if in reality the percentage improvement is likely no more than 10%-15% "better" in ultimate detail retrieval. Not that Transistor or IC Phono stages can do the detail our Custom Valve phono does. So to try the SL-120/SME next for this review, if we'd played it earlier with a few 45s to see it was set up right. There is an almost surreal difference as the SL-120/SME brings just a little more focus on the 1955 track, just a step closer to the performance. The 1967 track similarly has better focus. A sort of audible difference like using a modern aluminium step ladder that does the job but you're a little unsure of it, compared to a vintage c.1970 steel ladder that you feel at ease balancing on one foot on the top platform. Playing a recording of the 1967 track via both players for quick comparison the difference on a distorted busy track is very subtle. The 1955 track cut cleaner shows the difference a little more clearer. The idea is the SL-1500 as upgraded is 90% of the SL-120/SME. For the price of a serviced SL-1500 compared to a serviced SL-120/SME, the SL-1500 at under half the price represents awesome value at the price. Would you actually hear the 10% difference with a 'normal' Phono stage? SL-120 vs SL-1500 build quality. Both are the same size & height, the SME versions have that odd 'bubble' on the lid to accomodate arm height of certain cartridges if ours barely extends into that space & other cartridges of lower body height wouldn't really need that extra space. The original feet on the SL-1500 aren't very good as either the spring or rubber cup version, we fitted solid rubber feet, sorbothane pad & felt pad which is a good improvement. The SL-120/SL-1200 feet are more substantial, plastic pillar feet that attach to the metal plinth with very slight springing & felt pads. These are much better & no need to changer those. The weight of SL-1500 as stock is 7.8kg & SL-1200 is 10kg with most of the extra weight in the plinth & bigger motor. The SL-1500 platter is 1.68kg if it has a part of the motor fixed to it & SL-1200/120 is 1.7kg. Hinges differ, some with screws others with a fixed bar piece if the modern Technics lid springs are easier to use. Mechanically the heavier plinth is the main difference if the SL-1200 motor is more substantial & is quicker by a tiny amount in settling on speed. Therefore it would be fair to assume the SME arm probably counts for the tightening of focus. Again the SL-1500 for it's price with the Technics arm, if serviced & adjusted right is still great value.

SME 3009 Turntable Arm: Reviews, Views & Setting Up.
We first got one of these with the Garrard 301 grey grease bearing in about 1997. The 301 was a NOS first used about 1966-68 by the ugly cabinet it came in, a home-made effort as was the way in thise days & with the Dynaco ST-120 & PAT-4 preamp plus the matching tuner, the Dynaco was first out in 1966 so not used until then. The SME 3009 in 1966 would have been the 3009 S2 non fixed counterweight with detachable headshell. The first ones were out in as early as 1958 & the S2 detachable or fixed headshell was introduced 1963, by info found online if reading through Hi-Fi News we could narrow the dates down further perhaps. We weren't keen on the 3009 S2 for the rattly knife bearing, rubbery plinth fixing washers & most of all the lousy "soup strainer" headshell with over 100 holes drilled in the top plus 8 graduated ones on each side. This compared to the Garrard TPA arm we found the SME with that 'flexible' headshell was blurring the sound. The modern Technics headshell you can still buy today improved it, but we found the 3009 S2 clunky in use so bought the SME IV instead & in the end sold it as it's a bit limited in use, is it really so great? Getting the Technics SL-120 with the SME 3009 II Improved, to at least try the thing out again, how is the 'Improved' version? Far less clunky, the arm still moves on the knife bearings but better held in for the changes. The SME underside oval case is very tricky to put back together still & it has to come off to service, if not an item to fully take to pieces as it'll have ball bearings that will cause difficulty most likely, or maybe they are a ball race like VHS heads used? Not going to find out as it works fine with no sticking, if one someone oiled may need work, don't oil it though. Setting up the Arm Geometry is easy enough, you need a Cartridge Alignment Protractor, the perspex mirrored one the best. Set it up to be square on the patterns which means it gets pushed back from centre usually. The right angled bar with a weight in the day we had that, er what does that do? But the manual which we have as well as it being online says to adjust the amount the angled bar sticks out according to your cartridge weight, as in the physical weight of the piece. Our Goldring G-850 'budget' one says it weighs 7g on the info sheet, so to set the arm to the "7g" position. The further right the angled bar sits, each line means 2g, so for 7g to show 3 lines 7 midway of the 4th. Then zero the counterweight by having the arm 'in equilibrium' as they say, removing the Bias weight first, if balancing straight as not too light or too heavy. All seems good, but not quite. The weight on the bar is adjustable, you poke a screwdriver to depress the sprung ball inside the small round weight to get it on the bar & each line adds 0.25g weight, with "0" with the weight pushed back. The problem is that only goes to 1.5g so you have to add an extra 1g tracking weight by adjusting the counterweight & using 1g on the bar to track at 2g, so you will really need a SPG to perfect it, an estimate will likely have you tracking too heavy. We've seen these with extra weights on that bar, if that will still not be correct & probably too heavy. Similarly the DJ headshells by Technics have a hole that takes 2g or 4g weights to track DJ cartridges like Stanton make for 'Rough Use'. The Bias weight has notches to allow variations, 0.25 to 1.5. Usually Bias number matches playing weight number if tracking at 2g there is no option. Bias isn't so critical so you'll just have to set it to 1.5 on the end notch. After just a few records played, bias is best set at Half the Tracking else it wants to slide off the run-in groove, so we set it at "0.75" & it physically behaves. Where to fix the Bias weight post, we fit it with 90° angle in relation to the outside edge of a 45rpm 7" disc to have the travel of it midway of an LP. The last adjust is to use the mirror of the protractor to see the cartridge tilt isn't off true & make sure the bias weight is in the pulley groove. Also the Bias weight post may be bent down too far, see the angle in the manual, the pulley at the same height as the bias thread hook post. Quite a bit to set up, but as we found with the SME IV, it stays put unless you change cartridges. But on testing further, the SME needs more than just belief in their method... see the blog below. Is The SME 3009 II Improved Easy To Play Records With? We didn't like the SME IV so much as travel as limited & it stopped us playing records so much beyond recording Vinyl to Digital is the truth of it. The Technics SL-1500 is nice & easy to use, good arm travel so you can use it without have having to worry about bumping stops. The SME 3009 S2 we didn't like as it was rattly on the bearings seeming unsure in use. But the "II Improved" certainly is improved, we're playing 45s like with the SL-1500 & realising that it's the SME. The arm clip on ours was "the wrong way round" as in you passed the arm up & over the clip to settle it with the opening on the right. Pics online suggest that's the SME way, if we don't like that so rotated it to be the way the SME IV arm does it, clips on the left of the clip post. The plastic clip automatically closes & locks the arm which can be avoided by not putting the arm fully in the clip to not forever be undoing the clip which is easy to do. Therefore no less restricted than the SL-1500 way which suits us.

Setting Up An SME Is Too Much Bother?
The Technics SL-1500 is much easier to set up, fit cartridge, use the alignment protractor the headshell fits in & then zero the weight to balance then dial in 2g. How accurate is it? Read on. The Technics SL-120 came with a circa 1978 Ortofon VMS 20 II with a stylus of unknown useage. Didn't like the thin scratchy sound of that... "The VMS 20 is probably one of Ortofon's most highly acclaimed cartridges, incorporating a nude, diamond elliptical stylus." says VinylEngine & other sites say it was 'high end' in it's day. Funny how we prefer the cheapo 1970 Goldring G-850 at a fifth of the price at the time. It's in the SME headshell & untouched in decades it might service up a bit better if the cartridge is a lower height upsetting the geometry & only 5g weight. Setting Up The Geometry & Getting The Weights Right is crucial as it makes quite a big difference for how the Diamond rides the Groove, fitting better you get better sound. We have a Garrard SPG3 pressure gauge, an early item that weighs up to 10g playing weight & needs a calibration with the 5g weight inside the compartment as it wasn't accurate, the SPG3 is crude, weighs up to 10g & for 2g weight how do we know it's accurate? To use the 5g weight to calibrate showed it was 0.25g off & balancing is all guessing with it. Digital Scale. So to charge up some batteries to use a digital jewellery scale that weighs in 0.01g divisions is far better & why we bought it years ago. Set level or sat on the mat higher up it weighs the same. What the SPG3 once calibrated said was 2g was severely out, it read 1.45g & was previously about 1.2g before calibrating. The SL-1500 zeroed & dialled in as 2g was far better, it read 2.11g. You have to work & have external scales to get the SME 3009 right. 28% error on SPG3 junk vs acceptable 5% tolerance by the fast setting of the SL-1500. Technics Arms are Designed for Fast Adjusting. DJ's don't usually use SME arms as too precise for these settings, the Technics arms in the SL-1210 Mk VI being much like the SL-1500 are adjustable with a different cartridge in a few minutes, the SME 3009 to do all the settings & weights as well as knowing the Cartridge body weight is at least a 30 min job, or 3 hours if you've not done one before. SME needs a small hex wrench, alignment protractor & digital scale. SL-1500 you can do on the machine with no extras beyond the "Technics Overhang Gauge" & get accurate results. The wikipedia page for the Technics SL-1200 is more about the Mk 2 to Mk 6 version with the Pitch-Speed control slider. Historic Turntable. Grandmaster Flash in the early 80s went on about ‘The Wheels Of Steel’ if actually the SL-1200 is all aluminium, but the Garrard 4HF 1959 turntable has a Steel Platter though & not good for magnetic cartridges, 4HF was used by Reggae ‘Sound Systems’ in the 1960s & possibly these 4HF were found first in finding old family gear. The SL-1200 & SL-1210 are given the credit for Reviving Vinyl for the DJ use with dodgy white label bootleg 'dance mixes' of the 1990s & of course the early 1980s DJs when Hip-Hop was still creative used these turntables for 'scratching' as the motor has good torque to not slow down like belt drive ones, if the idler wheel ones are even stronger torque.

Vintage Hi-Fi Needs More Makers Of Repro Parts. A Business Opportunity.
The Success & Popularity of a Genre depends on seeing how many make Repro Items of certain parts that are needed to keep Hifi alive. The Vintage Car scene as shown by the TV Shows like 'Wheeler Dealers' shows in the USA a lot of Custom Parts are buyable. Quality Varies but as the Car Scene gets so many TV shows there is a lot of interest. NOS parts plus skilfully made Repro parts are needed. In Hi-Fi we can see the advances in Hifi made over the last 7 years since we started our Hifi Pages. You see Wikipedia pages for some Hifi like the Technics SL-1200. The Service Manual Sites are probably the biggest help in getting interest in keeping Hifi alive if that goes into Tech Work. We see our Influence & there are other sites giving potted info on Hifi but none as concise as ours. Before 2011 the best-only Hifi Site was the "The Vintage Knob" one run by a EU person who stopped updating several years ago. They covered some of the early stuff but not much & at that time anything pre 1977 was generally ignored as not understood to be worthy. Hifi Forums are hard going as so much amateur input that is mostly waffling nonsense, bad ideas & opinion based on little experience. Those more professional who tried forums don't stay for long as the audience are beginners & for that a Forum is a good place to start as you'll get an idea of what people are interested in, if it's really too random, so we started putting pages here to fill in these gaps in knowledge & via Google we got found. Back to Repro Parts... The USA scene for Repro McIntosh wood cases we knew of with buying some McIntosh amps in 2002. These Repro cases are worth having to cover the McIntosh gear that is with metal casing not really for seeing as these were built into cabinets with the Panloc fixings. Free Standing McIntosh needs the cabinets. But have originals with the nice slanted feet or repros less well made & easy to prefer the originals if now 16 years later these will be rare & expensive. We saw a basic 2 side boards & top plank with large holes cut for the huge Marantz 2385-2500-2600 ones sell for nearly $1000, you see why there are various repros made as there is a demand. For a Fisher X-100-B amp we're rebuilding for a customer, to just think the caps are bad for the L+R imbalance, but then once recapped to realise the Volume Control is bad despite the amp's high grade. To never think some mean person would have swapped their worn one in a bigger model for the nice one in that amp, but looking closer revealed it had been unsoldered so swapped. Karma helps the customer who finds a Repro Volume Control as the seller had similar issues so had to get a batch made of a certain minimum order amount to get what they need. Custom made by a company if unmarked as to by who, these are not cheap, £100 delivered if at least no Import Duty somehow. This is a well made part with a better turn-on click as the Volume has Loudness & Power Switch too, the old one needed heavier handling to turn on so it wore it more. Once the batch are sold there will only be more if another gets them made or the seller sees the demand gives a profit to make more. Money talks, demand talks, if demand is still growing as people see these Vintage Amps are worth keeping alive. For all the amps we've had, it's rare to get a bad Volume control if it can happen & to replace that means searching for amp parts or getting another to take that part from, hoping it is better condition. Most of Amplifiers can be renewed as the big sellers like Farnell & RS still sell capacitors, resistors, transistors etc that are of the type used. But when it comes to cabinets, fascias, lids, volume controls, switches, amp feet, tuner glasses & 240v transformers for 110v, there is a lacking. We hope in years to come with advancing technology more repro parts will get made. Here's the Opportunity for someone to make a lot of money by manufacting high quality Custom Repro parts. The difficulty is knowng which ones will be wanted beyond the McIntosh, Marantz, Pioneer etc biggest models. Will anyone make a missing lever switch for the Trio-Kenwood KA-6004 or 8004 as the originals break off? Actually we made some from pipes & rods, look at our KA-6004 gallery page, we made those. It just takes someone creative & visionary to further Hifi by Manufacturing Wanted Parts. From Our Experience we find that Volume Controls can occasionally need replacing, we'd try to repair first but worn out track means you need a new part & possibly can swap bits around. Recent Amps with those Miniature Volume Controls & Balance like on the 2007 Marantz PM 6002 are very prone to failure & unfindable or very expensive. We serviced an early CD player, never again as they are just too much aggro & the ownder bizarrely used it often by the Headphone output amplified by an IC. The tiny Volume Pot was worn out if somehow via his Japanese contacts managed to get a replacement one as these tiny style ones are still used. Power Switches can be a pain too, these illogically have silver plated contacts which tarnish to black & lose contact after sparking for years. If you have an amp that makes loud cracking noises or the lights flicker with no sound, or flicker for about 30 seconds to settle, then the Power Switch could be bad, if it could be many other reasons too. To replace a power switch is as tricky as a volume as you'll never find parts if we keep amp bits from failed ones so have a chance to find one. As with any parts that may need replacing, to try to service & repair the original is always a far better idea.

Why Do Some Early Amps Use Paralleled Output Transistors?
The 'Monster Receivers' & similar High Power Amps get a lot of their Wattage from using Paralleled Output Transistors. This starts with Double, ie the Push-Pull Left Channel uses 4 Output Transistors instead of Two. It grew to Three, four & possibly even more in sone 500w Modern amps. Double Output Transistors theoretically Doubles the Current, if looking at the HT of the 1970 Akai AA-8500 is a Capacitor Coupled amp with a 76v HT. The Trio-Kenwood KA-6000 is a CC design too with 86v which is rated 48w RMS both channels if the similar KR-6160 receiver is rated 55w & the previous TK 140X of either amp board is rated 53w. 76v HT equates to ±38v in a (Semi-) Complimentary design & a similar ±40v in the Sansui 3000A from 1967 rates 45w. The Akai AA-8500 is rated 65w RMS which on Single Output Transistors rated about 38w with 28v clean sine as we read on the last one of this amp we had, as on the 'Power Ratings' page. 28v on other amps can be done by some 35w-40w amps depending on current output of the design. Take 40w as a base, Doubled Outputs brings 65w, not quite Double the Current if it depends on the Transformer & Power Supply. 40w to 65w is a 62.5% increase in Power. But Why Do Early Amps Use Doubled Outputs is the question... The answer on early amps like the 1965 Sony TA-1120, 1967 Sony TA-1120A and 1965 Fisher 600-T is simply the Wattage Required wasn't available in the Transistors at the time. The Sony used NPN Silicon transistors rated 50w & the Fisher used Germaniums if the 35144 outputs are probably 50w too, if no info is findable. To look at the Sony, rated 50w into 8 ohms & 120w "Music Power" as the specs are known, the very first outputs as the Manual shows were 2SD45 rated 5A at 50w. There is no extra power beyond perhaps 10w for Peaks & "Music Power" so Sony doubled the outputs to get that 120w rating, giving the amp better headroom in use, insteasd of just flattening out. The 1967 TA-1120A uses these too if by the time the 1968 STR-6120 was out, also rated 50w it used 2SD88 which were 5A with 80w giving the extra headroom to not need Doubled Outputs. The TA-1120(A) puts out 29-30v clean sine which doesn't really show doubled current as the circuits are designed a certain way to not give higher wattage as 30v is typical for 50w in other standard design amps. Both the TA-1120(A) & STR-6120 work on 93v HT, so in effect to only get 50w from Doubled Outputs shows the TA-1120(A) is designed safe if the STR-6120 is a more open design & once upgraded we hear how good it sounds, if the 1965 TA-1120 we can hear is tamed in the design & for sake of keeping it original, we didn't upgrade, but in theory the TA-1120(A) could put out about 80w if "maximised" in design. The Trio-Kenwood KA-6000 inside has spaces to add more transistors to do similar to the Sony TA-1120 if by the time it was released, the 2SC898 transistor was available with 7A & 80w to not need to used Doubled Outputs, if Trio had designed the heatsink to use these but just used what they made. You hear of "forum types" putting in the 250w MJ- type transistors saying they upgraded the amp, no you didn't, the power will be no different. Which leads to this Old Chestnut...

The Age Old Question: Can I Make My Amplifier Higher Power?
It's One we asked starting into Hifi & "No You Can't, It Depends On The Amplifier Voltages". But that's strictly not true... the above shows The Wattage can be increased by Doubled Output Transistors. As the above shows, the Trio-Kenwood KA-6000 has spaces for Doubled Outputs to Increase the power by increasing Current, but not Voltage. to Bridge an amplifier increases the Voltage if not the Current if today there are Bridged-Paralleled circuits doing both. We Do Not Recommend You Do This... The KA-6000 is overspec as vintage amps usually are, so to make a 48w into a 80w amp is possible here. You need to understand how it's designed, look at the Sony TA-1120(A) or Akai AA-8500 designs to see how, but to be aware if you try this you may overload your Power Supply & get a wrecked amp. We're not telling how to do this more than this, but in Theory & in Practice, to make a 48w into 80w is possible. Problems you'll get can range from overheating on heatsinks, overheating the transformer from drawing too much current as well as the Power Supply & Fuses will need to be capable of the extra wattage.

So If 1965-67 Amps Needed Doubled Outputs, Why Does the 1970 Akai?
There's always one who has to ask difficult questions... By 1968 there were affordable Transistors capable of 80w & the Date Sheets show rare ones rated up to 200w if these wil have been very expensive. The 2SD 203 as originally designed is 6A with 50w, so the same problem as the Sony TA-1120(A) if by 1970 you'd think designs would have progressed, but the reality is the AA-8500 might have first been designed in 1968 as a Prestige Item, as it is, if only released 1969-70. Our one has 2SD218 with are 7A 60w. Akai here weren't pre-emting the "Monster receivers" with 2, 3 & 4 paralleled outputs, they just wanted to offer a higher power amp than just a typical 50w one. The Next Amp we see Parallel Outputs in that we are aware of is the 1975 Pioneer SA-9500 which is using a Fully Complimentary design as was the fashion by then & 2SB541 & 2SD388 outputs, ignoring the 'P' tag, means the 85w rated SA-9500 on are 12A 80w/8A 80w meaning here they are using Transistors only rated at about the rated power as 80w-85w is the rating on the SA-9500 depending on frequency. so here, by necessity or by using cheaper transistors as by 1975 there were higher power NPN if getting NPN-PNP pairs, as the 1975 Technics SU-8080 has too, is less easy so they must double them up. But by the 1977 "Monster Receiver" era receivers of 180w-300w made by Marantz, Pioneer, Sansui etc were usng the Parallel Output transistors in threes or fours to get these very high powers. The Highest Power 340w Marantz 2600 sadly has no manuals findable yet as so few sold, if the 300w Marantz 2500 does & shows quadruple parallel output transistors, a total of 16 output transistors instead of the typical 4 & works on ±87.3v for it's 300w if the 185w rated Marantz 2385 works on ±75v with triple parallel outputs, the 2385 is either underrated-tamed or the 2500 is pushed to the limits. The Monster receiver era is all very silly as blogged just above, if it shows progress that can be made & led to even higher outputs using different design types. By 1980 the Hifi scene dropped all these huge amps that likely lost the companies a fortune, as who needs them beyond those wanting to try extreme amp design & power.

The Early Amps By Akai: Part One
For the amount of Amps we've had, after a while you can find which is their "Best Ever". To be upfront about Akai, they hide the quality of their amps on the ones mentioned, only by upgrading to they sing nicely. as original they are nothing special, For this section, we look at Akai, a Japanese company that started off very 'High End' for it's time if economic pressures of the early 1970s had to make them change their standards, ie cost-cut to keep going. The 1972 Akai AA-5800 45w amplifier is a particularly good one that was quite ordinary as Original but we know the designs & got a great sound out of it, but decided for the Midprice Quality of the case that we'd stay with the 1969 Trio-Kenwood KA-6000 instead. The AA-5800 has a great design if tamed down & limited to sound no better thasn they want you having, if before we have found great designs that got tamed to hide. The sort of "Design As Good As You Can Design" if then reduce it to not have it too good. Only our unique way of Design-Upgrading brings this out. The 1966 Akai AA-7000, the large sized slim profile one was a fascinating amp, we got two of them showing we liked it, if eventually did sell these as they are too big to have around. It upgraded well if as too aged we never heard it as original. They also run quite hot for the Transformer Coupled early design if this does sound great. So in 2015 we saw the 1970 Akai AA-8500, didn't know it but saw it was worth a try. Condition wasn't great & needed a lot done to get it to our standards, if it's one we didn't upgrade too much, an Unfinished Idea really & the AA-5800 reminded us of it. Fate has things come your way & to get another AA-8500. The design of this is pleasing, the fascia is very "Space Age" & probably the most futuristic classy design you'll see & no-one else copied this. It has a drum to show the Tuning, so the Tuner window is square with 2 meters to the left. Large Rotary Controls for Tuning & Volume, Big Sliders for Balance & Tone, a Lever for Tape Monitor & 7 large push buttons for Power & other Tuner, Loudness & Filter uses. On first geting it, we assumed it was quite a small amp, but in fact it's fascia is large 461mm x 147mm & the controls are all bigger than you'd expect. This as blogged above is one of the Rare Paralleled Double Output Transistor amps, initially done to give higher power for Transistor Spec if actually the Higher Current drives speakers better as per the 180w+ Monster Receivers. The Akai AA-8500 is their best early receiver therefore, but read on for how it sounds as Original. But it still is 1970 which is 48 years ago & the transistors usually hiss as the Hitachi 2SC458 that was a standard transistor hasn't aged well. Here the AA-8500 has Volume before the Tone stage so the hiss will always be heard, we'll just replace the lot. For 1970 the main capacitors are a high value, 3x 1000µf paralleled to give 3000µf, if the Sony TA-1120 in 1965 used one large 4000µf one as did the Trio-Kenwood KA-6000. The AA-8500 appears to one of the earliest Relay amps, if again the 1965 Sony TA-1120 was the first one, if the AA-8500 uses it for the 'Audio Mute' mode to silence, rather than protection, the "EPC" stage is the Protection, if with Capacitor Coupled Outputs it just Mutes the Early Power Amp Stage as there can be no DC voltage onto the speakers, assuming the Speaker Capacitors are good. It's not perfect though, the Filter stage is fussy if the AA-5800 one could be made good & the Tone stage is a bit tamed. Power Amp board is a pleasing design, pre Differentials & may possibly better the UA1384 Trio-Kenwood board, as in TK-140X Mk II & KR-6160 if that doesn't have Bias Adjust, only Midpoint Adjust. What becomes of the AA-8500 is to be found, we just see it's the Best Akai & how it upgrades with some subtle redesign is to be found out. Keeps hi-Fi interesting, if this is a Revisited Amp. See Part 2 In August Blog covering the AA-8500 further as we Upgrade Ours, the Sound actually isn't very impressive as Original.

Be Sure To Set The Right AC Mains Voltage.
Some amps are Multivoltage with easy ways to set the voltage, the Plug-In blocks, or Fuse-Middle round ones with a plug to adjust. No excise not to see that. The Quadraphonic Marantz 4070 & others are unwisely awkward to know what the voltage & the reason for this blog is telling the Marantz 4070 was bizarrely set to 200v which according to Mains Voltage sites is in some of Japan or Bermuda. Wherever it came from, it never worked again as the Preamp Regulator won't be the right voltage. What the Wrong Voltage setting using 240v does is trash transistors, wear out Mains Switches & generally cause a lot of bother meaning the Marantz 4070 as blogged above really was "Too Far Gone" if at last after replacing 2 transistors for the second time after wondering about the voltage settings if there is no info ecept in a we finally get it playing stereo. If it wasn't a Marantz we'd not have bothered with it if you'll not find another 4070 fully recapped as 4 channel amp in a modest sized case is too much & similar to why no-one fixes the 5.1 type Amps as it's too complicated, if today there are all ICs. Marantz of this 1973 era are a top brand & the work was worth it. Only the Marantz 2230 receiver shows these screw boards to set it right, if following the screw wires, not wire colours. So to get a 220v amp as some Luxman are only one voltage setting & use 240v, you may get away with it as 220-240v is 9% out, just within typical tolerance. But 200-240v is 20% out & this will more or less trash the amp.

1970s Quadraphonic Amplifiers Are Actually Worth Buying.
Earlier opinion on 4 Channel 1970s Amplifiers based on a Marantz 4230 we had in the early 1990s was that they sounded slow & blurry. But we're not happy leaving that Stone Unturned so decided to get the 4ch Marantz 4070 & despite the amount of work it needed, success was the only option, see blogs above. So after running it in for a while as technically it's not been used in decades beyond our new parts added & then we set the Bias & DC Offset, following our Bias setting ideas. The 4070 had locking paint & dirt marks to show the original settings so we left them set as that for the First Try of the Sound. The Power Amp is on the original transistors & not done the ceramics yet, the initial 4ch setting was a bit blurry on treble which was a bit imprecise but a good sound, switching to Bridged Mode the sound doubled the imperfections & blurred further. This is the Typical Quadraphonic Amp sound as Unserviced & still on original capacitors, the 2ch mode will make the sound soft & blurry as not adjusted right. In fact all Unserviced All Original Amps will age & go off spec, if few ever bother to get them Serviced, not realising that the sound isn't what it could be. Now Adjusted right, the 2ch or 4ch mode sound the same & the amp itself sounds a lot better than we expected if there's more we can do still. The thing with Quadraphonic Amps is 4ch Sound is pretty useless if you'll use it for 2ch by Bridging, the Marantz ones have a switch at the back, if the 2ch mode Bridged will sound twice as bad as the 4ch mode with half the power. Naturally to redo a 4ch amp is Double a Stereo one & even if Decoder & Matrix Circuitry doesn't get used, it's still part of the Preamp & needs redoing too. The Marantz 4070 was worth us getting to research, but the reality is for all the problems & rebuilding it needed, a customer would end up with an Upgrade bill higher than they'd want to pay, not realising it's Double the work. Look at the Circuit Diagrams, the complex circuit needs understanding to fault find from & this 4070 amp was one of the most difficult we've had to get working from being unuseable. The 1984 Sansui AU-G90X amp is an X-Balanced Design which is actually a Bridged design we discovered from learning the 4070 design. The 90X was a complex one to adjust as so many things to adjust as it's technically a 4ch amp Bridged to 2ch. When the Bias wasn't right it lost Bass & Treble to a lesser extent. Bridging can work but it requires adjustments to be accurate.

August 2018 Blog

Shuguang EL34-B Valve Review. Do They Better The JJ Brand Ones?
We got some of these for the Luxman LX33 as the JJ EL34 are still cracking. Nothing solves it. Bias Voltage & Current is set right. The crackling comes & goes but it clearly is picking up airborne interference for a design weakness which we've tried everything to solve. So to try a different Valve brand. Heard of Shuguang which are supposedly rated in Guitar Amps, they get further selected by other brands & rebranded at higher prices. They arrive looking like bigger bottle JJs with a 'Svetlana Winged C' look for the base colour & having the Wings inside the case, if otherwise unrelated. We plug them in, very tight fit & turn on. Such tight fitting means the pin wires get pushed about & time wasted wondering why the new valves manage to Bias so bad, blame them for not being run in properly & then the JJs bias up as badly, as a wire... came... loose. A wire to the Output Transformer meant V4 had no Anode connection & the valve is very noisy after that so it damages it. The Shuguangs sound extended like the JJs do, crisp treble & deep bass. Oh, and none of that Infernal Crackle the JJs torture you with. To set bias, play it for 20 mins & then to set AC Bias as detailed below. After doing all the settings after 1 hour+ use the Shuguangs better the JJs for treble detail & none of the rustling noise. we've avoided Made In China valves since the late 1990s with the 'Golden Dragon' ones & stuck to the Russian ones which sadly have lost Svetlana now. The Chinese valve is still under test in use & see how long it lasts, the LX33 amp was hard on the JJs probably the ultrasonic rustling wore them out fast even applying all the tricks. As for Musical Pleasure, the Shuguangs do sound better than the JJs, the better treble shows more finesse in the sound, the JJs last time playing .wav files from the Computer was found not as good as transistor amps, here the Shuguangs bring the 'transistor quality' to valves. After nearly a Month, the Shuguang's are behaving very nicely. Good find.

How Do We Bias Our EL34 Amps?
We put test points by the EL34s to adjust bias without having the amp on the edge as the original way had to be done, so easy enough. The Tube Technology 100w vave amps have Bias per Valve which is easier to set, but the LX33 way is OK. You have one Adjust Pot for the Master Bias on the Push-Pull pair & then another Balances them to be the same. Supposedly you buy Matched Quads of EL34s to not need to balance if these do age in use so balance may be midway true when new but can drift either way after use. Once that is done with the amp being on at least 20 minutes to get used to the settings & make sure it's correct, the Balanced way is less precise than the individual pot way. Then to do the AC bias which makes sure the driver valves are putting out the same level of Sinewave, the AC bias is on the Splitter circuit. To adjust that to use a 1kHz test tone & an oscilloscope on the output from the Splitter if before the Grid Stopper resistor. To use a Multimeter to read the DC voltage will only bias the driver stage which may differ from using the 'scope or Cathode Bias. Precise AC bias adjusting of the splitter gives very crisp treble to the point Treble needs -1 to a previous sound. This will likely upset the EL34 Bias values to a degree so you just need to recheck they are right & they will vary to a degree but not much. The Bias Balancing Way isn't perfect though, try to test it the next day & it'll be a little off, but it's within tolerance so no need to rebias daily. Modern amps with Autobias probably Autobias it every second & the circuit will limit the sound someway, so we're not keen on Autobias like the Prima Luna amp had, if the IC fails you have no amp.

How Rare Is Your Amplifier? How Many Were Made?
As with any good product, as in Records, many great 45s & LPs sold nothing as badly promoted or ahead of their time. It takes Decades to realise the Best Of The Past in any Genre & can only be done with hindsight by comparing it with the contemporaries. As an example, the 1966 Sansui 3000 receiver was out by Dec 1966, the 3000A version came a few months later, but why the 'A' version? The 3000 was a great amp but buyers wanted Two Speaker Pairs now as other amps like Fisher had on the 1965-66 Fisher 440-T & Fisher 600-T, Sansui missed recognising the want for this so swiftly updated the 3000 to the 3000A. The 3000 version is a rare find as few were made & few sold, the first small batch will have been made & distributed in the USA & selected EU Countries. It is possible that 100-300 were made, if you never see it. But the 3000A was a popular amp at the Army & Navy stores & sold well for there to be a steady amount on USA ebay, maybe 5000+ sold. It's a great amp & hearing an original one it was as good as anything Fisher made, if likely sold cheaper to get the sales. The 3000A is found with '1969' date codes & it got a 1971 mods supplement as it aged. It sold well & was still around when the rarer 4000 came & went. A manufacturer in Hifi soon learnt the trouble of the Television Overproduction that is mentioned in 1966-67 Hifi News magazine, don't overproduce, test the market that could be fickle & get an updated version out fast if needs be as Sansui did. It leads the question, how many did a successful amp sell worldwide. This info you never see published & we've read the HFN mag 1956-80, yet you do get the idea a popular amp can sell 20,000 as is suggested by the Quad II if that was sold 1953-68. Low sales on Lowther amps that were made 1959 & still 'available' in 1971 are revealed by very low serial numbers. The Japanese makers can number amps to not be so easy to follow as they number amid all their ranges as well as using different numbers, possible the Yamaha CR-1000 could have had 5000 made. But then the 1965 Sony TA-1120 is numbered to 4000 on the manual if ours was just over 5000. Did they really make 5000 of them? Highly unlikely, the serial numbering must include Tape Machines. The SME 3009 arm is numbered to suggest "Series 1 1959-1963 10,000 built. Series 2 1963-1973 180,000 built. Series 2 Improved 1973-2003 260,484 built." says one on a forum, and based on Serial numbers it is possible them numbering all product in the same series. As with Records we know some Beatles 45s sold 1 Million+ & these are very common to find, if SME really made 450,000 arms there'd be a glut of them which there isn't. Onto the huge "Monster Amps" how many of the Marantz 2385 were made? Six are on ebay with some 110v only & some missing original parts, they aren't selling. The amp was £977 new in 1977 the equivalent of £6000-8000 today. Did Marantz make 1000 of these & just sit hoping for sales? No, Marantz know marketing & sales so these Prestige Items were made in small quantities to test the market after getting Hifi Mag reviews where Sales will have been generated plus with a Waiting List as is mentioned in the HFN especially in the late 1960s, they made enough for the demand. Marantz will likely have initially made 50-100 for the Reviewers & big Hifi Dealers around the Country, assuming they'd risk buying the amp in. In the early 1960s, one UK shop proudly said they had the only Tannoy GRF pair in the country, if at the time it was a tiny market in the UK. For the EU market as is revealed by how Rare 240v 1960s Fisher Amps are, they may have made around 50 for the biggest Hifi Dealers & then waited for the reaction & sales orders. An amp on order taking 4 weeks is being made for you, it's not being sourced from another distributor, we know that on ordering a silver SME IV, there were none on the network the shop said, so a wait for one. It's like Cars today, Black White or Silver are in stock, other colours are Special Order which is why the roads are so tediously Monochrome. Soon Marantz found sales likely sold perhaps 200-300 worldwide & they're not going to make more to set up the factory if there are only a tiny few orders so it's out of stock & the distributors shuffle them around to the last buyers. The web presence of these big amps is high for their extravagant size & power, if how many are out there? We can only guesstimate. How many got thrown out when they got damaged, people do & we read of one being found on a kerbside. We had a 1977 Yamaha CR-2020 the buyer bought in 1981 in Singapore with the sales bill in the box still for about 25% of the list price as really the end of line in a market that fell off late 1979 as the 1980 ranges reveal, see our List Of Amps-Receivers pages. Marantz 2385s that went unsold would be discounted too, as the Quadraphonic amps were discounted minus the decoders & likely shipped to a different market that would buy them as cheap. As with any Collectable or Vintage item, even looking at those Sites that list old Auction prices, the odds are the same one reappears. Then to see how easy it is to find one to buy. Some UK pressed records on major labels, there should be 300 demos made at least, we've not seen in 25-30 years despite knowing them, they don't turn up. Look for the Marantz 2385, they aren't selling as overpriced & could be listed still after a few years. a 41 year old amp isn't for daily use, so why buy it unless you find someone who dares to work on these, how many even vaguely like us. A SME 3009 S2 Modified arm isn't easy to find, plenty will be with owners naturally, if turnover of items if 'scarce to common' is quite regular. The notorious & best at high prices turn over. In Records, a record that is genuinely rare can make a typical price each time, but the bubble bursts when all the 'Deep Pockets' buyers have theirs as the demand is satisfied, you only want one copy. We saw this on a £600 item in 2015 that suddenly only made £300 for a nice copy, then even worse with another decent one around £225 the next month & none seen since as this scared the market. Still one of the Best 1960s UK 45s. So however Rare an item is is pretty irrelevant, is it Wanted? Is it Overpriced? Will it be reliable despite being 40 years old?

The Reality Of What Happens To Vintage Hi-Fi Today.
As with a lot we put on this site, no-one else writes about these subjects. Here's the Reality of What Happens to Vintage Hifi. Our Marantz 2385 we got in July we later saw had been up for sale since Dec 2017 in one country, it was relisted slightly cheaper for a few months & then sold Apr 2018. The buyer in another country didn't like it so got rid of it within 2 months at a loss. Then our seller got it & they kept it for only One Month before listing it as they didn't like it either. It worked but as we review, the aged dull sound was far from "what they expected". We used to watch Quad 33/303 systems get bought & similarly relisted a few months later, a big supply of them is what this looks like but the same ones offered for sale as buyer tries & buyer doesn't like. Our 'Other Amps' page tells we'd never try the Quads as we see how mediocre the circuits are. Before the 2009 cash crash, there were regularly dreamers who'd buy 'High End' High Priced Modern Amps, CD players etc & proudly state "3 hours use" yet these items were barely used yet swiftly rejected & up for sale at a huge loss to the price paid. In 2002 we got the Musical Fidelity A308CR huge pre & power at a cut price as ex-demo, we too didn't like it & sold it on fast, but as the entry price was already quite low we got our money back. So people buy amps blind & swiftly don't like them. The Toshiba SA15Y amplifier was on ebay as 'working but faulty', we didn't buy as the seller's terms were poor, if another bought it, spent ages redoing it badly & a few months later they give up & sell it on to get rid which is where we get it & rebuild it properly. Our Marantz 2385 has had 4 owners in 3 countries in 9 months as the amp didn't please any of the others. We got it to upgrade as you can imagine, to take a tired 41 year old amp & refresh it into a use-daily safe item. Using a big Marantz as original is high risk, the repairs Marantz need get intense. Buyers have expectations, our reviews aim to tell the amp as Original, as Serviced & then as Upgraded with our Unique Skills where we carefully buy & aim to get 'Excellent' out of these upgrades. We watch ebay & here we rarely see our Sold amps up for Sale again as the Buyer is happy with what they get. Some the buyer might not understand or have it match their speakers, so they sell the upgraded amp instead of trying more speakers, if that's Rare and only seen with the 1971 Sony TA-1130 & the 1973 Yamaha CA-1000. Some will hear the upgraded sound & want the higher models, some of our buyers can buy several amps & have fun comparing as well as use them in different rooms. Where does "raw" Vintage Hifi go? It goes into a Grey World of buyer unsatisfied & selling on, yet buyer won't think to service or upgrade a good amp. You think for all we put here we'd have lots wanting amps upgraded, if the reality is it's still showing progess. The fact you can buy brand new Amplifiers as cheap as £200 sadly gets buyers getting those cheap disposable items, plus there is an unending supply of mediocre late 1970s-1990s amps on ebay for around £50-£150. Those who want the Quality are forever searching for it & many are happy listening to budget gear & still thinking it's "awesome" as they know no better.

What Are The Monster Receivers? * = Ones We've Had Here To Review
These are Tuner amplifiers of 150w or more. Some as wide as 636mm & 45kg weight. They are oversized & over heavy, not many sold & many had a hard life, By using multiple parallel transistors to get the high wattage, if still keeping under 100v on the ±HT rails. All 1976-78 models. Marantz 2385
* is 185w (490mm wide 26kg not too big face on at least), 300w Marantz 2500 (scope & noisy fan) plus the later Marantz 2600 at 340w with a revised tuner (both 27kg same width as 2385). Sansui G-22000 200w (insane huge size 636mm wide & 42kg) & Sansui G-33000 300w (same size if 45kg). Pioneer with the 270w Pioneer SX-1980 (too huge size 35kg, 560mm wide) & the 160w Pioneer SX-1280 at 27kg. Yamaha CR-3020 160w (again too huge 37kg with 632mm wide). Rotel RX 1603 * 180w (33kg at 600mm wide with rack mount handles) & even Trio-Kenwood KR-9600 160w (24kg & 580mm wide). Sony were not so hot at the time so only manage a 125w Sony STR-7800SD. Less known is a USA company 'SAE' with the SAE 'Two R-18' 180w, if HFE only has the Two-R9. Some of these we looked at on 'Other Amps' a few years back. Fisher RS-1080 is another that didn't get to the UK but at least did to Germany, 170w at 33kg from 1977, 605mm wide, 470mm deep. The worry here is Fisher sold to Sanyo & this amp just seems to copy others in looks & circuitry, prices on the 125w RS-1060 suggest not much buyer confidence as Sanyo were a budget brand. There will likely be other 'Monster Receivers' that were not Imported of at least offered in the UK. One Forum lists all the 100w+ Receivers made pre 1985, in a 2010 post a lot unknown to UK buyers or post 1980 to miss the Yearbooks, they list a staggering 95 of them. Search for "So are any of you guys into the old school stereo receivers?" Whether any are any good is for those interested to try out, just as they are 100w doesn't mean they weren't cheaply made or just ones to suit a market.

Why On Earth Would You Want A Monster Amp?
These excessive power 1976-78 amps fell off a cliff by 1981 as designs by 1979 were already a lot more modest plus the dubious idea of pre & power amp even for 50w, just getting you buy 2 units. But some USA Makers like Mark Levinson & Krell reintroduced the high power amps back as Power Amps into the late 1980s-early 1990s. Why you need an amp the size of a tea chest putting out 500w is clearly just an ego thing. Our Opinion of Monster amps was made by hearing a Pioneer SX-1980 in 2002 & then geting a Marantz 2385 which sounded as aged as that SX-1980. But who else would dare get one to fully upgrade just to see how good it is even knowing the Tone has ICs? Only us it seems, others service to a degree & 'repair' but our 2385 will be the only upgraded one. Read futture blogs for how we get on with it. Those buying these huge aged amps & using them aged & raw are gambling with 40+ year old high powered amps & as blogged above, they appear to get bought, not liked as too aged sounding & sold on again. We'll find out the more we do to see if these are Monsters on the Way Out, or worthy of a proper rebuild. But Why Would You Want One? There is a Blokey Idea the Boy Racer has to want the highest power yet Quality doesn't seem to figure, like 1000w Car amps. Bragging Rights that you have a 300w amp will impress some. Actually the idea by the 1980s was 300w amps to drive very insensitive 84dB speakers, a pointless idea that as with any dumb idea will always get followers. In reality, you sat at home could live with a 20w amp & 95dB speakers to have enough volume. You can buy 95dB 200w PA speakers & the Sound Level will be way higher than you'll ever need. The appeal of more Thoughtful Types to have the Ultimate In Design at the Time appeals, the reason why aged tired sounding Monster Amps get bought & sold on fast, if no-one thinks to get them updated. We got ours for the need to try the excesses of Hifi having sold other Hifi items & to blog about what no-one else has tried, to upgrade a aged tired amp to see how good it can be. We get the Bragging Rights as the First To Rebuild & Upgrade a Marantz 2385, if whether anyone will want theirs done will depend on our future opinions of it. Currently it awaits a spares balance control as the other was broken & not repaired well, if beyond that it worked good as our Review tells.

The Early Amps By Akai: Part Two
The Grim Reality of The Akai AA-8500... As Original it's Sound is actually rather disappointing, then again so was the AA-5800 & it upgraded to sound very decent. The AA-8500 is as dumbed down as the AA-5800, so don't go thinking it's great as original, as it's not. But it has a lot of potential as we state. The Original sound is Not Very Loud for a 65w amp, on Headphones volume goes past Midway to show it's not so good. Even after redoing the Tone Board it doesn't sound anywhere near "Excellent", it's a bit grainy, the sound is small & a bit blurry
. It doesn't sound like a 65w amp at all, we've had louder 15w amps. It looks great, one of the Best Looking Receivers, but it sounds lousy explaining why it's a Rarer one. Whoever dumbed down the Circuit really overdid it, this amp should sound as good as the Akai AA-5800 was our reason for trying one again. We can hear our Tone-Preamp has tightened the sound, but it's struggling against the rest. It has Pre Out-Main In Connectors to see which half is the weaker as using the whole amp it's not possible to tell which is a first. This 16kg amp really does hide it's quality, be sure other amps we've had do too, compare the Before-After Ratings. 'Main' Input is shown with a typo as "0.77mV" instead of 0.77v or 770mV so will compare with most amps. Soundcard into the 'Main In' is typical of the Standard 1v type level. reveals the Power Amp sounds better than the Preamp stages. Now Aware of The Power Amp sound to crank it up louder, as in past midway & listen for the quality which is there, so things to do... Well Is It any Good Now? For our Redo of the Tone Stage & some alterations, if the amp is still partly unserviced & the rest is original, it now sounds as good as the AA-5800 in many ways. Great Amp Hidden for sure. Punchy Amp with Wide Stereo just like we like them. The extra weight of Parallel Outputs is noticeable now, it wasn't before as Original. Why are Manufacturers so Cynical about Dumbing down what are Great Amps & make them just average? The 1970-72 era is where this is done most we've found.

Why Are So Many Good Amps From 1970-72 So Dumbed Down?
We've had a few from this era that as Original are 'Unremarkable' to the point of mediocre, but for us knowing circuits we can upgrade them to be some of the Best Hi-Fi Ever, but most hearing the dreary originals with so much dumbing down, limiting & deliberate spoilers, it is actually surprising that this happened so quickly. 1964-67 Transistor amps are the First Generation, 1968-69 are the Second Generation but so many that we'll detail by the 1970-72 Third Generation are just cynically hiding great designs with dumbing down. Different to Cost Cutting Dumbing Down that started by 1973-74 & hit a low by 1979, this is designing great amps but Not Letting Them Have That & by the time the Discounting Era arrives, the cynicism goes elsewhere. Here is a list of Amplifiers & Receivers we know are pretty ordinary as Original but Upgrade really well, beyond general aging, the designs are overtamed. On our Reviews page a "Recommended" rating yet an "Excellent" rating as Upgraded tells. All amps are never as good as they can be, as they are made to a price level to be universal, our Custom work brings the best out. Even the early JVC & Trio-Kenwood amps have very low spec in some places, afraid of Bass is a common one throughout the era we cover with Valve amps often having very limited Bass as the spec of the time was only modest. The Deliberate Taming is the Problem here with these 1970-72 amps. 1970 Akai AA-8500 great looker as blogged above but very tamed with low volume for 65w. 1970 Sansui AU-666 with some very tamed severe bass filter & very low spec throughout sounded awful on speakers. 1970 Hitachi IA 1000 was rather tamed if still sounded 'Very Good' as original. 1971 Hitachi SR-1100 similarly, both Hitachi were capable of far better than the Original design allowed. 1971 Marantz 2245 was surprisingly average as original, soft blurry sound with some strange design, Marantz are a varying brand often way overpriced if sounds do vary amid their 1970s ranges, the simpler designs being wonderful if the over-complex ones suffering. 1971 Sony TA-2000F/TA-3200F Pre-Power is a design you'd think at 100w would be as good as the STR-6120 but it's very tamed especially on the preamp, the designers appear scared of what they are doing so keep things very tame. Even upgraded by us, it's still not as lively as it could be. 1971 Sony TA-1140 is where the cost cutting shows, despite TA-1120 looks this is a bit of a weak design with Power Supply on the Tone board, one we've not thought worthy of upgrading more for this, plus the Manuals are too lofi. 1971 Sony STR-6055 we get just a few weeks after this blog & again it's thin bright sound scared of bass hides what is a good circuit. 1971 Trio-Kenwood KA-2002 upgrades to sound lively for 13w if cynically tamed to hide the usual nice Trio sound. 1972 Akai AA-5800 was pretty average if it hides a great circuit & upgrades well, this seems to be the Akai way if by 1973 Akai AA-8080 the sound is far better as original if now the Cost Cutting is what limits that amp. 1972 Harmon-Kardon 930 we thought was pretty average as original & not a great design despite double transformers, the circuitry wasn't so good. Did upgrade to just get an 'Excellent' but it seems the layer H-K are the better ones. Some Lower Power Models of Trio-Kenwood & Sony by 1971 are just too basic to really consider as ones upgradable to 'Excellent'. Other amps we've reviewed that got 'Very Good' were of acceptable sound as original & it can vary amid brands. 1971 Yamaha CA-700 & CR-700 were before their classic silver range & bit average with several minuses.

Updating Your Older Opinions.
We've managed to do that with Two just in the last few weeks. We Question all we see in Hifi, why do they use that, what is that for & go find out why. Often it's part of Dumbing Down & Limiting, or it's poor design that we try to better. So much in Hifi is based on accepting Old Ideas by Tame Grey Old Men yet a lot of it is Out Of Date & has been for decades. We see modern Valve Amps still using the 1950s Mullard designs & still using the same values as back then, rather than thinking "how can we make this better?" but that takes skill & unfortunately Money which they don't want to spend but still charge you High Prices for amps that mostly have out of date designs. Old ideas of Toeing In Speakers to get the 'Stereo Sweet Spot' are hopeless but still used. The long running "Gold Plated" ideas with connections still keeps the hype going but use these things & see how fast the 'Lick Of Gold' wears off to make you wonder if it was just Copper as it's gone brown now. But to our Revised Opinions... Monster Amps are slow, dull & overweight in sound. Yes they are as Original & Unserviced as we first heard with a huge 1978 Pioneer SX-1980 in about 2005 played through Tannoys which we liked with their owner using a different amp. It sat on their floor like a coffin & sounded as dead, the guy used a different preamp & it still sounded lousy. That was what we thought hearing the 1976 Marantz 2385 the first time, that same thick slow sound. But there's more to it as the 2385 Review page shows. Fully Serviced which is a difficult take-to-bits job & then to recap-upgrade at the same time save risking the wrapped pin connections, the dull dozy thing came to life again, a good service will restore the sound to a degree, but remember it could be up to 42 years old. We've put on this site before that Quadraphonic Amps are similarly slow & blurry, we first had a Marantz 4ch Receiver in about 1995 bought for a whole £20, probably the 1973 Marantz 4230 at 30w x2 or 12w x4, or the 1977 Marantz 4240 at 40w x2 or 17w x4, both look very similar in & out. Got a photo with a Rogers Cadet III on top plus the Technics SL-1500. After other amps we found it disappointing as it had no life in it, even in the 2ch mode.Looks from the pic that we used Marantz as preamp & Rogers as Power Amp though it could have been the other way round as a later pic shows a Musical Fidelity E30 100w power amp that was only out in 1998, boring thing that was too. We digress as often, but the Quadro amp even at the time after 22 or 18 years was clearly out of spec to sound so boring. Our Marantz 4070 we never got to hear as original if recapped & then biasing the Power Amp left mostly original the Biasing right really brought the sound into focus as it had drifted from the original Pot setting points as are paint sealed when made new. The Lesson Is... Question what doesn't seem right, would these Quadro & Monster Amps be sold sounding so lousy? No, age had taken them over. We'd dismissed these for too long & these are advanced amps to work on that now we can put ideas learnt into to reveal how good they can be. "Proper Hi-Fi" from Quadraphonic & Monster Amps was really not expected. The Marantz 4070 was only got as a gamble on seeing it had a nice fascia despite a mess if the Marantz 2385 was just for selling the Sansui AUG90X & SME IV so at least put the same into a worthwhile amp.

The First Hi-Fi Discounting In 1967.
Beyond Shops offering occasional 'Shop Soiled' items, Ex-Demo is the term of later years, there really were no Deals in Hifi such as heavy discounting of all of a certain item. But by 1967 the Valve Amp scene was starting to get Old Fashioned & some makers were making both types of Amplifier as Valve or Transistor such as Sansui, Pioneer, Trio-Kenwood if other Brands either carried on with valves or had stopped making them over the last few years. So to clear out End Of Line Outdated Valve amplifiers & receivers was the deal done by the big REW (Earlsfield) shop in Upper Tooting Road, London. They got the Trio-Kenwood valve amps that had been available for a few yeara but clearly they didn't sell too many so July 1967 p.110 has them clearing out the Trio range cheaply. Trio W41U valve amplifier List 55gns (1 guinea = £1.05) now a mere 22gns, so you could save "26gns" acording to their ad, perhaps done purposely to get you asking if it was a typo. Trio WX-400U valve receiver 99gns now 65gns, Trio KW33 valve receiver 89gns now 59gns, Trio WE24 amplifier 39gns now 25gns plus Trio W38 79.5gns now 47gns shows these capable amps, the WX400U with MPX Stereo were really being cleared out. The shop also clears out the Nikko TRM40 15w transistor amp 45gns now 22gns & the Pye Brahms HFS30T transistor amp from 1963 53gns now 29.5gns. Clearly they bulk bought in the remaining unsold stock & offered a good range very cheaply, if some being 1963 models were looking a bit old fashioned beyond just being valves by mid 1967. It'd take over 30 years for these to be considered Retro & worth having again, they had a long time in the Wilderness if the nice grade valve ones still around exist for being cared for or just left unused in cabinets. But there is the First Hi-Fi Discounting, selling you 'outdated gear' if the reality was Trio-Kenwood in 1967 with Transistors still weren't their best until the 1969 ranges.

The Story Of The Fisher 440-T Receiver Apr 2016-Aug 2018.
We got this amp, recapped & upgraded it a lot, such as plug-in sockets were not a good idea on Driver transistors. It sounded great for it's 25w rating & if we were collectors we'd keep it as it was like New inside beyond the need to recap 52 year old capacitors. It gets listed Apr 2016 & sells within a Month to a customer who just orders it. This is unusual, all buyers message us first to Ask about the amp & if it will suit their needs. Once they say they got the amp they ask about speakers so we recommend Tannoys as typical if no further word heard. Nothing until Aug 2018 when they contact us saying the amp "that they just opened" has a problem, can we repair it & sell it on for them as it's not needed for their Project anymore. A little odd that, but we message back & say to repack it & we'll have a look. But then they say they don't have the packing despite it "just being unpacked". They don't know what to do with it & say "it might end up in a skip" which is disrespectful to our work. We question why they haven't got packing just allegedly unwrapped & their 'easy-going' manner changes, so we decline to get involved as they are trying it on. A week later in Aug 2018 it ends up on ebay with a slightly libellous comment saying it makes pulsing noises & all ready to mention us. To answer Trolls is our way so to put a comment on the 440-T review page linking to it. The 440-T is a great amp, we'd not want to buy it ourselves on seeing it, so recommend it to a customer & put the sales page back on once they win it for a mere £242, when we sold it for £700 in 2016. So as you can imagine, who else can deal with an amp like this, if who the underbidder was remains unknown, likely they'd bring it to us too. We Get It Back. Arrives to us in a different box if packed safely. We open the case & metal covers, a bit dusty inside & on the heatsink tyransistors cover, not our dust. Looks exactly the same inside as our pics & nothing wrong visually at all. Sounds perfect on Headphones, so we go to wire up our 4mm socket on ring connectors. This is how the 440-T should be wired, we use These exact ones now. That's strange, the Right Channel screws are very tight as screws can get if never moved after some time. So we compare the Sales Photo with the Amp itself. The R ch screws are exactly the same position as sold, if the L ch ones are all different, as you have to remove the screws to get the ring part connected. We always check Mains Plugs too & their one we saw the E wire was barely hanging on, 13A fuse used & the cord grip broken which pulled the E wire nearly out. This is the type of buyer, one who doesn't know stuff. So buyer can't do a plug safely & therefore has connected Two speakers to the Left Channel & not connected Anything to the Right Channel. Verdict. Buyer Misuse, tries to play us after a cheap repair & us to sell it on as unwanted now, we decline so they sell it on very cheap, we get to check it over & find out the truth. On using our small Test Speaker that it's been used on as well as on our Tannoys, it does make noises now, so their misuse has slightly damaged it as it won't drive speakers if Headphones sound fine. Repair needed on the Power Amp somewhere.
On checking further the Output Transistors are good if the drivers are slightly off & further use on speakers could damage more, so at least they didn't use it again. We learn customer's ways every time & one like this is it seems best just letting them send it to us so we can see for ourselves.

0.05% THD Total Harmonic Distortion: Who Cares?
The Pointless Specification of Total Harmonic Distortion isn't that understood, most read it as the Sound Itself has only 0.05% Distortion from the Mastertape, which is most certainly isn't. Harmonics as you can read deeper into on Wikipedia are Overtones of the same note. A Violin has a huge amount of Harmonics to create the sound from what basically would just be a Sine wave without any Harmonics & Sine waves have no character, yet are often used to Test Hifi despite no-one beyond Techs hearing Sine waves on testing Amps. Sine Waves are totally predictable, the wildly varying Music you play is totally unpredictable. You can see these Harmonic Graphs on some of the early Hifi Reviews with the Tone at 0dB with the Harmonics way down & often lost in the Background Noise of the amp, they can be as far as 70dB to 90dB down & masked by other sounds. Whether these are Distorted when at such a low level appears to be the Spec that gets Amplifiers sold. If that matters to you then you're believing Hype. Why Do We Upgrade Amplifiers? Because the Sound we hear is imprecise, slow, rough, lacking depth, sounding blurry, having no proper Bass, weak grainy treble etc. This in reality is the "Distortion" from How Music Should Sound, but there is no way of measuring that, beyond how tired the sound makes you or can you play the Amplifier for Hours? Some amps we've heard Mangle the Sound so severely, how distorted or far from the 'Original Sound' is that? As we have on the Hifi Intro page & a self-quote we wrote early on... If they were more honest they'd rate it as "Percentage Of The Real Sound we actually Lost in search of High Specifications". That's the real truth of Hifi, yet until you've heard better, you will think your aged weak sound is acceptable. Amps get sold on as the Sound isn't liked, the need to compare several amps to your speakers before you realise they are lousy despite others saying they are "The Best In The World" which just reveals how little they know. Comparing an amp on several speakers has the Bonus of Headphones which we find are the Leveller of All Amps as the Headphones are direct from the Power Amp via a typical range of Resistor, not going to be affected by direct coupling to Loudspeakers which still is the ultimate test of Amplifiers, to see they match eachother plus to suit your ears & room. So when you hear an amplifier is 0.05% THD but hear it has no proper Bass, narrow Stereo, little Kick to the sound plus with Grainy Gritty Treble & a recessed Midrange, you'll realise THD is utter rubbish to even consider important, when a Factor like Slew Rate that was briefly shown in Hifi Reviews in the mid 1970s until realising it's the Factor that tells more about an Amplifier Sound than any other. We've blogged about Slew Rate before. But doesn't 0.05% THD look impressive. Don't believe the Specs hype.

1977 Rotel RX-1603 "Monster" Receiver: Is It Any Good?
This is the 'Big One' in the Rotel range, if we've not had a look at this before. April 1977 HFN/RR mag reviews it, see our Review of the amp, as we get one this same month to restore. 1978 HFYB lists as 180w for £525+VAT but up to £701+VAT in the 1979 book, the similar 185w Marantz 2385 was £977+VAT in the 1979 book. Rotel are a good brand in the late 1960s-late 1970s, they made cheaper gear if it still sounded good, the RX-603 in the same range we've had & it's not a bad amp but not the most exciting one either. The styling may not be to your taste, as with the Luxman R-10xx range, it looks very 1970s in a Cheesy Way with the big perspex lit tuner panel looking like a 1950s Radiogram & Rack Mount handles that some brands used around the same time as an option with Pioneer & Marantz. Rack Mount handles are for Pro Gear as tall towers of equipment show, useful for the purpose, if just decoration on Domestic Hifi, the "Go-Faster" stripes of the Audio World, the RX-603 ones were plastic so not useable really as handles. But looks apart, the RX-1603 is an interesting amp & from a lack of info we've not covered it if we've had the Manuals since 2012 when doing 'Other Amps' page, the bitty scans are hard to follow. The Hi-Fi News/RR magazine reviews this & it gives a better idea of using one as it's a 2-part amplifier that's hard to understand from bad pics. Comparing. The RX-1603 is 33kg & £701 when new & the Marantz 2385 is 27kg & £977, so quite a difference. Rotel size is 600 x 180 x 400mm WxHxD, Marantz is 491 x 178 x 435mm, Rotel is not as big as the Pioneer SX-1980 at 560 x 211 x 497mm. All a bit silly as over 400mm deep it's going to overhang a typical sideboard & probably too heavy for most furniture too. But size mattered & it was a "Monster Receivers War" after all, if few will have sold in the UK. Circuits. Bearing in mind it's a 1977 amp, the circuits are predictable, as in fashion-led & overdesigned.
Phono is Differentials with EQ then the Class B push-pull design, all unnecessary if standard stuff, at least no ICs. Mic Amp is ICs if unimportant to most users. Tone-Control circuit is quite complex if with 2 transistors per channel with one a buffer and no differential-Class B which is good to see, if the early stage has fairly high NFB which is unusual to have on a 180w amp. The HFE scan of the RX-1603 circuit is bitty & hard to follow with bits repeated & chopped halfway, but you get what there is unless someone nicely scans the booklets not just old blurry Photocopies. Power Amp has Differentials with diodes between the Long tailed Pair part which isn't one we've noticed before, then into another Differential as part of the Class A Driver stage then into Bias & 2 Push-Pull Driver stages & onto Doubled Paralled Outputs which are all NPN so a Semi-Complimentary design which we'd not expect for 1977, if perhaps Rotel kept the price lower by using NPNs. In reality it doesn't make any difference as Semi- or Fully Complimentary. A mix of design ideas here, the Phono stage overdesigned if the rest is typical for the era & seems fine. The diagrams show plug in sockets on many connections. Typical Power Supply Regulators & 4 relays. It should sound decent, if one tells us the RX-1203 is a bit lifeless, it probably would improve to a degree for Servicing & a lot more for some quality Upgrading as these bigger amps got used for much longer than lower power amps that got replaced on believing 'new is better' as was the idea into the 1990s. Looks-wise looking on Google, the styling with the handles & yellowy tuner lighting is a bit cheesy compared to more classy looks, lots of buttons as typical with later bigger Amps, if the top slanted section midway for the inputs will just leave wires in sight, plus the AM Antenna stuffed in there is not very user friendly. A 'Tapeheads' forum site has lots of inside pics & it doesn't appear to be splittable into 2 halves to be Used, if does for Servicing. The inside looks packed with big boards again typical 1977. To see those 1960s Carbon Composition resistors in a 1977 amp is a bit surprising. Whoever redid the amp did it neatly, taking time to straighten uneven components as we do, but again they just do it like-for like, missing out on Upgrading the amp, if we've yet to find anyone who upgrades amps like us because it's design based & potentially risky unless you understand stuff. Plus they leave things we get rid of... The big boards are Tuner ones so after seeing the rest, the RX-1603 does appear a good amp of it's type. Appears a 110v one hides a Multivoltage Block under the Rotel rear badge which makes it a lot more worthwhile to have. The minuses are the fascia styling plus the difficulty of top mounted inputs that trail over the power amp half, leaving thick cables with Ferrites a messy sight. Rear of the Power Amp has the Speaker Outputs. As with any Huge Amp, it'll have things you like & things that aren't so good. What it'd sound like Serviced & Upgraded is another thing, the 185w Marantz 2385 appears a little scared of it's power to keep Deep Bass quite limited plus the original Spec of the amp is still 1977 Spec. A deeper look at the circuit if the values are too blurry to read, the design looks more than a bit lacking in several ways we'd upgrade. It probably sounds quite dry & disappointing even for their Service & Like-For-Like Recap. There are reasons why amps sit overpriced & unsold or reappear again a few months later, the buyer doesn't like the sound is the main one. As is generally the deal with Rotel, they are OK but not too exciting, but are generally good basic designs that would upgrade to be a lot better.

1970s Marantz Amplifiers: A Quick Look at All Models 1971-79.
The Numbering on these is a little confusing, as it doesn't separate them into a year grouping like Pioneer do with the SX838 being the range 2 years before the SX-939. The range we'll detail covers 1971 to 1978 & Marantz are a company that got Better as the 1970s went on if dipped by the 1978 ranges. In our experience the 1971 ranges aren't as good as the 1973-76 ones & that's after upgrading. The Marantz numbers in the Amplifiers equal the Wattage per channel added, so the Marantz 1030 is a 15w RMS into 8 ohms amp. So power ratings are easy to work out. But the numbers cover several years. The joy of sites like HFE (Hi-Fi Engine) put these into numbver order & to see the info on the pages, if there are many errors in year & power output from wrong info being found or misunderstood, ie 80w amp on one is a 40w one in reality, so care in believing any specs without checking. Model 30 is a 1970 amp of 60w, still in their earlier numbering. 1030 is a 1973 amp of 15w & the circuits are good on this amp if 15w is a bit low for many. 1040 is a 1974 amp of 20w with the part black fascia, circuits look good. 1050 is a 1978 amp of 25w & is a bit cheaply made and basic compared to the earlier two, one big circuit board beyond the tone sliders board is disappointing. 1060 is a 1971 30w amp with nice looks and 6 larger rotary controls plus a "1060B" later version with 4 larger rotaries probably by 1977 with simplified fascia. The 1971 has more features & no Differential, the "B" version is updated, both look good on circuits. 1070 is a 1974 amp of 35w with the part black fascia with a good circuit. 1072 is a 1978 amp of 36w, part of the 1050 range again with the cheaper one-board design. 1090 is a 1977 45w amp, still of multiboard construction like the 1152DC if the circuits look good still, the inside looks budget build. 1120 is a 1973 amp of 60w, all silver fascia. This is an interesting one as 1973 shows the First of The Class B type Push-Pull circuitry, here it's on the Phono stage after the Differentials. Tone-Pre has Differential if Class A output, Power amp Differential if looks like the lower power designs 1122DC is a 1978 amp of 61w as the numbering suggests, not 75w. Phono is 3 Transistors, no Ic-type circuits here, Tone is much like the 1973 design, but after that decent design the Power Amp is overdesigned with what looks like 4 Differential pairs if not all for Audio & into 2 pairs of Push-Pull Drivers. Power amp lets it down a bit. 1150 is a 1976 amp of 75w with the half black fascia & a 1150D version with more buttons & inputs on the fascia is a Dolby Version. Back to the Overdesign & IC styled Differential & Class B Push-Pull on Phono, Tone amp is overdesigned with Differential & 4 more transistors, Filter amp like Yamaha used is 2 more Transistors, Power Amp is 15 transistors if included Protection if fairly typical. Preamp stages overdesigned. 1152DC is a 1978 amp of 76w, one we had early on, the odd push pin construction. At the time we found it very bassy if dull sounding with not much volume for 76w & it had problems we could sort now, but early on it was too complex. Overdesigned like the 1150 preamp if they managed to stuff in more differentials & transistors somehow. Power Amp is 21 transistors, Doubled Outputs explain 76w, bassy but not as loud as a 76w amp should be if it works on ±48v HT. Power amp with 21 transistors isn't quite as overdesigned as it seems having FET differentials & Transistor Differentials, if the middle part has a lot of transistors for Drivers & Protection. The Preamp overdesign would put us off now. 1180DC is a 1978 amp of 90w, almost the same as the 1152DC in design if adds a Peak Indicator. 1200 is a 1973 amp of 100w don't remember seeing this one around & 100w is high for 1973. Design is much like the 1120 of the same year with all the excessive Differentials & Class B stages. Power amp has Doubled Parallel Outputs & looks a sensible design like other 1973 Marantz. Works on ±52v approx. 1250 is a 1977 amp of 125w much like other 1977 with the overdesigned preamp if the power amp is more sensible HT is ±62.3v. 1300DC is a 1978 amp of 150w, their biggest model. FET Differential on the Power Amp like the 1152DC, 22 transistors including Doubled Outputs, if despite the Transistor count does look a decent design. After that the PM-x00 series began with PM-200, PM-400, PM-500 & PM-700 as on our "List Of Amps" page. PM-700 is that 'Graphic Equaliser' front design & only 70w highest power now. So the Overall View is the Marantz amps are All Transistors with Good Designs varying between models, some with Overdesigned Preamps & only really 1152Dc & 1200DC having overdesigned Power Amps. But the 1978 ranges we're not keen on with the cheap one-board design, heading into what became the typical build quality by 1979-80. The 1971 Marantz aren't so good designs which matches Yamaha for Improving by 1973 as the designs are a lot Fresher & this generally continues until 1978 if by 1979 the quality dips as Cost Cutting takes hold. 'Classic Audio' site adds the 1260DC which will be like the other 1978 'DC' ones. There is no direct equivalent of the 4070, the 1030, 1040 & 1060(B) are all different & all having lesser design that oddly the 4070 doesn’t have. 4070 has some NFB but not excessive, even the 4140 4ch amp differs.

Trio-Kenwood KR-7200 Receiver Plus Later High Models.
For us having the KR-6160 recently, two now have mentioned the KR-7200. On looking on ebay, we see one, it looks fairly like the KR-6160, if it's not one we've seen. 55w as the KR-6160 is, with the KR-6200 at 45w & KR-5200 at 30w. Seems Trio-Kenwood did new ranges every 2 years & this 1972-74 range isn't much around for the Discounting Era heading into the Cost Cutting Era. One on ebay overpriced at £420 for a Raw amp you should pick up for £100-£150 shows the problem a lot with Hifi on ebay, it's foolishly priced like Serviced & Upgraded gear, when it's just an 'as found' amp. The circuits of the KR-7200 look not unlike the KR-6160 if the main difference is Power Amp has Differentials & no Capacitor Coupling which other brands were into by 1971, also it adds a different Protection Stage and adds a Relay, more to 'follow fashion' perhaps & despite it looking a good design with no ICs in the Audio stages, it's one that didn't sell. In 1974 came the KR-7400 range at 63w if this is a good looking amp, it has ICs in the Tone Stage & Phono, plus the KR-9400 is the Top Range 120w if HFYB doesn't mention it. KR-7600 (7060) range in 1976 at 70w with 17kg starting to look like Pioneer if again Phono & Pre-Tone ICs. Next Top Range by 1977 is the 160w KR-9600 at £587 is quite a bit cheaper than the Marantz 2385, it has an IC Output Stage 'TA200W' is why... Trio-Kenwood just seem to have lost their individuality by 1974, losing what makes their earlier amps appealing. KR-6030 by 1979 is 80w moving away from 100w+. By 1980 the range changes to the
KT-313L, KT-917, KT-815 ones that HFYB lists if nothing on HFE about them to know, so assume just the typical slimline midprice gear of the early 1980s. a KR-9050 is a 200w one from 1980 supposedly, we'll blog it below.

Vintage Valve Amps: Is It Worth Getting A 1965 Rogers Cadet III or HG88 III Rebuilt?
One asks about getting either amp Upgraded, as they've had the 2-part earlier Cadet III & taken it in for repair twice plus returning under warranty more times. This exactly proves why "Repairs" on Vintage Amps especially Valve Amps are a waste of time. Rogers valve amps need a full recap & rebuild, they are now 53 years old & the high voltage caps will be long since dried out, to use regularly is not recommended if it works. Another just "repairing" them more than once is sadly not an efficent way to deal for the customer as we say, the whole amp is way past it's best & risks damaging output transformers. Old-time hifi guys don't understand the upgrades as it's not to stock. They don't understand how to subtly redesign because they can't fault-find the issues that upgrading can bring or understand how to even start upgrading, so they won't be able to fine tune it. We can & for spending nearly 4 years altering & totally redesigning our Luxman LX33 valve amp from 1979, we have proven upgrades that other Valve amps can benefit from. Cadet III is only 10w & the 2 part version is pretty basic, probably not worth spending on to rebuild either version as space is so limited, plus those awkward 3-capacitor cans of very low spec, it's really only a budget amp & 10w with those tiny output transformers really isn't enough volume for many users. The 15w HG88 III is what we'd consider "entry level" for a worthwhile power in valves. HG88 III we rebuilt one in 2012 as on the Solds Gallery if that was a few years ago, a big job to do. We did that for our own research if in reality to do that today would be an advanced job into 4 figures, plus the trouble with Rogers is the valves aren't available beyond as used or rarely NOS, the ECC807s are about £40 each & usually part used which can mean they are 'burnt in' to the limited original circuit & can't cope with upgraded design. The output valves are like ICs as they have 2 differing valve stages in one case, the ECL86 is a Triode stage plus Pentode output & long obsolete if these were likely used in TVs so even NOS ones are findable with Mullards at £30 each. Another asked about a HG88 III rebuild & ending up buying a much smarter looking Fisher X-100-B as reviewed which was a far better buy than the HG88 III, if to find 240v ones is not easy. Valves done right are expensive as redesign is needed, 1960s valve amps are weak designs & rather crudely done in places, if the results on the Fisher were very decent, to the point of "Use Daily" which you can't trust on 1960s parts.
For 1960s Valve amps, we've rebuilt Rogers HG88 III, Trio WX-400U receiver with a full rebuild including Tuner, the Trio W-41 which is the amp version of the WX-400U. Later valve amps we've got our 1993 Tube Technology set plus the 1979 Luxman LX33 that gets used most days for playing vinyl plus getting a Prima Luna modern valve amp & realising how poor the modern valve amps are desite IC-driven Autobias. The worst 1960s Valve amp was the 1966 Sansui 500A that pushed 18w from valves that are only safe at 15w, terrible design on the Tone stage & Filters, obscure obsolete valves in the preamp-driver & then for the very high HT it trashed output valves very easily as the design lacks a balancing load resistor like Trio worked out in 1963.

ICs... ICs... Why Don't We Like ICs...
Because they are Generic Low Spec mediocity is why, earlier opinions on the Valves & ICs page. Some contain 14 transistors, resistors & diodes in one tiny package, they will not be the same spec as individual components & they will be a safe generic design that allows little individuality in design when it's used in a circuit. Aug 2018 got us trying a Monster Receiver with IC Tone stage. To try it without all the Taming Revealed it picked up 27MHz Computer Mouse noise so it's way too wideband for Audio & must be tamed down. The Marantz 2385 Tone IC is a fairly basic TA7136P 7 pin DIL type IC, the internal circuit type, if not values, can be found. It's rated 400mW if max current it can draw is only 4.2mA as the Hitachi spec sheet tells. Inside there are 11 transistors, 2 diodes & 8 resistors of unknown value, including one on the output. Compare that spec to a typical common transistor. The Tone Stage comes after the Volume so it's not working at 0dB level if once turned up higher, the IC will 'crap out' for it's low spec. "Crapping Out" is where the signal gets flattened off as there is no more power, we had a 40w IC output amp & the ghastly mess of 'sound' once it crapped out was truly unmusical. It's the same Miserable Crap Class B design that Yamaha started putting in Amplifiers about 1975, if as Transistors. Earlier Amplifiers could so a Tone Stage with 2 or 3 Transistors, one a Buffer if 3 was usual & running in Class A. But the trouble is Class A needs 'more power' as Class A amplifiers run very hot yet the Class B, or AB as some get called, will run cool. The TA7136 looks like a Mini Power amp if for use at low level, it has A Differential, a Constant Current Source then it goes into the Push-Pull Class B type design for later stages. This is all totally unnecessary if earlier amps could do this with 2-3 transistors, but sadly the "follow fashion" ideas meant the superior early circuits that use Capacitor Coupling & no Differentials all by 1971-72 on Japanese designs had to be this way. It heads into overdesign. Constant Current Source we have in the 1970 Sont TA-3200F power amp, it's a limiter rather than being a Regulator. In the 1990s as blogged-page written before we got the Tube Technology preamps that had Regulated Voltage on everything. Regulated means Tamed, Zener Diodes to limit voltage is a cheap way of doing that. To get rid of the Regulated Valve supply improved the sound a lot. Restriction is not a good thing in Hifi, yet it's in everything now. Computer Soundcards are Today's Digital, you'll not find the Circuits of these boards but be sure it's Class B or another letter, but never Class A. Soundcards with all the Tech advance do a good job for playing audio, but as we found using the Oscilloscope on Square Waves, these Dumbed Down Circuits give really poor Square Waves over 10kHz. This is why ICs need so much taming & then they'll sound acceptable but be far from as honest as discrete components such as Transistors. The Worst Ever ICs are the big STK blocks, the Trio-Kenwood KR-9600 blogged above used a TA200W IC as the entire Power Amp stage after the Differentials that were in Transistors. This is truly Rubbish Design & be sure if you damage it, death of the amp as none of these Custom ICs are buyable let alone any Spec Sheets. Built In Obsolescence in the most cynical way & we do avoid amps with IC outputs, V-FETs & MOSFETs as often they are custom made for the amp & as we found with the Marantz PM62 we got in 1993, after about 2 years the supplies of these Custom ICs or Output Transistors dry up so the amp may be useless after a few years as no spares. But your 1968 Sony STR-6120 can be fully rebuilt with Transistors you can still buy & the odds are in 50 years you could still do the same. But your IC amp will be Eco-Waste long ago & why these IC riddled amps generally are Disposable. There are other design & spec factors why ICs are bad, but to try the Marantz 2385 as a 185w Monster amp with 2 ICs per channel always in circuit to see what can be done to try to get a decent sound from these unwanted ICs. In fact as original, switching in the Tone quite noticeably reduced the sound quality by blurring it & making it sound smaller, if so far with our upgrades to do the Tone On-Off actually made no difference with our upgrades, if that was only played once before needing a spare part that hasn't arrived as of typing. To test this further on the Oscilloscope will be blogged, to push it to see it "crap out" just to see if there is any hope for ICs. But an IC typically is a cheap way to do what could easily be done in Transistors in a huge amp like the Marantz, but they chose to cheap out on ICs on a £977 amp at 1977 prices. Tuners are stuffed with ICs by 1977 if the 1968 Sony STR-6120 is one of the few FM Tuner stages that are all Discrete Components. In Hifi, such as Amplifiers, Tuners, Phono Stages, Tone-Pre Stages & Power Amp stages there is No Need to Ever Use An IC... except to cut costs & pretend the 0.05% THD actually matters. Be sure they built the CD player DAC as Transistors before making ICs, how big would today's spec of Computer need to be if all Transistors? The Computer Processor as in IC needs cooling, but if all Class A transistors, it would be huge & run so hot. ICs have their place, but to cheap out on Hifi isn't good.

Later 1970s Trio-Kenwood Amplifiers.
Meaning Post 1972 ones. KA-8004 from 1971 continues into 1976 says HFYB, are they snoozing? We've not been so keen seeing ICs, but to have a better look. KA-7300 from 1976 we've looked at on 'Other Amps' & found it has an IC output block, which kills it to us if a pity as a step up in build quality towards the Pioneer style. "Their second top model with the KA-8300 being 80w & the KA-9100 a 90w 1977-78 model & the KA-9800 a 1975 80w. The circuit looks pretty decent, all transistors & not overdesigned, but the killer is that IC output block TA-80W no specs findable, but it appears to cover the splitter, driver & output stages as a 10 pin STK type block unit, one per channel. Be sure these are long obsolete." says it all as we wrote before. KA-7400 from 1975 "63w Sadly another larger one is positively choked with ICs in the Phono & Tone amp sections, though the output power amp is all discrete components." as we wrote before. Not doing well here. KA-9400 "ICs spoil it. 120w from 1975 but sadly again ICs in the Tone-Preamp. Why oh why. The Tone has a common TA7136P IC stuffed with loads of averaged circuitry and then a second IC with more. Utter junk & never going to be Hifi." But interestingly the Marantz 2385 has the same IC in Tone. Opinions on 'Other Amps' were from 2013-14 before we started upgrading a lot more, so to see we dismissed the Tone IC will be blogged as we try the Marantz 2385 more as upgraded the IC actually doesn't affect the sound, but we need to test to see where it 'craps out' as blogged in the ICs blog above. The KA-7100 from 1977 is 60w & it has No ICs, not even in Phono or Tone, but it's that one-board type construction with various stages on one board instead of done separately, actually preamp all on one & power amp & power supply on the other with the cheapo heatsink in the middle of the board style build, so still not so great. 1977 75w KA-8100 similar if 1977 90w KA-9100 has the dreaded IC output block & naff rack mount handles if otherwise looks good. Model 600 from 1977 at 130w is one out of the usual numbering & was £538 in the HFYB. This is all Transistors & appears to be a 'Prestige' Range of some sort, away from the IC gear. We blog more on this in Dec 2018. 1976 100w Model 500 & 130w Model 650 too, not heard of those before & all likely rare ones. Not sure why 600 & 650 are both 130w if the manual confirms it. Ebay one at £1150 says "600 Supreme" which isn't the right name, just a plain looking amp that hides beneath a generic looking outer plus having rubbishy screw-tight bare wire connectors. The "Supreme 1" is that strange split-circuits amp from the late 1960s as blogged before with Bass, Mid & Treble stages. Clearly the Best later Trio-Kenwood are not so easy to spot. By 1979-1980 it all changes as KA-907 (KA-9077) 150w is that big-board type construction, all transistors except the Tone & Filter Amp which are ICs, KA-801 110w from 1980 has IC for Preamp part if the Circuit looks confusing in 2 parts with overdesign if the other IC is the Meter stage, KA-701 80w, KA-601 60w. Trio-Kenwood did some 'High End' Pre & Power Amps too, as on our 'List Of Amps' page for 1979.

Ordering Electronic Components Online.
We use mostly Farnell if have used RS-Online before. Ordering Parts can often be a real chore with the fiddly selection boxes on these sites, so we buy enough to fill the parts drawers of regularly used ones to not waste ages on each amp. Still took over 1.5 hours to get what we needed found this time. Over the last 5 years the Range varies to what's out there, Panasonic being the worst for having abandoned a lot of the large capacitors plus smaller film ones, you may find NOS ones on ebay, but New Stock they're just not available. Finding less easy parts like axial capacitors by size is time consuming, having to rake through spec sheets to find out the size of items that aren't noted takes ages. To avoid Out Of Stock items that may be on back order for over 6 months & then find they never got any as no longer available, as of typing an 8.2K resistor in the type we use is "no longer stocked" which is illogical, but the reality is they've likely run out of these as we get the carbon cream coloured ones that look vintage as they could be 20 years old now, not the blue metal oxide ones that are still made, if lower power ones are findable though. To stick to the better brands we've bought many times to trust in the bigger caps as plenty on ebay are cheap nasty ones we throw away if we see any used in amps, to cut them open to see expected size but lightweight cans with not much inside is the cheat there. Certain favourite parts are always in stock if last time we ordered smaller electrolytics the whole lot came on tape as Farnell just added them but didn't say tape ones, the loose ones we prefer as unpicking from tape took ages. "How can you not have that?" gets yelled & sometimes to find a switch or fitting is actually easier to do on ebay as several sellers put huge markups for buying Farnell stock which helps if you don't need to do a big order also. Find the part on ebay & look on Farnell to buy it. Some larger capacitors are light blue which can show through grilles & parts are not for show so we go for the Black cased ones just to look more mellow as the light blue ones look a bit amateur. So you fill up your basket with lots of parts that will disappear into drawers making you wonder what you spent the money on if this time we caught their Bank Holiday deal & got 15% off, which is nice.

The Severe Problem Of Electrostatic Headphones or Loudspeakers.
We first heard of a possible problem when a customer got us to upgrade their Sony STR-6120 & then with them using 1978-era Stax Electrostatic Headphones, on them trying Bass on +5 via these Headphones that as with Electrostatics generally, don't do Bass very good. The Full +5 Bass plus playing very loudly they add on reading this, caused the amp to damage the Driver stage, it was left to smoke until it appeared through the case top. Why did it do that? They drove it too hard for it's 50w power is used up just past midway, to start with clearly. It's taken the customer a while to find a Circuit Diagram of the Stax Headphones box & then it's obvious why it caused problems. The Stax SRD7 Mk II circuit first has some limiting Thermistors to stop Wattage over about 30w causing bother, but then it has a Transformer & then Surge Limiting Devices like those blue MOV 'capacitor' looking things used in Power Supplies. The trouble with Transformers is they don't do Frequencies under 20Hz as linear as you'd expect, they have losses in the design that cause a shunt load across the amplifier outputs that could be extremely low, almost a short circuit. Overload an amp or short it & you draw excess current & something gives to cause damage. Amplifier Testing as blogged before about the HFN test reviews, the Electrostatics are notorious for 'blowing fuses' as well as damaging amps that they likely won't tell so readily, it's because they are a bad load on amplifiers like speakers Celestion Ditton 22 etc that have severe impedance dips. The Quad ESL57 puts the Amplifier Output straight onto a Transformer & at certain frequencies the ESL puts a very hard load on the amplifier. Look at Quad Amplifiers, these are very tamed purposely not to get into problems with the Electrostatics, Deep Bass is very limited & Treble is Tamed not to cause problems. The thing is people get used to a certain Speaker or Headphone & despite 'better' being around, they won't change. We don't like Taming Down Amplifiers for Mismatched Speakers but it's their decision to buy another amp, so as we suggested we will alter the amp so they can use Low Filter at a different frequency to the designed one to not lose upper Bass, but we will need to further tame Bass elsewhere knowing that Electrostatics & Transformers can't cope. July 1967 HFN has an article about Transformer Coupling in a Gordon J. King article, pt 21 of "Understanding Hifi Circuits" when he first looks at Transistors. Here they ask about Matching Transistor Amps to older 15 Ohm speakers, suggesting a 3 ohm Speaker output, possibly early EU ones, and to use a Wharfedale Matching Transformer. But a transformer becomes Lossy on Deep Bass with the article suggesting 20% loss at 20Hz & 37% at 16Hz. But if there is a Heavy Loss at the Deep Bass Frequencies, it will make a harder load for the Amplifier to play into as the Ohms value takes a dip. Most Amplifiers can cope with 4 or 8 ohm speakers, but as with Electrostatics, if there is a Heavy Loss the Amp will be overdriven. The HFN article tells that an amp outputting deep bass info such as LP warps or Needle Drops can put out a heavy Sub-Bass signal that gets into problems with the Lossy Transformers causing Protection Circuits to kick in or Fuses blowing, or component failure. The General Idea with using these Difficult Electrostatics is to use a Quad amp which are purposely tamed on deep bass & high treble, the areas that get into problems with the Electrostatic circuits or to add a Resistor into the Cable to stop the Circuits upsetting the amp when they dip very low, to add a 2 ohm 50w resistor In Series with the Speaker as in Speaker + output into 2 ohm resistor & then to the Electrostatic. Why these awful Electrostatics are popular when they have been known to damage amps for decades is a Real Mystery of Hifi, people clearly believing the Hype. Tamed down amps may cope, but fully upgraded wider bandwidth amps will just be trashed. We've sold another amp to a Stax Electrostatic user & we'll have to tame it down more than we'd expect. They know the risks after all. We suggest you Avoid Electrostatics. On designing our Valve Phono stage in the LX33 without yet putting some limiting of these 10Hz type signals the amp gets into problems, imagine being able to 'hear' every warp on a record as it upsets the amp stage causing that 'valve bounce' as the voltages dip & restore causing a gain loss, very bizarre to hear.
Our Solution after researching this is to make cables that add an extra 2 ohm load in series with these Stax headphones. Enough old Hifi Mag tests show they start to add the 2 ohm resistor as earlier tests were just trashing the amps that were wider range than the old limited valve designs plus the valve amp already has a Transformer on the output. Later tests still did get into problems though, if more for less good designs. A transformer as a Speaker Loads is far from ideal yet this "difficult" idea has been around too long to just ignore it. The ESL 57 was first out in 1954-56 & Valve designs were very limited so no problems were noticed, if by the Arrival of Transistor Amps by 1965-67 these were getting into problems. The Sept 1967 review of the Sony TA-1120 if they picture the TA-1120A shows the circuit they use to Simulate an Electrostatic load & not Trash the amp. The circuit they use adds the 2 ohms load plus a 20µH choke inductor to reduce the highest treble, this is in series with the following amp load to tame it & as the 'Load' across the altered + & - amp outputs it uses a 15 ohm resistor paralleled with a 2µf capacitor. The Electrostatic load you can see needs to be tamed with having a base-line Resistance load of at least 4 ohms plus the choke to limit the highest frequencies. The ESL 57 & similar are really not as Hifi as many think, they are a very harsh load & the fact of the large area of the speaker unit it has a smooth midrange but notorious for having poor bass. You can get far better sound from a 15" traditional Cone speaker. But Electrostatics still live on...

Marantz 1970s Receivers.
Might as well look at the 1971-79 Marantz Receivers, none of the Amplifiers have ICs for Tone so why does the huge 185w Marantz 2385? The 2500 does too. Our "List Of Receivers" page starts with 1973
Model 19 50w £800 the crazy oscilloscope one. 2215 15w, 2230 30w, 2245 45w, 2270 70w £347. 1974 adds the 2010. 1976 adds 2220. 1979 after HFYB messes up not including the brand brings 2215 15w (again), 2226B 26w, 2238B 38w, 2285B 85w, 2330B 120w, 2385 185w plus the 300w 2500 & the 1980 2600. We'll not include the Quadraphonic ones. 'Classic Audio' Site lists more receivers like 1968-70 era ones 18, 19, 22, 25, 26, 27, 28 & 29. Also more of the 'Classic' era style 1515, 1520, 1530, 1530L, 1535 & 1550 which appear to be more budget or minimalist versions of the '2xxx' range. The 50w 1550 manual from 1978 shows they were also the more budget 'Superscope' brand as MR250 or MR255. The 1550 has classic Marantz looks but the insides show the cost-cutting with the main board having Power amp & Power Supply on if only the Phono is an IC, probably still decent if maybe lacking in spec that would still upgrade. The isn't much as an IC is the power amp early stage if with the last 2 drivers as Transistors & Tone is Transistors. More. 'CA' site appears to list 2015, 2200, 2210 (??), 2215, 2216, 2218, 2235, 2250, 2252, 2265, 2275, 2325 plus variants, some the 'CA' site has no pics so assume they don't exist. Why so many similar ones? Clearly some of these were non UK & for certain regions, a 2385 in Black you have to doubt a bit as a home-made job, or it was a prototype. Far too many to be looking through, generally the earliest ones will be 1971 models like the amps, the 2245 wasn't such a good design. By 1973 the designs improved & again by 1979 the quality will have dropped. 2265B & 2285B have Differentials in Tone. Our interest was seeing which had ICs in, 2500 has the Tone ICs if looking at some, No ICs beyond Tuner are 2235, 2245, 2252B, 2265B, 2270, 2285B, 4230 4ch, 4240 4ch. The 1979 HFYB ones with 1978 additions to check... 2226B 26w is a revised version of the 2226 if no ICs beyond tuner if starting the putting Power Amp & Power supply on one board, 2238B 38w similar to 2226B, 2285B 85w has 4 transistors for the Phono, Tone has 2 differentials if otherwise no ICs & like other amps, Power amp is 16 transistors, Doubled outputs at 85w will mean it's more like a 50w amp for volume, just higher current as affects the 1152DC we had. 2330B 120w is the same as the 2285B overall. What was revised between the "B" and "Non B" versions is probably mostly Tuner related as the 2600 was a revised Tuner to the 2500 if the "B" versions have the Tuner fascia section in Silver not Black. Only the 2385, 2500 & possibly 2600 have ICs, perhaps in the 1976-77 era they were seen as better?

Marantz 4070 4ch Amplifier From "Too Far Gone" To Rebuilt & Upgraded.
Probably one of the hardest Transistor amps we've had to get right & then upgrade too, a tricky one to work on as it's the standard smaller size so is very well packed. Not an IC in it. Now playing after Power amp upgrades the sound is rather addictive. the Marantz sound as upgraded is a neutral one, not as Bassy as some amps you may think on first play, the 185w Marantz 2385 is similar. Bass certainly is there & the sound playing the 4070 as 2ch Bridged 35w mode is no different to the 4x 15w mode if the added Bridged Power gives more weight. Above we've looked at many of the Marantz 1970s Receivers & Amps to see which other amp has the same Design as the 4070 is straightfoward & is actually much like the 1971 Marantz 1060 if the 2245 receiver from 1971 was overdesigned. Possibly Hifi Mag reviews picked up on the difference in sound as Marantz designs despite getting in to 'fashionable' design on some are generally fresher sounding than other post 1972 brands even with the 185w Marantz 2385 having a similar sound. The problem with Marantz is they didn't get put into the attic after a few years as was the idea that 'newer was better' so Marantz amps are often very tired sounding after far more use. The 4070 sounds as good as you'd want from any amp, detailed precise sound with a solid bass. On Speakers now upgraded more, it's a fast fresh sound still with good bass, not the weight of the 2385. Which is best on Speakers? Is it really that once-tatty old thing now sounding like that? Yes it is.

Day One: Compare Marantz 4070 to Marantz 2385 For Sound Quality.
This is in Two Parts. Get used to One Sound from an Amp & then find a quite different one not pleasing at all. Quadraphonic 4070 played in Bridged 2ch mode at 35w. 2385 at 185w. Been playing the Marantz 4070 for an hour on 1980s Stereo tracks, currently on Soul-Dance ones. It doesn't sound limited for the 15w version, no softening of the sound, if we've only heard it with upgrades & recapped to not know what the original raw amp sounds like. Play it for hours sort of sound as precise clean sound revealing the vinyl flaws honestly if not uncomfortably. Bring the 26kg 2385 in & the sound is quite different, not as precise on the lower treble-upper midrange sounding a bit blurry & smearly, blame the ICs. The slight lack of confidence, a solid chair to one that's a bit ricketty but not unsafe is the idea. The focus just isn't there, the sound is softer & not as upfront. But read the "Full 2385" part below, all is not as it seems... On volume with headphones we're putting at about the same pointer position as the 4070. The Tone amp has 2 ICs per channel & "Out/In" doesn't bypass either IC, it just nulls the Tone Controls. There is a 'glassy edge' on treble, where is it in the amp? Blame the ICs? Read on... One track from 1987 Sherrick "Just Call" sounds especially edgy, that sort of metallic edge which will show on an Oscilloscope as clipping on the wavetops on eg a 10kHz test tone. The 4070 we really can't find anything wrong if perhaps not as strong on Deep Bass as earlier amps can. So the Natural Test next is Power Amp & Preamp Swapping: 2385 Power + 4070 Pre. Using Blanking Plugs on the unused stage. Interestingly the 2385 power amp with 4070 still has the less upfront sound of the 2385 if is much improved with the 4070 no-ICs preamp, still not as sweet as the 4070 power amp. Midrange appears recessed & still a slight grain to the sound revealing the 2385 power amp despite 185w isn't the sort of "pro" sound the 4070 has. 2385 bass sounds a little restrained when the 4070 was more open. The 2385 power amp doesn't bring the 4070 pre out to it's best as the simpler 4070 power amp stage does. 4070 Power + 2385 Pre is next. Do we blame the ICs again? This combination is much preferred of the swaps. The 2385 ICs preamp actually doesn't seem to be the 'problem' with the 2385, the Tonal Balance of the Power Amp is. The 4070 preamp with Transistors is still preferred if the 2385 Preamp as with the Power Amp is just a little soft on the midrange. Back to the Full 4070 leaves the 4070 sounding a little less trebly for a brief minute as the reduced midrange on the 2385 pre accentuates the Treble. Tonal Balance understood again, the 4070 is spot on & the bass in the 4070, on headphones at least, is preferred. Verdict on The 2385 Sound after knowing 4070 better. Neither Preamp or Power Amp sound as fresh & accurate as the 4070, both upgraded similarly. The 2385 ICs don't appear to be any problem at all, for our upgrades elsewhere. The sweet fresh precise 4070 sound on 2x 35w can't be matched by the 2385. But that's only half the Story...

Day Two: Compare Marantz 2385 to Marantz 4070 For Sound Quality.
NEXT DAY: Back to the Full 2385.
The trouble with comparing is that once an amp has been played for an hour, you are used to it & tonal variations will often get you confused to which sounds 'best' so to play the 2385 the next day. The 2385 does differ from the 4070 in tonal balance, if the 2385 as upgraded is fast & punchy. We looked at the 4070 preamp to see it could still be upgraded more. the 2385 ICs are extending into MHz as we found, the 4070 is a little tamed & on speakers needs a little more treble, when the 2385 was different. So to listen aware of what is being listened to. The Sherrick track extends further on the treble is the reality, the 4070 rolls it off to sound 'nicer'. Once used to the 2385 sound after about 10 mins on familar 1980s Stereo tracks, it's not edgy & this 'phenomenon' we have noticed before with amp comparing & it does upset opinions. It's because your Hearing compensates & adds a little "EQ" yet on hearing an amp that isn't a little duller it can sound awful. We used to use the "Axel F" theme as a test track if tired of it so hearing it again we don't remember it sounding quite as fast & clear as the 2385 plays it. Today the 2385 sounds very precise with mind-numbing Bass which is nice, tight bass not the Low Damping Factor type Bass. The 2385 is a much wider Bandwidth Amp than the 4070. To leave it written as it happened to show how your Hearing can get used to one Tonal Balance & after being reset the Next Day your opinions can be totally different. It's how people are happy with their Radiogram or i-Pod until they hear Better Hifi. we recommend you play your Hifi to other people & watch them soon realise how lousy theirs is. The huge dynamics of the 2385 remind of hearing Late 80s Dance tracks in Pubs & Clubs at the time. Compare back to the Marantz 4070. We expect it'll sound a bit dull in comparision as the "little less trebly" comment before tells. Indeed the High Treble is rolled off as we see in the Circuit if the Sound overall isn't that dissimilar. Hasn't got the huge dynamics or Big Bass but has the Stereo width & Speed. Still has a lot more kick than a typical 35w amp & now for hearing more extended treble, now the 4070 does lack a little finesse in the higher treble. The 4070 does have NFB on the Tone-Preamp & on the Power Amp Differential unusually & sounds a little compressed as NFB will do, if it's more Domestic Sounding. The thing is once one Amp Sound is familiar, you only really want it. The 4070 performed very well for what it is & we'll upgrade it more, it was a lot more listenable than the big jump to the more trebly amp for the Hearing Compensation issue. Compare 2385 to Luxman LX33. The midrange instantly noticed as a little more full. The 2385 has bigger dynamics, more extended treble with the multiple outputs richer bass. Beyond that there really is still no real difference Transistors to Valves except 185w of Transistors with high current capability leaves the 30w Valves sounding a little more contained. Perhaps the 2385 is bigger sounding than hearing 'live' if we're playing processed music from Vinyl. Playing the busy 60s Ska the Valves plays it better balanced for the Music itself & brings out the Room acoustic more. On some fast treble sections Valves doesn't quite cope as well, before we've found Valves slew rate isn't as Fast as Transistors. Back to 2385 on the same Ska track, Roland Alphonso 'Cleopatra' from the UK Doctor Bird 45, the room acoustic sounds the same if the sound is a wider bandwidth hiding subtler detail with wider treble. Yes, Record Dealers have better test discs to really know which amps cope best. Easy to play perfectly recorded tracks, to get complex & possibly muddy sounding ones to really test detail resolution & this was always what we wanted: more detail. The difficult treble section just before midway doesn't trip up the 2385. This Is How Amp Comparing Should Be Done. We've levelled the field by servicing & upgrading both amps with the same ideas, yet the 2385 on trying after 4070 was considered 'difficult' as you can read. But then used to the 2385 sound the 4070 sounded good if revealed where it was lacking, if much less 'offensive' as without the Hearing High Treble Compensation. A swift swap from late 1980s Stereo into 1960s Jamaican Mono Ska with much smaller dynamics & not have it confuse is a great amp test & the 2385 does both well with hardly any 'mind-muddling' for the want of a better word... Got us playing Calypso & Mento from the hoary old UK 45s as recorded over the years, these on headphones are usually hard going if the 2385 plays them to be enjoyable. You can pick out one voice in a noisy crowd as you tune into it, surprising not more research by the White Coats into this, if probably why not is most people play dumbed down or aged amps to not notice...

Marantz 4070 Compared To Trio-Kenwood KA-6000.
This was comparing the day before the 2385 was found to be a lot wider Bandwidth than the 4070, as in after writing Part 1 above. Our KA-6000 is much upgraded. The 6000 reveals how different some amps sound in Tonal Balance, it has the same quality as the 4070 if has higher treble with a slightly recessed midrange, giving a different 'listening experience' revealing the difficulties of amp comparing. Marantz 4070 Compared to Sony TA-2000F/3200F. Sony much upgraded & after the 4070 power swich went noisy, on speakers we found the Sony very like it for that precise clean midrange with both amps having very wide Stereo. Marantz 4070 Compared To Luxman LX33 Valves. 30w LX33 our design on their chassis, now with non-crackly Shuguang EL34 valves. Actually sounds very like the Marantz if plays a lot louder. Essentially the Transistor Marantz 4070 sounds like the Valves Luxman LX33. Valve sound? Transistor sound? Very little difference in it. Valve Midrange is more open for the lower amount of amplifying devices. Valve Treble is sweeter similarly. Which is the nearest Marantz to the Marantz 4070. The 1971 amplifier 1060 looking at circuits does show more design differences beyond similarities, the 1060 doesn't have a Differential. 1050 or 1072 is quite different. 1030 has no Differential. The 1040 from 1974 with 20w is very similar on the Power Amp & is the nearest to the 4070 if there is no direct equivalent & the 4070 is bridgable to 35w.

Marantz Quadraphonic Amplifiers & Receivers.
In Amplifiers only the 4070 with 4x 15w or 2x 35w & 4140 with 4x 30w or 2x 70w, the 2440 is an add-on amp to make 4ch using a regulat Stereo amp plus te 2440 to add 2 more amp channels. Receivers are 4220 with 4x 8w or 2x 20w, 4230 with 12w x4 or 2x 30w, 4240 is the one we had in about 1998 as it has the bigger spring connectors than the 4230 with 4x 17w or 2x 40w x 2, 4270 with 4x 25w or 2x 70w, 4300 with 4x 40w or 2x 100w, 4400 with 4x 15w only, 4415 with 4x 15w only & 4430 with 4x 30w only, these last ones are not Bridgable. A lot for a Multichannel Format that didn't take off. 'Audio Classics' Marantz section puts 1972 on 4300, 4415 & 4430 if they add a spurious 4420 that doesn't apparently exist. 4025 is a 2ch Stereo 'Cassiever' a Receiver with Cassette player as was a brief fashion. 4000 is a 4ch Preamp. 4240 receiver is the nearest to the 4070 amp if designs always vary & the 4240 service manual shows the 4240 had a few issues that needed 'dumbing down'.

1964-65 Kenwood KW-70 Valve Receiver
This appears to be a later version than our 1963 Trio WX-400U & with a 'Kenwood' name on suggests it was sold in a few countries, if these were all Export-Only as regarding Japan. Beware the misleading "25w per channel" rating, it's actually 25w total meaning 12.5w RMS per channel both channels playing. This uses different valves to the WX400U, the 7189 is in the Sansui 500A where they unwisely put a very high HT to get 18w from 16.5w valves. The KW-70 uses 6AN8 splitter-driver valve which should give a little more gain than the WX-400U which wasn't as loud as a 10w Rogers Cadet III. The KW-70 comes as 117v or Multivoltage as the rear sticker tells, a small slider just inside to the left of the antenna switches voltage, if it's not got an added blanking plate to stop you switching voltage in use. A customer asked about this to upgrade, the one on ebay Italy is in good visual grade, but it'll need everything rebuilt & redesigned to be worth having to use. Conical input sockets are not much good for modern cables, lots of very low spec inside, Hum Balancer is a lousy old circuit instead of using DC heaters. The Tuner is Valves can be rebuilt giving a very fresh surreal sound like no fizzy ICs tuner, if again a huge job. People buy these thinking they are easy to just replace a few things & realise it's not very good at all. As you can imagine for us having rebuilt & redesigned the Trio WX-400U no-one else on the Planet can 'Rebuild Him'. We'd do another, but to be aware the rebuild & redesign costs will be very high. Perhaps getting a Fisher valve amp with better design & DC heaters would be a better buy is what we suggested. We've thought to look for another Trio & this Kenwood KW-70 would fit the ideal plus it being improved slightly over the WX-400U, but the amount of work to have an amp we've already dealt with via the WX-400U plus getting that one back half trashed, we'd sort of been there & done it.

Marantz 4070 On Loudspeakers.
Another Marantz blog as having Quadraphonic & Monster amps at the same time brings up a lot of interest, considering both we fairly dismissed as "avoid" based on how aged raw ones sound. Not so once Upgraded. Marantz 4070 is 4x 15w & 2x 35w. On Headphones by switching the 2ch to 4ch mode the volume is the same if in 2ch it is slightly more weighty for 15w to 35w. But on Speakers we tried it & found on 2ch mode it's a punchy lively sound & more that a little hard to believe it's only 35w, it's fast, punchy & delivers deep bass more like a Parallel Outputs amp. To turn it to 4ch mode, what will happen, is it a risky thing to do? Only one way to find out. It just makes a small click & then... Volume is cut in half. Bridging doubles the Voltage gain & also halves the Damping Factor which is why we get this surprising sound if Speakers are connected Direct drawing current unlike Headphones through the usual resistor circuit which draws very little current explaining why Headphones can make amps that may not match all speakers sound good on headphones. The 15w mode once turned up to the same listening level has mostly the same characteristics if at 15w it doesn't kick as much, but it still sounds good. Finding a section with Sub Bass, the 2ch mode plays it so it's heard if back into 4ch mode & set to the same level the Halved Damping Factor does give it that extra Bass confidence. Bridging on Loudspeakers on an amp upgraded right gives a sound like you'll never have heard & the 2385 on speakers with Triple Parallel Outputs sounds different too. The extra voltage gain, double in theiry plus the halved Damping Factor on speakers is what makes Bridging worthwhile, if what it sounds like as Original we never knew for the 'Too Far Gone' grade it was.

Bridgeable Amplifiers aka BTL- Balanced Transformerless Operation.
The 1984 Sansui AU-G90X was a Bridged Amp as designed, hidden by their "X-Balanced" name, if the circuit actually was 4 channels Bridged into 2 with their unexplained "Hot" & "Cold" outputs for "+" and "-". Only by getting the 1973 Marantz 4070 did we realise on looking at the circuits, that's exactly what the AU-G90X was, the 4 main capacitors in that only read ±31v. a case of getting a good sound on Headphones, but it didn't match the Tannoys so we never really got into the amp enough. the Marantz 4070 matches the Tannoy 15" Gold Monitors perfectly which is unusual for a 1973 amp. So we can now hear what the Bridged amp sound is like. We've had the 1995 Spectral DMC 30 & DMC 90 preamp with power amps that can be bridgeable, if unfortunately these have no circuit diagrams to understand or even adjust the amp right. They were also 110v only so to Bridge to 200w would need a hefty step down transformer, the typical 300w we use doesn't have enough power. It's the 2not knowing" that frustrates with Amps. Back to the Sansui AU-G90X, the HFE site has the User Manual we notice, before that only seeing a 1985 ad in HFN/RR told us of the "X-Balanced" design as the Service Manual doesn't even explain the Circuits, unlike how Sony did on it's earlier manuals. The User Manual tells you nothing either surprisingly. To wonder why the AUG90X has so many adjustments to do & now realising the circuit wasn't as "special" as they suggest we see their settings aren't optimal either on some. The Marantz 4070 is understood & biased using the 4ch mode it can be set exactly. It's 4x 15w and 2x 35w. 35w amps usually are quite restrained to not be too upfront or punchy, to not deliver too much current & get into clipping. 4070 sound on speakers using Bridged Mode playing TV shows with THX type big sound effects, "Animals Behaving Badly" the second half of the 3rd episode, to watch in 2 parts as too much info on one hour numbs the mind a bit. The soundtrack voices are very clear without having the 'mismatched' peaky midrange, treble is crisp if we haven't done the preamp too much as really it's not worked reliably beyond 2 days use. The pleasing thing is the big dynamic bass even with the Volume control only really at the 9 o'clock position, the bass realy kicks & is poperly extended. All on a modest ±26v HT. The AUG90X claims 130w on ±31v yet the 4070 claims only 35w. The 4070 output transistors are TO220 sized ones rated 30w. Yet it delivers "that sound" which is not expected. Bridged Amps as with any amps need good design to sound their best & critical adjusting to keep sounding their best, the AUG90X was very critical on adjusting & could lose Bass for being only slightly off. It was a rather complex design though with "IC type" circuitry, three Differential & then into 4 stages of Class B circuitry before the Output Transistors. We managed to improve it hugely & the buyer of it said they were surprised how detailed it was compared to other amps & they bought our 1965 Sony TA-1120 & 1973 Realistic STA-220. The Spectral pair we found the Power Amps sounded good if they were altered between runs giving difficulties, the preamp was not so good as way too overdesigned with ICs & Class B circuitry. Not knowing how it Bridged the amp we didn't try it as it's not our amp to experiment on especially for it's design & "unrepairability".

Beware Very Misleading Valve Amplifier Ratings.
A customer is looking at Trio-Kenwood early receivers, ones styled like the Trio WX-400U we had. Unfortunately the HFE site is putting the misleading "Music Power" ratings which could show 60w which people get excited at. But you're not learning valves properly to understand this is far from the truth. Learn the Valves. EL84 in the WX400U and KW55 uses 355v plate voltage & an EL84 in Push-Pull can only manage 10w RMS per channel. KW-1100U looks impressive, 37w says HFE, this is an uprated amp using 7591 valves on 490v. It'll realistically be about 18-20w RMS. The 7591 rates 28w max plate dissipation if in use designers don't usually push to the highest power as it causes problems, the Sansui 500A running 7189 valves at 420v was very high, actually higher than recommended & caused us lot of problems, run to get 18w which is more than the 16.5w specified. The Fisher X-100-B we found Fisher rated it at 24w RMS per channel, perhaps that is is "one channel playing" & it's more like 15w RMS both channels playing. 7868 valves on 435v if the valve is rated 19w max so 15w is more realistic. So much deception in Power Ratings if by 1971 laws changed this "130w Music Power" on Amps that were really only 30w RMS. You still get similar nonsense on “400w PMPO” with a 45w amp. Unfortunately whoever uploads data to HFE does get it wrong, we've seem "80w" amps that are quoted as Music Power in the Manuals & only 40w RMS really. Do your research not to be misled. 10w in Valves isn't enough power as we found with the Trio WX400U, we've found 15w in Valves is the minimum needed. If you want higher power, in Push-Pull EL34 can do 50w, KT66 can do 25w, KT88 can do 50w for Hifi uses. EL34 in the Tube Technology Genesis monobloc is rated 100w as it parallels the EL34 to get more power.
The Highest Power Valve Receiver is the Fisher 800C with 7591 valves with a likely 20w RMS rating. Marantz & McIntosh didn't make Receivers until the Transistor era with Marantz 18 in 1968 is their first & McIntosh with MAC 1500, MAC 1700 & MAC 1900. Marantz Valve Tuners 10 series, Preamps 7 series & Amps 2, 5, 8 & 9. McIntosh made quite a few Valve amps, the MC275 the best known. A 'Roger Russell' site gives the most info on McIntosh.

September 2018 Blog.

1967 Bring The First Package Hi-Fi Systems To The UK.
USA makers like Fisher had been making Consoles with separate Tuners, Amps & Speakers fitted in one cabinet since the valve era. UK had Radiograms or build-in gear like Quad II & 22 preamp-power amp. The idea of building gear in to cabinets may have looked smart in the adverts for these cabinets, Hampstead High-Fidelity, Largs & Imhofs were the main makers of these, but the Reader's Systems page tells the truth. They are clumsy & untidy, with Record Players put in a well & still reliant on the wooden lids so the Dustbug still sold. But since 1964 with the introduction of the Perspex Lid for Turntables as blogged before, things start to change. Soon come the TV-grade makers with systems that are 'for the masses' & generally very cheap to replace the oversized 5w-8w Radiogram with. Sept 1967 HFN mag has tyempting ads for ones like Sharp with the GS-5000 a combined Turntable, Tuner & Amp with matching speakers. This has 12w Music Power so likely 7w RMS if so did your Radiogram, this admittedly neat & attractive unit would sit on the sideboard once you paid your 145gns (£152) & the Radiogram went in the Landfill. Other Arena ones like GF1225 are a basic record player 7 amp with 2 speakers, "8w output" probably means Music Power so 4-5w RMS but for 65gns (£68). The Sharp one you are paying for the convenience if to buy a Tuner-Amp, Turntable & Speakers could be done for less in reality. The interest for this blog is the First Proper Hi-Fi "Audiosuite" by Goodmans. This is forward thinking if using items you can buy separately as they've been around a few years. The Maxamp 30 is a 15w amp that got good reviews & sales, their AM/FM Stereomax tuner plus the MT1000 turntable with arm & perspex-wood lidded case with a choice of Maxim or Magnum speakers. The only thing missing is The Discount to buy the lot in one go. Maxamp £49.50, Tuner £71.90, Turntable £53.75 with speakers £17.75 or £36.75. Makes £192.90 or £211.90 which is comparable to a better Radiogram if here you get 15w plus Hi-Fi separates of a certain quality. The idea of having all of One Brand Amp-Turntable-Tuner continued in to the 1990s adding Cassette then CD to get those Midi Systems that by this era were not of much quality, but they sold well as not many understand Hifi to go into a Hifi shop & be dazzled by Salesmen more interested in selling off Ex-Demo gear. These sort of systems were bought at Dixons, Currys, Catalogs paying on credit, or Department Stores. The Goodmans one in 1967 was the start of all this & of decent quality with good looks.

What Do You Get As A Package Hifi In 2018?
Look on Amazon for "Hifi System" & what you get is depressing... Their No.1 Best Seller is the Panasonic SC-PM250BEBS DAB Micro Hi-Fi System has a RRP of £109. What it does needs the .pdf reading, a 2014 design with DAB radio, FM/AM Radio, CD player, Streaming, USB, Bluetooth & a Remote. No Turntable, No Minidisc and No Cassette won't shock anyone. It's just a device to put Music onto an i-Pod or Phone, if today be sure the Phone has the music as an i-Pod is obsolete now really. Importantly 67% of Reviews say it's "Five Stars" showing they've never heard Vintage Hifi. Advances in Tech mean items once expensive are now so cheap so it will impress many, but Amplifier Stages will sound lousy to us. It has no Headphone connections says one reviewer. They're more interested in features than sound, their music appears unimportant & that's not just us criticising what they play. The "One Star" reviews tell you it's cheap & you'll know it, but they will know older Hifi. "Rich Bass & Clear Sound" it proudly states. For the advances in Computing Sound Hardware, it probably will sound clean, but how tamed the Amp stage is would only make us laugh. The amount of "Rubbish" our Soundcard has, Crystalliser, Surround, Smart Volume, Dialog Plus, Noise Reduction, Acoustic Canellation, Bass Management, 5.1 channels plus Windows with more Audio Enhancements, we have to be sure all are "Off" as they are all unwanted garbage to us. It makes you realise how Rubbish Sound is today, no-one understands it as "The Gadget Show" reveals & forever adds Effects & Enhancements. In earlier ones you got Effects like Arena, Nightclub, Small Room etc if those seem forgotten now. The Panasonic is like a fancy Clock Radio & the specs show it's 10w RMS meaning 20w RMS in total yet a laughable 220w PMPO in the millisecond before you destroy it, a thing to bear in mind. The interesting thing is for it's 10w that if a Transistor amp you'd expect to see 35w (35VA) max, the Panasonic only uses 14w at max power & 0.2w in Standby. They have to be using a sub-Class B technology or similar IC to draw such low power plus the power the rest uses. 220w PMPO for 14w, huh? Audio Alchemy. Speakers are 4" 6 ohm weight 1.3kg if both or one? Current Amazon price is only £89, we should buy one, try it out & send it back, but it'd only annoy us instead of amuse as it does here. Looking at others on Amazon... LG CJ45 - 720W RMS LOUDER HIFI Entertainment System with Bluetooth Connectivity /CD / FM PLL / Karaoke Creator / Multiple Connection / Semi Light Show / Twin USB / Full function Remote Control is beyond laughable, 720w RMS, really? 20kg of crap for a mere £195, utter ridiculous rubbish, the Amp Box is 35cm wide if tall, with speakers probably 8". It's called LOUDER, their caps not ours & 2 speakers pus a sub. To look on the LG site to see how they get 720w, 3 speakers 240w each they say, yet {uncontrolled manic laughter from us...} it only draws 80w max from Mains. Their speakers are a very low 83dB sensitivity with just 6.5" bass drivers with 3 ohm. 3 ohm will draw more current than 8 ohm. 80w aka 80VA on a Vintage amp means it's about 15w RMS per channel, there is no way you can get 720w from only drawing 80w from Mains, what circuitry do they use? It's sold as a Teenager's Party amp. How they can call it 720w RMS is clearly beyond dishonest. No reviews on this. Buying Cheap Mass Market Junk is the thing here, but sadly these 5-Star review buyers don't know any better. Grading Turds as we call it. The Budget Priced Mass Market goods have always been crap, the cheap Crap started in the Early 1970s for Discount Stores. To be fair, what you get on paper at least looks impressive & is exactly what Today's Buyer needs with paying such tiny money, a temporary belief you are getting better. Audio System & Speakers for £89 delivered. The speakers will be rubbish & using better ones will just reveal the limits of the rest which is sub-budget price in reality. What you need to do if you have a Good Vintage Hifi System is invite your friends who say "how great" their £89 'Stereo' is & ruin their lives by playing your System at them. They'll then hate theirs & probably never speak to you again as they were mindblown by Real Hifi. Use your Weapons sparingly.

1967-69 Amplifiers As All-Original Once Serviced.
As time goes on the little-used Amplifiers & Receivers are coming out, often from the Original Owner's estate. We've had the 1966-67 Sansui 3000A as original with little use to hear & it reveals how good these amps will have been when new, a slightly Retro but very Musical Sound, at least on headphones. Then we get another 1967 Pioneer SX-1000TDF as the first one never worked right, so to hear this as Unused For Decades it was really aged sounding on headphones, but after Servicing it came to life, lacked enough Bass for modern tastes if a bit on Bass sorted that to a degree. Both these amps reveal an amplifier sound still based on the valve sound on these high power ones, if that quickly faded away by the 1969 ranges, good designs with some limiting, but high on Musicality meaning Pleasure In Hifi. With some Amps up to 1972 it's possible on low-use amps to hear what Buyers Heard when they were new. We've played the SX-1000TDF for an hour on headphones to hear what 1967-68 buyers heard. As mentioned in the Blog below the early Pioneer actually has a Bass Reducing circuit which is an odd thing as they didn't use it after 1968 as the 1969 SX-1500TD doesn't have it. Read more below as to try them on speakers of the same age...

The 1966-68 Pioneer Receivers.
Pioneer only did higher power in Receivers at this time. 1969 ranges SA-500 only 13w £54, SA-700 34w £91 as our List of Amps page tells, as Pioneer stuck with Valve Amplifiers into 1966-67. As the "...So Dumbed Down" blog from early August 2018 above shows the makers by 1970-72 really didn't want you having the 1965-69 sound. So how buyers put the 1960s amps in the attic to buy "Better" that sounded worse is the Power Of Hyped Advertising. The 1967 SX-1000TDF sounds so sweet with wide Stereo & no grain or harshness. sounds great on Reggae. To try Rock is a hard test on an amp as original, but the SX-1000TDF delivers it with good weight & detail which really wasn't expected, many amps as original & even upgraded still wimp out on Rock. The Pioneer betters the Sansui as original. The Reviews page shows the Pioneers we had, the 1967 SX-700TF, then 1967 SX-1500TF & 1968 SX-1000TW which is a later version with less Retro looking tuner glass and an updated Tuner in a wood cabinet. By the 1969 SX-1500TD we noticed the 1967 sound was tamed down as the circuits tell. The SX-1500TF was a 45w version of the SX-700TDF if the SX-1000TDF is an updated version of the 1966 SX-1000TA that has a Nuvistor Tuner. Both SX-1500TF & SX-1000TDF are quite similar. Looking at our pics, the 1967 Pioneer surprisingly have a "T" Bass Filter on a small board next to the Power Amp. So even in 1967 the Bass was limited for the Spec of the era, if it explains why the SX-1000TDF is a bit bass light & similar is on the SX-1500TF & SX-700TF. The SX-1500TF has serrated control knobs, metal over a plastic inner which makes the SX-1000TDF the better looking one of the 1967-68 ones. The SX-700TF has a cool wood panel on the fascia but the later serrated control knobs. The earlier 1966 SX-1000TA has the switches grouped less neatly. The SX-1500TF & SX-700TF have wood side cheeks on the earlier ones, the SX-1000 we had the TW one in the big woodcase that looked a little awkward if appears to be on several online so was a Pioneer one. The 1969 Teac woodcase similarly looked a bit mismatched.

Into the Time Machine 1: 1967 Pioneer SX-1000TD-F On Loudspeakers.

To hear what this sounds like as all Original if Serviced on 1969 Tannoys it was likely designed for is a must. To have a 1967 amp in this grade & working is rare, so to hear what the 1960s Buyer would have heard. For the fact we got the 1967-68 ones as early as 2011-2012 & last heard the SX-1500TF in 2013 if it had problems, we've Never Heard the Early Pioneer on the Tannoys. The difficulty with Pioneer into 1972 is those darned Speaker Plugs. On the SX-1000TDF we remarkably have the set of 4 original, try find those. Ebay shows some 'PerfectFit' very crude looking modern ones, fills the hole if not great quality. An Australian seller will deliver a pair for £35, we bought these before & they are modern repro ones but of a good quality, if not quite the originals. The trouble is these plugs don't have much area to grip, on looking inside the grip area is just part of a sprung metal strip, not as strong as a Mains Plug part. It will take 5A mains wire as the remains on two of the plugs reveal, but put heavy modern cable & it will just fall out. We've never tried to replace these Sockets, if a set of 4 of the VOSO 4mm sockets fitted to a new panel would do, but do buyers like the Pioneer Plugs as original if not so useful? The screws with a ridge between make them like the Sansui 3000A connectors, Fisher & McIntosh, but on a plug block is an idea that lasted 6-7 years before updating. Maybe pre 1973 buyers liked them? Next day after the 1 hour+ play session to check the amp is still reliable after it's long sleep yet getting a workout the day before which we rather enjoyed. Sounds fine, check DC offset as is required. Tannoy Golds first advertised new in Nov 1967 so spot on for the age of this amp as ours has a "1267" date code on the main caps. Amp rated 40w, Speakers rated 50w, a perfect match apparently. But does it sound good? Ours needs bulbs so first turn on showed no sign of life beyond a gentle bump on turn on. The 4mm connectors onto a screw block onto the originally used fork connectors on the blocks on this amp proved successful, as in they stayed put. The last Pioneer we tried on Speakers was a SX-990 from 1970 & they kept falling out needing the cables supported. We don't like losing an original part so unless it means paying £70 for a set of 4 the plugs on our one will stay. The Sound on the Tannoys was a Great Match as suspected. The 1967-68 listener would have marvelled at the expansive big sound with very clear wide Stereo, it will easily have been the best they heard. We played the same TV shows we'd just played using the Marantz 4070, an amp now mostly redone that sounds far better than it should. The Pioneer gave a good sound with no difficulties or background noise. But for knowing Our Upgraded Amps, the Sound shows it needs improvement. High Treble we found wasn't fully "getting into the corners" leaving voice sibilants only partly resolved. The "T" Bass filter made a mess of the Lower Midrange & Bass, it just mangles it leaving the listener a little confused as these areas are not as they should be. Far from the awful hard ringing Retro Bass of the Sansui AU-666 we tried, but inaccurate & stodgy lacking a particular focus, the old "One Note" Retro Bass is a confusing one to even consider when overall the SX-1000TDF sounds of high quality if looking beyond the Duff Bass & Limited Power of the Treble. This amp will upgrade very nicely & for the Low Damping Factor of 25 it will be worthwhile. More to Blog on this amp.

FM Tuners In Receivers With No ICs.
Beyond Valve or Nuvistor pre 1967 Tuners, the IC is a staple of the design, coming before FETs. We'll list those we've had & have circuits for, so not including the HH SCott 344B as no circuits are available. We've rebuilt & upgraded the Valve Trio WX-400U & All-Transistor Sony STR-6120 to know how good Tuners can be without ICs & giving the typical spec a quality no tuner has seen. So to look through the Receivers & Tuners we've had. The progress in Tuners from Valves briefly to Nuvistors in 1966 then by 1967 a mix of Silicon, Germanium, ICs & FETs. Some Brands updated the Tuner often in the 1966-69 era & only by this can you help date which is earlier, as with Pioneer. Fisher 600-T from 1965 has a tiny 6HA5 valve on the Front end plus some 6CW4 Nuvistors with the rest as Transistors. Pioneer SX-1000-TA in 1966 has the same. Akai AA-7000 in 1966 had the same Nuvistors if no valve & the rest as Transistors. Fisher 440-T from 1965-66 has All Transistors which seems to be the First One as is their larger Fisher 700-T, if the Front end has Germaniums AF124 & GM760 which has an AF239 equivalent. Rotel 120ST tuner from 1966 that matches the Rotel 100AMP we've not even tried yet has Germaniums 2SA234, 2SA49, plus whatever's in the semi-sealed front end, small black ones. Sony ST-5000F early tuner from 1967 with the 3 lever switches on the front not the later ST-5000FW with the slider is nearly all Germaniums. Sansui 500A was all valves except a transistor phono. Sansui 3000A from 1967-68 is all Transistors with Germaniums like 2SA 525 in the FM Front end, ie the first stage after the aerial & with the tuning, but one Apr 1969 made one with a "FAMT 103U" front end has 2x Ceramic Filters, obvious to see the 2x orange square shape-three legged items F103Z & the 1968 ones don't have this board. Another board the "FIF-203" again is updated & has quite a few, 4 legged B4SCO101 x4, 6 legged B6RD0104 x1 plus a 4 legged larger case B4ZM0205. All marked 'Murata' if the boards look much the same as the 1968 versions, just the filtering will be better instead of using separate capacitors, an IC of capacitors. The JVC 5040U from 1967 has a basic IC in the Phono stage if the later "Run 2" manual shows a FET front end which dates it to at least 1968, we had the earlier one that shows Germaniums. KLH 27 from 1967 is with a FET on the front end, possibly the first one to do this, if still a Germanium there too, the rest are a mix of Germanium & Silicon. National Panasonic SA-65 from 1967 is a First too, FET, Silicons but sadly ICs in the IF stage if the MPX is transistors. 1967 Pioneer past the early SX-1000-TA mentioned already have Silicon Transistors like 2SA372 & 2SC535. Pioneer SX-700TF from 1967 is all Silicon Transistors. Pioneer SX-1000TDF from later 1967 has a FET front end if an IC "µA 703" with 5 transistors and 2 resistors inside. Pioneer SX-1500TF is similar with the same ICs W12-020 as the SX-1000TDF if the smooth control knobs of that show it came after the SX-1500TF. Trio-Kenwood TK-140E or U is a strange early 1967 Trio if the FET & all Silicon Transistor tuner never works in the Receivers until the 1970 range, whatever ages badly affects all we've had, if a Tuner by itself not being powered up lasts. Trio-Kenwood TK-66U from 1967 is similar. Pioneer SX-1000TW receiver from 1968 has the FET IC label like the SX-1000TDF, appears just to have the later NFB Preamp stage to the earlier one plus the different tuner glass. Sony STR-6120 from 1968 has a very good tuner all on separate boards, FET front end & the rest transistors. Toshiba SA-15Y from 1968 has FETs plus all Silicon Transistors, a very good sounding tuner if too messy to rebuild like the Sony one can do. Trio-Kenwood TK-140X either version from 1968 has FETs but IC IF stage & the rest Transistors, but sadly a dead tuner is what you'll usually find. Bang & Olufsen Beomaster 3000 from 1969 is a mix of FETs, ICs & transistors, if has 3 Ceramic Filters like the Sony STR-6050 below. Pioneer SX-1500TD from 1969 with the new styling is like the earlier Pioneer with FETs & ICs plus transistors, if the SX-1500TD takes another step into ICs with the MPX stage "needing" the output 2 channel stages on an IC with M5109P the number. Sansui 4000 from 1969 is like the Pioneer SX-1500TF design with ICs. But Sony STR-6050 in 1969 bucks the trend to be all FETs & transistors adding the "CF"s like 1969 B&O does which are Ceramic Filters much used in later tuners & different to earlier Tuners. Teac AG-7000 follows the Pioneer SX-1500TD idea of more ICs. Akai AA-8500 from 1970 is a stylish receiver if the first we've seen since the 1966 AA-7000, but the IF stage has complex ICs. UK's Goodmans Module 80 from 1970 manages to be all Transistors as does the Hacker GAR500 from 1970 , if UK Hifi was often slow to pick up on new ideas. KLH 52 from 1970 needs an IC in the MPX if the rest is transistors. Pioneer SX-990 from 1970 is like the SX-1500TD with the ICs. Sony STR-6850 from 1970 manages with FETs & transistors, no ICs here & starts to answer why we've done this blog. Hitachi SR-1100 from 1971 continues the IC in IF stage & Sony's Ceramic Filters. Leak Delta 75 has ICs & Ceramic Filters, probably the first UK brand to use these. Marantz 2245 receiver from 1971 shows the USA if Made In Japan ideas, this shows FETs & Transistors, no ICs here if does have the Ceramic Filters. Sony STR-6055 we have sat on the desk, where are the ICs? It's FETs, Transistors & 3 Ceramic Filters. Is this rare by now? Even the Tuner Sony ST-5150 that matches the Sony TA-2000F/3200F has 3x ICs in it. • Early Conclusion. The blog tells that soon Tuners became loaded with ICs, Ceramic Filters became the normal, there still will be Transistor stages well into the 1970s & 1980s. But ICs took over the IF & MPX stages which may give a cheaper product, the individual Transistors & FETs will still give the best sound. Marantz 2385 from 1976 tells what Tuners became, 5 Ceramic filters, ICs number Five for this tuner if still with plenty of FETs & Transistors plus even a Differential. Yamaha CT-1010 tuner from 1977 is similar with 5 ICs, a Differential but only 3 Ceramic Filters. The typical 10.7kHz Filter first seen in 1969 Sony & B&O did away with a lot of adjust coils to simplify the Tuner, yet space saved didn't stop the ICs. Yamaha CR-1000 from 1973 has to be the first one-board FM tuner beyond the front end, if it has 2 ICs early on for the IF stage, it shows how compact a Tuner could be as early as 1973 for having the Ceramic Filters. The first Tuner we heard to think it was better than the fairly average sound of most tuners, before getting the Sony STR-6120 was the NAD 300 from 1975. The Amp part was disapointing if the Tuner was open & clear. So to see it has 6 Ceramic Filters, if a huge 7 ICs including one per channel of the MPX stage is surprising. But to read again.. "the Amp part was disappointing" for hearing the Tuner through it, the amp designed to compliment the tuner? who knows. But how about Sony? When did they go for Tuner ICs? Sadly by the Sony STR-7055 in 1973 the quality Nose Dived as 3 ICs with 2 being complex ones, plus the Phono & Tone having ICs. The Marantz 2335 range from 1975 has Tuner ICs. The 1971 Sony STR-6055 & STR-6065 plus Marantz 2245 & 2270 range are The Final Non-ICs Tuners. Just as we thought, by seeing no ICs on a 1971 tuner this seemed very late. There still are at least Three Non-IC Tuners right up to 1971, if as early as 1967 ICs started in circuits. All very interesting, but the Reality of Tuners in the UK on FM is there aren't that many channels beyond Chart Pop & Ads, only Radio 2 which can be very tame is uncompressed on FM. We've found a Recapped & Upgraded Tuner does give a far better sound as the buyer of our Sony STR-6120 found, Tuners typically deny you Bass & give a gritty treble, but get a Non-IC Tuner & even as Original you'll hear FM sounding better, smoother & less edgy than the IC versions.

Into the Time Machine 2: 1968 Sansui 3000A On Loudspeakers.
The 1960s amps are usually a bit far gone by now & certainly not ones we'd trust on our Tannoys, but as with the Pioneer SX-1000TDF blog above, we get one to upgrade that's had little use, is very clean inside & out so after Servicing & adjusting, to see if we trust it on the Speakers. actually this one has the 1971 Bulletin Updates with 1000µf bipolar output coupling speakers which allows for maladjusted amps that could put 8v DC onto speakers which isn't good. the coupling capacitor is typical value of the era if will limit deepest bass so to just hear what it would have sounded like to the 1968 buyer who bought Tannoy 15" Gold Monitors as the 45w Sansui 3000A is the ideal partner. As is typical of pre 1972 it only has the 2 core single insulated mains cable, we always rewire to 3 core ading Earth for safety & for the fact modern gear isn't usually grounded. The Pioneer added a ground wire to the Phono ground point which is how we used it temporarily, if the 3000A still has a USA 2 pin plug that will get a 3 pin plug for obvious reasons, but as all 3 wires are black, not one we recommend you try. As for the worry of stray DC voltage, we read about 400mV both sides with no speaker load if oddly about 1.4v on the speaker outputs, but connect a Speaker & the DC offset drops away to a very low number so safe to use. Once adjusted right you don't need the Output Capacitor, but the truth is a lot of amps make a click on plugging in speakers as a small standing voltage sits. Only if adjusted very wrong or damaged would it be a problem. Mission Aborted: As we've tested & read the DC offset on test spreakers, to try it quickly for sound on small test speakers it seemed fine but on big speakers one channel was slightly distorted meaning maybe the old capacitors couldn't deliver the current to drive 15" drivers. Old & Original after all, plus the owner was sold it was Working, the joy of buying used Hifi once again. Verdict is the Amp Needs Recapping as it's 50 years old. We prove ourselves right on saying 1960s amps are rarely good to test as original, if miss hearing how the amp sounded to a 1968 buyer. Try It Again. So it needs work, to redo the Power Amp stages & check all is good, plus ditch the Output Capacitors which may have been faulty to, no point testing capacitors, redo them. Still with all else original. DC offset read under 10mV with a speaker load & played music fine on the small test speaker. But again the big 15" Tannoys that need more current to play showed that soft blurry distortion again on the Left Channel which means it's probably the power supply bad as the amp has a Dual Power supply. What's wrong with My Amp? is what people ask. To try it in stages is the thing as a fault can have many reasons why. Unfortunately Mission Cancelled now as the amp needs fully redoing to get it working right. so much for getting to hear a 1968 original amp on 1968 speakers of the type it would be used on. At least the Pioneer SX-1000TD-F above let us have a listen. The reality is 1968 is 50 years ago & most amps are way past their best, including one that looks only lightly used, as parts still age.

We Will Continue To Push The Boundaries In Hifi.
If we get the same amplifier again, we don't bother too much with our old paper notes & as with the Sansui 3000A with 2014 ones we start looking at it to upgrade with current ideas. Only by upgrading over 100 amps can anyone really understand why recap-upgrading is necessary. Who else is doing this & has the confidence to try things & then have them reliable to sell? No Shop Bought amplifier is on it's best design & spec as it's costed to the penny to fit into the Marketplace. Even the First Generation Transistor Amps from 1965-67 that are based on Valve sound are often with very low spec, we rebuilt the Trio-Kenwood TK-66 power amp to our ideas as the original was rather crude. Our version was great & the lucky buyer of it was very pleased with it. Us experimenting to see what can be done on some amps rather than pricing an upgrade just to sell it. This is why we progress & still are, whilst old-timer techs are way behind, not willing to accept the old designs can be bettered now despite being good in their day. We do look online to see if anyone gets a lead on our ideas, the most we've found is those doing photos like our pages do if many just put 1 or 2 pics, others are realising the more detail the buyer sees, the more likely they'll trust in it to buy. To find a 2010 forum saying how good the Sansui 3000A was is unusual if it shows interest was there if it had need a focus. 'Messing' with the electronics' is rarely done, to recap like-for like or stuffing capacitors is what others still do. Experimenting & then refining ideas is why we look afresh to upgrade a known amplifier, knowing what worked, what wasn't quite right on reflection plus knowing capacitor values that are right without overdoing it with oversized ones that really aren't needed. The Teac AS-100 amp one is on the way to be restored & our 2012 photos we now see as 'not optimal' for the design, having done other Teac since. To be your own critic to get the best when no-one else is doing this, it's 'winging it' often. Look at early Transistor Amps Sony TA-1120 from 1965 & Sansui 3000 from 1966, these are very high power designs ahead of what anyone else was doing. They were 'winging it' too, making it up from fresh with little standardisation or proven ideas to rely on so especially with the TA-1120, to make an amp that's way too advanced meaning the 1967 TA-1120A soon replaced it. So when others say they don't like the Idea of some of what we do yet haven't even heard it: It's their Unqualified Opinion & they should know better to criticise what they are unaware of, but human nature can be tedious. People ask our opinion on amps they are thinking of buying. If there are sometimes no circuit diagrams then we don't know what the amps are about, but can only draw on knowledge known, ie a Fisher RS-1080 Monster Receiver from 1977, we'd be wary of a Sanyo-made item that just copies other designs & has some odd design of it's own, a Digital tuner display Heathkit AR-1515, no circuits easily findable if knowing the AR-1500 it's probably worth trying. You only know what is presented to you, we get amps for our own interest based on what we can find out & the reality of the amp on the desk in front of you is often very different as to see how it's built, often with cost-cut ideas that aren't liked. Looking for Forum Opinions on amps is a risky game as be sure every mediocre amp will have it's fans as they've not tried many amps. As of typing, our Amp reviews pages based entirely on Amps we've had are up to Amp No 176 which is the 1966 Sansui 3000 as it's different enough to separate from the 3000A on comparing.

What To Do With Quadraphonic Amps.
Some are made with the Bridging Circuit that as we found with the Marantz 4070 actually sounds great with the Damping Factor halved so an expressive bass is there, if only once properly upgraded. Another use is the weary old idea of Bi-Amping, being reminded of this by a March 1968 Hifi News Reader's letter showing how valves are used as a Buffer, if their circuit is rather contrived & limited. For the 4ch Mode on the Marantz, you need 4 inputs, or a Splitter that makes a Mono input into a Stereo cable pair, these are findable. The snag to this is the full 4ch preamp is used & tolerances will mean they will ever so slightly differ. The idea of Bi-Amping & Bi-Wiring is an idea the Hifi Mags promoted, especially Bi-Wiring as it sold double the amount of cable. It really makes no difference & the Speakers with no Bi-Wiring capabilities using a single source compared to two slighly different by tolerances ones can only mean the single source is more precise. As blogged above & on the 4070 review, the whole amp needs accurate adjusting to sound it's best & the extra power of the Bridged Design is a better use than the Bi-Wiring idea. There will always be those having believed the Hifi Mag hype for Bi-Wiring & Bi-Amping will say it's better, no, it'll just be different as tonal balances by loading the amp differently.

Knowing The Upgrade Marantz 2385 Sound Better On Speakers.
To offer this amp to a few to see if there are any takers, but we've way outpriced it for the current market for our work as expected, it's still an 'unknown' to what these can sound like done right. But it's not a problem, we got it to replace the Sansui AU-G90X as a crazy big amp & that stayed 3 years after selling the Sansui 3000A that we currently have one back to upgrade. The 2385 sound is quite different to other amps, despite the ICs once upgraded they aren't a problem or a limit, at least at the volume we play it at. But as original they sounded lousy, no way to avoid telling that. Using the 2385 for TV sound a bit of Midrange reduction on the Tone helps as we found with the Realistic STA-150 220 to keep it a bit more Domestic sounding. The design is unlike most amps in the fact NFB is not used anywhere beyond the NFB at the
main amplifier stage & it's unusually low NFB too. The nearest design we can match is the Trio-Kenwood TK-140X version 2 & KR-6160 UA1384 board, the AU-G90X still had NFB in the Class B Preamp-Tone stage. To use a 185w amp on 50w Loudspeakers is possible as you'll likely never get past 10w on bassy peaks on TV soundtracks, like the heavy bass slams on 'Storage Wars' as we heard on this amp the day before. For the non-NFB sound there is a strange feeling "you can't hear" the amp as it's not upfront, the sound just flows into the room, but if big bass or crisp treble in people's voices as sibilants is there, you know about it. We've yet to do too much to the Power amp if there is more than can be done as we found with the AU-G90X. Before trying the 2385 again on speakers, we got used to our version of the KA-6000 with the UA1384 board we fitted & the sound balance of both is fairly similar. The effortless sound of the 2385 as serviced & recap-upgraded is near to what we heard initially with the 100w valve Tube Technology Genesis monoblocs, if the last time we played those using the Sony TA-2000F preamp, the Sony TA-3200F was considered far superior to the rather soft valves sound. The only valve amp we play regularly is our version of the Luxman LX33, their design was lousy if our redesign of just about all of it has the same sort of sound the 2385 does with it's 30w EL34 output valves. The Only Problem with an amp with such Low NFB is it's not Domestic sounding, watching 'Eastenders' on the normal volume bits it sounds good, but then as the show often does with people 3ft apart, they shout & without the NFB to keep the volume more together, it gets as loud as having the people there yelling at you. These days you get pointless features like "Dialog Enhancer" that just boosts the midrange as well as compressing the sound, here the 2385 will get you reaching for the Volume on those loud bits as Hifi Usually doesn't sound that huge. Found the same problem with the LX33 valves. A great sound, if not for everyone. Aged & Wallowy. But hearing how aged & wallowy the Marantz 2385 sounds as original, it's no wonder peple buy these big amps expecting great sound but find they are disappointing, ours had 4 owners in 9 months, the last before us kept it 6 weeks as they didn't like the dull slow sound. The sound we upgraded in ours to bring out the fresh Beauty of the sound, way better than the original design. So bring us your Tired Monster Amps, we can make them sound a lot better than you'd expect. Big amps, lots of work, high Upgrade Costs & chances of lots of problems within, but you should expect that.

1977 Fisher RS-1080 Monster Receiver. A Sanyo Product.
A lesser known 170w Monster Receiver that made it to some of Europe but not the UK. Retail price at the time unknown, but likely it was priced around $599 to get the Bargain Buyers in. One on ebay just made £900, so what is it? Firstly it's a huge one. 170w at 33kg from 1977, 605mm wide, 470mm deep. The thing is this isn't the Classy Fisher of the 1960s, Fisher sold out to Sanyo by 1974 if had already sold in 1969 to Emerson and later to Panasonic asthey bought Sanyo, as Wikipedia says. First sign of Sanyo is by 1967-68 with Hifi News ads for a DC534 12w Music Centre of the era, turntable & tuner-amplifier on one package. Their advertising sells it a little optimistically "Sanyo Puts You In The World Class" is their Jan 1968 ad for the Sanyo DC60 receiver which appears to be 30w per channel if not saying Music Power or RMS, if the 87gns (£91) suggests it's a Music Power Rating, unless made & sold very cheaply, the 12w DC534 suggests it's likely the 12w unit less the turntable. To 1980s buyers, Sanyo were cheap Dixons type mass market gear, so to think they made a Monster receiver, not much cred there. But look at our 1973 Sanyo DCX-8000 their biggest receiver at the time with 40w & it was advertised in HFN/RR at the time if missed the Year Book. We upgrade it to a degree to get "Very Good-Excellent" out of it, but for th we didn't think it was worth doing more with. It sold very fast & others asked for it before it was delivered, so a brand that is known to be worthwhile. Our Sales Photos show the DCX-8000 to be a smart looker in the style of the time. To remember capacitors on the audio stages weren't in good condition, as in leaky, if the Rubycon main ones were & the metal casing was a bit thin. The spec of the amp was rather poor as the circuits reveal, too much cost cutting, if making sure the fascia looked expensive if a vinyl wrap case. So to the Fisher RS-1080 circuit. We had a look at this for a customer interested to buy, we advised them to be wary of it as the Sanyo RS-1060 at 125w is only about £300 suggesting it's not rated, but then the RS-1080 gets a high £900. The circuit diagram shows it's just a copy of other amps of the era, nothing new here overall. Phono is 2 Transistors, Tone-Pre surprisingly has a Differential after the Tone Controls & a Buffer after. But it has a strange "Bass Range" control before the Power Amp stage, can't see why that'd be any use from the circuit looking like some sort of Bass EQ Boost feature. But then illogically the Power Amp input has an equally strange harsh "T" Bass Filter on the Input, so Bass on this amp will be that thick Retro-One Note Bass. Looking at pics online, it's not that impressive as it doesn't look classy or expensively made like the other Monster receivers, huge stupid looking thing is our first opinion seeing the average quality back panel too, but to see "Studio Standard" briefly impressed to look further but then realise that's on all of the range. The Bass Messing is far from Pro Standard. Inside pics show it sort of copies the 2-part idea of the Rotel RX-1603 if in one unit & with multiple boards. We didn't recommend the customer bought it, hopefully they didn't as Sanyo is no better than Midprice. As on the above blog telling of a site with 95 Monster Receivers pre 1986 shown including several more Fisher & Sanyo ones, Remind yourself of how Lousy the 1986 Sony TA-F550ES, 1983 Technics SU-V707 at 90w & 1985 Yamaha A-700 at 105w plus the 1986 Pioneer M90-C90 pre-power at 200w were. High Power but far from Good Sound.

Buying Vintage Hi-Fi Online Is Gambling & Can Be Dangerous.
We do Gamble a lot on Buying Hi-Fi because we can sort out any problems. We don't care if it blows up or is a mess inside because we can do the work & know the risks. but Do You? The trouble is even if an amp is said to be working, it'll still be 30-50 years old & unserviced. No-one has checked it & often you find amps left for Decades badly stored. People buy these thinking they are a Bargain, yet they blow fuses, burn resistors to almost Catch Fire, smoke, hiss, hum or just plain Don't Work. You need to be Careful buying anything Vintage & Electrical as they should be checked over by a Qualified Tech before use. But that costs Time & Money so most don't bother & just plug it in. You're risking trashing your speakers if the amp is bad, do you check the DC voltage on the Speaker outputs? We don't trust any amp until we've fully checked it over & as the above shows we rarely try Amps on the speakers as all Original as it's risky. Do you plug in on a Circuit Breaker & test it on Headphones first? Most non dealer sellers of Hifi on ebay are chancers, hiding faults or just not bothering to check gear as they are a Recycling Centre selling what was Another Person's Rubbish because they see it has value. Seeing amps recently that are great amps as Recapped & Serviced, to see filthy aged grotty ones bought because they are a bargain is just too risky. Do you buy an Old Car & just Drive it? No, you need an MOT as your Safety net. A PAT test is worthless as it tests an item for a minute or two, yet we see that 'they' don't even bother doing a PAT test these days, just sell it vaguely to the unaware punter. Even with us trying amps once done on the speakers, they don't get trusted to be left plugged in overnight or when out, to use for a week leaving off during the day gets them trusted. Unless you are Qualified & more importantly Experienced in Dealing with Aged Electronics goods, for your own safety leave the Risky Gambles to those who can cope. But with a Vintage Hifi Market mostly selling aged used & unserviced Hi-Fi, the Market still is Young on this scene. We can do the Restoring work for you, if generally we put more work into Our Selling Amps than we charge for, aware of the Current Resell Prices. To get us to work on a difficult messy amp, we can do the work, but it could get more expensive than you'd want to pay.

Changing Germanium Transistors to Silicon.
The 1966 Rotel 100AMP as blogged in June 2018 above already needed this on the outputs as even NOS ones were too leaky. Took ages to do. But the Rotel is not great sounding still for a weak Germanium sound & the Background Noise is too much plus the Aux Input is too loued on the original design, are we wasting our time? We can't sell it like that as the looks of the Tuner & amp in the Woodcases looks Smart & retro, if the Amp sound isn't good enough. so redo as PNP Silicons just to see what it brings. Then the problems start. It was already a lit too loud for a modern Aux output if now it's far too loud & just clips off unless the Soundcard is reduced to 40% volume. Not hard to put an input resistor circuit copying other amps, to get it to sound acceptable is the deal. We've left the 4 driver Germaniums to see what they sound like & to maybe at least keep some Germaniums in it? Rotel are usually great amps, but this 100AMP isn't up to what we've have expected. But to test the Phono, not recapped that yet, is it too loud also? Unfortunately it is, the whole amp has too much gain. With no circuits except a similar Rotel RA-110A from 1967 in Silicon, this is just not going to work out. It's just a difficult amp & not as expected from Rotel. Background Hum is still a bit loud too, it just redesign that can't be done with No Manuals. We could put Gain Controls inside instead of using the limiting Resistors if we'll put it all back together for another day. It's just an ornament currently. See if anyone wants it for the Retro Visual appeal of it, just to cover costs, so put it for sale. It's useable with an external volume control on the inputs & too nice to break up for spares. Lets it sit a bit longer for being For Sale, might try again another time.

Hi-Fi in 1965: A Digest.
Time for another yearly Vintage Hifi News digest. Finding out when items we know were first advertised is sometimes earlier than the accepted dates you find online so well worth a trawl for further years. Jan 1965 doesn't have much if 'introduces' the Rogers Cadet III as first advertised Dec 1964 & the updated Mk II Switched FM tuner & shows the 2-part amp was the first version, if when the one-part arrives we'll find out in future years. Radon R600S Mk II introduced, the Mk I mentioned in 1963, a 10w UK made transistor amplifier with Germaniums if not mentioned. Fisher TX-300 Stereo Amplifier gets a review, rated 36w per channel if often that means one channel playing & it's a 30w RMS amp to us. Seems a Silicon version of the earlier Fisher 600-T still with Transformer Coupling as the splitter onto Doubled Output transistors. Looks a decent amp with the typical early era Fisher Sound shaping & NFB in the design. The review tells the TX-300 doesn't like Electrostatics & there is no protection circuit on Direct Coupled Output transistors. Feb 1965 has nothing new, the 'new' ads are gear mentioned months before in 1964. March 1965 again slow if yet another Trio with the Trio W-10 at a mere 7w music power at 45gns. The Goldring-Lenco GL-58 is one of the Very First Turntables sold on a plinth with a Perspex Cover, if in 1964 you could buy the perspex lid-plinth to fit your own turntable, the GL-58 appears to be the First sold complete. Headphones on Pt 2 of the scene survey shows that very few were made & sold in the UK with only really Koss being a recognisable brand from 9 brands mentioned. Grundig SV50 amplifier gets a review: 20w per channel, all transistors if likely all Germaniums as AC151 outputs, the square wabve performance isn't great & power at 20kHz is half the 1kHz rating, so not one we'd bother with. Tannoy York speakers, the pre-Lancaster cabinet with 12" or 15" Tannoy Silver drivers & Ralph West the reviewer is rather smitten with it, smooth sound & high efficiency really tells it's the Only Loudspeaker worth bothering with if Money & Space aren't an issue. The Abolition Of Retail Price Management In The UK tells the forthcoming Roots of what killed off Hifi progress in many ways & brought in the Hifi discounters & cost cutting by the early 1970s. Already worried about 'too cheap' meaning poor service if later letters revealed RPM initially brought a two-tier market where you paid more for getting nothing for it in effect beyond having a salesman & being offered service facilities as shops wouldn't do repairs on gear they hadn't sold, very naive trading times. Over the following HFN years much is argued about this & some big traders just sell up as the market has changed, if markets always do change is the reality. When RPM was abolished is found online as Apr 1965 based on a 1964 act. You see UK EMI pressed Records with the "Sold In The UK Subject To Resale Price Conditions" which disappeared by c.Apr 1969 & it appears Books were the last item to lose the RPM, if Diamonds are still fixed to prices by the Cartels as Diamonds are not rare at all, just cleverly hyped. Apr 1965 has Dual with a double page ad for the Dual 1009 autochanger-manual turntable & CV2 amplifier of 10w. Capable looking if we've found Dual turntables clunky & as with these other 10w amps, with Germaniums not for us. Akai have been stepping up their advertising the last few months if just with Tape Machines, their AA-7000 receiver & AA-5000 amp didn't arrive until 1966-67. Truvox is being cheeky saying 'Immediate Availability' on their amps as Leak were in high demand so a bit of a wait was mentioned, but in 1965 the Leak 30 for similar money was a better buy. Garrard LAB 80 introduced, the one with the wooden arm & no-arm autochanger plus the lever switches like later Garrards used, 'elegant styling by famed designer Eric Marshall'. Mullard have a full page advert about new Transistors 40mW to 40w. May 1965 another quiet month if the Rogers Cadet III review, see our Solds Gallery for lots of pics of the early one. This one was reprinted in the late 1990s Vintage HFN supplements. They like it if mention of the quirky tone controls with treble needing turning anticlockwise for gain is a bit illogical. They get 8w from it with 20Hz & 20kHz at 6w-6.3w which is reasonable for the era. Jun 1965 has a first "Stereo Portable Battery Powered Record Player" with either 2 separate speakers or headphones. The Brown Stereo it's called & made in Watford, UK. Hardly that portable with the speakers. Introduced is the Armstrong 221 the quick knocked up version adding MM Phono with transistors to a valve amp, We thought it was lousy if looks were better than some. The first of the Celestion Dittons, the 'Ditton 10' new out, a popular range if notoriously hard to drive some early 1970s ones as blogged before about bad Impedance Curves. A loose card for "United Kingdom Provident" Life Assurance aka Insurance offers options 'specially designed for the Married Man', simpler times when people conformed. As you'd expect yet another Trio valve amp, they certainly knocked a lot of these out for the Export Market, the Trio WE-8S is the same feeble spec as the W-10 from March if now 49gns. Their ad lists an unknown Trio TW30 all Transistor 'Pre-Main amplifier' if no details, but looks c.1963 on online pics, possibly 7w-10w & a rare one. Jul 1965 is a quiet one again, Pioneer EX-42 is a new Receiver stated as 40w total which is an unknown searching with Google, not a thing found if the picture shows the number on the tuner glass. No mention of transistors so expect a 10w RMS power. ad shows the back panel, screws for speakers so no Speaker Block Plugs introduced yet. Aug 1965 has a Record Player that plays a soundtrack & put a still picture on a TV set. "Vision On Disc" by Westinghouse USA branded 'Phonovid' with the picture info on the disc, 40 mins of sound & 400 pictures on a 12" disc via scan & hold method once the picture data is complete. It failed, but progess. Rogers HG88 Mk III introduced, Rogers certainly very busy with two main models that both sold well, case options are Teak or Dark Australian Walnut Formica finish, never seen that one. The idea of PWM Amplifiers is on Part 2 this month, a lousy idea that really doesn't work this early as heavy steep filtering needed to stop the sampling waveforms being heard as one later PWM amp reviewed told. The Trio WX-400U from late 1963 gets reviewed belatedly, the pick of the many Trio at the time if the slighly later Kenwood KW-70 appears the best one. HFN mistakenly think "20w Continuous" means 20w RMS per channel, the amp is a 10w RMS but the old 'adding numbers' game that they should be aware of by 1965. The A.W. Wayne guy of the 'Shirley' amplifier brand is the reviewer & reads 12w-13w at best if no mention of distortion levels on a 10w amp to get 13w. They find the FM section very good, it's why we upgraded our Tuner to see how good it was. Phono stage they state is very low on treble if we found bass lacking too. But by mid 1965 it was a bit old for the progress since late 1963 explaining why these were discounted. Sep 1965 gets 3 page Fisher ad with the first page a waste saying to look at the next page, advertising "40w" Fisher X-100-A, "60w" Fisher X-101-C plus Fisher XP-5 & XP-6 loudspeakers without saying what their power rating is. 'Rupert Neve & Co' have made a 16-Channel mixer unit for a leading London Studio, probably EMI's Abbey Road. SME introduce the lightweight headshell, it shows it's age, the 'soupstrainer' one that may be lightweight but it blurs the sound yet stayed in production for at least a decade, the arm still has the fixed rear weight at this time. Weary reader arguments about 'Serious Music' Fools rubbishing all 'Pop' music regularly crop up & only by the late 1960s fo the Stuffed Shirts admit there is pleasure in Pop if going for Beatles 'Sgt Pepper' plus Simon & Garfunkel 'Bridge' LPs, yet these days (2018) BBC4 puts 'Pop' music rightly in the 'Arts' category, after all what we call Classical was 'Pop' in it's day. The first "silly" turntable arrives, the 'Transcriptor Turntable' loses the platter & rubber mat for a lousy 8 point suspension idea leaving the disc loose in the air, instead of damping it. These silly ideas continued for many years. Pioneer swiftly ditch the July advertised EX-42 for the Pioneer ER-420 that must have sold well as they do turn up & we looked at one on 'Other Amps' page. But compare the photos, it's the same picture as the EX-42 as on the tuner glass & even in the Dec issue it's still the same pic, bizarre, if could just be a numbering error as the ER-420 is identical. Scott 200B Valve amplifier gets a review, 12w 'steady state' shows as 10w RMS per channel if by 12w it's 5% distortion. The Square Wave for 10kHz is very poor, if 1kHz has a tiny peak if otherwise square, shows how feeble the designs are on these early valve amps if they do upgrade to be a lot better. Oct 1965 has a flashy ad by 'Studio 99' a London NW6 shop. They really do appear to give 'ideal' sales & service if probably scared a lot off by appearing so upfront. Later ads by 1968 really see their Ego as 'Best Shop In The World', an interesting way to deal if sadly the Discount Stores put them out of business. The big 'Largs' shop on Holborn, London WC1 have a full page ad about their 'Comparator' a large fixed until containing buffer stages & a wide range of hifi units to select & play via your chosen speakers. 43 million combinations. 1606 switches, 40 relays, 108 buffers & 4750 yards of wire. A nice idea in theory, but the problem is output levels will differ, the cheaper items won't sound as good as the expensive items & trying more than 2-3 items will just confuse which got criticisms in later letters as other shops with the comparators were using them to offload lesser or favoured items to the bedazzled listener. The Garrard LAB 80 as mentioned earlier has a full page ad saying they were overwhelmed by the demand & got caught short on supplies. Today they'd know the market to predict a demand but the trouble there is too many factors can get high sales or low sales and overproduce. Bang & Olufsen Beomaster 1000, the first of their slimline receivers, 2x15w if unquantified. Looking quite like the Arena budget hifi & prices today show not much interest as under £100, not one we fancied trying either. There is a HFN review of this, keep reading below. Trio-Kenwood KW-33L is a receiver in their new plainer styling, valves, HFE site wrongly puts 14w which is the 'IHF standard power' if 9w RMS is stated. Lots of Fisher adverts, if for how rare the 240v versions are, Fisher didn't sell many in the UK. Nov 1965 is one of their biggest issues yet & a big range of ads if not overly interesting. Article about the Shirley SB/1-20 amplifier & preamp is unusual, the brand makes & sells the amp yet the Arthur W. Wayne guy who reviewed the Trio WX-400U lets his circuit diagrams be published. Today this would be seen as an Advertising Article. It's still a valve amp with what appears MM Phono as "Gram" if the Tape Head input shows it is MM, the Gram input means Ceramic, so a bit out of date. The rest of the circuit is fairly standard, passive tone not great using a ground reference as this design can be inaccurate. Power amp typical design avoiding the Mullard design splitter interestingly. The article describes the amp & offers it as a Construction Project if oddly Kits are marketed under 'Wayne Acoustic Labs'. The 'fun' thing about any circuit diagrams HFN prints is the next month or so they print corrections as there are always errors, so it makes you wonder who proof reads these. 'Readers' Hi-Fi Installations' shows cabinets & gear that readers have, the industrial looking cabinets with the tuner 8 inches off the floor & a turntable in a well with amps behind doors is the typical idea, all not very user-friendly, but it was the way promoted as 'right'. The days of building into Antique Furnite or getting Repro cabinets continued into the 1970s & with TVs the old CRT TVs put in a tacky chipboard veneer cabinet with doors was a much wanted item into the early 1990s. The Entertainment Centre. Sherwood S.9500 Amplifier gets a review. All Transistors & 20w continuous, if 14w is just under 1% distortion. Smart insides if messy interior they say & the Sherwood valve amps are chaotic, if some is a PCB design with hard wiring like Fisher. This is progress from the Germanium transistors & all Silicon transistors plus no splitter Transformer but it is Capacitor Coupled on the outputs, so not quite the Sansui 3000(A) design. Square waves are way better than the Scott amp above, 1kHz is perefct & 10kHz has some curving showing it's not as fast as later designs yet. HFE shows it ran to "B" and "C" versions if the 20w rating. The circuits look good for this early as the Square Waves tell, not much 'shaping' of the sound like Fisher do. This will be a good amp. Quite a dry review, no word on sound if it is Recommended. To show it's still 1965, the Decca Deram Anti-Rumble pick up arm is hardly needed on the Garrard 401-Thorens TD124 of the day, it just has damping to reduce deepest bass & likely blurs the rest of sound up with it. Aged ideas, if be sure many are still in use unaware of it's design idea. Dec 1965 has a Garrard advert with the Garrard SP 25 first version. Prices at the time are 401 at £32, LAB 80 at £27 & SP25 at £12 showing how Budget the SP25 was if it did sell well, the SP25 Mk III was a common find as it was around in the 1970-72 era that brought in the Comet discounting ideas. H.A. Hartley (not J.R.) was a Hifi Pioneer actually the first to use "High Fidelity" as a term on his amplifiers, we have some paperwork about his early amplifiers if better known for loudspeakers. The "Hartley-Turner Tone Control Preamplifier" plus Model 215 speaker, TRF Receiver unit (Tuner), H-T 25w Amplifier & power unit, the Tru-Bass Boffle plus a price list dated 1948, found it amid some Hifi Books probably. Tannoy advert says the Lancaster cabinet "introduced last year" so these are as early as 1964. Garrard 401 turntable gets a review that picks on it quite a bit but blames Plessey who now own Garrard for knocking out a bit quickly by changing the motor so it's not so stable on mains voltage changes, if perhaps in 1953 compared to 1965 it mattered & doesn't later? The 401 does get cheaper made over the years & the plinth corner isn't SME friendly which puts buyers off & how it wasn't aware of the SME fitting is a bit strange. Tolerances of manufacture weren't as tight as the 301. Summary of The Year. 1965 was a bit of a slow year after 1963-64 progresses. More Transistor amps appear if by their Rarity as UK voltage models, UK buyers stuck to Rogers, Leak & Quad still. The Gates opened up to Hifi Discounting is the hidden thing here if generally nothing much happens until Comet arrive in the late 1960s with their Securicor Delivery service that gets well mocked. There's still enough 1965 Hifi you could use today that would be of a quality worth keeping going.

The SME 3009 Mk II Improved Arm Isn't Playing It's Best: Now Solved.

On preparing our Sept Record Update, by playing these Records, the SME is found to be mistracking in the same area of a record. For the Summer not taking much notice, but listening Critically the problem is now clear. You can see Photos of the inside of this 3009 version online, it's not got loose ball bearings like some early Arms do, no bits to drop all over the floor & never find if some screws need care. Ball Races, Hex Bolts & a bit of unscrewing the black pillar with the bearings in. 1/16" Hex wrench required, a 1.5mm doesn't grip right. To buy a proper tool, not the feeble Allen Keys of today that chew up, we got a 'Fastrax' 1/16" Hex Wrench like a screwdriver using properly hardened metal, spot on, as used for Radio Control Cars so of a quality. Care needed as whatever old oil was used doesn't last 40+ years & this is what we originally thought was why it's sticking slightly to appear to mistrack, which gives a muffly sound to the record in certain places only, not needle fluff. But the problem was more than that, needing a Spare Part found. Check the Bias String pulley also as this can stick & cause problems if not set up right, if that won't cause mistracking. But after servicing it for the first time the Ball Races were already poor due to the lousy ebay seller swapping what looked a one-user turntable with bad ball races as the thin cartridge wires appeared resoldered to the SME cable connector. The trouble of buying online & the trouble of buying 40 year old precision items, be sure the seller knows as they swapped it, right? We did find a spares arm by remarkable luck if the seller's misfortune & for a mere £30 the bearings are good here, no grumble or sticking as well as once the black pillar is back on the arm, give it a spin & it goes for ages until slowly stopping without a jump to stop. The bearing ball races you may be able to shake out fist-on-hand way, or a tap with a non-metallic biro or pencil will help them out. In comparison our original one wasn't as free as the spares one & back together it'll get a good testing, to mistrack on quieter records as the groove excursions are much less to not 'help' the arm move across the record. These Ball Races are the same as in Video Heads & they must spin at fast speeds without any bearing grumble as the picture would be affected. The 3009 is a bit of a job to put back together, resolder the wires & fiddle the oval case screw posts all to fit back. Planning needed as it's not quite as straightforward. Some may put 'better' cables inside, 'Silver Litz' or 'Cardas' often found mentioned, again can't see any great point to that. But to see the £30 spares part from a high grade arm parted seems a wise buy, if fate wants us to have it, you never see these parted out usually unless they are in poor grade with corrosion meaning the bearings will be bad too. Over 6 days it was serviced once, serviced more with the WD40 & then playing records finding the mistracking vagueness, to just move the arm side to side then play the same music part revealed it's not the recording at fault. This time as the spares bearings were good, we just used the bearings & pillar as the bad one may be slightly damaged from the bearings being forced in causing loss of precise Tolerance. Looking inside the old bearings, a plate both sides holds the ball bearings in, any slight upset could get one to stick, the bearing case might not be perfectly round or anything from clumsy handling. Probably very unlikely they'd wear from normal use, we had our SME IV for years with no issues, but user misuse trying to clean them or damp causing corrosion will be what ruins an SME arm. The Technics SL-1500 uses pin points as bearings & once serviced that is an easier one to keep in good order. The replacement bearing plays perfectly with no vagueness on playing quieter recorded 45s that sounded muffly & even the SL-1500 arm wasn't perfect on one 1955 UK 45, if playing it now it sounds spot on.

SME 3009 II Improved: More Upgrades.
Beyond going for the 3009 III introduced 1978 or the later 309, IV & V, why not just improve this more? We've had the SME IV to know where it's good if it's not user-friendly with a fixed headshell & not a 'quick' arm to use like the 3009 is. One problem with the 3009 II Improved is that sodding arm clip, it keeps locking when you're just resting it, some arms have a longer rest area. To solve the clip falling down & making you pull on the arm possibly causing the bearing damage, take the two pins out, add a bit of superglue to widen the clear plastic bit so it stays put until pushed down to lock when needed, if not glue it solid. The earlier c1970 era SME 3009 we had years ago had the wire catch that was a pain too. The Technics SL-1500 arm clip is much easier & so is the ease of adjusting weight, if the arm doesn't quite sit parallel to the turntable. The 3009 II Imp is generally difficult to work on, the arm lift part that screws onto the bearings pillar needs critical setting to not impede play & still work on the arm lift. The black ground wire connects to the front screw or you'll get earthy noises & the screw never tightens. One "Upgrade" we see on ebay is not very good at all. Involves fitting a plastic plate to the 'short' screening can & then rather foolishly letting the 4 cartridge wires be unshielded. The 'long' screening can is better if still why use plastic as even a small area not grounded could pick up hum. Someone not thinking there. You can fit the OFC Copper Litz wire like the SME IV uses, this is just OFC stranded cable wrapped in a sort of thread binding that's Silk, if Silk does disintegrate over time. Looks like the sort of wire used in Old Valve Radios wrapped round coils & it's on AM antennas. Copper or Silver is available, OFC Copper will do. Prices range from £180 because it's "always better as it's more expensive" hype, to £4 & even £2.25 for the same thing, or get a full reel for £15. Appears 'Cardas' wire is further twisted together, bad idea as this creates inductance together with cable capacitance so creates a LCR filter taming the sound so one to avoid & to explain why we don't go for accepted opinion. What do we do about the plastic coated original wires? Leave them be, no 'upgrading' needed as these twisted cables are LCR filters, in old valve amps the Heater Wires are twisted to reduce noise, don't these "experts" understand the reasoning behind design. We want Untamed Sound, not softened off sound. The "it sounds better" to the unaware listener as it's filtered appears to be the Game here & keep those with Shop-Bought Hi-Fi happy thinking these cables are a good idea as the mag reviews tell you. Not putting the SME back together until the Bronze bit arrives, if the SL-1500 can be used.

SME 3009 Brass Knife Bearing Upgrade.
Further Upgrades involve making the arm as solid as the SME IV was. The Bronze Knife Bearings on ebay for £35 from Czech are interesting, the original ones are just plastic which is not good enough as it's not rigid. Amateur Reviews tell that these make the arm "Sound Worse" which we find a positive aspect as it means they are adding rigidity to tighten the sound & unawares who say it "sounds worse" have poor Phono Stages that can't cope with the extra detail & precision. We're not swayed by other's opinions if to see why they say that helps. So we buy one, the original plastic one is a feeble thing. Arrives quickly, looks a professional item, if it's Gold not Black being the only difference visually. Fitting it is a bit tricky especially getting the arm grounding Black cable back in, to use long nosed pliers & a bit of tape to hold the coloured wires away. A Professional Opinion of the Upgrade is what we can tell & it was obvious on first play. This Brass Piece is a Genuine Bargain upgrading the arm into a very different grade of item. Bear in mind we know the SME IV & how smooth & detailed it can be. Putting the arm back together for the brass piece & our further upgrades it's a very rigid item just like the SME IV was. The improvement on playing 1960s Singles that we played only a few days earlier is a Huge Increase in Quality. Previous Edginess to Mono 45s that can often be quite rough cut on the 1kHz area is focussed a lot better sounding smoother. Some may confuse losing the Grainy Sound with Losing Detail, but an experienced listener can hear the soundstage is deeper as we've heard many times upgrading Amps to increase Resolution. In use the 3009 arm appears more confident, holding to the Bearing Posts very solidly. Playing some very Loud Cut 1966 UK Decca 45s the focus is way improved revealing Bass that was once hidden, overall Bass is tighter for the sound being more focussed. The only annoying thing now is the pointless rotating headshell arm fitting. It's set perfectly square & then to swap cartridges & the thing goes off angle. It needs sorting as it's not useful, we do this & it's set perfectly square to the reflection in a vinyl record, one further upgrade once again tightens focus. Everything in Turntables must be Totally Rigid, anything that creates Damping will lose focus & detail. But to get the Benefit of this, your Phono stage needs to be a Great One, from our Turntables page we found most Phono Stages are mediocre. Vinyl Does Not Sound 'Warm'... it's the poor "everything" playing the Vinyl that blurs the detail.

1966 Akai AA-5000(S) Amplifier.
This is one that's interested us before as the "Other Amps" page shows. But the one on ebay at £300+ delivered is too expensive to buy blind. We've searched in vain for the Service Manual & one that claims to be "AA-5000" is the 1971 AA-5800/AA-5500/AA-5200 series. But a post Jan 2017 after we last looked has found a AA-5000 schematic on a French site, not stitched together as one page but at least to have it at last. The list of Transistors is shown, such as 2SB440 (Ger), 2SC362 (Sil), 2SB54 (Ger) with a selection of output transistors like 2SD46 (Sil) & 2SC493 (Sil). So is it worth trying? There are 2 versions, AA-5000 with Germanium outputs & AA-5000S with Silicon, the same Bendix output transistors the AA-7000 uses. The Aux goes through a large resistor into the Phono stage, we don't like this design as we first found on the 1969 Sansui 4000 as it compresses the sound, the 1968 Toshiba SA-15Y had this design too. But "Tape In" as often with this design bypasses the Phono stage. Circuit once stitched together as one page is a strange one, quite a lot of limiting, NFB & sound shaping. It is Capacitor coupled if with a very low 500µf axial that we can see is fitted on the board similar to how the AA-7000 does it, No Transformer Coupling here unlike the AA-7000. It works on 75v HT which suggests about 20w-25w at least. For "Tape In" use, the circuit goes to Passive Tone direct as the AA-7000 does. T1-3 are the Phono-Inputs stage, T4 & T5 are the Preamp transistors, with T6 onwards is the power amp. The power amp is very strange as was the AA-7000. The opinion on this is it looks very Retro Cool, but the circuitry isn't very good & will sound very tamed, if the 1970 AA-8500 receiver & 1973 AA-5800 amp did as original, but both upgraded well. The AA-5000 we're pleased to have seen the circuits, but suspect the sound wouldn't please & it's not really one that can be altered too well by the strange circuitry. We like the AA-7000 mostly, if the AA-5000 looks like a design that's been over-compromised as the designer altered it to have it sound right. One we'd still try if a UK-EU one turned up, but now we're not so keen otherwise (read on...). This is after finding the 1966 Rotel 100AMP similarly compromised & finding it best to sell as an Ornament which is a bit of a shame really for the brand's later quality, but not all early Transistor Amps are as good as the 1965 Sony TA-1120 or 1966 Sansui 3000(A). Update: It kept nagging at us, to see the Akai AA-7000 here to upgrade & see the 1972 Akai AA-6600 is the same design, to try the AA-5000S had to be done. An earlier AA-5000 up for bids with Germaniums was 110v only & a bit too rough. The AA-5000 works on 75v HT as Capacitor Coupled, the AA-7000 has 75v main caps, so the AA-5000 could rate at least 30w.

Vintage Audio Cables 1967-71 Era: A Revealing Comparing Session.
A test we did with a loud cut UK 45, The Who "Pictures Of Lily" to compare the Technics SL-120 with SME 3009 II i and the Technics SL-1500 showed the SME turntable was still ahead of the SL-1500, but really not that much. So as we had an amp arrive with 1967 era cables of some quality, to see what Cables that old actually sound like. they are usually "Steel" wires, actually this is Nickel Plated Copper, meaning it won't tarnish. Looking at 1960s Mains Cables, they are usually browned even inside the plastic insulation, showing that they aren't so conductive with Oxide Coating. These 1967 cables had pre SME type solid ground section on the plugs, the sort that fits the older bigger Phono sockets some early amps like Sansui used around 1966. Surprisingly these old cables sounded fresher than the "Straight Wire Blue" as blogged about before on Phono-Cartridge compares. Another unbranded cable that came with the Rotel 100AMP when it was likely sold new in UK in 1971 sounded fresher too. But it's very unusual to get old cables & if we do they usually go in the bin as skinny ones in poor grade which aren't of any use so we thought & to just assume Stranded Steel cables weren't good as todays are OFC Copper. But here we get some thicker ones with brown rubber-cased cables, not the usual cheap ones which are only stamped 'Japan'. One is a pair connected as a 9mm wide pair so each cable is 4.5mm round if joined together. The other we suspect is the Phono one as it has the same design but adds a 5mm flat strip between much like some modern Speaker cables we've had does. This uses 4mm round wires with the gap at 5mm making 13mm wide. What is noticeable is slight Vinyl Crackle appears less mixed into the music & a 1966 Ska 45 on UK Island appears to sound fresher. The answer why they sound better is simply the LCR effects are less in good simple cables, lower capacitance, lack of the braided ground losing inductance too. FERRITES we didn't use on the 1967-71 cables as they'd need cutting & for the chance of that it revealed Ferrites aren't needed on the Phono Stage now as we've upped the Resolution. Ferrites are good in certain uses, they do compress the highest frequencies. It works where the Hifi is lacking focus or the wire is long like TV Sound Cables & Speaker Cables. The Marantz 2385 has Ferrites from the TiVo box & DAC so we'll ditch them for next listening. The verdict fairly quickly is that the DAC cable being of a longer length does need the Ferrite else it's lacking Focus on the Treble. Ferrites are not as essential if the resolution is very high & the cable is only 1m long, but for Longer wires that act as Antennas picking up RF Noise, they still are useful.

October 2018 Blog

Why Don't Others Upgrade Amplifiers Like We Do?
Because it brings lots of problems. Often upgrading needs more work to fine tune the amp, overcome problems & that's like Fault Finding & Redesign. We can recap Tuners, but having done the Sony STR-6120, the whole tuner then needs realigning which based on the Tuning Meters & by ear is a bit of a job, then you get problems with Ferrite Cores to be adjusted & the risk of cracking them, even with the Nylon tools that we can't find now. Tuner Upgrades are not cost effective as the low power used by the Tuner means usually they still are good if they do work. One Hifi tech specialising in Tuners won't replace any Capacitors unless they are failing, not even 50 year old valve 300v+ ones that we know are dried out. We know if one capacitor is bad, the rest are likely on the way out too, so to not recap the lot is a wasted effort. Redoing the lot is more cost effective than Fault Finding, especially the Intermittent ones. Many on Forums recap Like-For-Like that to us is pointless as it doesn't bring out the Best of an amplifier. But if you do Upgrade one stage, the rest of the amp has to be upgraded to cope with it or you'll get wild problems. We upgrade amps that play fine if aged on the original design, but then by improving one stage, the problems that can arise that need rectifying are as extreme as a Faulty amp needing Repair. We do amps stage by stage seeing which give the most improvement over several upgraded amps & generally either the Preamp, Power Amp & Power Supply can give the best improvement if amps do vary, which doesn't tell much of where the most gains are, except the weakest one. Some amps we've worked on Blow Fuses as the Spec of the Original Design can't cope as it was borderline as original, the Power Supply not fully redone with upgrades brings Mainsy Hum noises plus the Pulsating Instability of some amps due to design compromises. To know that Shop-Bought Hifi is priced to keep it within it's market, with only the really high priced items daring to not be constrained by price, corners are going to be cut. The non Upgrading aware tech will think they've ruined the amp & now scared put it back to original as they think they've done wrong. What they have actually done is expose design weaknesses. Only by one Upgrading over 100 amps & encountering these problems and being able to understand "why" the problem happened can improve the design to contain the issue. It's Wild, It's Crazy & It's Experimental. The skill to get these amps into line to be Reliable & Stable is what we do, from daring to question design features knowing that there are corners being cut. By daring to do everything to better one amp & then "tuning it in" to sound right because it was a Courier Damaged Freebie on a Payout is what a Pioneer SA-9500 was a few years back, so not caring so much to try these ideas yet actually get good results is what gets the progress. To find the limits of the design & pull it back is the General Idea, if this is what we do on Our Own Amplifiers, to do Crazy Stuff to Customer's Amps doesn't happen, the ideas they get have been refined from our experimenting do get used & give excellent results. We've sold on many of our Experimental Amps once they have gone as far as ideas at the time could send them, if then to get the same amp back a few year's later will be looked at quite differently based on learning from other amps. The Learning Curve may be Flattening now, but new ideas will always crop up so Progress will forever continue as long as amps we've not had before are found.

Is There A Design Feature That Means An Amp Always Sounds Good?
Looking at Power Amp stages in both the Capacitor Coupled era & the later Differential: Is there a Design Feature that means an Amplifier Always Sounds Good. No there isn't. End of Blog? An Amplifier's Sound is a mix of what the Preamp-Tone, Power Amp & Power Supply brings. In Power Amp design, what makes the Marantz 2385 sound great made the Sansui AU-G90X sound thin & harsh. The Yamaha CR-2020 & CA-1010 sound very different despite being quite similar, 2020 is softer & more wallowy even much upgraded & the 1010 is thin, dry & a bit harsh sounding even much upgraded. Interestingly Power amps aren't much different sounding as there should be no Tonal Difference if you will hear differences with factors such as Damping Factor & Slew Rate. Very similar design on the NAD 300 & Akai AA5800 but the Akai sounded great upgraded, the NAD sounded pretty weak for it's 85w. To play a Power Amp stage direct from the Sound Card using the Computer Volume, generally a Power Amp will not really differ that much as long as the Sensitivity is the same, the typical 1v of most amps to the 100mV of the earlier Trio is really the only difference. The only amp we managed to get sounding better by changing the Power Amp was the Heathkit AR-1500 to get it sounding much smoother on our Tannoys, the preamp stage wasn't great on this amp & the power amp done a certain way complimented it better, but interestingly the buyer had Heathkit speakers of the era, so we changed it back to spec & they said it sounded great as things matched. If the Power Amp is much the same sounding, just amplifying not altering a Tonal balance, the Preamp must affect things. But once again. comparing amps that sound good or ones that are a bit too 'flat' sounding very few amps really don't please us on our Tannoys. The Marantz 2385 & Marantz 4070 amps have quite different designs, the 4070 uses more NFB than the 2385 yet at TV listening levels they aren't that different sounding, if the 4070 with the Bridged Power amp has a lower Damping Factor so is more Bassy than the 2385. We have two old favourites here as of writing, the Sansui 3000A which uses NFB in 3 stages beyond the main output one & the Pioneer SX-1000TDF sounding much like the 700TF & 1500TF we had before. The Pioneer has no NFB in the Preamp if adds some on the Power Amp. How they'll compare once both done will get a future blog. The Trio-Kenwood KA-6000 we used the superior UA1384 board from the KR-6160 in, the amp uses no NFB in the preamp with a unique design using two small amounts in the power amp. But overall compared to the Marantz 2385 and 4070 our KA-6000 version sounds much the same as the Marantz. Of course all amps are upgraded to our ideas in the first place, eliminating a lot of differences you'll find comparing the amps mentioned here as original. The only "unknown" is why some amps match our Tannoys well & others even with Parallel outputs don't match, what factor affects the amp appearing to heavily lose treble & bass to sound "too midrangey". For the few Yamaha CR-1000 we've had, we had one only a few months ago & another a year before that, they always sound different on speakers. To get a 1975 dated CR-1000 as the recent one, compare it to the earliest circuit & every thing is exactly the same, yet one matches better than the other, plus the first opinion of a CR-1000 on our Tannoys was that is was a poor match, yet the same CR-1000 sounded great. Now that is a Mystery.

Now What... Design. Not Exactly Many Good Amps Left To Try.
For all the Amplifiers & Receivers, some we've liked enough to Revisit, as the Reviews page shows, if not all we've got to Revisit. The thing is the more amps we hear, to think "why doesn't that sound like that amp". It's all in the designs. To us the Best Sounding Amps on Speakers are ones with straightforward designs without High Negative Feedback (NFB). Some amps can appear great on paper, but to see very high NFB with very high gain circuits just is not a good sound. It plays it very loud & then flattens it off, which on Speakers more than Headphones sounds flat despite it sounding clean & precise, it's been through a Compressor which does a similar thing, ups the gain & chops off the peaks. Maybe you like that tamer sound, we don't. We played Valve amps for many years & that sound suited us well for it's clean sound with no NFB beyond the main loop & on Tone & Phono. The Low NFB sound is in amplifiers, especially ones post 1975 if the trouble is the design needs Quality, but instead it got Cost Cutting giving that awful thin grainy sound that is the Typical 1980s Sound not helped by small speakers. Altering designs is a long job to do, results may take many months to perfect, trial & error as well as "designing by ear" can take a lot of time to get right, to sound right & to test right. In two Marantz amps we have the 2385 has very low NFB, the 4070 has some NFB in two stages, but on speakers at TV Sound level they sound quite similar, made by the same company & upgraded by us. But then playing the Sony TA-2000F/3200F the sound wasn't liked as too 'flat' sounding with no real kick to the sound despite the power amp testing very fast on Slew Rate as blogged. To suspect the FET preamp is the weakness here plus the Power Amp is unuusual on it's Differential compared to the 1971 Sony STR-6055. To try to alter one amp with NFB to something different, being aware telling more gets forum readers to do things they shouldn't, beyond the Main Power amp output one does give subtly improved results if on an original spec amp it might make it sound worse as per the SME brass bearing. All things to try, forever in search of "The Perfect Amp".

The Curse Of The TV Grade Repair Guy With 40 Years Experience.
We've seen two Valve amps recently, one on ebay Germany, a 10w Pioneer ER-420 receiver from 1967. "The amplifier was completely overhalled (sic) from professional technician" says the listing. Really? thinks us, the work is pretty poor. They leave All the 50 year old grey power supply capacitors top & bottom. Quite Ridiculously they put a Fan by the power amp stage 4 valves. Do not they not realise Valves get hot or is the amp Biased wrong, or pehaps Faulty from the bad old caps so the Output Valves get really hot, glowing red, so they'll fail soon. The price of £405 converted with Best Offer is telling, it's not a reliable job. The underside is a typical rat's nest of wiring & parts, if these we understand once the sections are worked out & they aren't as illogically random as they look, Here their "pro tech" has just replaced a few parts to keep it going, typical TV repair man rubbish work that keeps them in work as it'll be in for Repair soon. Another is a Rogers HG88 MK III a customer wanting a proper rebuild has bought as "Just recently Extensively serviced by an audio engineer of over 40 years experience in valve eqpt (sic)." The amp itself is the interest & why we recommended buying it as it's even cleaner than the one we had on our Solds Gallery page. Again the work to us is strictly amateur, lots of rubbish work with random resistors changed, a few capacitors changed under, the main caps disconnected & small ones tacked on underneath, one with a big blob of silicon attaches to the mains transformer with the silicon onto one of the wiring tags. Again dismal rubbish work. These Old Timer techs just do it the lazy old way of "keep it running" & often their ideas are bad especially on valve amps. Transformers fail so they just fit any old output transformer instead of the correct one, one Kenwood KW 70 on ebay has one very mismatched size transformer that'll not be much good, but the TV Repair Guy thinks it'll do, as we've found equally rubbish repairs on Quality amps. But this was how TV & Audio Repairs were, we knew one local Repair Shop near to the Family Shop in the 1980s, it took them 6 months to find a mains switch to fit the Philco-Ford amp. Our first Hacker GAR 500 packed up working on one channel & they said it was unrepairable, far from it we know now, but they couldn't be bothered. The Old Timer's work on Hifi we do dread as it's often of rubbish quality using poor parts, even the recent Toshiba SA-15Y was "repaired" by the seller, missing the actual cause of the problem. They just use any old parts & their soldering was terrible. We just "rip out" all their poor work & do it properly. There are many doing restoration work that we see online, some do it nicely, but we still feel we are the only ones doing what we do with bringing the best out of Amps with subtle Upgrades. It Takes Years plus nearly 200 amps to get to the standard we are at & even looking back at amps we did 4-6 years ago, we see a lot of progress in ideas, streamlining the ideas. To get a Sansui 3000A that we sold our one in 2014, to do a customer's one, we do it with ideas afresh, not taking much notice of what we did before, if having learnt the amp, it's strengths & weaknesses to bring the best Upgrade at a realistic price, without going to excesses that charging double wouldn't really bring much improvement. The lazy TV Techs worked on a production line with a Boss counting the pennies. We still do a lot of Reaearch into Uprading Amps that are Our Ones & this is where the progress happens.

Trio-Kenwood KR-9050 200w Monster Receiver.
This one on ebay as a 110v model shows it wasn't a UK model so not in the Trio blog above looking at later models. On ebay it doesn't look too impressive, it looks like a 60w amp but it's nearly as huge as the Rotel RX-1603 at 602 x 177 x 465mm at 24kg. But looking at the similar ones on our 'Other Amps' page they are nasty IC things even on the power amps. Is this any better? Phono is Transistors as is the Preamp-Tone. Power Amp is a little hard to follow if it has a first stage then goes to what looks like just Single Output Transistors for 200w which is unusual, other amps have Double or triple Parallel outputs. It works on ±74v which is nearly the same as ±75v on the Marantz 2385 with triple outputs giving 185w. This doesn't appear to be a 200w amp therefore. The Sony TA-3200F works on ±61v to give 100w. But the Schematic shows the specs as 200w per channel both channels driven. Output Transistors are 2SC2607 and 2SA1116 both rated 150w at 5A. Can't be 200w RMS? Whoever did the Circuit Diagram confusingly put One Transistor Pair on External board ie a Heatsink, but Q5-8 are 2SC2607 & Q9-12 are 2SA1116 so they Are Paralleled Outputs. But 2 of the 4 appear on the PCB & 2 on the Heatsink is a bit strange, because further looking shows 4 per channel on the oversized thin cage heatsink, 1979-80 designs aren't that good as inside pics suggest. Build quality isn't like the 1976-77 ones. It looks Cost Cut is the opinion, it is all Transistors though, but hpw good it sounds for one as late as this with the cost cut design could be a bit disappointing even upgraded. It's just not got the build quality.

1967 Sansui Amplifier on 1968 Tannoy Speakers: Into The Time Machine.
This is the Third of our Try Out An Early Amp As Original On The Speakers. The Pioneer SX-1000TD-F gave us a worthy result, the 1968 Sansui 3000A didn't want to play so to get a 20w 1967 Sansui 400 receiver in good working order is a must to try. After a service it got over an Hour use on headphones & as the Review Page shows, it sounded perhaps the Best Original amp we've heard as the design is a great one. So to let it sit a few hours on the day it arrives still, try it again, all is ok, no DC offsets on the Speaker Outputs, fit the Gold Blocks to the Amp Screw Connector bars & as the Vintage Cable mentioned above has the earlier type of connector that fits on the Conical large connectors, wheras a modern cable plug won't fit properly, so old cable, F to F connector onto the new connectors worked fine. Makes a brief bassy noise on turn on if then sounds fine. Minor Transistor hiss at TV sound level if generally inobtrusive. To get the Tone controls set to a typical setting & then try TV sound, the "How It's Made" intro is a lively one that's a good test track. Big wide Stereo, sounds impressive, perhaps even better than the Pioneer sounded, if both are over 50 so aging will keep them to a limit. Sansui has no harsh 'T' Bass Filter & the design is a good one with NFB only on the main Power Amp loop as well as being a 1967 design, limiters in this amp are surprisingly few. The design is what it is with parts we'd upgrade to bring it to a better standard if it's far from a bad listen on Speakers. Bass as typical on old amps is a bit cardboardy, the Tannoys show it up & seeing what full bass on Tone sounds like, it's rather limited. The output capacitors are better than the Pioneer value if still Bass isn't the strong point of the amp. Some lack of resolution was noticed on some sounds if loud crisp treble was cleaner than the Pioneer managed. A 1968 buyer of the 20w amp & 50w speakers is maybe less likely, as to buy a more powerful amp & disregard 'the little ones' if the Sansui 400 design is actually fresher than the Sansui 3000(A) which has quite a few NFB stages. The 400 is a very impressive amp even as original, ours still on the original bulbs shows it's not had much use. Rare to find amps this early as original, but the thing is it may be great today, but next time as we've found with other amps, your use of it brings on problems, it could have been unused in 30 years by the owner who bought it aged 30 in 1967, added the BBC Radio waveband change stickers in 1978 but rarely used it & for it to emerge on a house clearance. Research On Original Owner: The amp has the previous owner's address label on, to search finds the house last sold 1998. Oddly the address is now an Electrical Services one if the sticker looks early 1980s. Unusual to know of previous owners if no-one's taken any interest in this amp since 1998 so it could have been in Storage & cleared out. The Surname is an unusual one & one of that surname born 1925 in London & the address is where they'd move to from London, only 7 of the name born 1920-1950. Was it Beryl's amp? But women marry to change names, so perhaps not. Name & Place into Google finds a Roy in the same town, so it was Roy's amp, or his wife's. Roy born 1934 not so far from Newcastle so in 2018 he'd be 84, bought it when 33, but his place has been cleared, maybe into a Home as no recent info found, if not all families care. So that's who owned it & probably the amp just in the general unwanted stuff & either Council or Recycling Yards get to pick through. The dozy seller didn't even try the amp, power switch was sticky & their price showed the level good items get to by ones unaware. Looking further, Roy's on LinkedIn as Retired from an IT company that has his wife's name in too & that's his Son on Facebook still in the town on the label & guess what, he's in the same job. Even more unlikely is he went to the same school as the typist. Further online shows the son who's only a few years younger than the typist is the sort of arrogant corporate prick not to care about Dad's amp like they do on "The Repair Shop" so it's best it got to us. A little more on Roy finds he was into music playing the Clarinet & Piano, as well as getting a Diploma in Piano to maybe teach also, so likely the amp got a bit of a shock with what we played on it. People into "Serious" Music actually rarely play music for pleasure, as all the High Grade Classical Stereo LPs we used to see proved. Probably the amp was used for Radio 4 mostly. Dust patterns inside show it was mounted vertically in a cabinet, dust setting on the inside back panels, so possibly it was left in furniture on an installation & thrown out without realising what was inside? Fascinating if ultimately pointless & a little sad how little people care, but these amps had owners. Roy, we've got your Sansui amp, we'll do it proud & probably keep it if we like it once upgraded. As if he's reading, but shows someone who cares got it.

Hi-Fi Forums Online.
There are quite a few that take an interest in the Vintage 1965-77 era, if ones back into 2005 really haven't a clue about what they are & we know our pages telling how good these amps are does appear to have given buyers confidence in these 'sleepers'. One of the Forums we tried briefly was "Audio Asylum" when we were only looking about Valve Amps pre 2002, a difficult sort of site where you're not welcome was the idea, new ideas not allowed. Never bothered again after that, but researching amps one of the best is Audio Karma as they seem more willing to help, if it brings in the difficult realm of the amateur with narrow opions & bad ideas, so to tread carefully. We avoid putting hints about Hifi as early on we saw people take a germ of an idea & put it totally wrongly into their amp & make a mess. Our Solds Gallery Photos tell what we do if only in pictures. Some Forums have pictures of 'Restorations' usually well-meaning amateur jobs with capacitor stuffing & small caps in foam in the original 35mm clips. A French site we've been told of AudioVintage.fr that can be translated, to just see how other people do amps, the TapeHeads & VintageAudioAddict ones show photos. People paying good money for what we see as 'unadventurous' work just replacing like-for-like. They miss doing certain things we see as obvious, but we've jumped into Hifi Restoring very deeply to learn about design & bettering it, daring to question the designs. Anyone keeping these amps alive with Tidy Work as these sites show is a good thing, not so good is seeing clueless ones like a 1960s Fisher with boards ripped out & ICs put in. All Techs Pro to Amateur have their own ideas, some may see buying exotic oversized parts a good idea, or to sensibly use high quality parts giving a subtle refreshing of the amp without losing the originality. As with any Forum, you may not know the person's Hifi Experience when they say the Sony TA-1150 is a great amp (for example) when we know it's got a lousy IC in the preamp & bad resistors giving uneven voltages. Then you see one in 'raw' grade for £350 on ebay by some dreamer & without knowledge of the amp, you may think it's a good one. At the extremes of Opinion, you'll find those who'll only listen to a £30,000 system & then happen to hear one of our Upgraded amps as some customers took round to such an owner & they all agree how much more Musically Appealing our 20w 1960s Transistor amp was. Then you'll find those who say some cheap nasty IC power block amp sounds "valve like" hoping to get a sale to an unaware.

Do You Want To Learn To Do Vintage Hifi Repairs?

The only problem with Hifi is the advancing age of it. We had a 1969 B&O Beomaster 3000 in 1990 when it was 21, still quite a recent amp in terms of what needs servicing, you could get away by just using it. But now it's 49 years old, the B&O low grade capacitors usually all leak & go crusty, the 28 years in between can age amps heavily, yet some can still be used if 50 years old, if we'd not trust them for much use, some do until they fail. What will happen to these old amps in the Future? As with Roy & his Sansui, the amp just got thrown away as rubbish if there are people at this end of the supply chain that see value to get them. You'd think they'd have searched online to see the opinion, but they probably just found a 2005 forum saying it was $240 new & worth $25 then so they put £20 on it. We did a BTEC in Electronics & the nearest to Hifi was TV & Video repairs. So... Would there be interest in people learning how to Restore Old Hifi like they do Cars & Antiques? Look at "The Repair Shop", none of the 'experts' into the finer restorations are young, they've taken decades to learn & perfect their work, you can only do 'best effort' on certain things, there is unlikely to be any perfection to one who knows how they do it, if what they do can give Excellent results. The BTEC on TV Repairs was very limited, it gives you a Qualification showing you can do a basic level, but like passing your Driving Test, you're hopeless by yourself without practice & someone there as a passenger. How many amps get wrecked before you tighten up your game? Unless you get a job doing Repairs, it could take years to get better at it & you'll do repairs for others but find you didn't do it right & be put off. Or other things come along & you lose interest if then to find a half-trashed Sansui G3300 at the back of a charity shop & just for the hell of it get the thing working to sell it just to cover costs. These days you could start buying the cheap 1979-82 type amps on ebay for £50 or so, but the trouble is the risk of ICs, not just for sound but the unavailabilty, what we could find in 1995 was 23 years ago & shops that used to have boxes of NOS parts, be sure they went long ago when the shop went online. The availability of Service Manuals makes what was almost impossible in 1990 as no data was around, now into a good start. But to understand the amplifier parts, what they do, how to fault find, how to understand good or bad design & upgrade like we do takes a lot of Amplifiers to get that far. Our Reviews page adds the Sansui 400 as 'Review 178' meaning we've has 177 more amps before including lots more as the same amp again, at one time the Yamaha CR-800 was easily found & we've had 6 of them, but tell the world they are good & others get them & up go the prices, they're not £65 anymore if they used to be. How could you Teach Hifi Restoration? Do you really want to give your Tricks Of Your Trade away? Look at the TV & Hifi Repair Books, they actually tell you very little. Electronics Coursework books & even 1930s Radio Repair books give you a lot of Hints as do any sort of Practical book or magazine. You have to dare to try what others are scared of or can't even face wiring a plug. You'll get Electric Shocks, half ruin amps, put parts in wrongly, solder & not check so you miss a solder blob shorting the track together. You may believe the old way of "high fuse & let it sizzle" to find faults like TV repair guys used to do, if so then stay away from Hifi, it needs thought & care. Only Experience will get you Mastering any Skill, aim to do a job better & neater than anyone else to find fault with how the Forum Guys do their upgrades. Use Quality Parts always, if you need to spend more money or more time to get an amp right, then do it. Jobs we Quote prices on often end up needing far more work, just to do it right. Time how long it takes to do something that may seem straightforward & then wonder where 4 hours has gone. To order parts, find equivalents etc can be time consuming, you're just buying parts but again hours can fly by. But you will know if Hifi is for you, as a kid you fiddled with technical things, smashed up old Radios & TVs, got electric shocks as you ventured too far & thought by twiddling that inside the amp it'd be better, if instead you messed up the bias so the amp burnt out. Our first Hifi Repair was the family Bush-Arena tape deck, the Pause button wouldn't stay locked as the spring-lock part was faulty. Aged about 11-12 to unplug it, undo the screws, see the bit had fallen off, work it out for what it did, all totally unknown to us, then put it back & it worked again & did until it was sold. No-one ever asked how it worked, 'the elves' must have fixed it or it just worked again.

Sansui 1966-68 Top Range Sansui 3000A vs Midprice Sansui 400.
Having the 45w 1968 Sansui 3000A now recapped & the 20w 1967 Sansui 400 still as original, to look at both some days after the 400 arrived & impressed. The Sansui 400 was £124 in the 1968/69 HFYB & the Sansui 3000A was only priced in the 1970 HFYB at £170 if was an obsolete model by then & the 400 didn't last long as an updated Sansui 800 28w at £145 in the Sansui 4000 styling replaced it. The 3000A is a heavy 15.6kg & the 400 is 10.3kg which still betters any later 20w amp. The 3000A has an 11 x 10.5 x 9cm transformer, the 400 has a 10 x 9 x 8cm one which is big for a 20w amp. The 3000A has a heavy metal frame & boards are neatly done, power supply is tidy. The 400 shows the cost cutting with Half Wave rectifier hanging off tags onto the one main capacitor. it reads 51.1v DC with only 43mV ripple on which is a lot lower than expected. The top inside of the 400 looks tidy if the underneath looks of less quality, the Phono board unshielded near Tuner boards isn't good & some random added bits like a transistor & capacitor under the power amp look messy. It does look a bit TV grade underneath. But the design is simpler than the 3000A without the coupling transformers, no dual power supply from separate transformer taps with ± voltages, the 400 has a good clean design. £124 to £170 in 1969 is £1940 to £2660 which in paying that for Today's Audio & TV gear isn't a huge difference, probably why the 3000A sold better. The 400 can be upgraded to lose the cheapness in many ways & for the looks being similar, the 400 is still worth having. But having played both, the 3000A design has NFB on several stages that the 400 hasn't got so the 3000A is a more tamed sound with smaller dynamics & actually quite a narrow Stereo width when the 400 as original is a much fresher sound with wider Stereo. The 400 does cheapen itself with "Noise Filter" sounding rather simplistic, it's a High Filter, if perhaps making it for a more budget conscious buyer. In 1969 the 25w Armstrong 525 receiver was only £87 if comparing to the Trio-Kenwood TK-66 at £122. Having had the TK-66 we rebuilt it quite a lot as it wasn't so great as original, the Sansui 400 as original, well you can read the blog above to tell what a 1968 buyer would almost have heard, the Sansui 400 easily was the superior item soundwise. More Sansui 400 blogs to come as the design is a good one.

Why Recapping Like-For-Like Is Often Disappointing.
You see quite a few Vintage Amps, recapped, some done better than others if they actually show their work as they could have used cheap Made In China caps that we just throw away. You can read in the 3-part Sony STR-6120 upgrade blog that recapping a tired old amp that may still sound good will then make it sound Brighter. Together with nearly every amp being limited on Bass, this extra Brighness unbalances the sound so the Amp sounds Thin & Bright with Bass being poor. We noticed this early on in redoing amps & this is why we learnt to upgrade which takes over 100 amps to learn right. You can't just upgrade one stage, the whole amp needs the upgrade & it's a black art as is Fault Finding. So the well-meaning person recaps the amp doing a nice job using better quality parts, but look at what they do, they don't like the Sound so sell it on, often for little more than a "Raw" unserviced amp because the Results are not as expected. New Capacitors can sound awful on first use, we've heard this but in use after 10-20 minutes they sound right. Valve Amps with much higher voltages may take a little longer to settle in, but really no more than 60 minutes. The old Hi-Fi Mag "expert" idea of Running An Amp In For A Month is actually a load of rubbish. The amp does not need a heavy run in, it's just that over time, often 2-3 days of you hearing the amp, you get used to it & your hearing accepts it as correct, good or bad. Valves don't need much running in either, again 30-60 minutes will get it settled into the circuit & often valves are already run in to test to grade them as a Matched Quad. We see upgrades on the "Monster" Receivers & to see they charge heavy prices yet leave lots of old parts, old limitations & don't learn the circuits to get the best out of them. The Person who doesn't like the Amplifier Sound goes looking elsewhere 'hoping' to better it, be it as bought or recapped. Shop Bought Hi-Fi is always tamed to be Universal, you'll never find your "Holy Grail" in Hi-Fi Sound as no manufacturer will sell it. Some sellers get new Amps & 'upgrade' them to sell as Improved Versions, but usually they just change a few capacitors that will not make much difference & leave all the Dumbing Down as it was.

1976 A&R Cambridge (Arcam) A60 Amplifier.
This was a popular amp in it's day, in the HFN/RR adverts a lot, but despite us looking before, we've not tried one. It's a midprice long slimline amp following the Bang & Olufsen - European type design size if only a 5kg weight reveals it's not a high quality amp if UK Hifi at this time was very limited as only really Rogers, Armstrong, Sugden & Goodmans of more established names still around as many other UK brands faded away in the early 1970s. The A&R Cambridge brand first appears belatedly in the 1980 HFYB with the A60 30w for £140 when the 30w Technics (Panasonic) SU-2400 was £80, if many still chose to Buy British. Not related to Cambridge Audio. We've not been too happy with UK & EU amps so generally don't bother with them now as the Japanese & USA amps are of far better quality & power. The A60 is a One-Board job with DIN inputs if Sockets for Speaker outputs, again DIN sockets puts buyers off & we avoid them as not worth putting good upgrades into & not get the right prices. But beyond what sells for us, the A60 on ebay a £45 faulty one sold and £90-£119 bought working ones if a £200 one is clearly optimistic. That's the trouble we found with the Leak 30-70 amps, they are easily found & don't make much money, they are Bargain Buys today. The Circuit Diagram is in the EU style of circuit like B&O, hand drawn circuits is a bit amateurish, if the 1966 Akai AA7000 one is also. Limited Bass as typical, differential Power Amp, all Transistors, Semi-Complimentary outputs with the UK BC547 & TIP 3055 outputs with 1.6A fuse on the Outputs. For 1976 this cut-price design clearly led the way, one board simple construction & basic case work. Circuits a bit hard to follow if it looks fairly typical with quite heavy NFB in one place that will give a Domestically pleasing if rather tame sound. A later circuit is not hand drawn if probably just slightly updates the amp to the "Plus" version if that has an IC phono stage. This sort of Hifi is probably good for what it is, like the big selling NAD amps it's still not going to interest us in the slightest, but as time proved, it's what people want as a certain price level & should serve well. Nothing to get excited about, upgrade to sound hugely better. For us to buy one at £100, carefully choosing the early non-IC one with a good case, then put our upgrades into it, the Reality is we'd outprice a Budget Buy into a territory better served by the Japanese amps. It's like upgrading the Bang & Olufsen ones we had early on, they just don't have the quality to go further. We tried our Upgrades on the Goodmans Module 80 & all it revealed was how poor the design was, cleverly tamed to be good amid it's design but awful given the upgrades that similar Japanese amps can take to give great results. This is why we avoid the UK & EU amps as the quality isn't there. It's like TV grade quality, designed to sound good at a price, but upgrades, forget it. One who lives in a distant country asked us about this amp to upgrade, so to blog it. For the Shipping Costs it's not worth upgrading, even if in the UK, the results would be disappinting as we found with that Goodmans, so we'd not consider it a worthwhile upgrade. Some may just take your money & do a mediocre job, but to work on an amp like this doesn't appeal. Which is why we've never tried one. Unique opinion here.

Capacitors Aging & Failing: What We've Found On 100+ Upgrades.
Capacitors are a roll of foil, paper or plastic in a light acidic water liquid. The Capacitor is sealed to stop the liquid leaking out, if even the 1977 era ones that are sealed with resin, they still age & fail. Amplifiers from 1967 we've blogged above the Pioneer SX-100TD-F & Sansui 400 & to have these working & useable on 1967 capacitors is unusual. The general 'Forum' opinion is replace the Big Capacitors because it's the unthinking 'thing to do'. They do nasty things like stuff capacitors, put undersized ones in foam to fit the holders, or use the garish light blue Vishay ones which we avoid in vintage gear as it looks naff. The only light blue caps you'll see on our gallery is the 1967 JVC Nivico 5040U amp. Large capacitors like the ones in the Yamaha CR-2020, CA-1010 etc we don't replace, they are still sound. We used to cut open every big capacitor we replaced to see how they aged, some like Leak Delta 75 amp were always crusty & leaking. Some on high powered amps like the 1968 Sony STR-6120 are always bad on the first main one & the base covers show these failed & leaked long ago. Some amps from 1967-69 can vary, some cut open are still wet & smell fine, others are getting crusty as they dry out & the failure of a capacitor reduces it's capacitance value until it dies, shorts or leaks. Ones on 1966 Rogers Cadet III & HG88 III are usually still looking good & they may work, but cut them open they are Bone Dry because they dried up long ago with the 300v-350v HT on them. You can use these amps as one Tech will send out as "Repaired" but you're playing a risky game as sooner or later they will fail & you'll likely ruin a transformer so the amp is dead. Look at 1960s Valve Receivers on ebay, some have mismatched output transformers from failing. Naturally most broken stuff gets thrown out if today a lot of Vintage amps get into the 'rubbish' category to be found, sold & bought by ones who appreciate, like the Sansui 400 story above. In that amp is an example of a good maker of capacitors, "Elna" but the grey ones with the long arrow & blue print are in the 1965 Sony TA-1120 & the earlier 1967 Sony TA-1120A. These we've found looking good, but audibly bad so to cut even small ones open they are crusty, dry & bad. You're more likely to get Small Bad Capacitors than the large Power Supply ones, but ones near Heat or ones that draw higher current or with voltage over 63v will fail. We just recap the lot these days, fault finding on capacitors is a waste of time & if one is bad, the others will fail soon. The huge Rotel RX-1603 we have to upgrade for a customer, seller wasn't honest to say it didn't work on one channel. A few tests by us revealed bad capacitors as it typical of this era, bad enough to not give any signal through, or shorting to ground. We've had 2 of the Pioneer SX-1000TD-F & the first one yet to work right with 1967 capacitors, they were still good. Another 1968 amp, the Sansui 3000A we tried on the speakers as original if it wasn't working right shows caps aging, in this instance too weak to deliver enough current. We've known for a few years that even the 1976-78 era Marantz & Pioneer have bad caps, the thing is that after 40 years capacitors can fail because of cheap or poor manufacture. Storage & Use of the Amplifier over it's Life affects how the capacitors age, ones left in a cool cabinet or even an attic or shed could be better than one kept inside a warm house or in direct sunlight. Attic stored amps are often in poor grade anyway as they get the full outside weather except wet, the cold & heat as well as damp & putside air don't keep things nice for long. To recap or not on Post 1977 amps is up to you & most just use them unserviced or unchecked until they fail, if even if still working they can be past their best. The False Economy of a Repair we don't want to deal with based on results, the Fault Finding is wasted on a good amp that will be Far Better as Recapped with our upgrades, ages spent fault finding to find one bad part or just redo the lot in the same time plus parts to give a reliable item is our way. You want these Vintage items to be use daily, not taking in for Repair as seems to be the way some amps live, your Tech is wasting your time as without recapping you're gambling each use that the capacitors & other parts won't fail. To even try 3x 1967-68 amps on our speakers, they were only briefly used to be safe. Yet people buy these Aged Beauties & just plug them in unchecked & unserviced. Then wait for it to go 'bang' or start smoking. We deeply check amps over & won't put mains near them until parts have been replaced. In Computers, the Solid Capacitors have taken over the early 2000s 'exploding' ones, but they're not Hifi ones & likely the 'wet capacitor' will live on as for costs to replace is cheaper than to make large solid capacitors.

1978 JVC A-S5 Amplifier, Plus Ebay Browsing.

Just saw one on ebay & after many years wondering What Amp Uncle S had in 1978 as he took it to University... it's the 35w JVC A-S5. Is it worth buying? No manuals on HFE if to see a preview on a pay site the thing has STK 0035 output blocks as does the 50w A-S7. Not for us, if good to solve an ancient mystery on the same day the 1978 JVC JR-S 600 receiver arrived strangely. The A-S7 circuit shows Phono is x3 transistors, Tone is oddly passive on Line Level then into Transistor Differentials, Drivers then the dreaded IC Power amp block, STK 0055 on the 7 model. ebay shows the STK0035 still buyable for £20 if the STK0055 not findable, if these you could still buy in the 1990s, clearly remainder stock rather than being made still, like transistors are. It'll end up disposable like seeing modern Marantz PM6005 "needs repair", e-waste these days. Similarly seing a Leak Delta 75 receiver for £48, but we have 3 wood cases in the loft as the amp is so badly made, it's just not worth buying these sort of amps. Even a Yamaha CR-400 that we thought was decent for 20w, chewed case means it's not worth us redoing as the looks aren't good enough. Didn't fancy a silver faced Ferrograph amp & tuner either, just don't like these crudely made UK amps & they've ended up binned too often now, if we've sold all Ferrograph we've had, they are just too budget quality. So many good amps we'd like but offered for sale as unserviced yet 40 years old & for far too high prices like they are fully checked & serviced, there they sit as blogged before, as even a 1983 amp is 35 years old now.

Filters, Loudness & Tone Controls: What To Do With Them?
Not so obvious perhaps, as to what settings to use. Filters to us are a nuisance in upgrading as they often upset the circuit in ways inobtrusive to untidy. One of the only Amps without any Filters is the 1966 Akai AA7000 which to us makes it far better. A Filter used to be Essential going by reading 1956-1980 Hi-Fi News magazine, especially in the early years. People kept blaming the Record quality if the truth is the early Cartridges were rough & peaky, the Turntables into the early 1970s were made with cheap bearings if even having bearings, so Rumble which is a grumbly Bass noise was heard, so to use Low Filter aka High Pass Filter, as it passes the higher frequencies. Even Decca Deram arm had an Anti Rumble feature to limit noise from these cheap turntables, the 1970 Garrard SP25 Mk III was rumbly if the c1974 Mk IV was far better. High Filter aka Low Pass as it cuts the higher frequencies is also called a 'Scratch Filter' or 'Noise Filter'. Some use Inductors & can cause Ringing as heard on bad 1950s-60s dubbed 78s that they ruin the sound by over-filtering causing harsh peaky vocals if limiting 78 noise. To us, Filters are Obsolete & we have no use for them, if perhaps the only use is High Filter to reduce 78 noise if it often cuts too much detail. Leave the Filters set to 'Off' to hear the full range of the Music. If you need to use the Filters then question where the Bad Sound is coming from. Loudness is another useless feature, if we've heard of some getting our upgraded amps who use Loudness to make up for speaker mismatching & still add Tone, they don't really understand 'natural' sound it appears. Loudness on an amp is no problem, it just takes a tapping from the volume track in the volume control to give added volume in Bass & Treble. The Bass Boost to us is awful, it's far too thick sounding. Treble usually sounds scratchy. But some swear by it, so it's still included in Amplifiers today. An amplifier that sounds right can still give a rich sound at Late Night volume. Tone Controls are essential on Amplifiers, notice we only get Amps with Tone Controls as some boost is needed unless you're cranking the volume up high. The early Audio Fairs when in Hotel Russell, London pre 1969 the visitors used to complain that Tone was only ever set Flat & a snobbery exists about Tone Controls still to this day, but it's your amp, play it as it suits you. Let the "Source Direct" types get on with their dry sound & they don't know that most amps just Bypass Tone settings still with Gain, so it's hardly CD player to Volume to Power Amp. But in all these User Controls, there are No Standards. Some don't have enough useful gain ±5dB is pretty useless as late 1980s budget amps do & ±18dB as the Hacker GAR 500 does is far too much. A typical ±10dB is what most amps have, if who actually turns the Tone Down, the Minus half is likely rarely used as Sound Today is better balanced. But in the Early Days, the Tone Controls + and - were used to play Non Standard records without RIAA. You might like Bass & Treble up full, it's your amp, but play TV or Radio with speaking voices to match how real people sound in the room & you'll sometimes find you use too much Tone. As with any user control, picture quality on LCD TVs takes a certain skill to make a midprice TV look like an expensive one, but in the early Wide Screen TV days, people often stretched a 4:3 ratio picture to fill the 16:9 screen, unaware of reality. It's what you are aware of really.

LED Bulbs To Replace Filament Type Bulbs.
We Blogged on this before Here if to update it further as more types are around now. The 30mm Fuse type bulbs are sold as 8v ones or 12v car ones, both exactly the same brightness so there are no 8v ones really. We got some supposed 8v ones for the Marantz 2385 & they are no different, so beware of paying over the odds for their description. The 30-31mm Fuse Type ones are "SMD White LED Vanity Mirror Visor Light" in Car parts. The 5mm Round ones that Yamaha & similar amps need are "Bright White LED 5mm 12v Pre Wired" which have the resistor in the cable so easy to to wire up, if beware some amps don't like LEDs as the Bulbs Power Supply shares another use & LEDs won't drop the voltage correctly. Some amps use the Screw Type bulbs "E10 LED Screw Lamp Mini Light Bulbs" will find those. The Bayonet Type used in McIntosh & The Trio-Kenwood KA-6000 are less easy to find, in fact only one USA seller has these for $25 plus $28 shipping. To find other various Bayonet sizes inc Home & Car Indicator type, but not these small ones. Search McIntosh MC2125 etc will find bulb kits with these in, but until we need some, we've not searched deeper. LED Problems. As stated with the 5mm Bulbs, some amp power supplies use the Bulbs in a circuit that supplies a Tuner etc & the old Filament Bulbs drew the right power to keep the Voltage right, In the B&O Beomaster 3000 the wedge type bulbs needed to be the right rating else the lights were upset, can't find any B&O bulbs. Another problem is the bulbs circuit is usually AC so the lights flicker & even ones stated to be DC are a basic circuit that may flicker still. One amp, the Toshiba SA-15Y has LEDs fitted, they flickered through the fascia & with the fascia off or looking inside the flickering was extremely disturbing, so we put Filament bulbs in instead. Overall LEDs are a good upgrade to the Filament Bulbs & a current Sansui 3000A with the filament bulbs was a orangey-yellow light if the LED was a white light that was the same brightness & looked better on the Blue Tuner Glass text. The Sony TA-3200F has front meters, the bulbs aren't diffused so the LED can't be used as too flickery, if you can add opaque plastic to tame it. We currently need to re-bulb the Pioneer SX-1000TD-F & the manual shows these are direct from the Transformer & unusually 5x 6.3v 250mA screw type bulbs. This will be as bad as the Toshiba for flicker so to get Filament Bulbs or risk insanity is the only option. We have the LED ones just to try, but the outcome will be the insane 50Hz flickering Strobe Show that you might actually like...

1971 Sony TA-1140 vs Sony STR-6055. Pt 1: Comparing As Original
On the face of it the TA-1140 is the amp version of the STR-6055 as things look quite similar. But the spec sheet says it differently, so to find out 'why' as is our usual way of questioning so worth a blog to understand it. TA-1140 is rated 40w RMS if Rated Output is 35w with no definers, so assume 40w, STR-6055 is 40w on RMS Rated Output if only 30w at 20Hz-20kHz, confusing, both 40w amps to us with 28v sine output, that is the typical 1kHz test rating. Had a few TA-1140 if not had one since 2013, one we got in 2012 with the TAC-1 wood case for a mere £40, those were the days, before 'someone' told how good pre 1977 amps were. The STR-6055 we last had in 2015 & partly recapped it. Neither 1140 or 6055 we have fully upgraded & recapped, so to get both together is an opportunity. The STR-6055 & TA-1140 have the same 3 large power caps, the heatsinks, transformers & basic type of power amp board match. As for service Manuals, STR-6055 one is a quality colour scan, TA-1140 is a lousy photocopy scan & the only one around is a bit surprising. The Power Amp board does differ though. The STR-6055 has 4 adjust pots on the top edge with 2 separate protection circuits on the lower edge of the board, it has a small Power Supply for the Differentials & the extra 2 pots are DC balance on the Differential that few amps offer. NFB is 68K. The TA-1140 only has 2 adjust pots & one Bridge rectifier on the lower edge, the Differentials share the main voltage with no DC adjust pots. NFB is more like the Sony TA-3200F with 2.2k. The Differentials Power Supply is oddly on the Preamp board at the top front. On Preamp stages TA-1140 is 2 Transistors for Phono, 3 For Tone with high NFB, including a Buffer after the Tone Controls which are of the Baxandall type, then Passive Filter stage. STR-6055 has 2 transistors for Phono if the design differs, then Volume with Loudness switch. Tone is 2 transistors of a different design to the TA-1140 with Ground references & as we found with the Sony STR-6850 it's a lesser design with Low NFB like the STR-6120 has, then follows High Filter if no Buffer or Low Filter. Differences therefore are the STR-6055 has a better Protection circuit like the later TA-3200F does, the TA-1140 is more like the earlier TA-3200F with the extra board. As with 1969 Teac AG-6000 to 1971 Teac AS-100 the Differentials & NFB are altered, if the AS-100 with the IC didn't really make it better at all, it lost the sweet sound of the 1969 design. The STR-6055 appears the better design, if we've found the NFB level can affect sound on Headphones, once it comes to using on Loudspeakers it actually makes little difference, with the Power Amp having more effect, as in Speaker Matching. But strangely the STR-6055 doesn't have the Pre Out-Main In sockets so we can't compare further that way. TA-1140 has 4 larger transistors on the board, driver, PP drivers plus a 'Constant Current Source' like the TA-3200F does, if further into the circuit. Build Quality of both is lower than previous amps with a lack of shielding between Power Supply, Power amp & Tuner on the STR-6055. The TA-1140 usually has the over-fluxed solder mess that can give dry joints, the one on our Photo Gallery got a tidying. The old Kettle Plug style mains socket is likely a first here & it's useful as working on amps, the mains cable usually gets in the way. Sound Quality as Original. Just to see how they are as Original & only basic servicing to avoid switch noises. The STR-6055 sounds clean & fresh, if Stereo isn't very wide & not much Bass. Even with Tone Bass at about +2 to fill it out it shows spec is low in this amp despite it having quality in midrange & treble, it's rather tame sounding. It could upgrade a lot better, if overall the build quality & spacing is lacking. TA-1140 is a bit different. Stereo still isn't very wide on known tracks, if the sound is a richer one the Deep Bass won't trouble you. The TA-1140 has a unusual manual adjustment saying Bias should be a high 50mV which is not good, ours read 71mV and 60mV. The Test Points read across 2 stages & actually to get even to 50mV wasn't possible one side. The Overall Opinion on Both is they do the job adequately but nothing further. Probably why they got put away in The Attic often, if the problem here seems to be these even for 1971 are Too Cost Cut & Quality although having a decent Sound, neither give anything away. Upgrade Potential. Their only hope. Both have a good enough basic sound that has scope to improve. The TA-1140 despite the high NFB is a better design as the Baxandall feedback type design, not the lesser Grounded version like early 1960s designs used. The TA-1140 has been playing as we type for over 30mins with only one grimace to one track so it's sound overall is preferred. The grimace track was Fun Boy Three 'Telephone' that shows the amp is low spec & slow, it makes a mess of the vocals at the start that are mixed wider into the Stereo Mix, here the amp can't cope & not good to hear. Other narrower tracks it copes better if treble sibilants aren't resolved too well. On 60s Ska that's densely recorded, the TA-1140 just blurs it. "Is it really Hifi" is a question to ask on some tracks. But to remember we've upgrades Sony STR-6120 & Sony TA-2000F/3200F to hear how good Sony can be, the Pre-Power pair sounded pretty lousy as original too.

1971 Sony TA-1140 vs Sony STR-6055. Pt 2: Comparing As Serviced
Just to show what Servicing does. TA-1140 After Servicing. Had it all apart to clean & Serviced it if no parts beyond the bulb changed. The 2.5v mains bulbs are like the TA-3200F which don't last long so put an LED one & it shines bright enough. Sounds noticeably better with Stereo wider, sounds faster too. The 'Grimace' track above is a little more bearable, if far from how upgraded amps play it. Treble is more precise & probably louder for the Servicing, shows Servicing brings aged amps to life to a degree. STR-6055 After Servicing. Not done this yet, but as doing both the same day, to notice differences. The 6055 has a smaller Transformer & the main Fuses are 4A not 5A of the TA-1140. Both are rated 200v (200VA) which suggests the 1140 has a better power reserve & it has no Tuner to power. The 6055 build quality is quite like the Sony STR-6050, the thinner casework & fascia with the control knobs not as solid metal but plastic centred. But you do get a Tuner with no ICs. Only one Aux socket & no Tuner one to double up on for reasons Receiver. The 6055 is a thinner sounding amp, to match the TA-1140 on Headphones about +1.5 on Bass & also -1.5 on Treble on some tracks. The 6055 fidelity isn't the same, the 'Grimace' FB3 track is still untidy, it doesn't please as the TA-1140 did to play for much longer. The 6055 is clearly later than the 1140.

1971 Sony TA-1140 vs Sony STR-6055. Pt 3: On The Tannoy Speakers

As both useable as Original & serviced, to try on the Tannoy 15" Golds. Ben using the Marantz 4070 already for watching TV, so on with the Sonys, testing the DC offset is safe first. Both have wide spaced screw connectors with tabs, so the Gold 4mm blocks can fit in at an angle to use safely. Sony TA-1140 has decent Stereo width if sounds a bit dull & flat, previous Differential era Sony like the TA-1130 we've not found a great match, but here the match is acceptable if the amp isn't as lively as found above, even with Treble Max it doesn't quite get the right sound, but overall it's not bad & could be played. Deep Bass isn't here for the design if it doesn't sound too unnatural, if perhaps a little thick on upper bass that makes it sound a bit flat. Sony STR-6055 tried next. Interestingly it sounds exactly the same on Speakers if on Headphones it was brighter & thinner, here it's exactly the same. Both sound like amps that haven't been upgraded, for upgrades brings out a more dynamic sound without the limits, if in 1971 if you bought Tannoy 15" Golds, the sound would have pleased, but compared to trying the 1967-68 amps you replaced them with, the 1971 Sonys from knowing how other Amps sound as Original in earlier blogs, you'd still be left buying The Next Marvel in 1974-75, unaware that the Bass was still limited, it improved from the Thick Retro Bass. This is why these 1965-72 era amps often got only a few year's use before being replaced. Only decades later can we see that Upgraded these amps can improve hugely. Anyone else out there questioning the designs to see what can be bettered? Er...

November 2018 Blog

1968 Sansui 2000 30w Receiver.
This receiver was repackaged with alterations twice, as the 2000A & 2000X from 1969 & 1970 most likely. The 2000 is the 1968 one as the styling matches the 3000(A) & 400. The first thing to look for on Sansui of this era is the Aux & it goes through a 100k ohm resistor into the Phono stage, predating similar on the 1969 Sansui 4000 we had. Not an idea we like as it compresses the sound, if you can use 'Tape Mon' as Aux to bypass it. Manual has a blank line thru the middle missing out a lot of info as missing is an area bigger than the blank part. It's not like the Sansui 400, this has high NFB in the Tone & the early Power Amp, it gives a more Domestic Sound perhaps. Capacitor Coupled Power amp, none of the Transformer Coupling & Semi Complimentary-Direct Coupled design of the 3000(A). HT is 70v on a 2000µf 75v main cap & the Protection Circuit is like the Sansui 400 one, not the unreliable 3000(A) one. No ICs in the Tuner if later than 1967 as a FET is the Front End so we'll put 1968 on it as it is styled rather like the Sansui 4000. The ebay one has the Original Box which is always rare. £245 delivered to us for a Raw amp is priced too high, it still needs a full Recap to be reliable is always the issue on these amps. It'll sound good & upgrade well though, if it's one you'd keep the price isn't so important, but for us to buy to upgrade & sell knowing the work needed, there's nothing to earn in it. To watch & see if it sells...

Marantz 4300 4ch Quadraphonic-Bridged Receiver.
For finding the Marantz 4070 amplifier so good, to have a look at a 40w x4 or 100w x 2 version. 100w Bridged to 2 Channels. 1972 model was $899 new in 1974 say the Classic-Audio site & 'Common' suggests it sold well or more likely they overproduced & it took until 1978 to clear them off cheap. But 100w Marantz will have ben a bargain at the time even if 4ch is as useless as it is today, the 2ch Bridged Stage is the wanted part, if it needs careful adjusting as we found with the 4070. Inside Photos found online show it's a densely packed amp with cages over the Power Amps & colvers over Tuner stages, a quality unit for sure. The Marantz 4400 is a 125w into 2ch & 50w into 4ch, if a 1976 updated version. The 4300 Circuit Diagram is very complicated to so understand the Audio parts with the board numbers: Phono is P400, P500 Vari-Matrix, P600 Dolby, P700 Power Amp, P800 Power Supply, PD01 Tone with all Transistors, PE/PF/PD01 Buffer & Preamp, plus other minor ones & Tuner. We had Dolby on the 4230 years ago & it's fun to play around with the threshold settings if pretty useless. Phono is x3 transistors with adjust pots for some reason on the input. The Dolby Circuit made of transistors, a tightly packed board we remember. Power Amp has x14 transistors compared to the x9 of the 4070, a complex design working on ±37v. Tone appears to have the Inverter stage as the first 3 transistors then similar to the 4070 Tone. The Marantz 4070 sounds great in Bridged Mode & the amp despite being very packed to fit the size has a good design. Here the Marantz 4300 has extra circuitry all around so may lose the appealing sound of the 4070. Outputs are 2SC1403 & 2SA745, proper 8A 70w TO3 ones unlike the TO220 regulator sized ones on the 4070. Considering the Sansui AU-G90X was a bridged amp design on similar HT, the design of that never gave the rich bass the 4070 does, sounding not unlike the Sansui 3000A. The Marantz 4300 or 4400 has the higher power but will it have the rich bass or the dry bass? NFB in the 4300 is higher than the 4070 if the 4400 is higher still which suggests the 4070 sound won't be in the 4300 or similar 4400. The 4400 has an Oscilloscope like the Marantz 2500 does. The 4070 only has the sound we like for our upgrades to it, to do a 4 channel amp is double the work. Ebay options are a 'Broken' one with crinkly top lid suggesting it severely overheated on Transformer & Power Supply, if not melted the plastic lid for £480 delivered, or a nice one in the Wood Case for £1350 delivered if the speaker connectors aren't the original ones or maybe just a later made one. One is a foolish too-risky buy, the other is probably acceptable if you want it as it looks good, but neither for us based on knowing both the 4070 & AU-G90X.

Tech Testing The Marantz 4070 & The Bridged Mode.
We've yet to test the outputs on this & how the Sine Wave & Square Wave reacts, plus the new Scope gives the Rise Time on Square Waves so time to see why we like the sound of what is a 4x 15w amp. Now Bridged Mode can't use the Mains Powered Oscilloscope as the Probe has a Ground Reference that Bridged Mode doesn't, the 1984 Sansui AU-G90X was a hidden bridged design & it "didn't like" a ground reference testing it, so we use the battery powered one which means we can't test the Bridged Rise Time. In 4x 15w mode it puts out 16v Clean Sinewave. In 2x 35w it puts out 34v Clean Sinewave. 16v is typical for a 15w amp looking at our Power Ratings page, matching the 16w Sony STR -6046, but 34v Sinewave is a lot more than 35w, into the 60w-75w range like the 65w Marantz 2265B. It all depends on Current whether it is a True 65w which is where upgrades come in. The way it handles Deep Bass certainly suggests a Power Rating like 65w if we've not upgraded it much on the Power Amp & it still has the 2SC789/O TO220-size outputs (TOP66), these are 4A 30w so it could do 60w as Bridged, if only with Upgrades. The Heatsink has holes to take TO66 if not as big for TO3s. Testring the 4ch mode with 1kHz Square Wave, a little adjusting of Tone to get the Squarest responses as there is no Tone Cancel, if the adjust needed is tiny from the midpoint as in Slider Control tolerance. Rise Time from Aux input from the Signal Generator averages about 1.8µs which is pretty good as the Sony TA-3200F got 1µs, this is what upgrading brings. The R channel needed the Tone adjusted just a tiny bit different, if in listening you'd not tell. Bridged Mode on the 4070 just filled the screen on the Mains Scope with HF noise, if the Battery one showed a very accurate Square, if the top of the Square at low level was showing noise, turned to a typical listening setting it was fine. On 4ch mode it showed a little noise too so more to upgrade here. The Marantz 4070 is a little bit awesome therefore & sounds great as blogged above.

Tech Testing the Marantz 2385 185w Monster Receiver.
To do this amp next. How much clean Sine Wave does 185w with Tripled Output Transistors give? How Accurate is the IC in the Tone stage when Pushed Hard? Can it better the 1µsec Rise Time of the 100w Sony TA-3200F? 56v Clean Sinewave we read both channels, beats the 52v of the 160w Sansui G-8700DB & shows the Tripled Outputs don't mean 185w is more Current than Voltage as we wondered. The Tone ICs we picked up Mouse Noise on previously & the Square wave shows there is a 1.3MHz 'RF Hash' that needs taming, which we do & retest it. The noise shows as a fuzzy top thick line on top of the Square wave & adjusting the Scope to read the Frequency. No RF hash this time once slightly altered, no overshoot or ringing either & to get the Rise Time which is still very fast, the Sony TA-3200F beats it as the 2385 gets 2.6µs from Aux in to Speaker Out with 2.44v Amp output. Rise Time does decrease with Volume gain, eg 5v Square Wave pk-pk with the Amp putting out 9v pk-pk the rise Time dips to about 3.2µs which is because the Voltage has further to Rise.

Time To Test Tone Controls: ICs in the 2385 vs Transistors in the 4070
This we did write up as we tested it, but to rewrite it once completed makes more sense. This is a hard test for Amps, we've heard some not cope with the high unlimited Treble the BBC does on some shows noticeably 'Antiques Roadshow' where at the Treble Tone setting, some amps get into Distortion too early, even Transistor ones. It's all in the Design. Several Tests on the amp as 0dB Sine Wave Test Signals Aux In to Speaker Out plus Aux in to Pre Out with the power Amps blanked off. As both 2385 & 4070 are upgraded & working right, to discount the Power amp stages as they don't affect the readings. Here's The Transistor vs IC for Tone Difference. The Transistor Tone stage often works on 25v-40v so the Transistors have a higher voltage headroom. The IC TA-7136P/AP is commonly used in Amplifiers of the age & here it's on about ±14v supply which isn't 28v in total, different + or - go to different parts of the IC. So the IC doesn't work on the same voltage & headroom as the Transistor. The IC with Tone set Flat or cancelled delivers 20Hz-20kHz correctly as it does at 1kHz. The Square Waves are tidy. Set Flat the IC is no different to Transistors in the Tone Stage, But a Tone stage typically has ±10dB gain & we tested both amps Preamp-Tone Stages with aux in & Pre Out Output to the scope. Both read 3v at 1kHz before clipping which is fine. The Transistor Tone 4070 with Tone Bass & Treble at Max 1kHz is 2.90v, 10kHz is 5.9v & 50Hz is 11.3v. The 4070 gives a lot of Bass Gain if it reads 3v set Flat, Treble doubles so it spot on at +10dB as specified. Exactly what you want & a bit more Bass is unusual. The IC Tone 2385 is different. 1kHz is 2.7v, 50Hz reads 2.76v & 10kHz goes to 1.7v. We tested it twice to make sure that's right, but the IC at Max Treble doesn't even give the 3v standard with Tone Cancelled. It's less as the input signal is too much for the IC. The IC hasn't got the Voltage & the IC power is limited. Rare you'll hear 0dB signals on TV but on CD many are Mastered to 0dB so on playing even a 185w amp loudly, you can't use full treble as it'll clip out. The 2385 Manual says the ICs give "9x gain" which if 9 is the gain factor that's 19dB of gain, but the Preamp itself has gain, it's not Line Level. The Marantz diagrams show 50Hz has 12.5dB gain & 10kHz has 10dB gain. Doesn't exactly match to what we've read. "Should Be The Same At Any Audio Frequency", but it's not. Conclusion is Transistor Tone Stages, if designed well can give far more Gain on setting Tone to Max compared to an IC which will run out of power at anything past TV listening volume, going by where the 2385 volume control was set to Full Treble on testing. Tone Bypass on the 2385 will be as good as any amp, it's just ICs on Tone don't have the power.

New Amps We Get To Review.
These go on the main 'Reviews' page that's been added to since 2012. We do add a "Recent Additions" and "Ones Revisited" to help keep track. So far in 2018 the New Ones are 1972 Rotel RA-810 amplifier. 1968 Toshiba SA-15Y receiver. 1963 Fisher X-100-B valve amplifier. 1979 Luxman L2 amplifier. 1978 Pioneer SX-980 receiver. 1966 Rotel 100AMP amplifier. 1972 Akai AA-5800 amplifier. 1971 Trio-Kenwood KR-6160 receiver. 1973 Marantz 4070 Quadraphonic amplifier. 1976 Marantz 2385 Monster Receiver. 1966 Sansui 3000 receiver. 1977 Rotel RA-1603 Monster Receiver. 1967 Sansui 400 receiver. 1976 JVC JR-S 600 receiver. 2000 EAR Yoshino 8L6 Valve amplifier. Plus there are several that have been Revisited. 2018: 1978 Yamaha CR-2020 receiver. 1970 Akai AA-8500 receiver. 1968 Sansui 3000A receiver. 1967 Pioneer SX-1000TDF receiver. 1971 Sony STR-6055 receiver. 1973 Yamaha CR-1000 receiver (again). 1971 Teac AS-100 amplifier (again). 1969 Teac AG-6000 receiver. 1971 Sony TA-1140 amplifier. 1966 Akai AA 7000 receiver. 1966 Rogers HG88 Mk III amplifier. 1972 Trio-Kenwood KA-6004 amplifier.

Four 1978-82 Amplifiers: Any Good?
We look at all interesting amps of the 1960s-1980s era, the ones past that don't appeal or are too expensive for what they are. But to forever look for good Amps of this era as only really the 1984 Sansui AU-G90X was one that impressed. The first is a 1978 Trio-Kenwood KR-11000G which is the 4th Version of the "Eleven" model, the Mk I was 60w, Mk II was 80w, Mk III was 120w & the "G" version also 120w. What a confusing range to be named so similar but go Double the power. One on ebay in untypical Black Fascia with Silver fittings looks a bit odd, the all Silver looks better. 120w so to see the Busy Fascia with a Graphic EQ on one at a mindnumbing $2500 when the customer who told us of it just missed one at a more realistic $600, so to have a closer look. The overpriced one shows the fascia, a vey average looking back panel for a 120w amp & then the inside which is Midprice 40w amp looking & "cheap & nasty" as became the typical 1980s amp. Vinyl wrap case & the inside does not give confidence, the amount of unshielded cabling inside carrying Audio & Voltages, just like the ribbon cable in mid 1980s amps. Build quality is awful & there is no quality in the design like you see in earlier amps. The Service Manual confirms that's the right photo, not the seller mixing up amps. The circuits are Phono with ICs, Tuner with ICs as are all Tuners past 1971, EQ is called 'Multiple Acoustic Control' and has ICs. Power Amp is a bit overdesigned with Current Mirror & Darlington Outputs, a Current Sensor & Limiter are not good for Audio yet these same. Not for us, no quality in it & heading too much towards crappy 1980s gear despite the power. Next one is a 1980 Pioneer SX-3900 Receiver. In the style of the 1976-78 Receivers if with the Blue Flashing Meters & Digital Tuner Display, rather stylish & 1980 Retro. But the HFE page says "15 ICs" which is a little shocking. To remember the 1980 Yamaha CR-2040 series stuffed with ICs sort of gives the idea this is the same. 120w & in Multivoltage or 110v versions. THD of 0.005% is utterly meaningless for how mangled the sound will be through typical low spec Pioneer & all those ICs, THD is so dishonest to quote, but it sells amps. The thin wavy 1980s heatsink, large boards with lots of circuit stages & fine PCB track does not appeal to us. So to the Circuits. Phono surprisingly is all Transistors if that pointless Class B design that became standard & is what ICs use to use less power. Power Supply is busy with Zener Diodes to save bothering to design properly, the Zener is a lazy Voltage Reference & it pulls whatever voltage HT to the Zener's one, ie 25v on a 13v Zener will keep 13v on the line with compromises. Tone Amp is one IC per channel if strangely a Passive Tone with Ground Reference which isn't as good as the NFB-Baxandall type, and here it looks very tamed. Power Amp actually is All Transistors, not one IC. 20 Transistors here with Doubled Parallel Outputs not including the Relay stage if Zeners again to restrict voltages. Power Supply is ±60v on 15000µf 71v main caps. In some ways better than expected, but the usual low spec Pioneer sound by 1975 & the rather poor Tone-Pre stage will leave it less than pleasurable, so you bought another one in 2-3 years, right? Next onto Technics SU-8600 a 76w amplifier from 1976-78, the one after the Technics SU-8080 we reviewed on having one to upgrade. Inside build looks decent for the year from pics found online. Phono the typical Differentials & Class B driver design in transistors. Tone-Pre has the usual TA-7136P ICs into a Filter Stage with a Buffer. Power Amp is not overdesigned with a Differential & 10 transistors in total. HT is ±48v on 15000µf 55v main caps. It's really not that different to the SU-8080 if without the limiter, the Tone stage was poor. Just an amp people bought, nothing too special & not really that interesting to us, but bypassing the Tone IC it probably sounds better than the two above. £250 one on ebay probably a decent buy. Technics SU-V9 is a 120w amplifier from 1981, the range before the ill-considered 'Computer Controlled' ones from 1984 Technics SU-V707 we didn't like the thin dry sound despite the Heatpipe nonsense. A little flair on this with a Glass Flap covering the lesser used controls & probably most broken off years ago as flaps on amps aren't a good idea. This one £150 on ebay if we didn't fancy any of these. Phono is busy 4x Transistors & 4x FETs into an 'Equaliser' IC to ensure it sounds awful so you went to CD instead. Then into an Op-Amp IC with Passive Tone with Ground Reference like another amp in this blog. Power Amp is all Transistors with a FET Differential else not unlike the SU-8600. IC 'Voltage Comparator' is a Protection stage for the Relay. HT is ± 55v on 56v 18000µf main caps. It's just a typical amp for the mass market, probably sounds better than the SU-V707 range but really by 1980 a 120w amp isn't really that special & it's at a time before the more Luxury type amps of the later 1980s. Not one we'd buy if we search in vain for Outstanding post 1977 amps, none here get us wanting to try as the circuits & ICs are predictable & often these amps past 1977 disappoint. We only got to try the 1984 Sansui AU-G90X for a customer wanting one serviced so we got one ourselves & kept it 3 years to upgrade. If you know of any Really Great Quality 1980s-1990s amp, do let us know.

Reviewing the EAR Yoshino 8L6 Integrated Valve Amp.
A bonus of offering Service & Upgrades on Amps is we get to try Amps that'd we'd never think to try or are outpriced to Buy, Upgrade & Sell on. The EAR is a design by a 'Valve Guru' as is often said. This is written after the early part of the review based on seeing the circuits & before we listen. Some design, quite a bit of the design actually is not to the standard we'd expect, if perhaps a £4800 amp is still a 'Cheap' amp in a world where you see £25,000-£35,000 used amps on ebay thinking someone will buy. We know the 1990s Tube Technology Valve amps from having one since 2000, the same year the 8L6 was first out. We know the designs in Modern Valve amps are lazy & still hang onto 1950s ideas as they never think to better them & always scared of Bass. So rush over to the Review page & see what we think of the 50w Class A Push-Pull EAR Yoshino 8L6. Our Final Verdict you can now read on the Reviews Page.

Five Great Amps Tested on The Tannoy 15" Golds.
As great as many amps are, we can't keep them all, if we're revisiting some of the best ones again. Here to try the 1976 Marantz 2385, 1972 Sony TA-2000F/3200F, 1971 Sony TA-1140, 1967 Sansui 400 & 1967 Pioneer SX-1000TD-F. They are all Serviced, Recapped & Upgraded by us. First the Marantz sounds great, if to try the others they all sound more upfront, the Marantz Tone ICs are known to limit gain. Sony pre-power pair, it's nice but sounds a little recessed on midrange if it's more lively than the Marantz. Then the TA-1140 with Bass like no other Sony we've heard, the amp is midway being redesigned a bit & to see where it needs more improvement, but it's preferred to the Sony pair. Sansui 400 is the lowest power at 20w if you'd not really know that as it plays well with the others. Pioneer gets tried last & it's got quite a remarkable sound with big Wide Stereo & very punchy, rather like the 1968 Sansui 3000A we only just returned to the customer. The Pioneer will get played more as we've only really tried it quickly with the Sansui 400 once, to give it a better go. Pioneer gets over 90 mins of TV played & the more upfront sound is good on speakers, it's less of a Domestic sound which is usually less loud to not annoy, but we like the PA type sound. Sansui 400 will be sold if you collected amps it & many more would be keepers.

What Makes the 1967 Pioneer SX-1000TD-F Sound Better Then?
It matches the 1967 Tannoy Gold 15" Lancasters very well. Even with Tone set Flat it has more of a presence than other amps. The 1966-67 Pioneer we had early on 2011-2012 if they're very hard to find now if probably around in USA if shipping & import fees costs. The first early Pioneer we had was the 1967 SX-700TF, then a 1968 SX-1000TW later version of the TD-F and the SX-1500TF. By 1968 Pioneer change the Preamp to have a NFB stage before the Passive Tone stage, the SX-1000TW has the W15-090 & the manual for the SX-1000TD-F has the W15-047 which has the NFB, but the two we have plus the SX-1500TF & SX-700TF had an earlier board W15-031 which is exactly the same as the SX-700TF W15-006 beyond one resistor change. Confusing it is, but the Tone-Pre board is what makes the 1967 Pioneer good. The first SX-1000TA that is spotted by the oddly grouped switched as 1-2-3-1 with the Valve & Nuvistor FM Tuner front end has the W15-006 board also. The TW one seems around on USA ebay if not the TA one & the SX-1000TD-F & SX-1500T(F) are rarer. The "F" is the Multivoltage version. The 1966-67 Tone Boards have the classic Baxandall Tone NFB circuit & a simpler High Filter, if the later 1968-69 Tone Boards have NFB, a less good High Filter & Tone is Passive with a Ground Reference which is never as good, it's cheaper to make & early Trio from 1967 had a similar Tone yet the 1969 Trio KA-6000 has the Baxandall one. In the 1960s Filter Stages were wanted to cover up Poor Hifi & perhaps the 1968-69 ones were steeper filters as the Market (sigh...) wanted this. The Sound of an Amplifier is created in the Preamp, all have Gain & this stage allows for huge variance. Even 'Source Direct' which had you thinking CD to Volume To Power Amp was far from that still relies on Sound Shaping by the Preamp. The 50w 1990 Pioneer A-400 that gets rave reviews actually has no Tone-Preamp stage, the Phono stage is Transistors & ICs, but the CD input actually does go straight to the Power Amp via Volume & Selectors. The Signal: Noise ratio is very low at -108dB which may impress but it's been tamed to lose the typical transistor hiss, much like we found removing all the dumbing down in a 2007 Marantz PM-6002. The A-400 has a strange 10k ohm tap to ground on the Volume, it's not Loudness so already it's taming the sound. The A-400 power amp has a lot more Sound Shaping to make the amp tamed rather than be resolved better. It appears to sound good to the amateur listener for it'll likely be a clean upfront sound, but as the Preamp is Passive, as we've tried with amps, the sound lacks a punch or kick, it'll bore you after a while & explains why a £240 new amp in 1991 doesn't make that much now. Back to the Pioneer SX-1000TD-F, the obsevant will notice that Pioneer didn't have Pre Out-Main In sockets until the 1969 SX-1000TD. The Trio-Kenwood KA-6000 does have these Out-In sockets if it's a 100mV level, the typical level is around 1v & even the 1972 Trio-Kenwood KA-6004 adds another gain stage in the Low Filter to bring it to the 1v output. The SX-1000TD-F by the sound is of that 100mV level, it works great as full Tone can be got at a lower level. Where the Volume Control is, ie before Tone or after Tone can matter on some amps, it takes a good design to handle full Bass & Treble gain at 0dB level 7 very few amps do this, the KA-6000 & the Realistic-Hitachi 1972 receivers do.

Badly Stored Amplifiers Need A Lot Of Work. Attics, Damp, Heat & Too Dry.
We first got into Vintage Hi-Fi, when it was just cheap Secondhand Hi-Fi, in 1990 getting amplifiers like 1969-71 B&O Beomaster 3000-2 which was then only about 20 years old, it wasn't aged at all, but seeing ones we got around 2011 the 20 years became 40 years & often 20 years of neglect really aged them. Getting 1978 Harman-Kardon receiver in 1990 it was still just 12 years old, in it's Wilderness years as Silver Amps at the time were unwanted as Black Amps were the fashion & ones that weren't were always £20 including big Marantz receivers & their Quadro receivers. Again getting these when they are over 40 years old they can be very aged if generally most amps restore up well. Storing Amps in The Attic which is exposed to the Outside Weather temperature & wind through the Roof do age quite badly on the metalwork as damp dust turns to a paste & starts problems. But usually UK Weather is more cool than Hot so these amps whilst looking aged are often working better than expected, but for the age we recap them anyway. One 1971 Harman-Kardon 930 receiver we had with the wood case, as on the Solds Gallery had clearly been sat on a sideboard with the amp rear to the window & sunlight. On trying the amp it sounded lousy as the Power Amp was at the back & it got the Sunshine, if recapping it things much improved. A recent amp to upgrade the customer had it dropped off to us, the huge Rotel RX-1603 33kg 180w receiver was owned by the guy's brother, with assumed the younger brother in his 70s, the owner liked it loud for Rock then they bought it in 1978 which is 40 years ago, so to assume the owner bought it in his mid-late 30s. We didn't think much of the amp after recapping the preamp which only worked on one channel previously. Recapping the rest of the amp, it still was not very good at all, putting it down to cost cutting & it sounded crude like the big Pioneer SX-950 do. But on Speakers it really sounded awful, the worst amp we'd ever heard yet the amp matched the speakers as Tone made a typical difference, if amps don't match our Tannoys they are far too much on the midrange & Tone makes little difference. Again to assume that's how the amp was, a Cost Cut play Rock loud sort of amp, to run it in for hours. On the first 6 hour run in the heatsinks varied in temperature, so to adjust & run in 9 hours further. This time the amp sounds a huge amount better on speakers, not perfect as Bass wasn't good. By running in we Reformed the Main Capacitors, but telling the customer the caps could still be below par to get new ones was decided. These old caps are a top brand Nippon Chemicon so what's the deal here? The rear of the amp was full of dust like a Hoover bag. Dust falls into the amp casing but to assume the amp was left by a radiator or in direct Sunlight from behind to create more air movement & the heat affected the capacitors. The amp was in high grade beyond dust so maybe not used in over 30 years, just left to sit keeping warm. on curring the capacitors open, proved us right as the rear one was almost Dry inside if the one further in was still wet. By running in we reformed a Bad Dry Capacitor & to replace was wise as once a Capacitor goes bad, surely it's on borrowed time before it fails or shorts internally. 22000µf 80w Nippon Chemicon high grade Capacitor still will fail if kept too warm. Heat Dries these Capacitors out. The Yamaha CR-1020/2020 with the large power caps tucked away underneath we've never had a problem with, if the reality is amps over 40 years can need the huge Capacitors replacing.

Comparing Seven Amplifiers, But We're Not Telling Which...
We just did that, if not to give a Top Seven list as that isn't too helpful as all the Amps are Upgraded, some more than others & it's based on our playing on Tannoy 15" Golds, some amps may match better to other speakers. Blog over, but no, to tell What We Heard to consider them Superior to Us. The "No. 7" one had a decent Stereo, a lively sound, but a rather dry one lacking the character of what we prefer, playing' Bargain Hunt' which is a TV show recorded flat, the Car Auctioneer male presenter didn't have the tonal balance that would typify his voice, it was left unresolved & just didn't please. Other TV shows that amp did better at & had a decent tight Bass, so was still a high rating amp to us, but just that so many others are too. The "No. 6" one was a recent arrival, with high hopes for it based on another amp that's to come higher up. Again it lacked the full range of Tonal Colour, Tone gave good variance so it matched as did all these amps, but it was left rather short on the Bass if the slightly fresher sound gets it a point higher. To wonder why that amp wasn't as pleasing really. Later on, Main caps redone it sounds much better. "No. 5" was an amp we've had on speakers for over a week & found it's sound very impressive despite it not being too much upgraded as slightly wary of it for it's duplicate. As good a sound as you'll ever find, if others more upgraded better it. "No. 4" is a weighty amp with a clean fresh sound, not that it arrived sounding like that. A cool confidence to the sound just betters the previous. Not as Big Bassy as you'd think but the first of two of this brand. "No. 3" bettered the Bass of the previous together with a more airy treble. The same brand as No. 6 it is one we've had here to upgrade for a few years now & it always gets better which is not a typical situation. "No. 2" is the same brand as No. 4 & for what it appears, how the hell does it sound that good? The No. 6 has the same design feature yet this No. 2 just sounds awesome with the Best Bass of the Seven. It could still do with a little fine tuning. "No. 1" when it arrived sounded truly awful, had we wasted our money on it was the opinion. It took so much to upgrade & it's not been played in quite a few weeks as others come & go. We forgot to play that one wethinks so on it goes. What a sweetie! Effortless huge wide Stereo like no other Amp, with such depth to the sound it makes the room seem far bigger. We weren't so sure on Bass & it could do with a little more openness on Bass like the No. 2 one & a slight background hiss can be heard. But the open sound & huge effortless dynamic & on a bassy segment it showed it was no slouch. Is it the Best Sounding Amp There Is? Must be, we rated it Top out of Seven. It's not Perfect though, but closer than the others. Regular Readers may be able to work out which amps they are, if no Prizes given. Compared to Five Great Amps blog just above, it shows how amps compared together can vary & knowing one amp to compare others to can so easily affect opinions as sometimes an amp that sounds a little less neutral can upset the hearing balance. That's why Reference Amps are needed. Three of those Five Amps were tested this time. Opinions do change within a few weeks of this blog originally. To understand 'how the hell' the No. 2 sounded like that, to find the No.1 a little lacking still despite the quality, it could do with better gain. No 2 & 5 since sold also & the No. 4 amp has qualities that keep it here & being used. No. 6 recapped more & it sounded a lot better if then found not to match our speaker so well. 'Funny Old Game' is the one of Hifi Comparing, the more you use & compare will forever change opinions.

Early Pioneer Amplifiers.
Pioneer got into Transistors with the Pioneer SX-1000TA receiver of 40w with a Valve & Nuvistors for the Tuner, later became the Pioneer SX-1000TD-F in 1967. But for amplifiers, they were quite late into the scene, still issuing a Valve Amplifier Pioneer SA-400 in 1967 that's only an 11w RMS one, 30w is Music Power & quite a basic amp it is. the First Pioneer Amplifier in about 1968-69 with the 1969 era styling was the 13w Pioneer SA-500 that turns up quite often on ebay if always missing some of the control knob caps. Then came the 27w Pioneer SA-700, the 50w Pioneer SA-900 is about 1971 as in the 1972 HFYB but to see one on USA ebay, it's got that awkward tiny power amp that makes 1969-71 Pioneer a bit hard going, plus the less good preamp compared to the 1966-67 ones. Pioneer SA-1000 is 93w into 4 ohms or 57w into 8 ohms both channels driven, if a 110v-only one on ebay with Vinyl Wrap lid & still the awkward Speaker Plugs sort of makes us less interested in the Pioneer Amps. Also a Pioneer SA-800 of the 1971 range at 26w. A Pioneer SA-600 is a 19w similar one. Not a very impressive range, Pioneer were more into the Receivers. Only by the 1975 HFYB do Pioneer step up the quality with the SA-7100 20w, SA-8100 40w & SA-9100 60w range & we've had the SA-9100 to upgrade. By the 1976 HFYB the Pioneer SA-8500 65w, SA-9500 80w, SA-9900 110w, M3 Exclusive 150w power amp, C3 Exclusive preamp. The Pioneer SA-9500 we've had 3 times now, it sounds pretty average, has aging problems but upgrades well. In terms of Pioneer Amplifiers their first 'serious' early amp really is the SA-9500.

Marantz 4070: Why Does It Sound So Good?
Because we upgraded it. Does the Bridged Mode bring the big Deep Bass? No, the 15w 4ch Mode has the same Bass if at a lower level, so turned up as loud, it's the same Bass. The Trio-Kenwood KR-6340 we got to try another 4ch Bridged Amp & found it a bit lacking in Bass & Bridged Mode made no improvement. A design feature in other Marantz amps is why, but only once upgraded our way. Only the 1050, 1072, 1090 have this too, the 4140 doesn't. The Marantz 1090 is rather dismal inside, 45w amp from 1977 with a cut price build that doesn't appeal, Marantz 1072 is a 36w of the same 1978 series as the Marantz 1050 again with that sort of build. Look at the lower model Yamaha to see similar. The fact the Marantz 4070 sounds so good & the Bridged Mode is underrated at 35w when it sounds like a 60w amp, where else do we look? A Marantz 4060 is on ebay, a 1970-71 capacitor coupled early 4ch amp without the bridging & a very similar fascia beyond the extra 'Remote Control' swich that just adjusts the Volume on an ptional extra part. The 4ch Marantz amps are 2440 which is an add-on amp to a Stereo Amp, then proper 4ch as 4060, 4070, 4100 2x60w + 4x25w, 4120 same as 4100, 4140 2x 70w + 4x 25w & 4170 which may not exist as no pics, as the classic-audio site tells, if they have the wrong info on the 4060, one on ebay is clearly 1970-71 & not bridgeable. The 4070 uses NFB on the Differentials to act as a Bass Filter in their design, if upgrading removes that but keeps the NFB. The only other amp with NFB like this that we are aware of is the Sansui 3000(A).

"High End" Hi-Fi: The Delusion, Fallacy & Overpriced Obscurity.
The scene of "High End" generally means Obscure Brands with strange looking items, often just plain boxes but with Big Money pricetags. High End Amplifiers & Speakers will be at least £2000, with £5000 to £20,000 and of course much higher. You see these Obscure plain looking items on ebay forever relisted as Nonbody Knows what they are & are they really worth the money? We've tasted High-End Hifi as well as had some here to Repair & Upgrade. The truth is it's not that special really, it may have a Look to appeal to a Certain Clique of Sunday Glossy Supplement buyers. We still have the 1993 Tube Technology valve amp system, it's just an ornament these days, even after so much rebuilding, as we use Transistor amps as blogged before, to learn them & hear what can be bettered. We foolishly bought a Musical Fidelity A308CR huge pre & power amp in 2002, hated the sound very fast & sold on as fast too, if did buy at Ex-Demo prices. The MF gear is just basic quality insides, ceramics & op amps with flashy casework. We found a site by the one who bought our Garrard 301, they'll not have found it 10% less on our site so we swiftly deleted it. this West End shop caters to that Dry High End customer replete with plain boxes, highly priced Filtering Cables, hugfely priced SME turntables & other Obscure Stuff that really has no presence beyond the Hifi Mags, HiFi News used to champion this sort of gear if KK used to just waffle about anything but the amp as it didn't inspire much & likely that's the deal still. High End puts a veneer of Prestige on these Obscure Brands, the basic cases look like Home Projects rather than give it a bit of style. The idea of Valves being the end-all to Hifi is still believed, but we had a year 2000 EAR Yoshino "High End" amp here just recently & had fun with it & found our own redesigned Luxman LX33 bettere it easily, we sent the link to the EAR owner & after they've had it back 2 weeks no response, probably as we told too-true on it, if we made a smart job of the mess it was. Testimonials from those who buy these Obscure Brands are interesting, they use Turntables with no Dust Cover, so play an LP & it'll have a layer of dust on. High End Turntables don't appear to have perspex lids, why not use a Dust Bug like the 1960s idea was. Thoughtless. No Tone Controls on these Cottage Industry amps & the Highly Priced Cables act as Filters to cover the Rough Sounds made by Not So Well Designed gear under the banner of "High End". For us upgrading so many amps now, we can tell if an amp is made with Quality, the tired Yamaha CA-1000 on the desk as we type we first got in 2012 & to get one again now we'll upgrade it very differently to bring out the best from it, having gained experience from many amps including the similar Yamaha CR-1000. These sort of 1965-73 amps are The Best Sounding you'll find, just 8 years of Hifi At It's Best before Cost Cutting & Mass Market took over. The Real High End are these selected amps from the 1965-73 era, they all need a rebuild but those who buy our amps compare to the High End & ours win each time, "may not have the 300w power but the Musical Pleasure is much better on that old amp" is the general opinion. High End is for those Chasing a Dream, who believe it is the Best in Hifi when it clearly isn't. The Best is in 1965-73 amps & just a few past that date. We see the huge increase in Overpricing of these amps on ebay, they see our Rebuilt prices & think their Raw once is worth that too. But it's like Vintage Cars, the Money & Musical Pleasure is only in Professionally Rebuilt Ones, we do that.

What Exactly Is "Valve Sound"?
The amount of Hack Sellers & Reviewers who say some IC-riddled amp is 'Valve Like' are really unaware, but you know that already, much Silly Hype has no Basis or Reasoning. "Warm Valve-Like Sound" is a tired amp like the 1976 Marantz 2385 amp sounded when we got it. Hifi it wasn't but the amp was long used & unserviced. What The Valve Sound Is can be compared to Low NFB Amplifiers, not meaning the Power Amp final NFB loop, but elsewhere. A Valve amp has Less Amplifying Devices, typicaly 2 for Phono, 2 for Tone-Preamp, 1 driver & 1 splitter stage & onto the Output Valves with many variants along the way. The More NFB Stages & Transistor Stages, beyond Buffer Stages, that an Amp will diminish it's sound however Clever the designer thinks it is to add in 3 Differentials & all the Junk Circuitry that is IC based. The Tonal Balance of a Complex Design may have the right Tonal Balance, but it blurs & smears the Music, to the point we really can't listen to amps like that now, it just sounds messy however much they are Upgraded as the Design Itself is the Limit. Some of the Lower Power mid-late 1960s Amplifiers & Receivers have deceptively modest design but it's actually very like the Valve Sound with some amps having no other NFB beyond the Main Output NFB Loop. This sound is very 'open' sounding if it can also seem lacking the more upfront sound of the NFB designs which most amps are. Some NFB can make Amps sound "exciting", not enough NFB can leave them Too Sleepy sounding. Comparing two Amps by the same maker from 1966-67 the one with NFB initially sounds more exciting but soon the sweetness is found lacking. Finding that amp hard to listen to now, to try the very minimal NFB one. Initially it sounds very strange with no apparent Focus, bass is much freer as the NFB isn't there to 'Wonderbra' the sound. It almost sounds distorted but listen more to hear the detail & dynamics in the Sound that the High NFB amp loses. as with Valves-Done-Properly this sound is an Acquired Taste as you've not heard it before, but it's a Sound We Crave. To hear it on speakers it can appear to lack dynamics, but listen & get used to the 'natural' sound & you'll crave it too, or not like it at all. The Valve amp can still be a bad design, the 1979 Luxman LX33 despite it's fascia hype is mostly an awful design with disappointing sound as original. So really what is The Valve Sound? Done right it's that very low NFB sound like the Sweetest Late 1960s amplifiers, but Valve sound depends on bad design, cost cutting, low spec & of course aged output Valves. we recently had the EAR Yoshino amp to hear how much improved we made it for tidying & recapping as well as new Valves. So the Valve Sound is only really applicable if you've actually heard an On-Spec, New Valves & Upgraded Valve amp. Otherwise you haven't got a Reference to be quoting "Valve Like". The Best Valve Amp sounds like the Best Transistor Amp is the reality.

Time Marches On, Big Main Capacitors from 1971-78 Are Going Bad.
So far this Month, three Quality Amplifiers we've needed to Replace the Main Capacitors. We've been doing this a few years & the Gallery pages show our Early Unrestored if Serviced Amps. Those 1971-76 Amps we considered the Main Caps were still good to not need Replace on certain Amps. The 1978 Rotel RX-1603 Monster Receiver had been stored apparently by a window or a radiator as cutting open the caps found one was still wet if the other was too dry & initially the amp sounded awful so we ran it in for many hours to "Reform" the aged Capacitor it appears. But a Bad cap may revive but not worth keeping it in a Rebuilt Amp so they got replaced. It didn't sound any better on the New Caps as the Old Ones were revived, but chances are they'd not stay good for long. Caps gone bad by how the amp was kept unused for decades. Next was the 1973 Yamaha CA-1000. This was obviously used too much in Class A & probably used unaware how hot it was getting so likely stored tight in a shelf to not ventilate. This vented one of the Main Capacitors & the main HT Voltage was way down if the Class A stage was fine. Again not what you'd expect, so they get replaced. Then the 1973 Trio-Kenwood KR-6340 4ch Receiver, After Recapping a lot it sounded thin with Bass strangely absent, it was expected to sound like the 1972 Trio-Kenwood KA-6004 that had a bad Relay Capacitor too. But recapping the KR-6340 brought back the sound we hoped it'd be & it plays as we type. all these Amps are 40 years old now, it appears depending on use, abuse & storage that the Big Capacitors after 40 years are past it. A 1965 Sansui TR-707A receiver is still on original capacitors, if it has quite a loud hum telling it's got bad caps. We did blog above on a 1967 Pioneer SX-1000TD-F that we could trust on speakers to hear it as original, but we'd not trust any amp for long with such old capacitors, if we know others do until problems occur. Capacitors are like Car Tyres, you see some very old Cars on USA TV shows with creased tyres from sitting & they still hold air, but as with Capacitors, to trust them to be reliable is a big gamble. Both could Blow Out when you've got a little too confident with them.

LED Desk Lamps... Are They Worth Buying?
We've had the Anglepoise brand ones since about 2002, both still in use, but they aren't made to last & the old Filament Bulbs ruin them. But we got one repaired & another one they replaced the whole lamp, so it pays to tell if you think ther product isn't so good, the Type 3 Anglepoise is no longer made for a few years now. To want a bigger light for Amp repairs, to see what there is. Look on ebay & the OTUS Architect lamp appears what we want. Ebay prices £125, Amazon Price £95, never buy new Electronics from ebay as usually much higher as this shows. Confusion about voltage, how can it be both 110v & 220v & still be the same brightness, a 12v LED we put in the Sony TA-3200F power amp for the 2.5v bulb doesn't last & it just lights up enough, but not the full 12v brightness. Then to read the info. We walk away fast on seeing the LED bulb... Is Not Replaceable. What a cheek. They Give 18 Months Guarantee & say it'll last 50000 hours with an "Expected Life" of 25 years. From what we know of LED bulbs, as one blogged last year, the Electronics inside are cramped & overheat so they fail, one Bulb was supposed to last 12 years & we found in the Feb 2018 Blog that it lasted just Nine Months. We don't like Disposable. A lamp for £95 with no option to replace the Bulb & stock up on said Bulbs is just not acceptable. Not even worth considering, the Lamp only new Jan 2018 so not outside the Guarantee yet, but wait for the Bulb Failures to grow over time. We don't trust Unreplaceable so not for us.

December 2018 Blog

The Best Sounding Vintage Valve Amp Is The Rogers HG88 III
As original if recapped to an amateur like-for-like level we rate it Recommended-Very Good if it does sound rather thin & screechy as we put in the 2018 Updated Review but now it Sounds Awesome Upgraded to Our Redesign based on the one we did in 2012 which was based on Tube Techniology amps we've upgraded since 2002. Whether this sound is what you expect or even want from a Valve amp is a matter of Taste as it'll show up Weak Speakers for sure. It does NOT sound "Valve Like" which based on what others use that Misleading Term for, the term is considered for slow wallowy amps with a soft sound & no detail, much like the 1976 Marantz 2385 amp was & ours went thorough 4 owners in 9 months as it wasn't liked. Our 2385 rebuilt stays on our Speakers as it sounds so good, but was lousy as Raw & Unserviced. The Rogers HG88 III sound as upgraded is Fast & Fresh, Good Stereo width & a bass that is not rich but get TV Sound with Deep Bass & it sure lets you know there's Bass, at 15w too. To get the sweet sound it needs New Output Valves, the old Mullard ones used even lighly since 1965-68 sound weak & blurry. If you like your Sound as sweett & effortless but with a tight bass, the HG88 III upgrades very nicely & could go further too. For a 1965 amp it shows how right the HG88 III design was, it sold fairly well if to find a clean one in the wood-formica case with all the correct control knobs isn't easy & they are getting very overpriced for amps on their last legs, 53 year old capacitors are well past their best. The Sound quality of an HG88 III bettered the EAR Yoshino we had just a few weeks earlier & both get compared to our 1979 Luxman LX33 that is their basics with our design & based on the HG88 III circuit as it sounded so good in 2012. But a HG88 III as original is still a "Bright & Screetchy" as well as Overloud with no subtlety, no bass & a flat unpleasant sound. The 'Overloud' still needs the Aux adjust pots reducing for Line Level, we set ours Horizontally to not get caught in the Volume Control Imbalance as low levels as it typical of earlier amps. We are Reviewing Our Own Upgrade here therefore, but not many amps upgrade to sound this good, Transistor or Valve.

Some Valve Amp Thoughts. Grounding & Valve Life.
On the Rogers HG88 III it has no Case Ground connection, but two on the Speakers strip marked "E" & these do go to a Ground Connection if not Direct to the case, the right E goes to the outout Transformer & via a wire to the Mains Ground. the left E goes to the Inpiut-Phono stage ground further up the case. This will both give a different ground potential, to choose which is the best. Later amps just offer Ground to the Case which works fine. Valve Life depends on how open the Valves are not to get too hot. The Rogers HG88 III owner wants to buoild it into a cabinet but we'd not advise that. The ECL86 output valves in the open case get to 100°C, the one on the right nearer the case so less open gets a bit hotter. With the lid on be sure it'll read 120°C at least & note Capacitors are rated 105°C if those won't get that hot if the amp is laid out well. We used the Tube Technology 100w Genesis monoblocks for up to 16 hours most days & the EL34 valves we checked Bias & after about 2 years they startred to get too aged & not Bias up right. 16 hours a day lasts 2 years so to assume 8 hours lasts 4 years & 4 hours if used to Watch TV with you'll get 8 years. so if your Valve Amp gets used fairly often, Valves over 10 years old are going to be past their best. They sound weak & blurry as well as they can add Hum, we found this with the year 2000 EAR Yoshino amp & new valves improved it a lot. the Rogers HG88 III was still on 3 of the 1960s Mullard & they were very aged sounding if new NOS Edicrons sounded spot on. This is for Power Amp Output valves. The Luxman LX33 the last valves we found crackled on the amp, the JJ brand if they are fine on amps that are more tamed, but again past 2 years regular use they started to sound aged & the paint lettering faded suggesting this is a clue to knowing thyey age, if the Svetlana Winged C EL34s on the TTs the paint faded long ago & still tested good after several years if not used as much & probably are good for another few years. Preamp Valves run a lot cooler, the HG88 III ECC807s ae long obsolete if they run cool so if undamaged the 1960s ones could still be sounding good, but be sure a new NOS set would sound even better. To stick to valve amps that use Valves that are still made, ECC81, ECC83, EL34 etc are the most popular ones.

1971 Sony TA-1140 vs Sony STR-6055. Pt 4: Comparing As Upgraded.
Both amps can do better, the 6055 we'd initially say is the lesser sound as original for being thin sounding but once upgraded the Bass is fine. For us not needing a Tuner, the TA-1140 may get more done if still to get a better sound from the STR-6055. Later... Some Blogs about comparing show the enthusiasm with these amps, if in the end we didn't keep either to upgrade more if did try with the TA-1140 but decided not to do anymore. They both upgrade to give a decent sound & both deserve the 'Excellent' as upgraded & both sound decent on our Tannoys if not a great match. These are both Midprice Amps but still with the pre cost cutting years so still keep a good sound. But with so many other amps to try more with, these will be for sale & the buyers will be pleased with them.

Searching For The Best Sony Amplifier.
The Best receiver is the 1968-70 Sony STR-6120. But with the early amplifiers there are only a certain few in the 'Classic Sony' styling before V-FETs & cost cutting spoils the brand. The Early ones are Sony TA-1120, TA-1080, TA-1120A, TA-1166 & TA-1144 as blogged above which are Non- Uk 1969 models, then the TA-1130, TA-1140, TA-1150 with ICs & then by 1973 a different design with low powered TA-1010 15w, TA-1055 23w & TA-1066 20w. The early omes are all worthwhile, if the ICs of the TA-1150 make it a marginal choice to us. The TA-1120 1965 amp is a masterpiece of design based on no previous Sony amps, they never did Valves, if it does suffer from Overdesign, Bass Limiting & a lot of NFB in several stages that flatten the sound. It's tough to work on & we did sell our one, if perhaps it could do with a deeper upgrade, the NFB keeps it not. But it's a Historical Amp for so early & a rare find too, if the fact it needs a rebuild will put many off it. TA-1080 is a lower powered very rare version of the TA-1120 if try to find a manual to see more. The 1967 revamp as TA-1120A simplified the Preamp a lot if it still has the NFB & as nice as the big film capacitors look, it's the start of Sony amps limiting Bass, even the STR-6120 has these, if we consider them as Upgraded, not the original spec. the TA-1130 by 1971 got a bit too designed with all FET preamp that the TA-2000F preamp has if that's a better design, the TA-1130 is a difficult one. The TA-1140 was out the same time as the TA-1130 if the design & build is very different. The Preamp here is weak if it can be bettered to give a sound that the other Sony amps can't do which inspired this blog. The TA-1150 is the First Sony we ever got in 1990 as a £5 wreck & it was beyond us to fix at the time, no manuals in those days, but having one several years ago, the ICs & design weren't really Classic Sony, if we'd try one again, the trouble is the Overpricing Online. Beyond the TA-2000F pre & TA-3200F power amp which once hugely upgraded sounds wonderful, the ones noted above are quite tricky to pick through. Based on knowing these, the TA-1120, TA-1120A & TA-1130 probably rate equally if one is better at what another isn't so good at, another has better upgrade potential. Perhaps the pick is the TA-1130 but the FETs are tricky, TA-1120 is too complex & far too hard to work on to upgrade further, the TA-1140 could be their best but after trying more upgrades the construction let it down. TA-1120 is perhaps the most useful if the useless Headphone & limited spec coupling caps make it less easy. all great in some way but not in the league of the STR-6120 or the TA-2000F/TA-3200F pre-power. On getting a TA-1150 to try it preoperly it sounds good, the ICs we're not sure of yet if the design lacks the weakness in the TA-1140, so to upgrade it. No definitive Sony Integrated Amplifier then, if the TA-1150 we'll blog on later..

Trio-Kenwood 'Model 600' Amplifier from 1976
We looked at the Trio-Kenwood amps & Receivers past 1972 in the Aug 2018 blog & the 600 series amp together with the 500 & 650 appear interesting.
"1976 100w Model 500 & 130w Model 650 too, not heard of those before & all likely rare ones. Not sure why 600 & 650 are both 130w if the manual confirms it. Ebay one at £1150 says "600 Supreme" which isn't the right name, just a plain looking amp that hides beneath a generic looking outer plus having rubbishy screw-tight bare wire connectors."... is from the earlier Blog, but to look closer at the 600 as one is on ebay if too expensive & worth a try? The Circuits are all 'Transistors' but actually FETs are extensively used like the 1971 Sony TA-2000F preamp. Phono is all FETs with the Class B Power amp design later used in ICs to use less power, 6 FETs per channel. Phono & Inputs go to Volume then the Tone Stage which is unlike the KA-6004 which has Tone before Volume which takes better design. Tone 'needs' 9 FETs & is hard to follow for us & likely the sound suffers with so much overdesign. Low & High Filter uses all FETs again, 4 more. the Power Amp is nearly all Transistors if it 'needs' 4 Differentials & one is a FET pair plus it has a lazy Zener Diode to set voltage. Too many FETs, what do you do if one needs replacing as the specs are so precise & long obsolete. It probably sounds good, but having a FET Sony preamp, to have another heavy-FET amp that looks that plain & not looking like it's a 'Supreme' design, it's just not worth half the price to us.

Marantz Big Amplifiers: 1180DC & 1250.
Both on ebay so to see which, if any appeals. The Marantz 2385 sounds great & we use it often, but have no real use for a Tuner & the Receiver is rather big. 1180DC is 1978 with 90w. 1250 is the second to Top Model from 1977 with 125w. 1180DC looks like the ill-fated 1152DC we had early on if these days we'd fix it right. 1250 is a bit plainer looking if with Tone Sliders for L+R as if anyone ever uses that & both are rather manically busy with perfect symmetry almost with 6.3mm jacks the same size as push buttons. 1180DC first as the build is like the 1152DC, push-together boards & components hanging down a real fun amp to take apart if the power amp is well packed if logical like the 2385. Transformer has 2 taps, one for Power Amp & the other for Preamp, one Relay. 2 main caps are 18000µf 63v like the Yamaha CA-1000 uses. Phono is all Transistors if that Push-Pull Class B type design on 5 transistors, 2 as a Differential. Tone isn't marked but 2 stages have the complex controls in between, 6 transistors with 2 Differential stages as is the Fashion by now. Filter amp very complex switching with 3 transistors if 2 are Buffer Stages. Power Amp looks complex with several Differential stages with one as FETs. we've not worked out the complex 2385 power amp fully yet if it does sound good, it is very busy with 21 transistors including Doubled Outputs. Not keen on the Class B Preamp stages, that sort of design ruined the Yamaha CA-1010. 1250 next. It's not that dissimilar, 17 transistors in the Power Amp if adds a Buffer on the Pre Out stage, 1 more Transistor for Class B on the Tone plus another before the Tone Controls, Filter just the 2 buffers. Both are Rather Busy but so is the 2385 & it sounds great, if only after Servicing & Our Upgrades. The one big capacitor as pics show is the 2x 14000µf 70v caps in 1 can idea like the 2385 uses, still good today but the amps are getting older. 1250 less appealing for too many features than the 1180DC which would be more like getting the 1152DC to Conquer this time.

Most Loudspeakers Are A Compromise Or Just Not Very Good.
We did Blogs on seeing reviews in the later 1970s Hifi News mags, there were some poor results. See Aug 2017 "
The First Subjective Group Test - July 1975 on Seven Loudspeakers." plus more after that, we've Blogged a lot on Speakers. We hear others are looking to buy speakers but the Tannoy Gold & Tannoy HPDs are now very high priced if worth it, you won't regret buying the 1967-80 Tannoys. Beware of Amateur Opinions on Forums. "Sounds Great On Acoustic Music" this is a worthless comment. Simple music is easy to reproduce, today's bland pop is made for Mobile Phone speakers, no Rock Music today as that sounds awful played that way. Any half-decent speaker can do Simple Music adequately. Another one is "Great For Vinyl" to us that means the speaker sounds soft to hide how awful Vinyl sounds through IC Phono stages & even on a Gadget Show test, modern amps still play Vinyl very soft sounding with poor treble despite being true to RIAA. If Music Matters, you want to look for ones that handle Rock Guitar to sound convincing, to hear big Orchestra full volume blasts with good detail, to play Simple music without a Boxy sound, to play 70s Reggae with a Bass line to Quiver your Liver, to play any sort of Loud & Busy music with the ability to show layers to the music, not just a thick blur of poor sound. Loudspeakers should sound Realistic & not tire you out for sounding unnatural. Most Loudspeakers Are A Compromise Or Just Not Very Good because the Hifi buyer often spent big on the Amplifier yet was not advised to buy speakers of the same quality. There probably are good speakers beyond Tannoy Golds & HPDs, really your only way to find ones that are good are to look at ebay ended items, look for the speakers that regularly sell for £500+ but beware there are sellers who Fake Bid to try to set a price on an item that in reality isn't that rated. You Hi-Fi Readers really need a Site that has had 180+ Speakers to Review them Independently & tell what they see. We have reviewed over 180 Amplifiers & Receivers from having them to try & upgrade. But until someone does that, buying Speakers is the hardest part of Hifi buying as so many are not of the quality. Our Brief Advice is if you want the rich open sound you need at least a 10" Bass Driver. Avoid the speakers with Midrange as that reduces the sound for complex crossovers, this poor idea is a fashion item from the 1970s that appears to be what you are told is good, but isn't. All those we've heard from that have 3-way speakers find the 2-way ones like Tannoy a huge revelation in sound from the sucked-out midrange of lesser speakers. Buy some, try some, compare some, keep the best one. Buying Speakers is like Dating, you'll not very often find the first you try is The Best, unless you buy Tannoy Gold or HPDs. Look at the 1960s-1970s Tannoy ads, a large percentage of Studios use Tannoys as reference speakers.

Looking To Get a Marantz 1080DC Amplifier: No Good To Us.
There are Four on ebay. One is priced up Double Price by dreamers, one not far off & nobody pays those prices is the truth. We found similar foolish pricing on the Marantz 2385. Two more though, but Neither are any good to us sadly, so as Readers will try to buy similar, here's what we see. The UK seller one won't even reply on asking for more photos as the listing says to ask for, really? Other items have totally different backgrounds to the photos that suggests they are a Hifi Broker. Custom Wood Case suggests it has no metal lid & just one cropped photo is rather hopeless. To find they block us from asking again shows they are not playing fair here, do they even have any goods? One to avoid. The next one is in Switzerland, it looks good if only 2 photos isn't very professional. Said to be Faulty on One Channel which from the amount of amps of this era we've had is typical, if it needs a full recap to be reliable. The price is a bit high & they put a very high shipping if will probably do it for a lot less once packed they said. Too much gamble here. But to then see Switzerland to UK gets Import Fees as not an EU country, typically 20% VAT plus a £12 charge. It's too expensive as the Total Price to buy the amp, to tell the seller this & suggest a better price where it would work. Too much overpricing on ebay, some sellers wise up if others let them sit forever, possibly they don't have the goods & are Brokers too? Global Shipping is cheaper than Customs as Customs also add on the Shipping Charge & often read non UK Currency as £ Pounds. It's easier to buy with Global Shipping which is a Pitney-Bowes service in USA & it comes very slowly to the UK & ends up via 13Ten & Yodel. But Global Shipping is very slow & it treats parcels Very Roughly & it needs the seller to pack the item properly, not in a box only slightly bigger than the amp with weak bubblewrap as be sure the amp will arrive damaged unless packed very well when it will arrive safely. Global Shipping is insured.

1965 Sansui TR-707A: It Fooled Us... It's Germaniums.
After the 1966 JVC MCA 104E we liked Germaniums if that amp was very sweet if not particularly lively sounding. Then to get the Duette amp that had Germaniums & found it fascinating but rather untamed. Then the 1964 Fisher 600T is All Germaniums beyond the Phono stage & it has a lot of Sound Shaping to get a very nice sound, if not as honest in design. But then the 1966 Rotel 100AMP upset the opinion as it had difficulties needing PNP Germanium outputs converting to NPN Silicon & without a Circuit Diagram, it's for Sale so it worked out, sort of. Th 1965 Sansui TR-707A we've known of for a while & finally got one from USA. Didn't look too much at the design as it was wanted so on Recapping it to see what spec is in the amp, it found relaced Silicons with the Driver ones being way off what the originals should be, typical TV-Grade repair where they just use anything. on playing it Recapped if not Serviced much, it sounded oddly Retro, so serviced it & had a look what the amp is. The Black 'Sony' Can transistors are all PNP Germaniums which is a huge surprise, just assumed they were Silicon as Sony brand. Sony have been using Transistors in Tape Recorders so these Germaniums must be for that design. The TR-707A is a few months ahead of the 1965 Sony TA-1120 if that's All Silicon. Now Serviced the TR-707A is a lot fresher sounding if not redone the 4 big caps yet or the wrong Drivers repair, it's not a much-used amp usually caked in Dust & Nicotine. To understand Germaniums do Hum & Hiss a bit can be accepted & to hear how a Properly Designed 'Honest' Germaniums Amp can sound. The TR-707A sound once mostly upgraded is a fascinating one, it has the Sweetness plus the Kick of what is still only an 18w amp (into 15 ohms) but has the quality of a more Powerful amp if not the Gain. A Rich sound with an open Soundstage. Even Rock Guitar it delivers convincingly, don't remember the JVC or Fisher sounding that good. As Original it wasn't really useable as a bit unstable & too noisy, but even a brief listen didn't say it'd be too great or suggest it's Germaniums. Comparing-Remembering other early Sansui, the 3000A wasn't this Fresh & Open Sounding, the wide Stereo of the TR-707A & 400 aren't in the 3000(A) as it uses a lot of NFB. The Aux goes through the Phono Stage via a large resistor, if it's done well. It has the Crispness & Bass of the 3000(A) if a much clearer midrange. The 1965 Sansui TR-707A is the Best of the Germanium Amplifiers with ease. Once upgraded the TR-707A has a little background noise but it sounds awesome, see the review.

European Amplifiers... Where Are They?
We've not bothered much with UK & EU amps for quite a while. The last UK Goodmans Module 80 we got to try to upgrade to the standard the Japan & USA amps can do but the Goodmans revealed what awful design it was, if carefully tailored to be good amid the original design but no better with severe control noises & insane Instability. A Belgium customer shows us interesting EU amps they find, Carad, Braun & ESS that show the quirky build but seeing the Circuit Diagrams they look pretty good. The main thing with EU amps is DIN connectors that Bang & Olufsen buyers don't mind but generally we found the DIN amps less popular to UK buyers. But there are still Good amps to try. We started out with Bang & Olufsen but now avoid them as we've had enough of them really as the build quality inside beyond outer looks just doesn't match the Japan & USA gear, the Beomaster 3000 has some poor quality, But for seeing worth in the EU amps again, to see a nice Revox A78 from about 1971 we have to get thart. This & the A50 we've looked at before on the 'Other Amps' page but never found one in good grade. Then to see a Grundig SV80M from 1966 if sold as a non worker a modest offer got that. All DIN connectors & a Hardboard back is a bit Radiogram but the circuits look good despite some of the bad EU type Germaniums. Both of those will be on the Reviews pages. In the days of the Family Shop we saw loads of Radiograms from the Blaupunkt-Blue spot ones to many types of other Gram from good ones like the Pye Black Box Stereo Coffee Table one to lousy ones like the 1967 compact HMV one. A lot of EU receivers are like Radiogram Innards as we put on the Receivers List page. The quality on one early 1970s we took home in about 1990 to borrow as ours wasn't working was a lousy affair. Radiograms were often lousy if the early ones 1930s-mid 1950s appealed by the later 1990s if more for the looks. So to be wary of the Quality of the UK & EU gear unless it's a higher power, 40w Revox & 30w Grundig have got our interest. See the Reviews for more. Update: The Grundig arrived damaged so got returned, if we had a good look to see how difficult it'd be to work on let alone upgrade. The Revox A78 we tidied & Serviced to sell rather than recap & upgrade for seeing difficulties there too. There are reasons why UK-EU amps soon were Made In Japan, the build quality is just superior. Did these two restore our faith in trying more EU amps? No they didn't, we did well to ditch the B&O amps we had often early on, that Trio-Kenwood KA-4002a amp certainly showed how much better the Japan & USA amps are & with them we've learnt the skills to bring the best out in them. The first try to better a UK amp to the Upgrade quality Japan-USA amps can take was the Goodmans Module 80, but it only showed how poor the design was, just heavily tamed to sound good amid the whole amp but do little else with.

January 2019 Blog

So What Do We See as the Vintage Hi-Fi Scene into 2019?
Interest in Vintage Hifi is very strong, in it's own still quite small market, as with anything Vintage that takes effort to discover it's worth over New. Amps that wouldn't have sold for £200 as 'raw' amps 5-6 years ago now regularly sell. The buyer is still getting a 40+ year old amp, we wonder what they do with it, appears if it works they just use it sounding aged & tired, so miss out on How Good It Could Be. Ebay is stuffed full of Overpriced Amplifiers that are usually the Good Ones but way outpriced, look at the Glut of Yamaha CA-1000 & Marantz 2385 ones at prices far too high, yet they don't sell as they are 40-45 years old still. We have both here as of typing to have noticed the very high pricing, a CA-1000 should cost you about £300-£400 & a Marantz 2385 is about £1200-£1400. Our Pages get a Lot Of Hits as people are after opinions & info, plenty of Info sites like HFE (Hifi Engine) & Elektrotanya for Free Manuals, some for General Info on what there is such as the long running McIntosh & Marantz sites, but still very little Opinion based on knowing many amps beyond the Newbie Forums that can mislead. The Hifi Mag sites review Vintage & get it quite wrong, just digging out an aged amp & accepting this as how the amp is. This year is 2019 so your 1979 amp is now Forty Years Old. The scene of £1000+ amps has eased off, you still see very plain Modern Amps at £5000+ but they never sell. The Wise Buyer is realising you don't need 300w & that lower power amps 20w-50w are all you really need with the best ones having a great Musical Sound unlike the overdesigned ones. The Modern Valve scene is still hyped as "The Best" if ones we've heard reveal dumbed-down designs if the looks & "Lifestyle" of a Valve amp is the selling point, the mess a EAR Yoshino Class A amp was after some years use & owner fiddling shows these amps need maintenance. Servicing Hifi is rarely done, we only get Recap-Upgrade-Restorations that can cover Repairs, no-one wants to pay to Service an amp, if just doing the Service can bring a muddy Monster Receiver back to life as with the 185w Marantz 2385. More are realising a Rebuild is what their amp needs as the amps we cover are at least 40 yearsa old now, if really who else but us is offering this with Upgrades based on Redesign, so it's still a niche market if those getting Rebuilt amps can often be mindblown by the improvement as the Rogers HG88 III rebuild we did just recently. To us, it's just doing it properly if that has taken over 200 amps to get right & be sure still more to learn. It's getting people Listening to Music, To Rediscover the Music that meant a lot more 20-30 years ago but have sort of forgotten it as later 'Stereos' don't give the Musical Pleasure. Good Hifi can make you a lot happier. It's not cheap to get it done right, but buy carefully, get it rebuilt & listen to a 1965-1977 amp like it's new again, with a fresher more lively sound for the upgrades. To try the Scene, go buy a late 1970s Amp or Receiver on ebay for £50-£100 by a named brand & get a taste of The Sound You Miss.

Addicted To The Upgraded Sound?
We still try to play Amps as Original, once Serviced, to hear what the Buyer 'Back in the Day' would have heard, we tried with Pioneer & Sansui amps as blogged a few months back. To hear the 'good' in the sound but feel frustrated by the limited sound of the Spec of the day, the lack of preciseness in Treble plus the typical Weak Bass even with some amps having harsh Bass Filters that really smear the lower frequencies. To us it's good to hear as Original to listen for what is good & what clearly needs to be better. We have Customers who buy multiple amps, they soon realise the Tonal Balance of each amp will differ somehow. It depends what Speakers they use & we keep going on about Tannoys which has made 1967-74 Golds & 1975-80 HPDs get very expensive, if you'll never regret buying them. One was finding the sound 'harsh', to suspect lesser speakers weren't bringing the best out, they decide to try some ebay 'raw' amps, a 1968 JVC amp they found sounded clean if it was noisy in use & had poor bass, then to buy a 1977 Trio-Kenwood amp of about 30w a midprice amp but just found the sound weak in general. They had sold us some amps & had got 2 great 1960s ones if still found they sounded 'harsh' which from knowing these 1966 Fisher 600-T & Akai AA-7000 they were very smooth sounding amps on our Tannoys. They're suffering from Bad Speakers, the 3-way type that pretend 3 drivers is better but the Midrange driver needs a complex crossover that actually ruins the sound by giving poor midrange rather than better. But after the customer tried the 'Raw' amps they realised the 'Upgraded' sound with proper bass & clean detail put the other two amps away as 'no-good' because they knew the better sound & have decided to get some Tannoys. We started Upgrading Amps years back to try to better the sound, to search for 'Perfect Sound' yet we can still find another amp that sounds better still. The amp we've had on speakers over Xmas was the 1965 Sansui TR-707A, all recapped it sounds wonderful, if the background hiss from the Germaniums can get a bit wearying, the TR-707A just sounds so right in every other way. To hear that 'sound' and try to get similar in another amp is the challenge. So far, several amps can tick 8 or 9 boxes out of 10, but never be the Perfect Ten.

Rarely Seen: Amplifier With Separate Transformer Windings Pre-Power.
This is far from the normal design. Many amps just use one Transformer Winding plus Big Resistors or Regulators if also the lazy designs get the Zener Diodes. Having a separate Preamp power supply does appear to have benefits without lossy stages. A Receiver often will have a separate winding for the Tuner stage, the Sony STR-6120 has this & many others do too. But here An Amplifier with more than one TX winding is rare. To look at some Amplifier Favourites to see they use One TX winding for the whole power supply, not including a winding for Bulb stages: Sony TA-1120 (A), Sony TA-1140 uses one with a variant, Sony TA-1150 uses dropper resistors from the main HT supplies. Akai AA5000 has one if uses half wave rectifying to get 2 supplies from it. Dokorder 8060, Ferrograph amp, Hitachi IA 1000, JVC MCA 104E, Leak 30/70 amps, Pioneer SA-900, Rotel RA-810, Sansui AU-666, Teac AS-100, Trio-Kenwood KA-6000, Trio-Kenwood KA-8004 others. Two Or More Windings: Sony TA-1130 uses three in a strange 'add-on voltage' type design as does the TA-3200F power amp. Akai AA-5800 has two. Luxman L-100 has three. Marantz 1152DC has three if we've not traced to see if one is for bulbs. Marantz 1030 two plus a bulbs one. Pioneer SA-9500 Mk I two, Sansui AU-999 two, Trio-Kenwood KA-6004, Yamaha CA-1000 & CA-1010 have three. Does It Make any Difference? Yes, any amp with separate windings or even earlier ones with two Half -Wave Rectified supplies from one winding have better detail as the Preamp & Power amp don't both pull from the same Power Supply at the same time. But Not Always. Some of the earlier Amps that use Dropper Resistors that get hot can still sound great. The Multiple Transformer windings on later 1970s amps will have a benefit compared to others of the era as cost cutting became such an issue. But the fact a complex Transformer is expensive, this is why they are rarely seen. It's an interesting Design Feature if probably only more noticeable 'as Original' on the 1970s-1980s amps.

Battle Of The 1966 Akai AA-5000S vs. AA-7000.
Both here Dec 2018, both recapped with upgrades. AA-5000S is still half Germaniums, they give a very smooth sound at the expense of background noise. The AA-7000 is all Silicon transistors but for the large size of the amp the long wires inside still pick up hum so it's not really that much quieter & for the design still based on Germaniums there oddly is a similar background Hiss even with quite a few New Transistors fitted. Not for everyone then on either, but the Music is what this Compare is about. The AA-5000 has NFB in the preamp so has a punchier sound, the AA-7000 with NFB opn the power amp on first hear sounds deceptively softer, but to get into the sound it's understood. AA-5000 played Rock well, the AA-7000 is a little softer if is a more open sound, after all we did use our first one on speakers daily for a few months. The AA-5000 is more precise, the AA-7000 isn't as focussed in the midrange as playing Rock revealed. Back to the AA-5000 it has a slight hum too, if not as much as the AA-7000 always had. The AA-5000 is more precise though if not as bassy so to see why & alter. The AA-5000 with the Preamp & Power Amp on separate boards all with shielded cable gives very wide stereo. Just about every amplifier has the Preamp stages L+R on one board sharing ground & power supplies. The rather modest-looking inside AA-5000 needs some upgrades to get the best sound plus the awful 'bloop' on turn-off needs redesign & to wonder why they did it like that. AA-5000 tried on speakers, we had a AA-7000 only returned to the customer a week before which we thought sounded great. The AA-5000 still does sound great, the Germaniums that are still in the AA-5000 S don't hiss much as the design is quite tailored to give a good sound which to our ears does lack a certain freshness. It's not one we'd play but one we had to try. The AA-5000(S) is a smaller item than the AA-7000 receiver & both are High Rating on Retro Cool Styling.

We're Forever Being Asked About Upgrading Budget-Midprice Gear.
We get messages asking if 'xyz' amp is worth upgrading. We could tell you 'yes' & take your money knowing that it's Money Not Well Spent, but that's not our idea of Uprading amps & it'd frustrate having to try to get quality from What Wasn't There to start with, we've found that with some 1980s amps. Average amps are Not Worth The Effort To Upgrade, we've tried enough of our own to realise. To think to Spend £300 minimum on a Recap-Upgrade & much more on More Complex amps, to tell the Potential Customer there amp isn't worth the effort wastes their time as it does ours Researching said amp. The Best Results are from Upgrading 1965-1977 era Amps that were High or Middle Range models. The 1973 Yamaha CR-1000 is the top one, the CR-800 the second one still worthwhile, the 18w CR-400 is actually better than what Sony did at the same time so it is worth upgrading & we've got a second one here to work on as we thought it was a good amp. But the Tons of 1979-1998 type amps are a different thing, big sellers like NAD & Audiolab etc are just Low Priced Amps as 'Richer Sounds' & 'What Hi-Fi' used to Rave about. But to us who from this site you can see we know a huge amount of Vintage Amps, over 180 are Reviewed, we see these really aren't worth spending Upgrade Money on. Ones we've tried we thought they were a bit crappy & were glad to get them out of the way, together with feeling like it was a waste of time as you can't really get past a budget design. A Good Straightforward Design can give good improvements, but Cost Cut designs with poor construction & known failure issues really do head into Disposable as are the Glut of Not-Working AV-Amps on ebay, they are e-waste. Good amps are never e-waste, they can be forever repaired or wanted for parts, but Average Amps are just £50-£100 budget buys. If yours stops working, go buy something similar as often lightly used ones get sold on. It's not worth Recapping or Upgrading by us, you can try to do it yourself & learn some skills, but again look on ebay at the Recapped Amps with no inside photos showing work, why are they selling it? Because it didn't sound any better. Some of these Budget-Midprice amps that are still considered 'good' today, to us are awful amps & ones we'd not want as Freebies as we couldn't be bothered putting a Good Upgrade into an amp that will not give good results.

Hifi Time Travelling: 1985 Dual CV-1460 As Original On Loudspeakers.
To hear what these Amplifiers sounded like at the time, as near as can be. Unlikely a Dual CV-1460 95w amp from 1985 has ever been played on Tannoy Golds perhaps, but if you bought it once having moved to Europe where these were a popular brand in France & Germany, to hear what they'd hear. Our Review of the amp tells we find it rather average sounding just like any other cost-cut 1980s amp if overall it shows upgrade worth & a customer is getting theirs Recapped & Upgraded. So to hear what it sounds like. But it appears we can't easily test this amp either, read on. But we do as the last comment says below by using 2 plugs, which is NOT Recommended for a way to overcome 2-core mains if we have seen this on some amps. Only rewiring will do & EU users can use 3 pin plugs easily enough. Play It. We did & actually on Speakers it was better than expected, a little "cardboardy" on the midrange is the 1980s sound if Tone gives a good range showing it matches well. Appears made more for 86dB speakers as listening levels are loud enough for TV sound at "1", Tannoy Golds are 95dB. There is some sense of a good amp in there, the sound was quite lively, not hard to listen to, a bit of Bass power if still rather restrained on Bass & Treble overall to give that midrangey sound. Sound was clean, no background noise. A far cry from the Rough Sounding Thin 1980s amp sound other amps offer with all their Power Amp ICs. An interesting amp to have to upgrade.

Three Core Mains Cables Are Required For Amplifiers Today.
We've been rewiring old 2-core single insulated USA style mains cables for several years now. This is because the Case is Not Grounded & as today many amps are use without a Turntable, the Amp is not Grounded. This means a "Floating AC" voltage is present on the Casework, usually 50-65v AC if some can be higher depending on Transformer Construction. Today's AV gear & TVs aren't grounded as the Main amplifier is considered to be grounded, or it's just left Ungrounded which 'helps' bring on Failure. It is possible for this Stray AC voltage to Trash Electronic IC based audio gear as we found with Soundcard Failure. Amps we rewire to 3-Core Mains we don't test to see the floating voltage as it's always there & the AC Voltage can vary depending on the way the unmarked or EU-US style plugs are used. The 1985 Grundig CV-1460 as blogged just above we tested to see what it reads. There is no 'Double Insulated' Square icon which only means the cable is Double Insulated & Connectors meet a certain standard. Too early for the "CE" icon. It read 55v & 65v AC based on how the EU type plug was plugged in. Our TV & DAC isn't grounded & we know from before that it "doesn't like" 60v AC ground potential. The owner of it will want the Moulded Plug so no easy way for us to Ground it so we'll not be able to try the amp as it stands. To test the AC potential on Electrical Items to use a Multimeter to the Case & the other probe to a Mains Ground reference. We rewired the 1984 Sansui AU-G90X to 3-core as it needed the Ground to lose a mains type high pitched hum that showed on Headphones, done to 3-core the noise goes. To wire an additional plug with Ground to connect to the case, the Phono Ground would do & then use 2 plugs on it. Hifi needs Grounding & relying on a TV etc to ground it isn't going to happen as these items since the 1980s are always 2-core mains.

Hifi Time Travelling: 1972 Trio-Kenwood KA-6004 as Original & Upgraded.
We have two of these, one we've recapped as we couldn't test it on speakers as DC offset was too high & the other one which reads fine so to try after trying the Dual CV-1460 on speakers the same day. The upgraded KA-6004 is upgraded to a quality to sell, losing hissy transistors & recapped, if not upgraded as much as our KA-6000 is. Pre Out-Power In on the KA-6000 is a 100mV level if the KA-6004 adds a transistor on the Filter Boards to give a typical 1v output, if using as a pre-power amp complete it makes no difference. The KA-6004 displeases for the messy Filter Boards with Unshielded Cable on some Audio & those overlong cable wrap posts which may cause difficulty in upgrading more, we tidied up the upgraded one as the pins are just too close together. 6000 is Capacitor Coupled with Semi Complimentary Outputs, the 6004 is Direct Coupled with Relay Safety & Fully Complimentary Outputs which is unusual for 1972. The KA-6004 is underrated for sure & we've had several of them now, if not for a few years. The KA-6004 is a great affordable amp now the Asking Prices on the KA-6000 are now very high, if you can still get them in USA Auctions at better prices. The 1969 KA-6000 does need a big rebuild, the 1972 KA-6004 is borderline usable if the Relay is reliable, the rebuild on the 6004 isn't so big. On speakers we've had our version of the KA-6000 fairly often & for the last week, to know the KA-6000 sound to rate the Dual CV-1460 below. The KA-6004 we have two of, one is recapped & now sold, the other is serviced but original, so gives two versions of it to try. KA-6004 as Original. This one tests DC offset well, so to hear the KA-6004 as a buyer in 1972 might have heard it. The Dual CV-1460 was decent if rather restrained, the KA-6004 as Original was much better, wider Stereo & volume set to a typical "2-3" level for TV listening. Not so far from the KA-6000 'signature' sound which is good for an Original amp, but soon it was found the Bass was a little Slow & Thick in that typical "Retro Bass" way that does spoil the sound of many amplifiers, not the bad "T" filter sound, if buyers listening to Original amps will wonder why we rate these amps highly once Upgraded if the Original Sound is with Tubby Bass. It's how they are made & to try to hear them in their Original State is why we do the "Time Travel" reviews. The KA-6004 beyond that does sound a great amp if it needs our Upgrades to be it's best. KA-6004 as Recapped & Upgraded to a certain level, if not as much as the KA-6000 gets a play next, what do Our Recap-Upgrades sound like? DC offset on the recapped amp is very low around 3mV which will reduce to near zero with a speaker load on. Noticeable instantly is to not need Bass & Treble set the same, a notch back on both gives a good balance. The Tubby Bass sound is now opened up to sound more natural, the amp just sounds faster & fresher. It is noticeable & some amps do upgrade well for our improvements. Our KA-6000 as a Reference. To try this next, the sound is a lot more opened up & "effortless" which is a huge job to do & took us 2 years to get to this level. It would take a Trained Ear & Top Speakers to hear the difference which is why we rate Tannoy Golds so high. Verdict. Original KA-6004 we'd find a bit frustrating as well as being wary of 47 year old capacitors, if many do use amps this old until problems crop up, we'd not risk our speakers. Upgraded KA-6004 is a quality sound & better than some other of the same brand, but Much Upgraded KA-6000 with a few years of upgrades is naturally the preferred one & why we keep trying to go further, Upgraded KA-6004 really is a great amp & more accessible to the buyer as not such a hard upgrade compared to the KA-6000. KA-6004 may not have the KA-6000 looks, but it has a sound that betters the Sony 1971-73 range.

The Bigger Trio-Kenwood KA-8004 Must Be Better Then?
We blogged about the KA-8004 before in a Feb 2018 blog about Overdesign as the Phono stage is like a Push-Pull Amplifier stage long before others copied it. But a feature that probably makes the KA-6004 better than the KA-6000 is lacking in the KA-8004, it doesn't have two transformer taps, ie one for Power Amp & one for Preamp. Remarkably it just has one if a Sub Circuit that lazily uses Zener diodes to pull the voltage down to the Preamp Levels that need the ± voltages for the Push-Pull Phono. It comes direct from the 2 Main Capacitors & Main diodes via a small Resistor. This is rather shockingly rubbish design for what is supposed to be a better amp. Be sure the Design of the KA-8004 inspired a lot of later amps, clever ideas but not in the name of quality. The rather Hidden Sub Circuit is a secondary Power Supply with No Regulator but the Restrictive Zeners that we see as lazy design. The KA-8004 is better built inside if the Heatsinks are on opposite sides so as with the KA-6000 there are long wires between PP Drivers & PP Output stages. Who else looks at these designs to see what is good & what is a cheap out? No we don't want a KA-8004 now & did see a 110v-only one on USA ebay.

EU & UK Amplifiers: Our Verdict On Trying More.
The sound of UK & EU Transistor amps in itself is not a Bad Sound, we liked the Leak Delta 70 amp on getting one in about 1991. We've had a few of the Stereo/Delta 30/70 & the Delta 75 receiver, plus several Bang & Olufsen 3000/4000/4400/1900, didn't fancy trying the Rogers Ravensbourne/Ravensbrook after getting the lower model amp about 1990 & the receiver as reviewed by us. We've recently tried a 1966 Grundig SV-80 as blogged above & were glad it got returned. The 1971 Revox A78 once serviced sounded nice if rather soft on treble, so we just sold it on as we didn't fancy upgrading more or recapping as we could see it'd not upgrade too easily & wary of the typical EU amp issues. We did try the 1970 Goodmans Module 80, an amp we used in about 1990-92 so in 2016 to give it all the Recap-Upgrades that are tried & tested on many amps it revealed problems as the review tells. Interestingly we get a 1985 Dual CV-1460 here to upgrade if it's quite a different deal here. The Trouble with UK & EU amps is they are made on the cheap. Look at the poorly made UK teak wood cases & then look at a Yamaha one. Look at the ancient Components cheeky Armstrong still put in their 1968-72 range. The EU amps suffer like their Cars do, they may have a certain style, the 1950s Citroen 2CV with the corrugated lid now looks stylish, but it's made like a dustbin beyond the bonnet, the corrugated look was as the metal was too weak. Cheaping out in that Continental Build way on the Revox with only the easily damaged control knobs holding the wobbly rod of the control in place. We've had enough TVs & Radiograms to see the Workmanship & frankly it's not very good. Metal Fatigue is a problem yet never with Japan & USA amps, beware adjust pots & push-on post connectors, the metal crumbles away & be sure there are more issues hidden the more you take it apart. A Ferrograph mid 1970s amp & tuner we had, the untreated bare metal turns to grey oxide dust, not red rust, to show bad metal. Ferrograph amps are very low spec with huge AC ripple that seems to be accepted on UK-EU amps. The thing is these amps can Sound decent, the designs limit our upgrading & even using new capacitors with wider bandwdth will cause issues as the design was made for those TV-Grade axial or plastic cased capacitors. UK's Armstrong was The King of Crappy Made Amps, the valve amp by them was laughably poor as are their bulk buy-out Germanium transistors used until 1973 on the 500 range. They are just product to last like your Phone today is only made to last 2 years. Here we expect the better amps 40-50 years old to recap & upgrade to be 'Excellent' as we rate Upgraded amps often. This is clearly not possible with UK & EU amps. So we avoid them as they are More Trouble Than They are worth. But There Is Hope. The 1985 Dual CV-1460 95w amp reveals why, as does the 1978 Leak range. They are Made In Japan. The labels say "Made In Japan under Dual specification" and the Leak 3200 with it's DIN speaker outputs & aerial sockets is made to Leak design. The risk by 1978 is that ICs will be involved, in the Phono is typical except on the top models sometimes. In Tone they are a bit limiting but in the Power Amp beyond things like 2 transistors in one package to have matched Differential pairs which is good, the IC is No Good for Real Hifi. UK & EU brands Made In Japan are a different thing, they use superior parts, be sure a budget amp will still be made like a budget amp with hardboard bases & rear panels, but your Budget Gear will last longer than UK-EU made gear or similarly the Made In China stuff of today. This opens up the idea of trying more EU & UK amps, as the Brand Names are familiar, but by 1978 the cost cutting & the consumer demanding low priced items still means there aren't going to be many. The Best Hifi 1965-1977 is made in Japan or USA, even USA Marantz got made in Japan on the 1971 Marantz 2245. a lot of UK-EU brands faded away by the early-mid 1970s as they could not compete with the quality & Price of the Japanese amps. Wise Man Copy Best & Make It Better At Better Price is the Ethos there, they copied the USA brands. Now Made In Japan quality seems forgotten a Made in China etc as they undercut, but the quality of Made In Japan hifi is really what made the Hifi Scene once it got big by the early 1970s.

1967 Sansui AU-777 Amplifier.
We've liked the 1965 Sansui TR-707A & 1967 Sansui 400 receivers, they are high quality sounding amps & upgrade extremely well. But they are Receivers with Tuner stages, so what else did Sansui do in Amplifiers? The Valve Sansui we've had the rather poor Sansui 500A & the bigger Sansui 1000 & Sansui 1000A are "difficult" amplifiers too. Sansui certainly their best with Transistors & the Sansui TR-707A does predate the Sony TA-1120. The Sansui AU-777 from May 1967 says a tube-amps site page that appears accurate, if it does miss the 1966 Sansui 3000 early version of the 1968 Sansui 3000A. Not a 1969 amp if there were later variations, the AU-777 is a 1967 design & the manuals are all crisply scanned which makes a nice read. Looking at the User Manual, it shows the back panel has 8 output transistors. The Fascia is the All-Black style that Sansui did for years. Manual states 25w per channel into 8 ohms, the Doubled Outputs suggest it's possibly underrated as the TR-707A was found to be 18w into 15 ohm as it read like a 30w amp. Gives 24 Damping Factor at 8 ohms. The Power Amp shows there are 8x TO3 transistors, if 4 are Drivers & 4 are Outputs. 2SD143 15w 3A for Drivers and 2SD46 50w 5A for the outputs like the TR-707A has on early ones. The early Trio-Kenwood TK-140E is the only other amp we've seen TO3 drivers on, if one was a TO66 trying to do a NPN-PNP pair. Aux to the Preamp, not the lazy Through Big Resistor & Into Aux that Sansui unwisely did on the 1969 Sansui 4000. Aux to switches, Volume, Balance, NFB Tone stage which is very complex with Flat, Cut & Boost switches plus stepped Rotary adjustment. Further along a Muting stage, the whole preamp is very busy & it'll not be as precise as the TR-707A or 400. Pre Out-Main In connectors. A 'Presence' switch is in the main NFB that'll add midrange, much like the Sony STR-6120 one adds extra Bass & the McIntosh early preamps do similar. Some of the design is very complex to the point of overdesign & strange things like an Inductance Coil in the Output Transistors to reduce HF is bizarre as this is done in Tuner stages usually. Design is as crazy as the TR-707A if the Sansui 400 is the total opposite. Sansui AU-777 certainly is an interesting one, too many features that will reduce the sound a little if otherwise it should sound very good, if a 1967 amp will need a full rebuild by now & this one looks a big job. Later versions are AU-777D from June 1969 now 30w with design changes & a AU-777A likely 1970-71 if they all have the 8 rear transistors & all on 80v main capacitor shown as 70v HT on one version suggesting 25w RMS into 8 ohms is correct. an interesting amp, if we have a few Sansui as of typing, so do we need 4 of them? One turned up on ebay with damage at the back if noice in the woodcase, but their £1150 price is just ridiculous, it'd make the £150 like that to one who can fix & get the broken bit, but sadly that's ebay greed for you. Let it sit, sometimes they do that & then offer it at a low start.

Tone Stages: There Are Two Design Types.
The Most Commonly used Tone Stage design is the Baxandall one designed by Peter Baxandall was introduced in 1952 in "Wireless World" says Wikipedia. It's in the Rogers Cadet III & HG 88 III amps & in just about every transistor amp. It does the job well enough as it relies on NFB which is Negative Feedback between two stages or around one Transistor. Easy circuit to build & the Standard Tone stage or variants are everywhere. The other type is fairly rare to find, you do see it in some 1960s Transistor amplifiers like the Sansui TR-707A, Sansui 400 plus more we'll search for & it was first noticed by us in the Sony STR-6850 which is based on the Sony STR-6050, the Sony STR-6040 also. This we consider to be "Passive Tone" as it doesn't rely on NFB & uses 2 ground references. The first amp we had with this was the 1967 Trio-Kenwood TK-66 & having got one more recently in 2016 we rebuilt the Power amp to see how good it'd be, but the Tone Stage was a bit muddy & despite the amp getting an 'excellent' as upgraded, the Tone stage was initially thought inferior as not a Baxandall type, if now to see it's not designed optimally. The thing with this design is it needs to be done right or it sounds inferior with Bass too thick & Treble too soft. This limited the 1963 Trio WX-400U similarly if we altered it to sound better, it wasn't easy to get right by trial & error. Other amps with the 'Passive' Tone we added here as we found them so it's a bit random, Akai AA-5000(S), Akai AA-7000. Marantz 1030 15w amp uses this design too interestingly & likely other low power Marantz receivers do too. National-Panasonic SA-65, Rotel RA-610, Rotel RX-800, Sansui 3000/3000A, Sansui 800, Hacker GAR500/550 & Toshiba SA-15Y. Akai AA-6300 a 20w receiver, not the 40w some say & Akai AA-6600 also. Pioneer SA-500 the 13w 1969 amp. Trio-Kenwood on the KA-2002(a) the 4ch receiver KR-6340 has this design too if the 3 other in the range don't which is rare as late as 1973 which is interesting as we only got that late 2018 & hadn't realised the benefit of the design until the 2 Sansui 1965-67 ones. The JVC 'SEA' EQ sliders use a mix of NFB & Passive Grounding, unlike the IC type Graphic EQ units of later years. So what's the Interest to blog & find out which Amps use Passive Tone? It sounds a lot fresher if done right, no NFB to flatten the sound creates a bigger more open soundstage. Midrange using NFB Tone still has the NFB at any Tone setting, reducing NFB gives the Tone Gain, the NFB level depends on the circuit & typical ±10dB Tone range is less hard on the NFB than some other parts of the circuit explaining why it still sounds good. Some Tone Controls are 100k ohm, if others use 25k ohm ones giving more NFB. But before you throw out your Baxandall Tone Amps in search of more clarity, the Passive Tone stage really only shows the benefit once we've upgraded amps & assuming this more complicated design, based on picking component values, is done right. A Variant to the Baxandall Tone is one seen in some 1980s amps: it uses Tone in the Main Power Amp NFB loop, not the preamp. The Dual CV1460 has this so once the one we have is upgraded to see what that does. Another Variant is the Sony STR-6055 one that uses both NFB & Passive.

The Latest of The Passive Tone Control Amps from 1973.
As the above reveals, we have that amp, the 1973 Trio-Kenwood KR-6340 Quadraphonic Receiver. We liked this amp, the Power amps are pleasing if the amp itself wasn't as 'expressive' as some. But to know the Tone stage probably isn't designed optimally so the Bass on the amp wasn't as good as expected. The Bridged Mode gives an output voltage in the league of a 90w amp if it's rated 50w, the sound was clean, but had quite a bit of unshielded audio cable as the amp is so complex. It's possible some later amps with too many ICs have this design if they are so overdesigned it's hard to tell on one such as the Trio KR-11000G/Eleven G. Any with IC Tone stages have NFB as per the 'op-amp' design so easy to ignore looking there. But looking at the KR-6340 Tone it's not quite the same as the other designs, it might work out well, but for how hard it was to get to the Tone board to recap, it'll have to go undiscovered which is a shame in interests of trying things. The 1973 Yamaha CR-400 we have here has a typical NFB tone, if one to look out for in future amps.

Luxman L-100 Amplifier - 100w From 1975.
We had one of these in Sept 2012 & it had a lot of messing inside, missing relays & plug-in connectors that we managed to find, if recapped it all beyond the 2 huge 'Soup Can' sized capacitors, if found it soft as original, better once Serviced & all Recapped still found it quite tame sounding & didn't like the Phono stage, but that was nearly 7 years ago & many amps here since. One we've not revisited yet. To re-read the review & see we didn't like the 22-Step Volume control & the insane thing goes to zero if you could accidentally put it to Max by going round one more notch as there was no zero stop & we did take the volume apart to see if perhaps the stop had worn away. Had it the same time as the Sansui AU-999, Pioneer SX-1500TDF & Sony TA-1120A & remember liking the Pioneer & Sony more, if we didn't used to play them on the main speakers, only smaller test ones. "Weak On Master Volume" isn't a term we use now in reviewing, but it meant the amp didn't have much kick to it even turned up more. the Headphone circuit was too low volume also. Further Luxman like the R-1040 receivers were just everyday receivers of nothing special-ness plus the gaudy looks. Then the Rosewood veneer on a thin wood outer case looked a bit cheesy if they are in Teak too. Revisit compete there, but the Circuit needs a look, it's not very well drawn not following the typical style so is a mess & hard to follow without typical circle transistor icons etc. The Circuits. Phono has a level-adjust pot like the Pioneer SA-9500 does, switches then a Relay, Phono Stage has a crazy 12 Transistors plus a few Diodes, it looks as overdesigned as it sounded, not even the 'Linear Equalizer Tilt' control that alters the Phono EQ could better it, if perhaps this was fiddled with on the 2012 one as were missing parts. The Preamp-Tone stage including Filters is a nightmare, is this a Tim De P design as he did the expensive Pre-Power C-1000/M-6000/M-4000 ones that we know are ridiculously overdesigned to get "Perfect Specs" at least on the C-1000 preamp as blogged before & started the 1976 'Specs Wars' where 0.01% THD is considered important yet the mangled sound isn't considered distorted. One stage is the Class B Push-Pull stage needing 10 transistors per channel. The 16-transistor Filter Stage is impossible to work out with all the circuit lines if it looks like there are 4 per section that are Filter amp or Buffer stages if we'll pass on looking further at that as it's just awful. Power Amp with Doubled Outputs are on two very small boards fitted to the heatsink & to remember that being annoying. Too hard to tell if circuit lines cross or joined here. Power Supply we remember was difficult & it has Zener Diodes to pull voltages rather than a Regulator. Just remember it sounding 'bouncy' on the Bass but just so Boring suggesting high NFB in multiple places & we can see it now, what an awful design. Looking At Our Sales Photos. We sold this in 2014 after letting it sit unsure what to do as some of the sound was nice, but it was just lacking any life to it which the circuits reveal now. Way overdesigned with some poor user features. The Photos fill us with forgotten dread, to see lots of unshielded audio cable, a pointless "Attenuate" feature again as the SA-9500 does to make finer use of the mediocre limited Stepped Volume Control. The "Winker" feature is a soft-start, rather than describing the designer. Layers of preamp boards with no grounding between as the Revox A78 has & we couldn't wait to get rid of that amp. Verdict. The Luxman L-100 is an amp we'd avoid for getting ourselves having had one to know the sound is overdesigned & very Flat sounding. Bass was nice & why the guy selling it was into Reggae with it, but he sold it & so did we. Smart-Ass designer doing far too much complex 'superior' design & ruining the sound in the process. Space limited inside for the huge caps & lots of problems beyond the ones of missing parts. This isn't Hi-Fi to us, it doesn't play Music well, some may like it as it could tame rough speakers if why keep them. Even the Gaudy 1978 receivers sounded fresher if rather cost-cut in build.

Luxman L-85V Amplifier - 85w From 1978
On seeing a L-100 as blogged above, to see a similar looking & similar power L-85V needs investigating. Not one the Hifi Yearbooks showed if they became inaccurate by 1978 so it will be a UK sold one. Luxman has a "Prestige" reputation, but so do Bang & Olufsen if more for the looks & user features than the sound & audio design. Their earlier late 1960s Transistor Amplifiers are rather basic made with lines of boards & not much space, they'd clearly not seen how Pioneer, Sansui or Sony did design & we're yet to find or want to get a Luxman to try earlier than the 1975 L-100. HFE says 1978-79 then says 1975, the fascia design looks more 1975 like the L-100 if the matching tuner looks like the 1978 receivers so as the L-80V is in the 1976 HFYB to go with 1978 on this seems best. Schematic shows a much simpler amp than the L-100 mess, if straight away ICs & Zeners for Voltage in the Phono isn't great if that's 1978 style, but an IC then a Class B push-pull stage for just Phono is overdesign, has the 'Linear Equalizer" switch as the L-100. Tone looks better, just 2 transistors per channel without the heavy NFB of the L-100 so might be worthwhile. Power amp the usual differential if a lazy Zener again if otherwise looks good with single outputs which shows it's 1978 as Yamaha put single outputs, ie not parallel pairs to get higher power. Pity about the Phono stage as the rest looks good. An 'insidehifi' site has lots of pics, if not taken apart further as boards face down so not to see, it reveals the sort of 1978 build the Gaudy Receivers have, not too impressive & shows the cost-cutting compared to the 1975 L-100. One on ebay for £450 for us to notice it, the Luxman numbering is very random not to tell which models are low or higher ones, this reveals the amp's looks. The cheesy 1978 build shows with the plain fascia & gold control knobs. High grade amp, the white paint in the AC outlets was from plugs blanking these so best left blanked as paint will restrict contact. For a buyer of an original amp it looks a decent buy, not for us to rebuild & try to get upgraded prices for though. The fact is a 41 year old amp will always improve with a Service, it may be fine on the original capacitors, but knowing their 1978 receivers, the spec is rather penny-pinched which could be hiding a decent amp based on the main stages.

Make Your Amp Seem Louder For Free.
This is just a Mind Trick, but as with Tonal Balance, you as a Human are easy to fool. The Sony Volume Control has a slow taper meaning it needs to go up to about 4.5 to be a typical volume yet by 6.5 it's very loud. This is offputting as it takes more turning to get it louder and risky as you could knock the volume & set it too high. If you have an amplifier with the pointer for the Volume not fitted right & the pointer is perhaps one notch up further than it should be, can trick you into thinking the amp isn't so loud as it needs to go higher, as in "needs to go to 5 to be the right volume". Amps we've tested with the fascia & knobs off you have no guide on a rotary, so to think the amp sounds good & loud, but then put the Volume Control knob on correctly & see it turned up higher than you thought, one amp was sounding good yet it was at '6' to be that loud when put back together. Yamaha CR-2020 amps we've had & seen used ones with finger dirt marks showing it never goes over '2' on the volume. The 110w amp seems very loud. So the trick is your amp seems louder if the pointer doesn't turn as far, as in put zero at a minus one position. Fool your Friends in how efficient your amp is by fitting the Volume control pointer higher than it should be, only needs to go to '2' to be that loud, just like the Yamaha CR-2020.

1973 Sony TA-1150: Testing The Preamp Tone IC.
You can see the results from the Marantz 2385 IC, it didn't do too well with high Treble using the Treble Tone control. So the TA-1150 is getting treated as harshly as it has an IC for Tone. Is it fine or does it limit? 1kHz at 0dB, with the Power Amp Coupler set to 'Off' has a 1v reading just a shade over the '5' setting, at the same settings 50Hz reads 0.9v & 10kHz reads 1.05v which is reasonable if could be bettered perhaps. On 50Hz with Loudness off, Turnover at 500Hz & 2.5kHz the typical settings, the Bass set to Max goes to 4.17v without any clipping. On 10kHz Treble at Max goes to 3.14v without any clipping. Perfect Sinewaves if Max Treble is a little reduced from Max Bass reading & this was noticeable on Speakers. This output is what the IC outputs, the Buffer transistor before it adds no gain. 50Hz on Max Bass goes to 9.5v before clipping starts which is just under '6' on the Volume. On 95dB Tannoys the amp was a good volume at '3'. 10kHz on Max Treble goes to 9.7v which is just over '6'. Is that any good? 10kHz when 9.7v at Max Treble reads 3v set to zero, the Tone knob pairs the rear one on a screw lock is set spot-on midway physically if the splines for the front one aren't in line annoyingly, if the pots L+R are set flat. 50Hz when Max Bass reads 9.5v is 2v set flat. Bass is a little restricted therefore by the design if the IC is no problem at all & compared to the Marantz 4070 it's clear it actually betters it. The TA-1150 preamp is actually better vthan expected if the power amp was later found to be not as good as the TA-1140 one. The TA-1150 preamp with the TA-1140 power amp would be the best, as in using pre out-main in cables.

The Smallest 1973-74 Yamaha Receiver: The CR-200.
We've had the CR-400 & have another here as of typing as it sounded a lot better than you'd ever think for a 16-20w rated amp. So to see the CR-200 on ebay with a Metal Top Lid with wood effect finish. The manual shows a CR-200 & a CR-200E which is the Export version with a vinyl wrap wood case as typical Yamaha. Far from being a Piece Of Junk as we found with the CR-400, this has IC for Phono similarly, Tone is 2 transistors per channel much like the CR-400. But what's interesting here is the Power Amp. It's a Capacitor Coupled design without Differentials, working on a 45.2v HT which means it's similar to a ±22.6v HT on a Differentials-Complimentary type design meaning about 16w RMS output. This appears in the 1975 HFYB as do the other CRx00 ranges that were introduced 1973-74. We have the 1969 Yamaha AA-70 receiver printed manual, this CR-200 is based on that design if not exactly the same, it is still an older circuit design. We've seen the AA-70 before but it's not found in nice grade as it's oversized to fit a record deck inside to be sold as a Music Centre as it's 480mm wide, 440mm deep & 138mm high. Power supply is very minimal with a Bridge Rectifier & one 3300µf 50v main capacitor with a basic regulator to get the Preamp & lower Tuner Voltage via a resistor. The circuit is tamed, but it's a quality design still. Inside it's a one-board job with all circuits & power supply together if white lines to split the design. Empty space at the back for the one board if a reasonable sized transformer & a modest folded heatsink panel. The 1969 styled power amp could sound interesting, the CR-400 we thought could upgrade more if space on one board is limited. Looking on Google to find Forums for inside pics, one is asking a stranger how to fix one of these. We get one so it'll be on the reviews page.

Retro Digital Clock-Lamp: 1977 President Timelite.
We had this as our Alarm Clock-Reading Lamp when at school, pictures found of it on Google. Actually had two of them as the first one went wrong somehow, so to find another one for Nostalgia purposes, they are around on ebay for about £35. The cream plastic like most plastic unless kept in a dark room & the lamp not used means it goes brown which is just how plastic ages. The unit must have been a popular one & not an expensively made item. Three screws you need to make holes in the green base cloth to unscrew & then to see the original colour was a lot lighter, but that's old plastic tech. Not much in it, a transformer, 2 fuses, a buzzer unit, a panel with 4 LED number blocks & a lovely piece of black coloured cardboard to hide the PCB. On the back of the PCB is a large IC with MM5387AA/N, the IC has 40 pins. the PCBs have minimal components & just 2 capacitors 220µf 16v & a 100µf 25v so the IC works from the Transistors which we assume are Regulators. To recap those as they are 40 years old. The IC has a "/814" which could mean Apr 1981 if the LED sections have "T7732" which makes more sense to be 1977 for the Red Numbers style isn't a later general type. The Problem here is the 6 push buttons, the front line of 5 & the Snooze. These are 'Momentary Microswitches' of sorts, the track on the PCB & 6x 10mm sprung metal discs create the 'pop' effect. But these are just held on with Sellotape with a thin Foam Layer to create the Bounce & holding high in pressing the button. Not high tech at all, it's just Everyday Electronics. The buttons will have been pressed a lot & this lets the buttons age as old foam turns to dust. But once the metal bits are serviced, seems fine, if then you find the plastic press buttons are malformed so the pointy middle bit doesn't push the sprung metal part right & why these fail as the buttons go bad, if you can have fun & rebuild them as we did. Lights up fine plugged in, the buttons are locked by a small slider switch behind the lamp arm. A piece of tape with 2 holes in limits the leftmost display line to just show dots, low tech again. The light has high & low settings, a little flicker on the lower one. The bulb is the same as a Car Indictator Lamp used in the mid 1980s so likely a LED one will do. The filament bulb is marked "12V15CP" which are on ebay, so CP means 'Caravan & Interior' type bulb, but this is 2019 we want an LED. To find one that fits & is a White Light not the Amber Indicator needs searching. How would the circuit cope with the High-Low brightness. As with LEDs in Amplifiers, the LED light is too narrow beam. Seeing what there is, we leave it be as the Filament bulb. To wait until they make the Bulb Shape ones like Domestic Bulbs, if that's not likely if none are out there now. Old General Purpose Electronics can be serviced & fixed, but to offer repairs on them we'd not do as once you encounter broken bits that are missing or can't be replaced, the item is only good for parts. To think it's an Hour job actually takes 3 days to get right, to rebuild the buttons section including drying time. Simple Jobs can take ages. Looks so 1977 Retro now with the old-style Red LEDs smaller than the type that has been standard since the early 1980s.

The Trouble With Not Liking Your Turntable In Your Hifi.
We got a message asking about the Technics SL-1500 turntable we have for sale. They have 3 turntables already yet aren't happy with the sound. The Sony PS4750 is a Direct Drive in the same league as the SL-1500 yet it's thought to sound "thin". They have a Goldring Lenco L-75 idler turntable & an Ariston RD11E and find these sound better if they lack detail. The L-75 was o step up from the Garrard SP25 Mk III used in many music centres at the time yet they weren't so reliable is the idea we get from reading the Hifi News mags. Ariston were early 1980s midprice sort of decks with belt drive, never of much quality if they sold well in the "What Hi-Fi" era as they were good value for not much money. If we had to pick one we'd go for the Sony as ebay prices show it sells for around £150 much like the SL-1500 used to. Direct Drive is the Best Turntable design, we sold our 1950s Garrard 301 after all as the Technics SL-120 could be upgraded to sound as good & be much better to use. Idler wheels are just below in qualoity, both have good Torque so DJs can cue up & 'scratch' on these decks. The Belt drive is the mainstay in cheap plastic turntables & despite some Expensive Turntables using it with a feeble motor & a glorified rubber band, these have poor Torque & Belt drive is way down in our estimation knowing it's the cheap option to build. So back to the sound, the Sony on a quality system will sound the best for detail, the others are mediocre so will not reveal weaknesses in your Hifi. The one realising they need 3 turntables has yet to question their amplifier. as out Turntables-Phono page tells, the majority of Phono stages are mediocre, they are soft & blurry to the point we wonder how people can listen to such imprecise mush. We've used our own Valve Phono stages since year 2000 & the one we record tracks to the computer with is a 2008 version of an earlier 2004 version. There is Mastertape Detail in Vinyl, yet all we hear told of Vinyl is "Warm Sounding" & hearing 'The Gadget Show' doing tests of ordinary Turntables & Phono stages in amps, the detail isn't just warm it's severely dull & weak. If you want to hear how Vinyl Done Right sound, see the 'YouTube' link at the top of the site, this sound beats commericial CDs with ease. So the guy with 3 turntables doesn't like them & really the amplifier's Phono stage is his problem. They should get a better amplifier is the real answer rather than get a 4th turntable that they'll likely think sounds "thin" too, but then if they manage to get an Amp & Turntable match then the Loudspeakers will be the next weak point. Upgradey-itis is a game to cost you money & some forever chase their "Ideal Sound" which in terms of Vinyl is not a cheap game to play. Then once you have Mastertape Quality from Vinyl, a sound that no amp ever commercially made will have, then you'll be disappointed at how Lo-Fi some records are mastered. Many go the easy route of CD, a format supposedly out of date for MP3 Downloads which is sad as MP3s are Not Hi-Fi. This Hi-Fi Site is based on Our 30 year Search for Hifi Perfection, the truth is it's not out there & you must hit a healthy balance of "Good Enough Not To Annoy" plus "Good Enough For A Five Hour Session".

1977 Trio-Kenwood KR-6030 80w Receiver.
We've looked at Earlier Trio-Kenwood amps & receivers if not as late as this one from 1977 that is All Transistors beyond the IC Phono stage keeps away from the IC issues with others. This is the one the Three Turntables guy has, to see what they are using to get opinions & try to see why they aren't happy with things, can we tell how the amp sounds just from the circuits? Tuner has a lot of ICs if this is pretty standard by now, the crisp Tuner sound of earlier years gets lost in too much circuitry. Phono stage is ICs if the less complex HA 1457 one per channel if Phono stages even with all transistors often sound blurry & far from the crisp sound TV sound is, not saying CD sound as most CDs we don't like their 0dB chopped waveforms. Phono has 50K ohm + 47pf loading which isn't ideal but at least the Resistance Loading is right. Typical sort of design if we've not really bothered listening to IC phono stages after knowing how awful the later op-amp type ones sound. Preamp-Tone is 4 transistors per channel NFB Tone if rather tamed in places suggesting the amp will sound rather Flat & 'Domestic' sounding like a Compressor does to sound to make it sound 'safe', not a sound we want to hear. Power amp design is typical by now if interestingly the Circuit Labels the sections, Input as Differential, or Paraphase amp as Sony call it, "Current Mirror" is now what they call the Constant Current Regulator as seen in later ICs, Class A is the driver with part of the CM stage, then the usual P-P Drivers & Outputs. Earlier amps never needed CM/CCRs so it's a part of the Spec Wars control like the Marantz 2385 below similarly has. 12000µf 63v main caps if the rest is typically cost-cut plus the 'safe' preamp together with the typical construction by now doesn't make us want one, if it seems to be decent for what it is & like any amp of some quality it'd upgrade to sound a lot better, if still be rather 'safe' sounding without some tricky redesign that we have had success doing on another amp. One on ebay for £250 as an 80w receiver is not a bad buy & other sold prices show it's standing. Looks-wise it is very generic-bland & really doesn't look like an 80w amp should.

But That's How Our Amplifier & Turntable Sound: What To Do.
The same person said they liked the warm sound of the non-Sony record players on that amp. They say the Bass is decent if we can see the amp is rather compressed with Real Deep Bass lacking. They actually have a Good Balance with what they have & if they are happy with it, then stop looking further. But the trouble is they have heard 'better' in the Sony turntable for it's greater precision giving better focus, but sounding "thin" as the amp is revealed to be lacking. Here we advise the SL-1500 they originally asked about is not going to give the sound they want & suggest to read this blog & maybe consider getting the Amp Upgraded as the Blog on it above sees the typical 1977 cost cutting. A Dilemma Indeed. We know many keep chasing their "perfection" despite being happy with what they have, or had until hearing something better. The Hifi Mags used to go on about people being content with the system they had, but heard A Friend's System that likely cost 5 times as much & not being happy with theirs. Much like a man with a nice but plain wife suddenly getting starstruck on today's Fake Looking females & seeing Frumpy Jane isn't what they want now, more fool them. Be careful what you compare to as you'll always want to better your lot. You can spend a lot of Money on "Better" New Hifi from Shops spending Thousands on some thing Stuffed With ICs & still never get what an upgraded amp by us can offer.

February 2019 Blog

Marantz 2385 180w Receiver: What To Do With You Now?
This still gets used on our Speakers for TV watching because it sounds great. Other amps we use as of typing are Trio-Kenwood KA-6000 which is modified a lot, plus Sansui TR-707A the 1965 Germanium one & the Sansui 400 which is an update to the TR-707A if with us putting 707A ideas into it. The Sansuis are very rich & bassy which can please as much as it can get a bit tiring as 'Everything' is Bassy which isn't really how the world sounds, but that is Hifi, your Recreation of Sound to your varying tastes. The 2385 on speakers as of typing, we've serviced & recapped the thing plus a lot of upgrades the other 'rebuilders' totally miss. To understand the Power Amp isn't an easy one as the design has several transistor sets for Bias & Protection plus others for Voltage regulation which often means Limiting. Looking online if anyone has described the 2385 power amp circuit, we're way ahead on considering that & just find pointless rebuilds of the Preamp ICs & those who feel new Relays & putting higher voltage capacitors actually matters, yet they leave all the limited parts which shows they don't have the first idea of design. We certainly don't understand the 2385 power amp circuit completely, some amps describe what the Stages are to help understand, but Marantz never do which gives the idea there are compromises. Q709-715 are 'unusual' & even the Marantz 2500 doesn't have this design. Sony TA-3200F labels the sections which is useful to learn from, R110 does a similar thing in Current Regulation to Q709-711 if why the need to regulate? Q713-717 are Bias & Driver related if Q713-715 with Diodes to the transistors is just obscure, why are they needed for the Q717 driver? A Power Amplifier is really just Input stage, Driver, Bias Stage, Protection, P-P Drivers & P-P Outputs. anything else is the whim of the Designer adding circuitry to get lower THD which usually limits the sound along the way. The fact the circuitry isn't in the 2500 or other amps shows it's probably not needed or is even a compromise to keep the Amp stable. A less kind term is "overdesigned crap" and many amps are guilty of that by the mid 1970s. We won't take out questionable circuitry because firstly the amp is 180w & not for meddling with plus it's there to keep the design stable to some degree. To try to improve on what there is unless it's clearly bad design in any part of the amp is how we do things. So this Blog has helped find what does what if seeing parts that are not in other amps means they'll be just accepted unless more info is found, if the Specs Wars 0.01% THD is likely why. At 8 ohms THD is rated at 0.01% THD if IM distortion is 0.1% which is on paper no better than September 1945 Harold Leak getting "Point One" distortion in his amp range of the same name. Some changes made the slightly tame 2385 into something more like the 1965-67 Sansui amps, which is why it's not on the Sales page now, if only really there to show what we can do. We can probably make your Dull & Boring Monster amps sound like they really should, ones without IC Power Amps though. We decided to keep it up for Sale as on the 'Sales' pages as it gets interest showing we can do amps like this & as well as if we get a sale on it, we'll try more amps in the same league as it certainly is interesting.

Current Mirror aka Constant Current Source: What & Why?
The Sony TA-3200F Power Amp from 1970 is probably the First Amplifier to use this design as it's not in any we've had earlier than that. Transistor Q104 has 62v on the Emitter, 61.5v on the Base & 0.5v on the Collector, based on our readings as the manual is barely readable on voltages. 0.5v to the Differential Long Tailed Pair as they get called. R110 is a 47K ohm resistor between +HT & - HT with a Double Diode in the Circuit. What that's for is a bit of a mystery, it seems pointless to us, but we'll find out more. The 1977 Trio-Kenwood KR-6030 has a similar circuit & calls it a 'Current Mirror', a term often seen on ICs if never explained or the compatible circuits shown. The 1973 Sony TA-1150 has ICs for Phono & Tone & it's similar circuit is called a 'Bias Circuit'. The KR-6030 'Current Mirror' on the Power Amp, done as all Transistors has the Current Mirror with the Bias which has no Adjust Pots so appears Autobias or Fixed Bias as some 1960s Transistor Amplifiers are, but isn't. The KR-6030 does show how to Bias if not by the usual Adjust pots but by awkwardly changing Resistors in the circuit if the reading isn't right, have seen this bad non-adjust design on one other amp if to remember which. Again to Wikipedia, their tech info is trustworthy at least, see the Annuals page for more on Wikipedia. Basically it's a Current Limiter & why these circuits are needed is the Mystery of The Specs Wars where restricting circuitry gives it the 'ideal THD'. Wading through theory makes your eyes go blurry as it never explains why it's needed. It's to do with Impedance, an amplifier is designed to be good amid itself so why need it to be universal if it'll never be needed. It's trying to control & regulate what doesn't need it, but again Specs Wars is why, restricting certain behaviour gives the 'important' specs. Older amps in the early Power amp stages you can see from Circuits that they never needed this, so do they sound inferior? It's probably like any Circuit, for us to think Differential era amps were not so good for the Differentials long proved untrue as by the time the Differential became standard the cost cutting reduced the sound. It's how good the design is & how freely costed it is, as what upgrading found with the 1969 Teac amps that have the early showing of the Differential. A lot of "Fancy Design" is more a fashion thing, we stripped the 2005 Marantz PM-6005 from over a hundred limiters to see the design was little different to a 1977 Yamaha one. There is no progress in Analog Hifi, just fooling you & giving you Built-In Obsolescence to go buy a new one in 2 years. The More Simple an Amplifier is, the less restricted the sound is. Any extraneous circuitry is a form of regulated sound shaping & compression, to get the Magic Specifications as started around 1975-76 in the Hifi Magazines & the Tim De P guy with that Luxman preamp in 1975 started it. Very Low THD if the sound is mangled, it only matters the THD is very low as you can't measure how mangled the sound is. As on our Intro page & what we thought several years ago... "If they were more honest they'd rate it as "Percentage Of The Real Sound we actually Lost in search of High Specifications". Some rough sounding low spec penny pinched amps are so distorted from the real clean smooth sound they could be easily 50% Distortion.

The First "Bad" Loudspeaker Review November 1970 HFN/RR.
Having read the 1956-80 run of the Hi-Fi News magazine that became HFN/RR with the previous October 1970 issue, to pick out Bad Speakers we see in Reviews as we've blogged before like the Celestion Ditton 22 and 44 that have very badly designed crossovers leading to the "Difficult Load" that these speakers get called, Amplifier Wreckers is more the truth. The one here is an obscure brand the "PWB Audio NS-4" that as with all of the 'Difficult load' speakers is actually a 4-Drive unit speaker, the company make a NS-2 speaker with the typical 2-Drivers. But the 4 driver one is the stinker. Seems to be a Cottage Industry from a housing estate in Leeds. PWB is Peter Belt, an unknown name. The review waffles on trying to justify 4-Drivers to match the ESL Electrostatic sound & claims it knows 'good engineering'. NS-4 uses a KEF B139 bass unit & 'three special versions' of the T27 tweeter if no picture is shown, the NS-2 is found online as an oval shaped driver with tweeter above. Appears to be using three tweeters to make the treble appear more smooth by having more. You may be able to see the problem with that already. The design is done by ear which is good to a degree but he's clearly not tested the speakers as above 2kHz the impedance using three tweeters at once causes an extreme impedance dip. The text says it goes to 2.5 Ohms which is bad, if the graph here suggests it dips to 1 ohm at 10kHz where there is still good treble energy in Music. Impedance Curves are the Load the Amplifier 'sees' at certain frequencies, it's not the Frequency Response you'll hear. This is a disastrous 1 ohm load for any amplifier, most amps will only take 4 ohms or 2 pairs of 8 ohms, only later amps by the 1980s can deal with 2 ohms. The reviewer, Ralph West is a well-known Hifi name if he says "shouldn't really upset any decent amplifier". But that also tells that Ralph West is one of those who are just using a Quad 33/303 that is specifically designed & tamed to suit the difficult treble load of the ESL 57 electrostatic, a second Quad bashing by us this month, but we're not here to massage Hifi Royalty if we see it's wrong. The Quad will cope with this severe impedance dip as it was designed for, with much limiting compared to amps we prefer, odds are a 1965 Sony TA-1120 with it's complex protection circuit would just cut out, but other amps could be Damaged by this Bad Speaker as pre the Relay era the Protection Circuits wouldn't have coped too well. The review goes to say the Crossover has a worring 13 components to tame it all down, there is something seriously wrong if we see no circuit, but assume the Tweeters are in Parallel to get the huge Impedance dip, if they were in Series the volume wouldn't be right. RW says "yes it is a good speaker". We say it's the First of the 'Difficult Load' Speakers & should be all long since binned after they ruined good amplifiers. In the Jan 1971 issue a KEF Concerto speaker, usually a quality brand, is reviewed by Ralph West again & no doubt with his Quads. The midprice Chorale is a 2-way speaker & it's Impedance Curve is very good with barely going under 7 ohms. But the top range Concerto is that 3-way design we don't like. The Impedance Curve is not good, it dips just below 5 ohms at about 125Hz which is not such a problem, but between 500Hz & 1kHz at about 550Hz to 700Hz it has a nasty dip to about 2 ohms. The Quad with all it's Taming & designing for the ESL57 will cope, but an amp that's rated 4-8 ohm that can take 2 pairs of 8 ohms to make 4 ohms will struggle to play into 2 ohms. This isn't even mentioned as a problem this time. Be sure the KEF Concerto unless it was later updated, has trashed many amplifiers that can't cope with 2 ohms as their circuits are more honest. In Feb 1971 the B&W Model 70, a high model speaker that Sony licensed to sell under the Sony brand gets a review. This is a standard Bass Driver with an Electrostatic Treble driver. Once again by Ralph West & this time as we said above, he's using Quad amplifiers which are carefully designed to deal with the difficult ESL 57 Electrostatic & this too. £140 for either case design 'Standard' or 'Continental' if only 25w rated. Here the Impedance graph shows the speaker goes no lower than 8 ohm up to 4kHz but then a huge dip to 1.5 ohms at 14kHz which amplifiers less tamed would likely have difficulty with. Ralph West reveals he uses the Quad II/22 valve amp which is nice but very tamed. Then he uses Quad 303 power amp possibly with the II or 33 preamp, Rogers Ravensbourne & Goodmans Maxamp, neither of which we've had if had the cheaper Ravensbrook in the early 1990s & thought it poor as did the Ravenbrook receiver. The text explains there's not much going on above 4kHz which on some tamed amps is probably true, but they unwisely say amplifier overload is unlikely to occur, but in 2019 using CD & Digital TV Sound this will cause a problem. We've played a few amps "as original" on the speakers & do find even ones we rare highly once upgraded are often weak on treble. Weak amps might not get into trouble on 'difficult' speakers but even using a 50w amp on 25w speakers is possible with care & maybe amp failure has been blamed wrongly, unaware of the bad impedance dip. Verdict: Check out the Impedance Curves of any speaker to be sure it matches for Impedance. Tannoy 15" Golds are 8 ohm with 5 ohm nominal, but be careful of any speaker that dips under 4 ohm & best to avoid any that dip below 2 ohms.

Snake Oil Sellers? The Murky World of 'High End' Mains Cables.
We always find this amusing, these highly priced Mains Filters are fooling many into thinking they are worth having. One ebay seller does his best to sell his, but why doesn't he want it now? "This is a Clearer Audio Copperline 6 Socket Hub + Silverline 16am one meter cable. These are still current models and the cost new today is over £700. It is considered by users to be a Russ Andrews beat." For those into Hifi from reading the Hifi Mags, certain names crop up that "Fill A Need" but others will question as they did the "Green Pen" 1980s-1990s Urban Myth for putting on the edge of a CD to 'make it sound better'. The Mains Cables we've written on before, all any fancy cable does is use the LCR effect with Inductance (L), Capacitance (C) & Resistance (R) to be a Mains Filter. These "Wondered" reviews are using Modern Hifi that has poor power supplies compared to earlier years & any tidying of RF Hash will appear to give the 'Magical Improvement'. To look at their description of the Plug Sockets & cable is this..."Copperline Hub Description: Full star-wiring with Copper-line Power Cable; Wandsworth unswitched sockets; Three channel "Gatekeeper Surge Protection" with LED indicator; 3 x Super Suppressors provides unrestrictive passive filtering; Furutech FI-UK Gold Mains Plug as standard; Ideal for use with our Copper-line and Silver-line Power Cables. Silverline Cable Description: 6N Silver-plated OCC Copper (99.9999%) conductors for exceptional performance; Five layer silver-copper active sandwich shielding system for superb noise rejection; CL3 PVC insulation for safety; Super Suppressors remove mains noise; 90 hour fully constructed burn in as standard." It's just a glorified Mains Suppressor using Capacitors between L, N & E, the Surge Protection is as in any £6 mains plug block likely adding in the blue MOV discs like you see inside TVs. They add in ridiculous things like Gold Plated Plugs, this will wear off fast & look inside House Sockets to see they are just copper or brass fittings on a small part of the plug pin. Silver Plated Cables are another pointless idea, it's 50Hz Mains that goes into your Amplifier via Copper wires in the Transformer. Their Sandwich Shielding is just more LCR construction. To us it's worthless & we'd have no use for it. RF can be dealt with with £3 Ferrites as blogged before. We just use 5A mains cable from a big reel, copper stranded wire as you need nothing better. The Reviews by users are all very deluded, are they actually real people, they may or may not hear any difference but it's the wonder-Cure for All Ills. Rubbish says us. Our TiVo was picking up picture distortion, the Coax Cables from outside had no Ferrites so to Add one for Tv & one for Broadband did sort the problem & the TV Picture watching Live TV was slightly crisper. All so true that there is a huge amount of RF around these days, but the £3 Ferrites will solve your issues. The excessive mains filtering is a joke really, Mains is 50Hz or 60Hz, the RF noise is far higher frequency. The old idea of a Mains Choke the 1965 Sansui TR-707A receiver uses as this reduces a lot of RF, but generally if there is an issue the £3 Ferrite you clip on the cable will sort it. The £700 cable & plug has one bid of £90 on it which will be someone believing the hype. If your Hifi Sounds Bad, it needs a lot more than a fancy Mains Cable that likely only sounds better as you want it to, but if it was unplugged with you unaware, you'd not notice for weeks. The seller with the Clearline appears to have got £230 Winning Bid but "strangely" it's Up for Sale again "my second one" if the blue triangle sticker has the same scrape on it. There is a lot of this 'fake bidding' going on, to try to catch a gullible bidder & they are always this obvious.

My Amplifier Makes A Thump Noise On Turn On.
This is quite normal on Pre-Relay era amps & even some Relays make a click on turning on & off. For Earlier Amps, to hear a Bassy Thump we think is reassuring as the amp has power, the 1967 Sansui 400 does this now upgraded if as original on lower spec it made a lesser noise. Some amps physically thump too, our last 36" Panasonic CRT TV did that, this we've seen called "Pole Reversal" if looking online doesn't find that term, it's just the 240v Sine Wave hitting the Transformer & pulling high initial current. After the thump noise, the initial currents & voltages settle after a few seconds to a minute. Some amps like the 1966 Akai AA-7000 turn on with a loud "boing", ours we had we upgraded to stop that as it's to do with the original design, it then takes a few seconds to settle the voltages & the background noise then suddenly appears meaning it's ready to play, if this shows on Headphones it won't on 95dB Speakers. The Hifi Mags of the pre Relay era, ie 1967-72 had people questioning why it makes this noise. The replies even by the Hifi Names back then mostly said "we don't know" but sheepishly agreed it's not a problem. Go turn on a big Marshall Valve Amp Speaker Stack or hear them do it on TV, it makes that meaty Bassy thump as the amp has power & plays very loud. Later amps or lower spec amps can be quiet on turn on if can make a small noise a few seconds after turn on as voltages are ready. Sony amps are always quiet on turn on. The 185w Marantz 2385 has a "soft start" which involves 2 relays & a small limiting resistor direct on mains. If the amp makes a loud crack noise that is much louder than typical TV-listening then you could have a problem or just a bad power switch or switch snubbers. We had one amp we upgraded as any amp would upgrade, to be a selling amp not an experimental amp & the thing made awful thumps on the Relay. No fault, but the design wasn't very good & to not be able to upgrade it spoiled the point of buying what appear decent amps to upgrade. Another highly rated amp made a bad click noise on turn-off that took some searching to see why but again resulted in the amp being less upgraded to be able to sell it as what a buyer would be happy with. The low confident-sounding bump on turning the amp on is fine, it's not very loud in real terms if one reader says it scared the Cat. Earplugs for the Cat then.

Volume Controls: Why Are They Widely Varying Values?
Transistor Amps.
Some amps like the 1965 Sony TA-1120 have a very low 10K ohm volume potentiometer, the Sony TA-2000F preamp & 1967 Sony TA-1120A have a 250K one. 1965 Sansui TR-707A has a 125K one, 1967 Sansui 400 has 250K. Marantz 2330B has 50K if the Marantz 2385 appears to have a 20K one, if marked 20K/250K as it has 4 stages. In Volume Controls like 'Alps Blue' they have a Logarithmic Taper & are marked "A" if Linear Pots are marked "B" & also there is a Linear Balance version with only half the taper that's called the Latching version with the mid click. Some older ones in amps mark Log as 'B'. Volume is always the Log version & Tone usually the Lin version if some designs use Log. The Volume Control is one end the Maximum Volume from the Preamp or Inputs stage, the other end is Ground & the middle is the Output as it wipes the resistance track. The Volume Pot value is apparently irrelevant, Yamaha CR-2020 gets loud quickly & has 50K, Yamaha CR-200 similarly loud has 250K so the value doesn't match how quick it gets loud on rotating volume, it's just a potential divider. Yamaha CA-1000 & CR-1000 have 100K, if CA-1000 tone are 10K Treble & 25K Bass. Similarly on Tone Controls the 100K ones as the Sansui TR707A & 400 or the 50K of the Sony TA-1150. Does this explain Speaker Matching is down to Volume Control resistance? Sadly not as the Sansui AU-G90X with 100K Tone & Volume didn't match the 1967 Speakers. The amps with 250K are showing more confidence in their design as the higher value could bring up RF noise, but not necessarily the most expensive to see the Yamaha CR-200 is their lowest model with 250K volume if based on an older design. Sneaky Double Volume Controls. The Marantz 2385 with 20K volume has Loudness but as with the it actually has Two Volume controls in one with the other being 250K Volume for another stage to avoid background hiss. The circuit hides this by not labelling things too clearly. The Yamaha CR-2020 has the 50K Volume control is after the Inputs & before the Tone, but the Tone & Filter stages create hiss so they 'hide' a 5K one after the Balance control as the dotted line reveals, to stop the Preamp Hiss. The Marantz 2385 does similar, hard to follow, so look at the similar Marantz 2500 schematic which shows the Filter Amp gets the second Volume control after it. The Yamaha CA-1000 appears to have this too, but it's just the Volume & Balance on one control, the CR-2020 has 6 parts on the volume. All variants of design, if generally many other factors influence the sound, from soft & wallowy to glass-cutting treble of the 1980s. The Quad 33 preamp from 1968 has very low values to help further match to their ESL 57 Electostatic, the RV1-2 is 50K Volume, RV3-6 is 10K Treble, RV4-7 is 47K Bass & RV8-9 is 25K Slope with RV5 is 1K Balance slider. Valve amps are typically 500K or on older ones as high as 1 Megohm (1000K) if impedance is different to Transistors. The 1965 Rogers HG88 III that sounds great rebuilt & upgraded as we did one only very recently has a clean open sound. Volume is 250K Log, Bass is 1 Meg Lin & Treble is 500K Lin with 250K Lin Balance as is the Cadet III. Our 1979 Luxman LX33 has Volume 250K, Bass 1 Meg & Treble 250K with 250K Balance. The 2000 EAR Yoshino has a 50K volume that is not typical. Trio WX-400U has Volume, Bass, Treble & Balance all 1 Meg.

Testing Amps to the "Guitar, Drum & Bass" BBC TV Show.
TV sound is a good test on Speakers as it's Modern TV shows often with the big THX type Bass & this show with Reggae Bass plus 'Live' Bass Guitar as they demonstrate. Hear the 'Chic' Guitar Bass Lines & then mixed into their rather Bland Disco Hits. The TV show doesn't really go into the Sub Bass like some TV shows do, to not really hear the under 40Hz stomach-wobbling Bass. Playing it louder than usual TV sound but not so loud you can't hear yourself it reveals the wattage needed is more than the 20w of the Sansui 400 that does Bass very well but the extra volume isn't for it even on 95dB speakers & we'd not expect it. The Sansui TR-707A rated 18w but that is 18w into 15 ohms which is about 30w into 8 ohms. The TR-707A does Bass extremely well & our recapped & upgraded one is certainly one of the best sounding amps we've heard, if the Germanium hiss was noticeable. Further amps tested reveal some amps don't have such great preamps, the Yamaha CA-1000 had the Bass nice if the rest wasn't quite what the TR-707A could deliver. Our redesigned Sony TA-1140 sounded extremely good, they had to dumb it down purposely with some poor design that took ages to redesign. The TA-1140 using the TA-3200F 100w power amp didn't sound that much different if the 100w power amp instead of the 40w TA-1140 one obvious power increase & confidence to the sound, if the Sony TA-2000F preamp with those FETs isn't in the league of the excellent power amp. To redesign FETs to Transistors is a bit difficult on the TA-2000F if it's a challenge that's worth trying. Beyond Sony in 1970-71 very few amps used FETs in the preamp, the 1977 NAD 300 did & it was a disappointing amp. The 1979 Trio-Kenwood Model 500 range uses FETs so we decided to not try that. But back to the Bass Test, a 30w amp appears to be the minimum to get a 'Party' sound from, 15w-20w is fine for TV & Everyday listening. But interestingly over 30w with the amps mentioned, Bass sounded much the same beyond testing for the highest volume which we didn't test. 40w Sony vs 100w Sony sounded more open but Bass with both amps with our Upgrades was the same. The 30w Sansui TR-707A has a remarkable sound for a 1965 amp & in comparison the 1971 Sony TA-1140 with our redesign added a slightly firmer sound balance as the Damping Factor will differ, if neither amp has this shown on the Specifications, we'd estimate TR-707A is a 15 & the TA-1140 is about a 40 Damping Factor, just by the sound & knowing the Sansui 3000(A) is DF of 15.

Playing Amplifiers Loud Isn't Easy.
Of course the louder you play an amp you may think the less important the actual Sound Quality is as the Room will put in so many reflections at High Volume that crisp sweet sound isn't really heard. The Quality of the amp needs to be good regardless of power to not flatten out or sound harsh up loud is where many amps fail so sound pretty awful, the low-spec mid 1970s Pioneer SX-850 sound where the designs were penny pinched to be £100 less than competing amps. Most Amps of High Power are in the mid 1970s Cost Cutting Era so sadly are pretty lousy sounding Turned Up Loud as they just flatten out for low spec even at 80w, current limiting & dumbing down which is 'built-in' to get you to go buy something more expensive, they can't have you getting the Best Sounding Amp from a 40w one can they? But so many factors determine how good the amp will sound loud, we could hear the 20w Sansui 400 not being able to cope on Loud Bass as it was heard to flatten when other higher power amps played the Bass correctly. It's 20w, it's not for cranking up loud, it's more about sweet detailed sound as we upgraded it to be. All the Fun of comparing Amps using the same segments of the TV show, some amps play the Stereo wider than others for varying design features. We want amps that can do Quiet nicely as well as Kick Out on the Bass turned up louder, it's why we upgrade as we want it all in one amp, if it's actually rare to get 'all' from one amp even upgraded, one can sound awesome at 20w but not have the 100w power. Also in testing in the Blog above, using two amps with Doubled-Parallel Outputs the sound up louder didn't really seem better from those amps, we didn't try the Marantz 2385 with 185w for Triple Outputs as the Tannoys are 50w rated. It just tells that a lot of "gimmicks" in Hifi Design don't really give what you think they should, other factors are what makes the Best Sound. Played Loud the amp needs to keep in control, the midrange suffers the most on cheaped-out designs. When it's designed well or unfortunately for readers with disappointing amps, this means upgraded properly, again the Manufacturers are priced to the Penny & don't want you having the Best. Some 100w amps aren't as loud as you'd think & some 15w-20w amps are a lot louder than they should be, it's all down to the design. Valve Amps sound better as long as the design is good as there are less amplifying stages & with transistors this can be done similarly. The Yamaha CR-200 has a simple 1969 styled design & sounds much fresher than all the higher models, but it's only 15w. The Game of "Current Limiting" is about Design & it takes skill to understand that, you'll find Current Limiting mentioned but it's several factors all spoiling the sound together, not just one thing. If you work it out & just try to change one thing, be sure the rest of the design won't cope well & you get nasty problems like Instability & Flattening of Sound, which is why most only Recap to try to keep safe.

1965 Sansui TR-707A: Hearing It As Near To Original As Is Safe To.
As of typing, we have two of this great amp, one is ours & the other a customer got on seeing us raving about it. Both amps bought from USA were sold at a cheap price. From testing it, we understand why. On the Customer's one from knowing what ages most on rebuilding our one, we recapped the Power supply & Power amp but we left the Input-Phono board & Tone as original. The Sound using Aux is perhaps revealing why this wonderful amp is not yet appreciated. Bass is very weak, like having Bass Tone turned right down & it's a bit rough also. FM Tuner with Tone gain sounded better if the Tuner does have de-emphasis unlike our Audio test tracks. This Amp Upgrades to be one of the Best Ever, but clearly as Near-Original it's nothing special so really hides the quality of sound only brought out by our recap-upgrading & the other stages done will have it sounding better if the weak preamp. Actually quite a few of the 1965-67 amps don't sound so great as original but they upgrade really well, the build quality is there if 1965-67 is really early in the Transistor scene, so perhaps those buying these & playing it 'raw' wonder what the fuss is about. It's in The Upgrade where the best sound is. You don't expect a 1950 car to be it's best as original with drum brakes & other aged but working stages. It's like amplifiers too. Some amps like the TR-707A are beautifully built but the limits of the age & era plus the age-old issue of "Not Wanting To Give Them The Good Stuff Yet" as in 'Back To The Future' means many amps are sold as "Nothing Special" from dumbing down but hide a great design with our Upgrading-Rebuilding bringing it out. We heard from one buyer the JVC-Nivico MCA-104Z which is the amp version of their 1967 receivers, he said it had No Bass if otherwise was a nice sounding amp, the buyer has two of our amps already and as they said they are "Addicted To The Upgraded Sound". So are we & we continue to push further with upgrading, losing the poor preamp issue on the Sony TA-1140 & are trying to do similar with the Yamaha CA-1000 which has an awful preamp especially the Filter amp. It takes absolutely ages to redesign these stages & test they are good, but "What else Is There" after having tried so many amps now? Redesign the ones that seem to be well worthwhile past the crappy stage(s). The sansui TR-707A upgrades to souns awesome, if those Germaniums are still a bit hissy. so to try to Go Silicon & expect problems, but the great looking & great sounding TR-707A is worth it. A rebuild on this 54 year old amp is a big job, you can buy one cheaply perhaps still, but the rebuild costs are on the higher side. On the basis of someone just recapping like-for-like on the TR-707A if they would tackle such an early complex amp, the amp still wouldn't sound so good as it's still on the limited original design. Seeing one guy recapping a Yamaha CR-400 on a social media site as we have one here to do, they recap it all nicely, but still as like-for-like. As with the Car Shows, the Upgrades & Rebuilds are what makes Old Cars exciting, as well as nice paint jobs. Upgrading is far from easy & untold problems can be found for trying to be clever to make it better, the truth is you'll reveal weaknesses that if not fully upgraded will make the amp sound... worse. So What To Do? Learn skills.

Want To Be A Vintage Hi-Fi Tech?
The Vintage Hifi Scene has certainly grown a lot since we started this Hifi website initially as just one page about Vintage Record Players. There are Hifi Forums, the very useful Hifi Manuals sites like 'Hifi Engine' & others, but still really not any doing what we do. Recapping Like-For-Like is growing & be sure even this can bring problems to solve which is why some won't even recap but would rather rake in cash for repeat 'Repairs' instead of just rebuild amps over 40 years old, that's 1979. The articles we write are us having worked out what the Books & Magazines never told, some Blogs are us finding out about something & writing it as it'll interest others. Have we influenced the Vintage Hi-Fi Scene more than anyone else, you decide. But What Can You Do to get into the Vintage Hifi Game? A family member of ours currently teaches their skills based on their progress from us suggesting ideas to start them on it & now to many others in a fashion-related scene where there is a lot of interest, but it's quite a narrow skill. The Game of Vintage Hifi needs so much learning & time invested as well as many amplifiers to 'try' on & mess up in your progress. To go to a College to learn Electronics only really teaches theory, much of it means nothing without any hands-on experience, the teaching we had in the early 1990s may get you a Certificate but hardly any Practical Experience. What we do now is based on what we've tried over many years & having the nerve to try & ignore the accepted ideas & rigid opinions of "The Grey Old Men" in tech. You can start by learning how to repair Electronics, but today Repair is not like it was in 1990 as today things last 2 years & you buy a new 'better' one. Today's Repair Tech probably knows very little but knows how to order a plug-in board & how to fit it. So you accept Hifi repairs is a dying art, but all these Vintage Hifi items people like & want working right. we get asked to fix 'everyday' electronics like Music Centres, Tape & CD if this is more trouble than it's worth & the customer expects a cheap job unaware of how much work it is. On doing our BTec the nearest one to Hifi was TV & Video Repairs, the tutor said how boring the job was to us, if not to the whole class. Repairs are boring, frustrating, time wasters & ultimately you can get caught by unfindable parts. The general idea of the TV Repair Tech is a older weary man with no personality or attitude, because he only knows formal ideas rather than dare to think or question. But you need to learn the scene doing the crappy jobs to realise why you should never touch them again. To try to explain by email how a customer can sort an issue they have is impossible, they should just send it to us instead of weeks of them thinking they can do it & we'd solve it in 30 mins. We get amps that we aren't happy with, the 1966 Rotel 100AMP up for sale isn't very good as no manuals & it's useable as stated, but far from what we'd hope it would be, this shows how important good Service Manuals are if we have sorted several amps with no manuals from working the circuits out. the Rotel wasn't even working right with bad resistors so what do you do? Wasting your time is unfortunately not rare in Vintage Hifi as it brings up weaknesses in the amp design, problems that are 'unfindable' result in whole stages needing rebuilding just as it's quicker to do. Going into redesigning stages that are poor can take absolutely ages, we did this with the Sony TA-1140 & the results were well worth it, if the Yamaha CA-1000 has a poor preamp & getting that right on awkward boards is a real challenge, but that is advanced stuff & might not work so well unless you get brutal with it. So Start Small, get Hifi in for Repair once you are to a standard where you aren't just going to trash their amp or give it back not working as we've known with Repair shops. We see those on ebay apparently selling 'upgraded' amps but never any photos of the amp insides to show what they did & the price is very low showing a lack of confidence in what they've done. It takes years to learn how to do the more difficult amps, it takes confidence in your work & a certain daring to try things to get progress. To do a lot of work to an amp & have it play right first time & similar with other amps is showing you're good. Vintage Hifi is rewarding for getting Old Wrecks going again, hearing great amps & then it Rewards for others seeing what you do & trusting you with their Amps to work on. But it takes Years to get to that Standard.

March 2019 Blog

ICs: Should You Get Involved? Snog, Marry Or Avoid?
The Thorny Question of ICs. We've tried plenty over the years if not many on this site, only the 1986 Sony TA-F550ES with an IC power amp driver, 1977 Marantz 2385 with IC Tone-Preamp & the 1973 Sony TA-1150 with IC Phono & Tone-Preamp. Start with the good: The TA-1150 Tone IC we tested similarly to how we did the Marantz 4070 in a blog earlier & it coped as well or better than the Transistor design in the 4070. this IC is long obsolete if it a basic design with 2 channels in one IC. With upgrades we did on the amp & to be sure the Voltages were matched, it actually sounded great as the rest of the Preamp was uncomplicated. The Marantz 2385 tone stage using the thin in-line ICs wasn't so successful, at Max Tone it didn't have enough Voltage to give a full output as the TA-1150 could, perhaps it needs better design? But to use Max Tone at Lower Levels will keep that being worthwhile. The 1986 Sony TAF-550ES we thought was the Most Boring Amp we'd ever heard on getting one in 2011. It had a large STK IC block for the Power Amp if Transistor Drivers. We also had the 1986 Pioneer M90/C90 Pre-Power 200w pair, the Preamp was stuffed with ICs & unshielded ribbon cable & the Power Amp used an IC for the Bias stage. We just sold it on as it was abandoned & not in good condition, we couldn't be bothered with it. So that's what you get, some are good, some are bad. But the Main Point is to Keep Or Avoid. We get amps to upgrade for our interest so what we get is what we want to try or trust. AVOID: Anything with Power Amp ICs of the multi pin STK type we'd never even bother with. Parts obsolete like V-FETs & many other Custom Transistors as well as MOSFETs that are more a fashion thing than better than the 1960s TO3 transistors. The risk of damaging Unfindable ICs or needing to replace ones already damages is usually 'Unobtainable' so ones we avoid. You can't rebuilt the IC as transistors as there is no space, the amp is sadly parts or disposable junk as there is nothing that can be done. Some semi-ICs like Darlington Transistors like B&O use are still buyable & that is where the lines get blurred, if you can still buy spares for the IC at reasonable then it's worth having regardless of criticisms of IC sound quality. For ones we've looked at, the Power Amp ICs can be £40-£75 so not worth buying amps with these unless you realise they are use until they fail. KEEP: Anything with Phono or Preamp ICs including Double FETs & Double Transistors that look like ICs but are just 2 transistors in one case, plus Op-Amps, those 8 legged "75p new" ICs to us means "it'll sound lousy" because it always does, if sometimes for for weak design than the IC. Early ICs like the JVC 5040 & Dokorder amp used are a different thing as are the thin in-line ICs, if sound depends on design. These are highly unlikely to get damaged beyond misuse so even obsolete ones like the Sony TA-1150, what's going to damage them? Nothing will is the typical answer. Again the exceptions, the 1971 Nikko TRM-1200 amplifier has ICs on the Phono stage, ones that always fail as we found on getting the amp. these failed early on in the life of the amp & the part fast went obsolete, if there is an equivalent circuit we built with Transistors & Resistors that worked fine. This is rare in a few ways if to have an equivalent circuit is the only one we know of. So the "Marry" & "Avoid" is dealt with, the "Snog" are the ones you Try to see what the ICs Sound like. Low Priced gear late 1970s to mid-late 1980s with ICs & Op-Amps means it'll always sound awful for the heavy costcutting. The thing is with ICs is today huge amounts of research are put into them, the budget IC riddled item of today with 2-5 years lifespan will usually sound better than the early 1980s IC amps. They've learnt the Class B circuits over time & how to tame the designs to sound acceptable if they are far from being lab spec "Hi-Fi", a £200 Amazon amp is not Hifi if it's still bought as it's all they want, Mass Market Goods. Amps like the 1980 Yamaha range CR-2040 etc we had a look at on the "Other Amps" page & were not pleased to see such heavy reliance on ICs at every stage & we'd never buy one as it's worthless for us to try to do anything with excess ICs. Some amps with ICs go 'flat' too soon & to hear them at high volume is an amusing mess showing how IC power amps are very low spec. We'd avoid Any IC Power Amp amps & unless they are cheap, even some Monster Receivers have them as Blogged before, these sort of amps are best avoided as once they fail, you'll likely never find the IC blocks unless at £80-£150 each as some sellers try to offer them.

Remembering Earlier Amps Plus The Intense Upgrading Manner.
Getting a 1967 National-Panasonic SA-65 to rebuild, the "Nat-Pan" as the buyer of ours in early 2015 thought of it plus the 1966-68 Sansui 3000(A) reveals a turning point. Early Spring 2015 we got a second Pioneer SA-9500 Mk I 80w amplifier from 1975. We'd upgraded one before & done quite a lot with it if it didn't match our Tannoys so well so sold it on. The Second SA-9500 arrived with the fascia with a dent on it & an insurance payout after a tough battle. "You're Free, we can do as we wish with you..." was the idea so to do all we wanted to try to better the amp if in 2019 we'd go even further with it, into the realms of 'too big a job to charge a customer' but this is reasearch. The SA-9500 unlike some amps we've had liked all we did & upgraded more than any amp before. 'This Is Good' we think & to do these tests using test gear to see they are good shows they are. Seeing now the SA-65 was sold just a few months before this as was the Sansui 3000A, shows the ideas from these amps plus the Sony STR-6120 that we got back fairly recently & had to rebuild it to be reliable. The Pioneer SA-9500 is a quality amp & upgrades well so other amps we've had & still keep as references get these Upgrading ideas further & further, just to find the Absolute Hifi. There are certain design features that mean an amp will upgrade better if to remember not everyone likes the PA sound at home. Hifi is a Domestic Scene, PA sound is a Studio Sound if some amps claim to be 'Studio Reference Quality' but really are far from it. PA sound can be very loud at times, such as on TV with normal soundtrack & then someone shouts & you jump to turn it down as it's louder than real life, the TV Monitor speakers aren't as Wide Range & Dynamic as Our amps. We said we get Intense on Upgrading, but that's not with Customer's Amps at all, those aren't for experimenting on, though you will get ideas from this Research into Upgrades as Standard once they are proven to be reliable & test well. Some Research Amps do get sold & to see the work and parts put in to only price it at a certain price for it to actually sell reveals the market is still growing on Rebuilt-Upgraded Hifi. One amp recently inspired us to go further with another amp for hearing that sound amid similar specs, so why not try to get that sound from this other amp. It worked & actually betters the 'best' by the same maker sold at the same time. Putting mid 1960s ideas into early-mid 1970s amps usually isn't possible.

High & Low Filter Controls On Amplifiers Are Often Very Poor.
You don't use them, us neither, so why bother writing about them? High Filter is a Low Pass Filter as it cuts the high frequencies & allows the lower frequencies through. Low Filter is a High Pass Filter as it cuts bass-rumble if your Turntable is a noisy one. But in Amplifiers, these are often very poor designs with ridiculoursly complex "Filter Amps" that clearly haven't got the First Idea how to do this right with it sounding good & giving enough cut to be worthwhile. Filter amps with 3 transistors, sound in & sound out is at the same level if mangled. Filter Amps with Large Resistors for the Signal to pass through do the Audio no good either. There is a "Perfect" High & Low Filter in the 1965 Sansui TR-707A. Low Filter goes through a limiting capacitor if the amp design is quite different so it will have Impedance differences if more typical amps can do this way also. High Filter is equally impressive, no limiting or tamed circuit, this simply uses a small value capacitor in an extra NFB stage to reduce Treble. Both Filters switched out impact the circuit in no way at all. No Limiting, no extra Transistors, just done intelligently. This is rare to see in any amp for either High or Low Filter. 1966 Sansui 500A filter was hopeless in comparison, the TR-707A designer is a Genius, the lousy 500A just disables the Gain half of Bass & Treble to fool you into thinking it does something in a Shop Demo with Tone added to deceive. the Valved Sansui 500A is a very mediocre Valve Receiver, almost like they didn't care about Valves by then, but the 1000(A) valve amp is an awkward one too.

Vintage Amplifiers With Silent Backgrounds?
This depends entirely on the Amp itself & can vary within brands. The 1965-67 ones can have a noticeable noise. On 95dB speakers this means you'll hear a low level hum & hiss just because of the early age. Some amplifiers can physically hum from the Transformer too & this was mentioned in HFN/RR into at least 1971. The Best Sony Amps such as 1968 Sony STR-6120 & 1965-67 TA-1120(A) have a very low SNR & the manuals tell you the 6120 on Aux has 90dB as "A" weighted whatever that is to alter actual readings, but the 6120 is as good as silent on 95dB speakers in the dead of night. The TA-1120 is remarkable for how early it is to have the same 90dB reading. The 1971 TA-1140 is even better at 110dB. Not all Sony are this quality, the STR-6850 EU type receiver wasn't the build quality of the 1969 STR-6150. Germanium Amps can be hissy if the 1966 Akai AA5000 surprisingly is very quiet & to estimate it's at least 75dB. The 1966 Akai AA7000 is not as quiet. The SNR noise level depends on the design more than the design type, the Transformer Coupled or Germanium amps can be noisier as they are earlier, if it depends on design. The 1966 Fisher 600-T is all Germaniums if well designed to get the best from the Germaniums with a very low SNR of at least 85dB. The 1965 Sansui TR-707A is mostly Germaniums but despite the great sound the SNR is pretty poor to the point it's distracting on 95dB speakers if we halved the hiss noise on one we did for a customer, the 707 manual oddly says Noise is "less than 70dB" which sounded more like 50dB on ours. To redo a Germanium Amp as Silicon is possible, but be sure it'll not silence it & there is a good chance of getting odd noises that need lots to sort, so this we'd only try on our amp & knowing the 1966 Rotel 100AMP didn't do very good if maybe we'll try more another time. An amp that is Hiss & Hum-Free with no Mechanical Vibration on pre 1970 amps is not the general standard, but the far nicer sound for a little noise is the trade in. Actually on removing all the dumbing down from the 2007 Marantz PM6002 it revealed some hiss just like any amp would do, it was only 87dB SNR as on the manuals & without their dumbing down it was more hissy than a 1970s Yamaha, progress there is none in Analog Hifi as it was just about perfected in 1965 by the Sony TA-1120 to get 90dB SNR that early. The 1973 Sony TA-1140 having 110dB SNR is very impressive, the TA-1150 doesn't mention SNR if the 1975 TA-3650 has the 110dB SNR. The Most Boring Sony we've heard, the 90w Sony TA-F550ES has Damping Factor of 100, THD of 0.003% only puts Noise as 0.9µV which is meaningless if also puts 108dB SNR on Aux etc. On MM Phono it has 77dB noise, MC is 95dB which makes us wonder why people bother with MM cartridges, the 1969 Trio-Kenwood with a MM stage was very hissy with 45dB as HFN reviewed it, clearly of little use with that much noise. Later Amps do 'cheat' to get better SNR by putting 2-Stage Volume Controls, some have an unexplained second one after a noisy stage like Tone or Filter, to avoid having to design the preamp to have Volume after all stages as designing a Preamp with Max Tone Level not clipping is far from easy. Most Amps put the Volume after the selectors & tame the preamp not to hiss so much which lessens the sound.

1977 Sony TA-F5A Amplifier: Any Good?
To try to find other good amps of this later era into the 1980s brings amps like this that look good, solidly made with some Luxman influence & Yamaha meters, but to then see the inside Photo the seller with one at £275 shows. 70w Amp for £275 today seems a bargain, but is it? Pulse Power Supply, much like what is in Computers etc of today, lots f circuitry that's "better" than a reliable Transformer is one we've not liked on seeing how Dangerous these earlier ones ate as with that Technics 1978 pre-power. To ignore that for the moment to see what else it has, oh it has ICs on the Power Amp Board with the usual 'rubbish' you see in 1980-s amps in a complex IC, interesting to see this is where it all started, if the Sony TA-F5 is the more complex version, no manuals to find. In one IC per channel it 'needs' 2 Regulators, 2 Differentials, Current Mirror & Constant Current Supply as two separate parts, Bias Circuit & Class B driver. Then in Transistors the bemusing Voltage Slicer & Stopper Diodes and Cascode Amp plus Current Limiter. why am amp needs all this Limiting & Controlling is a mystery to us, it sounds awful & the only 'Good' of it is to get pointless THD specs for the Hifi mags to say how much better it all is. Sony TA-F5A amp is a good looker of the era but filled with junk if it's not unlike Class B IC circuitry of today. The Seller says they have too many amps, this has spend much of it's time in the box & now they sell it sort of tells they don't like the sound of it so off it goes. The TVK site likes these sort of amps as they are more modern, but we see the Volume Control with an unshielded Ribbon Cable. Looking at the Preamp, the 4 Gang Volume Control is like ones we blogged above on, it has a Volume Control before the IC preamp & one after to keep the Hiss down, again to get the High Specs, 100k first one & 10k second one. All as far from the Hifi we like as could be. These later amps with several Class B stages & unnecessary Differentials are just Not Musical, they sound awful. Historically the Sony TA-F5A is Important as it shows where so many of the Ideas now used in Audio Gear & Power Supplies for TV & DVDs etc started. The Class B stages in ICs to use less power & create less heat. These Class B stages are on Computer Soundcards & they are designed to sound good with very low 105dB SNR Noise Floor, but if you try to play a Square Wave through the Soundcard & read it on an Oscilloscope, it shows the whole technology fails as the Square Waves are terrible. For Musical Pleasure, sadly the TA-F5A is one to avoid. Looking at our "Other Amps" page, we looked at this same amp in 2014 & thought the same...

A Nice Amp: 1972 Onkyo Integra 732 Amplifier.
To see an interesting amp but find no proper info is a shame. Beware the misleading power ratings. The 725 is in the HFYB as on our Amps page at 25w for £98 if clearly long before the brand was a mass market one. 1975-76 HFYB says the 732 is "56w max" if another source says it was reviewed in Apr 1972 if that's to be believed. Good looking Silver Face Amp, looks of good quality. The Top Cables connecting method suggest more 1975 as was used similarly by other brands, not a good look & the amp came with a black top cover with a clear window, so the ebay one in Hungary with warped walnut home-made case is what there is if you wanted one. Inside hard to tell if ICs in any stages if looks well built, but a bit of a gamble for no schematics. Actually HFE site has that 1972 review so to have a look. 59w 'beide canal' can mean 59w each channel, one channel played as per how other brands mislead, so likely it's 45w RMS both channels playing, as Trio KA-6000 is 58w misrated. The review shows Square Waves slanted as Bass will be limited, if it does test 59w, if all a bit guessing so 45w we'd consider is right. Another one for sale on a Vietnam site shows lots of inside pics, a bit random built if quality. Just too vague on the info, it's Made In Japan as another site says. The Hifi Info Sites have helped a lot with Manuals, if with this amp it's as vague guessing as it was in 2000 & we don't gamble that much with no manuals. The redone wood sides meaning the top lid is missing decides we leave it if to keep the pics if another turns up. Buying from countries like Hungary etc that you'd not consider for Hifi is actually fine, if the goods themselves can be a bit more aged & used, trade itself is reliable. ** Sept-Dec 1972 HFN/RR has ads for Onkyo. 25w RMS "725" is "70w max", the ad shows the 725 is "22w +22w one channel driven", meaning about 18w RMS both channels. Very confusing if the amp appears a good one sonically, "733" is 86w max so assume 25w RMS, if "732" is 56w max so assume about 14w RMS. Very misleading power ratings get people overspending thinking they are high power, the Sansui AU 999 is rated 180w in adverts at the time yet it's a 50w amp & fools appear to think it's worth £800+, see our Review of it. "433" Tuner & "M70P" turntable. Onkyo weren't good at selling their hifi or giving honest ratings so failed... 725 = 18w, 733 = 25w, 732 = 14w RMS both channels playing.

That's A Nice One Too: 1970 Luxman SQ202 Amplifier.
Inside rear cover of the July 1971 HFN/RR has this amp. Is it a receiver? No, the top row is lit wording for Button Input use. Not seen this one before. 80w+80w for £210 says the advert. Appears in the 1972-73 HFYB & by 1974 it's up to £267 which is for the high inflation then, if new range by 1975. One of those "we want one" amps if looking on ebay nothing & none sold in 3-6 months. Hifi Shark site shows one sold in Japan for £372 if the same one shows many times, to assume 'reserve not met' before 7 many others with higher & lower prices, the Japanese sellers are way overpricing, so assume £300 is about right for today. No Manuals easily found if usually these are the ones you need to buy the download. TVK site has it & they say what we thought, the first of the 'Classic' Luxman era after the rather basic earlier ones with lines of boards inside as the 1968 50w SQ1220 is. 70w RMS both channels is the real rating if still high for a 1970 amp. An Australian site shows them taking one apart & it looks well made inside & far from the basic early build style. Power Amp modules not unlike the 1975 Luxman L-100 which we found rather limited in space. The usual spec of the era does allow good upgrading though. Case has side wood posts as no full side cheeks or wood case. Certainly looks a good amp but yet again we are without Manuals as with the Onkyo blogged just above. Two interesting amps found on the same weekend, if to find ones to buy that are complete, the Onkyo lacks the top lid & the Luxman is a rare one.

April 2019 Blog

VirginMedia TiVo vs V6 Box.
We've had a 1TB Tivo Box for about 5 years, we were on the second box as it appears the Tuner doesn't last long & huge blocky distortion for a second ruining the picture is annoying. Try talk to VM & they are as bad as any other company now, they want to try to fix it or swap for the old 500GB box. You ring them up, they transfer you to the wrong department & the fight against people who don't understand English as well as the Call being dropped if on hold. Rubbish. Solution was to go to Account & see what upgrades you can get, a V6 1TB box with the 3.0 Hub for those who want to Watch TV from their Box on a Train etc, technology that will appeal to travellers, if likely 'TV To Go' is expensive & no interest to us. New 'Kit' as they call it arrives, not hard to plug in & be ready. Still based on the Tivo platform with no real differences beyond a better Remote Control. We're playing the Sony TA-2000F/3200F as blogged Pt 3 below & with the old Tivo the sound was a little loud on some amps if it was crisp & clear. The V6 box via the Optical Out appears to be about 5db quieter, it still sounds good but doesn't appear as upfront for being 5dB quieter. There is a 3.5mm Jack for audio out that we've yet to try. One thing you'll notice is the silly LED lights are way too bright especially if you see at night with no lights on, we just coloured them over with a Black Paint Pen to still see they are on but about 90% dimmer. Amazingly there are no settings to dim these lights, years ago VCRs etc used to purposely use dim lights to not show you had gear to catch unwanted attention, but VM clearly failed here. As for the picture, to have seen it do the glitch twice as of typing shows it's a VM issue in their system still, even adding Ferrites to the cables which did make the picture clearer, VM don't put any Ferrites surprisingly if their signal cables do need this. Interestingly it was found the Marantz 2385 that previously wasn't too great on the earlier TiVo box now sounded much better with the new V6 box, the 5dB reduction in level has brought more finesse to the V6 box despite the Sony pair having it sounding less impressive, but with the older Tivo it sounded better. Just shows how different Sound balance is, even from what you'd think is a standard digital output & we're still using our upgraded £10 DAC. Unfortunately BBC1 HD still records with the odd bit of picture distortion, three times in one 30 minute program, so it really is the VM system or a fault in the network or street box.

The Increasing Problem Of Bad Main Capacitors On Post-1977 Amps.
This we've blogged earlier about the 1977 Rotel RX-1603, the amp was likely stored in direct sunlight & dried the main Capacitor nearer the back. This time a 1985 Dual CV1460 amp sounded awful once recapped so to suspect Bad Caps & run it in for several hours which changed it's sound opinion from Average-Recommended to Very Good-Excellent. A huge jump in quality as the 1985 main caps were bad & not delivering the required voltage or current. So we take the old ones out & cut them open as pictured here. The caps are from 1985-87 so are 32-34 years old. First impression is they are still damp, not as wet as newer caps but not obviously bad. We probably 'reformed' them running them in for hours. You could probably use the amp, but you're living on borrowed time: The Caps Were Bad and are clearly well past their best if briefly "good" again. To get Bad Caps is either from letting them get hot from poor ventilation or possibly just not using for Decades. We've considered Main Capacitors still good in some amps into the 1970s with acceptable values, Yamaha, Luxman, Sony etc, but over the years we're seeing them start to fail more & a 1985 amp is a bit unexpected. A valve amp that gets daily use will have it's main capacitors losing quality after 10 years which matches the voltage-current-hours stats the capacitor makers give. Knowing that even a 1985 amp was bad means any Recap-Upgrade must include the Main Capacitors now. The big Yamaha CR-2020 with it's 2 non-standard size capacitors tucked away is probably the only ones that are still good. We have a 1973 Yamaha CA-1000 that was badly used with Class A & dried the amp out causing one main cap to leak, to match that size isn't possible now so we got 2 similar. The bad cap had leaked & was dry if not crusty & the other one away from the heatsinks was actually wet & good for years more use, but to cut it open to realise. Some of these big caps are £50-£80 to replace the pair just to buy inc VAT. For customers, to have them aware the big caps could need replacing is now required, if depending what the amp is like once seen & to at least try the rebuild-upgrade to see how the amp is.

Vintage Hi-Fi As Seen On TV: Phase Linear 400 Power Amplifier.
Good to see American Pickers Series 18 Episode 26 from 2018 have this amp featured plus a short Hifi section. Found in an eccentric guy's barns it's in useable grade, they haggle to $275 & value it at $550. All apparently without plugging it in or knowing if it works still. But to film them undo the case or hooking up to a Pre & Speakers wouldn't be good TV. The $550 value for a 210w Stereo Power Amp sounded a bit low, if actually Hifishark site shows that's a higher price & ones on ebay for $250 to $500. Be sure it'll need a full rebuild for the age, Mike himself says they make big money once "fully gone through" & way beyond just a quick service. Low price suggests it's an amp for the likes of us to get & rebuild, meaning that like 1965 Sony TA-1120 & 1977 Marantz 2385 they aren't that wanted simply as the rebuild is so high on these, if having done these & many more & having the 2385 on speakers currently, you certainly need to spend, but what you can get from them can be extremely good if realistically there aren't too many who will put £1500+ into an amplifier. Back to the PL 400, HFE site shows the range 200 with 105w & the big 700 with 340w are heavy hitters. What the preamps are isn't on HFE as only 1976 era earliest show when the power amp is 1970. What do you need 350w for? There are no 350w speakers, it's for driving multiple speaker rigs which were only 50w each at that time. PL 400 has a very high Damping Factor of 1000 which suggests it'll be a very dry & tight sound for PA work, rich Bass is not the thing as Heavy Damped amps damp the Bass. The Manual Shows the Rise Time is very fast at 1.7µ sec, we bettered that with the Sony TA-3200F upgraded & the Marantz 2385 upgraded was nearly that value. But it needs 1.7v to get full power so many preamps won't be loud enough so will not help the sound, Manual says 201w, big heatsink fins & the Schematic in the User Manual shows Tripled Output Transistors. The design has a lot of Diodes in it to keep it within itself, or to tame it which it admits to being stable into any load including electrostatics, 200w into a 50w speaker. Differential input after a high 10k signal limiter resistor isn't good, they are scared of it just as Sony were with the TA-2000(F) & 3200F pre-power. One on HFE says Diodes D1-2 get very hot, theirs needs repair then. Main caps are 5900µf 85v which are very high values for 1970 & will be huge items. Design looks tame, "rugged" design to put up with heavy use & not trash speakers. Ones on HFE using a 200w amp on 2011 era comments to use a 40 year old amp then, is way too risky. A type of amp that's not going to be what we'd like soundwise, wouldn't even trust a working one as a 1970 amp if rebuilt it will please some, but at 200w it's not an amp we'd go upgrading too much as it appears to need it's taming to get that scary 1000 Damping factor. We'd recommend it as a Collector's amp only, not one to use & that's why the prices are so low for a 200w amp, it's probably not very sophisticated & needs a full rebuild. The Phase Linear 700 with 345w into 8 ohms is worth a look. 0.01% THD & the 1000 Damping factor again shows the amp is overdesigned for specs & tamed if the fast rise time & Slew Rate of 11 volts per microsecond, if 350w is a way to climb. This time it has 5x Parallel Output Transistors with 9800µf capacitor value on ±100v HT. The Manual Bulletin tells of Transistors & equivalents if the SJ/MJ2741 are long obsolete & that other difficulties. Now you see why they are cheap, they're a Nightmare as too ahead of their time & lots of design changes through the runs. Does Mike still have his amp, those interested in these will consider them "leave it alone" as far more reliable ones in later years.

Is It Worth Spending To Rebuild An Amp?
We had a customer ask about rebuilding a 1970s Sony Receiver, the STR-7065A which is a rarer one as 65w receivers weren't selling in that difficult era. They pad £500 for it, a full recap-rebuild on all but Tuner will cost more than that. Is it Worth Spending The Money? On terms of you getting a 44 year old amp & risking failure, as of typing this April 2019 we are finding 1979 & 1986 amps are having bad main capacitors & the rest now being 40 & 33 years old really are getting old in terns of what you should trust using. Assuming you want an Amp to Use Everyday, then a rebuild giving upgrades & all-new critical parts
is sensible. You are then confident to use an amp you should get easily 20 years use from, not that this is a Guarantee, it's from knowing amps & ourselves being cautious to even try old amps in original condition on speakers, we'd certainly not trust our Speakers with a 40 year old set of capacitors though we do try some once serviced & tested just to briefly see what they sound like as blogged. We know many just buy a 1970s-1980s amp & just use it, not Servicing or anything, their risk & be sure these aged amps get problems sooner or later. The idea of just Servicing amps over 30 years old is money wasted really as it needs recapping & for the huge benefits of recapping, get it recapped if it's a quality amp. We Service the Amp on Rebuilding it anyway. It's quicker & more cost-effective to Recap an Amp than just Service as the amp needs taking apart in both instances. Then the Financial Aspect, is it worth putting money into an Amplifier & hope to see it's worth the sum of buy & rebuild? The market on that is still growing as not many recap & as far as we know, no-one offers upgrades like we do. We get amps to sell just to have a range of rebuilt amps to sell, these range from starter amps to more sophisticated ones & we see the work we put into these amps isn't always realised in resell value, if the margin is getting smaller. If you like the amp & want to get years of reliable use, then get it Rebuilt & use it without worrying it'll fail. Upgrading To A Sensible Price-Results Level. We don't put high price upgrades into amps we'd sell at £500 & to rebuild one similarly would likely cost the same or more than our sell price, so it's a bit of a loss leader. With customer's amps, especially ones we know & have upgraded far further than what we'd offer as an upgraded, these are priced to give the Best Improvement at a Reasonable Price. The Marantz 2385 as a raw aged amp has a standard value if working, the rebuild in our one & subsequent upgrades has value way over the price we offer at, if we don't expect it to sell & leave it there to show we can do these Monster Receivers, currently it's on our Speakers. Whether the Amp is then fully worth your Buy Price plus Rebuild Price depending on amp is close to a price we'd sell one at, ie a £900 buy-in & job may yield a £750 amp currently. But you're Rebuilding to Keep not turn-over & in a few years prices will only get better, we see our 2014 prices as rather low now & a little shocked at 2011 ones. With Amplifiers, we've done enough to price Rebuilds to give you a good value rebuild without going into doing more marginal upgrades that we know don't show as much for the Money spent as the "Standard" Rebuild. Example a Rebuild can give over 100% improvement on a working amp, if spending the same amount then going further upgrading may only better it by 20% which isn't Cost Effective. Be Aware The Earlier Amps Pre 1970 require deep complicated rebuilds as so much is old, to rebuild amps like the 1965 Sony TA-1120 & 1966 Akai AA-7000 are expensive jobs as so much needs doing. Summary. The rebuild costs on some amps does put buyers off, to buy a decent £500 amp & expect a £200-£300 job just isn't realistic. We'd not recommend a high rebuild job on amps that wouldn't give good results. You'll find those who'll service or repair it cheaply, but we've heard of those doing this & later send the amp to us & we see what awful jobs have been done. To think "Who Understands These Amps Now?" The TV Repair type has no idea as Tech of Today is about swapping boards. Rebuilding Vintage Hifi Isn't Cheap & these amps are only getting older, 1979 is 40 years old in 2019. We do Specialist Work that very few do these days.
This section was written for the Upgrades page if worth repeating as a Blog.

BBC "The Repair Shop": Glossed Over Sentimentality?
This is back for a 20-show run this month. It's an interesting show, if they do overdo the sugary sentimentality a lot, much like "The Antiques Roadshow" goes more for a story than goods sometimes, plus the BBC agenda that is notiecable. The Repair Shop has some skilled craftspeople, the Clocks guy, the two Teddy Bear women, the leather working sister of the Clock guy & others. They get brought in items that the owner has contacted the show about & they do get a diverse selection. The thing people don't realise with Repairs that the show really doesn't tell enough about is Repairs are often far more complicated, they show problems they get but not the many hours work & problem solving. The person doing the Repair is always shown as being 'delighted' to work on it, be sure there is a lot of grumbling having to work on such badly damaged stuff as it can be a Nightmare to get nice again. Doing Hifi is similar, the customer wants it working right & looking good thinking it's not a big job to do, much as the above blog tells. This series so far had a knackered old Transistor Radio that they should have binned & looked on ebay for a much nicer one, instead the tech guy had huge problems with it & did get another radio to cobble bits out of, the Antenna was too far gone & no way to know how to fix it. They cobbled together a handle, made the tuner dial from random pieces if left the tatty case. Piece of junk that works, value just about nothing, looks rough but the old guy was in tears with it as often "it's all they had" & put such strong emotions into it. The thing with Repairs is the item matters to the person, but these TV shown ones would cost far too much to get repaired, that Radio could be a £300 job to get going yet it's of no value. Another was a 1950s clockwork car, insides not made of quality to last so the guy had to design & make new pieces which the show had look like a 10 minute job instead of likely several hours. The trouble with cheaper goods is they can often be poorly made with compromises, frustratingly poor design & manufacture. UK & EU Amplifiers can be a real pain for this poor quality build. The hours work, the problem solving & getting parts to get Old Amplifiers into Use-Daily is a huge job, we've spent years working things out to make it easy, but doing the Yamaha CR-800 preamp stage the day before, it'd overwhelm just about anyone, bad circuit manuals & highly complex cramped circuitry would put any tech off working on it. But to plan & control the random chaos into a workable job & have the ability to check it's right after can be done & be pleased to have solved it. To look at some amps & think "You Horrible Amp!" for bad design & construction is quite common, if it's to be able to do the work to give a good Finished Product is what "The Repair Shop" glosses over too much, not showing the time & skill involved. the guy with that tatty radio isn't aware of the work as it was done For Free for a TV show. In our upgrades, you're paying for Parts, Labour & years of having solved similar problems plus our Upgrades that give a reliable improvement. Twenty Episodes is the BBC wanting more shows if you can see the joy is wearing thin on some of their faces, being told another story, two were seen not looking very interested. Still, that oil soaked Bear, "know what a bin is for" we thought but they revived a very dead bear into an old friend again. But what would that cost to do away from the show?

You Want To Do Hifi Upgrades But With No Effort To Learn?
One idealistic person messaged us looking to be told of a Book that tells all of what we do so they can do what we do without putting any effort into it. No reply to that... There are No Books, there are No Websites that tell as much about Hifi as we do. We never tell of the technical side as that is a person's Trade. You need to put 25 years & 200+ amps behind you, plus daring to try things well outside 'the box' to progress, before you'll understand what we do. Plus have "The Ear" to understand Good Sound that is only found in our Upgraded Amps to have a Reference to compare to. People are lazy & can't be bothered to learn skills, you buy on ebay & often see "Condition is Used" on Records etc when condition is important. They see an Unplayed Library copy made £75 if Discogs doesn't say what grade the ££ copy was so their tatty one is worh the same & there it'll sit for years. The Non Expert thinking they know it all is a menace to the buyer who expects a certain quality.

Luxman Valve Amp: Too Ambitious Upgrade-Redesign.
We have the 1979 Luxman LX 33. The design was terrible throughout beyond the three transformers. Because this is 'our game' to try to get it to be it's best which isn't quite done we notice & previously it took Three Years to get it to the current level. A customer with the 1977 Luxman LX 38 asked for us to redesign the thing from 110v to 240v & redesign to use less awkward valves. This is a huge amount to do & to get it right testing technically is possible, but remember our LX33 took 3 years on & off to get right. It's not really worthwhile going to change so much, the customer would be better off with a "starter amp" with the features & voltages as required & go from there. Yes, but what amp is there, you'd not bother with the Modern crop of Valves amps or even that EAR Yoshino one as they are all flawed from the start. People try to get transformers which usually are far bigger than the custom Luxman ones & end up making their Valve amp but it's not a tidy item. The preamp we used with our 100w Tube Technology Monoblocs was our 2nd Generation one we done in 2008, but now see it's not easy to take apart to do anything, so as we had 2 of the TT preamp chassis, a few years back started on building a better preamp that could be taken apart, but then it just sits in a drawer with no components fitted for the Phono & Preamp as realistically we'd like a LX33 4x valve board to start from & use that design. Good ideas hit stumbling blocks, our TT monoblocs haven't been used in years now since once comparing the Sony TA-3200F power amp & finding the Sony sounded better. Any sort of Custom Design Work takes a lot of time & fine tuning to get right, three years on the LX33, three years on the 1963 Trio WX-400U with both here at one time & getting ideas swapped amid both. We recently rebuilt a 1965 Rogers HG88 III that sounded really great as it's one we'd done in 2011 & just updeated with ideas found since. But to start from scratch on a bad design with awkward valves, not ECC83 & EL34 really isn't what we'd do for a customer as it'd cost a huge amount that really couldn't be estimated & probably be years to perfect.

Looking To Buy 1975-76 Era Amplifiers & Receivers.
55w Sony TA-3650 amplifier from 1976 & 50w Hitachi SR-802 receiver from 1975. Both known brands we've had several earlier models of. The Sony one we had before, if the mean seller passed of a flood damaged one that was junk as they knew & abandoned it. Workman type amp, nothing special or fancy about it, the big one capacitor is 2x 10000µf in one can, the trouble is we're finding amps of this age needing the main caps done & to do right means redesign, if it could be done, the thing might not look so great inside. Ones online around £150 if the auction one makes £83 delivered, we'd have to put a recap-upgrade into it & really only put £495 on it which doesn't really cover the work we'd put into it. The idea is to buy, upgrade & make a profit, not take a loss, so we leave that be. The Hitachi we liked their 1971 range if they needed a lot upgrading, here the SR-802 looks decent but sadly an IC on the power amp early stages for Differential & Pre Driver is no good to us. Again buyable under £100 but again there's not really a profit in it for the work needed. Some of the ones we have for sale continue this "not much profit" for the work done, so in some ways the quality work we do is outpricing the midprice amps. The days we could buy the better amps in at budget-midprice amp prices today is where we got many as this site proves if that is what has people putting too-high prices on "Raw" amps thinking they are worth "Rebuilt" prices. One customer with a boxed Yamaha CR-2020 that we did some work on if not a full rebuild prices it at fully redone price which is not realistic. Another Sony TA-3650 with a missing control knob thinks it's worth £100, who's got the missing part? Actually we do if it's too bashed up to consider that one. We keep looking for Interesting Amps if we've probably had nearly all the 1965-71 ones now.

Beware The Hype On Modern Valve Amps.
Actually beware the Hyped Power Ratings on Any Valve amp, they always are rated as "something unbelievable". One on ebay this month... "AudioValve Assistent 100 mk2 integrated valve amplifier 120 watts a channel" uses GU50 strange Russian Valves from the 1970s. These you can see easily are 50w on Wikipedia & other sites. 50w is all you'll get Push-Pull or 'single ended'. So where does 120w come from. It's nothing special inside, the PCB has 'Prometheus 100" naming. Several sellers on ebay appear brokers who put ridiculous prices on yet some just put one photo & very little info. Here 'audioprestige' put more info, but a price of £6000 for what we see is ridiculous. For 120w similar to our Tube Technology Genesis Monoblock that uses 4x EL34 to get 100w, where are the huge transformers, the 100 Mk 2 doesn't have them. Looks more like a 30w amp to us. These sort of amps seem bought believing the hype & soon sold at a huge loss, this amp with powder coated plain case & £5 remote control looks like a £1800 Made In China amp to us. These amps are always the same unadventurous rip-offs of the 1950s-60s valve amps, they don't sound very good & even with that EAR Yoshino we had recently, the designs are just not very good & have to be tamed.

May 2019 Blog

Don't Just Jump Wildly Into Our Amplifiers, Read Up First, Take Your Time.
The customer who asks about a rebuild on one amp, then thinks to get another, then we suggest ones of ours, they make a low offer & asks all the questions that the site answers for Buying really needs to Slow Down. They've not read anything & are seriously getting it wrong. We don't need unaware customers like that who will forever ask annoying questions & demand what isn't offered, so to say "Slow Down & Read The Site" so they better understand things needs saying. They have 30w Gold Tannoy 12" so they don't need a 100w expensive amp when one of lower power if similar quality will do the job, we see we are wasting our time here, 30w speakers they have. They are Wild & Unpredictable, to sell them an amplifier or do a rebuild is best avoided as they haven't bothered to read about what we do which no one else does, Rebuilds With Upgrades. If they did buy they'd forever ask weary questions that the site already covers & to regret selling to them, so we have to send them away to learn the subject better. Many would just sell the most expensive one to the inexperienced buyer & let them get on with their clueless games, but we want to sell you The Right Amplifier, similarly telling certain amps aren't worth upgrading to help you get what you really need. We try that person again to see if they calmed it down a bit, but suggest a modern 1992 Technics power amp with the big meters, that mass market IC junk shows that they really don't have a clue. We advised they sell the 30-35w Tannoys as they will just trash them with a 170w SEA-7000. You can't help 'stupid' & this person is just wasting our time. Thankfully most who contact us are better wised up to Hifi.

We Do Custom Upgrades, Not Like-For-Like
Hifi bought in a Shop is Always a Compromise between Cost & What is Good Enough. This is why Hifi Lovers forever search for "Perfect Sound" but will Never Find It as it's Not Offered at Any Price
. You see Recapped Vintage Amps online, but why do they sell it, beyond those who Rebuild-Restore to resell multiple amps. It's because it's not really that good as nothing is Upgraded, they just do Like-For-Like, ghastly Capacitor Stuffing etc & as they are disappointed, they want to sell it & keep looking for the Perfection that is Not in Shop-Bought gear. Only Custom work by one who dares to try further & ignore the "Grey Old Men" of the past & to question "Why" on seeing poor design will give you the sound you crave. Custom Work takes a lot of time to get right, to work out things that can be bettered on some amps took us 2-3 years on amps we got early on, like Sansui 3000A & Akai AA7000 from 1966-68. These ideas, now tried & tested we put a certain amount into Any Upgrade, if further Custom Work on our Own Amplifiers helps further what we can offer & keep our work Resonably Priced. We know people search in Vain for "That Sound" & never find it, but then they buy one of our Upgraded amps & as they may get one of ours we've Upgraded far more than an Amp bought to Upgrade & Sell, they've actually Found their Perfect Sound. It has taken Years for us to Upgrade to Find that Sound ourselves, using Headphones & Tannoy Speakers, the Best Amps can really be World Class & better anything you can buy at Any Price elsewhere. To see Bad Design-Dumbing Down in Hifi that is on any amplifier & correct it can be very difficult, we do 'Breadboarding' of sorts to get the right sound & then tech tests to see it's right to fine tune. To Upgrade right needs All Stages Upgraded, you can't just do one section thinking it'll solve the lot. This is what we have spent years doing & we get great results. Custom Work is possible to get the Best Sound out of many amplifiers, if those asking for 110v transformers upgraded to 240v ones will find no-one does this, even Transformer companies can't be bothered to work this out. Look online, you'll find some doing what appear Sophisticated Rebuilds redoing paint & casing. They brag about rebuilding boards & changing things, yet every single one we've seen totally misses the Real Upgrading Custom work we do. Try us.

Your Amplifier Is A Compromise, Dumbed Down & Poorly Designed.
The Harsh Truth of Hifi is most is just a compromise between Price & What will Impress you on first listen to buy it or decide to keep it. The more you listen, the more your Hearing Compensates for lackings in the Amplifier as you get used to it until you hear better. Further truth is some of our Favourite Amplifiers & Receivers are actually Nothing Special as Original & only come to life with our Upgrades, so don't all think the 1965 Sansui TR-707A is a brilliant amp as original as it's far from it & even upgraded to how ours is, it sounds wonderful if the background noise even without Germaniums is a bit high. We do tell that some amps are just that which is why we Rate as Original & Upgraded. Heavily Dumbed Down amplifiers we started to noticed with 1970-71 era ones, big name amps like Akai & Hitachi, these amps upgrade nicely with all the limiters sorted, but as original some are very average. The 1965-69 amplifiers are generally with the best designs if now too old to work right or be reliable for Daily Use, but they have been Our Favourites as they bring Great Results. These we've mentioned before, but Poor Design is just cynical, some amps have "rubbish bits" such as the 1971 Sony TA-1140 preamp & the 1970 Akai AA-8500 preamp. TA-1140 has a terrible spoiler in the preamp that we redesigned taking ages to perfect via Tech testing, it now sounds great. The AA-8500 we've had twice before & to know the problems but what to do about it as it's a complex 4-transistor design with a ridiculous high NFB. To sort that took getting the TA-1140 done so the AA-8500 gets tried next & brings success. But Tech Testing as in Sine waves & Oscilloscopes shows Poor Design on one stage we didn't alter, this is their design & it is just weak without giving a quality that it should, it clips assymetrically & this means all other transistor stages will get a poor signal at a level that is below Full Power on the Volume control setting, the signal at higher volume will start to flatten off & sound awful, in the mid 1970s Pioneer way that sounds dismal. Flattening off is the same as Clipping. Add to that Just about Every Amp Post 1967 Has Bass Limiting, the 1966-67 Pioneer even have a nasty "T" Bass filter that causes that unpleasant Retro Bass-Lumpy Bass which soulds awful on Speakers, the blurry one-note mess from Ringing. Reading the 1972 HFN/RR the LIndsey-Hood Amplifier is being released with the circuits & tests. The opinion is from the HFN lot is it's a great amp. To us, it's awful, Input signal goes through big resistors, heavy bass limiting, nasty Zener diodes & from reading HFN before, it has several later alterations done, yet people think it's a good amp? HFN has a heavy "Quad" bias, their ad is always facing the Editorial page yet from the circuits we see Quad are just dumbed down to make the ESL electrostatic sound good. All other people's opinions & we don't take too much notice of those "Grey Old Men" & the type of TV-Grade tech who insists the design is right unaware how Compromised it is. But the Good News is the better amps do Upgrade well, even ones with basic preamp ICs, the Bad News is no-one else has yet advanced into Hifi like this beyond us.

Your Amplifier Is A Domestic Hifi, Not A Studio-PA Amplifier.
If you've heard the Studio-PA type amp you'll have heard it's capable of being Very Loud without flattening off or sounding harsh when played Louder. A Clean amp with Huge Dynamics is a joy to hear but be sure you'll play it at home too loud & be the bother of Neighbours. Very Fast amps with Fast Slew Rate & Rise Time. We upgrade amps to max them out, because we can. Example the 1970 Akai AA-8500 is a bit too tamed for our taste if it is a great amp, it's too hard on the NFB giving a more polite sound that we aren't keen on. So we got ours & redesigned the preamp board totally to hear that Huge Sound again, if only on headphones, on our Tannoys it needs more work perhaps, if to sell it on rather than alter it too much. It has Doubled Output Transistors too & really is the only amp-receiver that does this beyond the 1965-67 Sony TA-1120(A), the Doubled-Tripled Outputs make the 150w+ amps of the later 1970s, if on the 1970 Akai it was as the output transistors they had were only 50w & they wanted a higher power amp. The Huge Dynamics are actually a bit Overwhelming as you're not used to such a big sound, it's a lot louder for the speed of the amp. Imagine if in 1970 Akai sold an amp like this, buyers would complain it was overpowering & not understand the big sound, much as the 1973 Yamaha CR-1000 receiver has a similar "too loud for Domestic" sound. This 'Big Sound' does need a lot upgraded to cope with it & an amplifier has to be of a good quality to take this redesign. The 1973 Yamaha CA-1000 we've tried to do similar with, but it's Filter Stage is truly awful, if the CR-1000 one is better if it brings up hiss & the silly FET compromise to lessen it. All Amplifiers are a Designer's Ideas at the time, sometimes Genius, sometimes almost Hateful of the job... look at how Sony changed their designs radically from each amp 1965-1974. These Somy amps as original all sound fairly similar, the Sony Sound if the designs are often completely different from year to year.

Oops! We Plugged A 110v Item Into 240v. Is It Dead?
We had a customer ask this about 2 Monobloc Amplifiers. There is no way to tell what happened. If it just blew fuses to try new fuses & see what happens. The customer said they did this & no life. Fuses in the Plug or amplifier will generally protect any Mains error as will a Circuit Breaker which we use on trying any amp the first time as it cuts out very fast. If it smoked or caught fire odds are the item is trashed, but Hifi usually has Fuses that will blow to save it. Fuses must be used correctly, a 3A fuse covers to 720W, a 5A fuse 1200W & a 13A fuse 3120W on UK's 240v. If you don't change a 13A fuse to the right 3A or 5A fuse you're not protected & your amp will fry, we had a 1969 Sony STR-6050 an amp that insanely has no fuses at all & it had a burnt out transformer as clearly the plug was a 13A fuse as was generally sold at the time. UK Woolworths in the 1970s sold 13A plugs but few bothered to buy 3A or 5A fuses or even the less common 3A plug, as they had no idea they were needed. We put the right fuses in plugs & after doing many amps we have over 100 old 13A fuses taken from plugs. 240v is twice 110v & depending on the item double the voltage & double the current will trash the item. 240v items plugged into 110v may survive a bit longer if could draw Double the current & get trashed. Today you see cheap electronics with Switching Power Supplies that say 100v-250v & you can plug them into any voltage. We're not keen on that as it can't be optimised for either voltage & using 110v or 240v is likely to burn it out faster, if today's Two Year lifespan of Electrical Goods & Phones means maybe it just lasts long enough in that Built In Obsolescense cynical way. A Burnt Transformer is very smelly as the varnished wires overheat & the smell as with the Sony amp will linger forever. To see if the Transformer is working or not takes easy tests by a Tech, not ones we'll publish, if it has voltage still odds are it's fine, but no voltage means the transformer is dead & we had this with a valve amp once to need to get a replacement transformer. You may have burnt out the power supply if the transformer has survived, but generally you have the gamble of a dead transformer with power supply damaged, or if you're lucky & your circuit breaker & correct fuse turned the power off, your item is fine, if you'll need time to trust it again.

Our Old Favourite Receivers From 1966-67 Revisited. Part 1
Fate nearly has Five of our favourite early Receivers here at once as of typing, the Sansui 3000 is the 1966 version of the 1968 3000A, the 1966 Akai AA-7000 is our first one we bought back from the customer, the 1967 Pioneer SX-1000TDF is almost the same as the SX-1500TF as we had one here only recently, plus two from customers, the 1967-68 JVC 5040U and National Panasonic SA-65. The Sansui 3000A & Pioneer are still findable in the USA if the earlier 3000 is rare like the other three receiver amps. All four once rebuilt-upgraded sound great if are different sounding as are all amps. A Severe Nerd-Fest on these Five really as they are ones we rediscovered & now others are now enjoying them, if be aware these all need an expensive rebuild as they are beyond useable really as so old, the money is well spent. Originally the Sansui 3000A we had ours three years, the Nat Pan we had two years, the Pioneer SX-1500TF we had about 18 months before old repairs caught it out, if today we'd not part it out so easily. Akai we had ours about two years if did sell it to now have it back after having one here to rebuilt & fancied a retry as we got the Akai AA-5000 amplifier. The JVC 5040U we didn't keep so long as the wood case was rough & the amp isn't the prettiest if the 75w makes up for it. All Fascinating Amps, all Great Sounding amps, but none 'perfect', but no amp ever is. In terms of Upgrading to our standards now, which would we keep longer to do more with? To hear them played as near together as a Comparing Session needs to be done, so that'll be Part Two sometime. We've got the SA-65 opinion based on the AA-7000, so once all tried to get more to tell.

Get A Nice Grade Amp That's Not Been Fiddled With.
The importance of that shown by getting one of our Favourite 1966-68 receivers again to work on for a customer. All rebuilt & upgraded it sounds great, but to have things meddled with sort of spoils the joy. Here it had been recapped badly with long wires left all over the place, untidy job, to just strip it all out & do it again properly as not worth risking trying it. Then it has a missing control knob as the balance must have got smashed & the potentiometer inside was replaced untidily. In transit the selector got broken through the front of the knob as it got a hit. They'd revarnished it badly with coloured varnish if again an amateur job. Then this person managed to lose the perspex type coloured sheet to give the tuner light the right colour and the red Stereo bulb bit. The wood case screws they used big wood screws as they managed to lose the original ones. Often amps that have been opened lack screws, do they not bag them to keep safe? The Akai AA-8500 on our Solds Gallery they replaced rear transistors & managed to lose the full width metal grille that covered them, so we had to put mesh to tidy it. The Joy of getting a cared for amp with all the right pieces intact, often ones untouched since new if some have had repairs & done correctly. Some amps you still get the Blanking Plugs & the old solder-type Phono plugs still there untouched from new, our current AA-8500 had these & to have a high grade one after having a less nice one really is nice to see. Some amps still have all the booklets & guarantees, plus shop receipts even. There's not really a Collector Market for these, if to have the manuals is nice to have to show some History on an amp as you rarely know anything. We'd rather get a nice grade outer with aged or damage inside as we can rebuild the insides, only when visuals are missing or tatty does it leave not much to do, we don't do cabinet repainting or veneering if can tidy to a degree. Lettering that wears off a fascia is a problem too as it was screen printed & ones like the Akai AA-5800 that lose the print haven't been well matched or cleared over, some that have the lacquer can wear off with a smoker's nicotine turning it soft. To put a good job into a tatty amp will get you a nice sounding amp still, but the looks will really only be what they are unless spare parts can be found or someone makes or refinishes the outer. Another Yamaha receiver we have here, the buyer got a bad deal as wasn't told of the broken antenna which had a loose wire that couldn't be refitted as part glued in, but amazingly they kept looking & found one on ebay from a parts seller so it's on the way. To find rare parts like that is pure chance, you might look years to find another as who'd part a Yamaha receiver out?

The Question of 4 Ohm & 8 Ohm Speakers, Power Ratings & Sensitivity.
In Theory an Amp rated 50w into 8ohm should output 100w into 4ohm, it's half the resistance so power should be double, but if you look at Amplifier Specifications, it's rarely this. "Why" is down to Amplifier design & the limitations of the Amp Spec, so you'll see some amps 50w 8ohm rated 60w 4ohm or even 40w 4ohm depending on the Amplifier. You'll read of extremely high power post 1990 amps Doubling, so 400w 8ohm, 800w 4ohm & 1600w 2ohm, but these are not really 'Hi-Fi' amps despite the manufacturers claims, they are just High Powered & Heavily Damped meaning they don't sound very Musical, if some think you need this power for Domestic use. An example on Speakers are Tannoy Gold 15"s rated 8ohm if 5 ohm nominal means the Impedance Curve dips to 5ohm. We've yet to find even the early "8ohm only" amps like the 1966 Akai AA-7000 having trouble, if we do know this amp doesn't like 4ohm speakers as it goes outside the design limits, we know exactly as that AA-7000 was our redesign & to use different voltages for the 4 ohm load it upsets the design balance we put in the amp. Many Amplifiers have Two Sets of Speaker outputs & some even have three, but these are wired to only use 2 sets, not 3. The Two speaker Amps often wire the Speakers in Parallel to not put a heavy load into the Amp, ie to push "Spkr 1&2" puts 8ohm in parallel with the second 8 ohm to give a 16 ohm load which won't be so loud, but it saves the amp for putting 4ohm + 4ohm together to get 8 ohm load. Other Amps add a 2ohm or 4ohm resistor when using two speaker sets. The Basic Idea is 8ohm speakers will be fine on any amp, they may match to give a great Tonal Balance or they may sound Unbalanced as we've mentioned on the Speakers page with many examples. 4ohm speakers need care for what amp you use & never try to run 2x pairs of 4ohm speakers from an amp unless the Manual says the amp can cope. If the amp sees a 2ohm load with 2 4ohm pairs it will likely overheat. 4ohm speakers have been around since the 1960s, as blogged before the Impedance Curve needs to be seen, as if the 4ohm impedance drops below 2ohm the amplifier won't be able to cope. Some Speakers as blogged before are "Notoriously Hard To Drive" this means they are badly designed & will potentially cause problems. We hear amps we sold KLH 52 & NAD 3030 which are decent midprice amps are struggling to drive 4ohm KEF floorstanders. To know the Model Number to see the KEF impedance curve could help, if both those amps are only medium power 30w & the dB Sensitivity of the KEF may not be the 95dB of our Tannoys & to push the smaller amps into distortion to get a louder volume suggests these amps & KEFs are not physically matched. To get a higher power amp will help, if ultimately the KEF specs need to be known. Speakers with 4 smaller drivers will not be the high 95dB sensitivity. Low Sensitivity Speakers. As an early example, we had a 1967 Sony TA-1120A when we had the Tannoy 605s & found the volume needed turning up high to get enough volume & this was almost at Full Power. The 605s are 87dB which is typical for the size, the bigger 609 are 89dB. These are rated 10w-90w & 10w-120w. The "10w" is the minimum needed to drive these, so no good for 5w Music Centres. With 95dB Sensitivity Speakers compared to the 605s you get 8dB extra gain. 8db is not far off Twice As Aloud (10dB), so see an amp gives 20dB gain add that to 87dB or 95dB to see the maximum volume. 87dB speakers are Strictly Domestic, 95dB ones are used in Studios.

The KEF C95 Floorstanding Speakers vs KLH52 & NAD 3030 30w Amps.
To see what the Customer is hearing in a situation many must be facing, to say "but have recently 'upgraded' to a pair of KEF floorstanders which are only 4 ohms, with both of my amplifiers struggling to drive them." We can play any amp of 15w or more with ease into our 95dB Tannoy 15" Golds we got in 2002, but they are a Top End Speaker that is now getting too expensive & even the later HPD ones are rising fast. KLH52 & NAD 3030 are midprice amps from 1970-78, the KLH the better of the two, the NAD showed it's 1978 cost-cutting. KLH52 puts out 20v Clean Sine as we read, if didn't rate the NAD if 30w is typically 20v output. We don't rate into a 8ohm resistor as no speaker is an 8ohm flat impedance. KEF C95 are 1988-91 says HFE, 3-way driver rated 90dB. KEF have been around since the late 1960s in the Hi-Fi Mags & are a Popular Brand with Better quality goods from an overview of the 1970-80 era. These can be Biwired or Bi-Amped, neither of which make any difference, the cohesion of one cable driving the speakers as designed is always the best idea, to avoid colouration by ringing, by leaving a big range of the sound unused by the speaker in Bi-Amping seems a strange idea, if good for Cable Sellers as you Buy Double. The last smaller sized driver speakers we had were the B&W CDM 1NT, sounded good loud, but too thin quieter & needed 1.5 "notches" up on the Sony STR-6120 when we had both around 2003, suggesting the Sensitivity is low, raking through the manual online shows they are 88dB & need 50w minimum. KEF therefore should play 30w amps with ease to a decent level & including Tone Control, but the 4ohm load is the added difficulty. NAD 3030 specs rate 30w into 8ohm & 50w into 4ohm & even rate 60w into 2ohm which is unusual to quote, but show the NAD should cope well. KLH 52 has the specs as 30w into 8ohm & 38w into 4ohm, this should cope well into the 90dB KEF. The KEF C95 manual suggests 10w-150w 8ohm & 20w-250w on 4ohm input in the specs. This seems typical, 10w minimum to use the speaker is an easy load for these 2 amps to drive. No Impedance Curves findable if other KEF look 'easy loads' to drive. The only question is how large is the room & how loud the owner wants to play music. Speaker & Amps should give a good volume but not "Party" level. The Quality of the Amps is another thing, both KLH & NAD aren't Top End models & to expect a confident sound up loud where the volume is likely at 12 o'clock or higher means you're just playing the amp too loud so it goes into distortion, flattens off & sounds rather unpleasant. We've done tests with 20w Sansui 400 from 1967 together with 100w Sony TA-2000F/TA-3200F & once you crank it up louder, the 20w amp just can't cope past a certain volume level, when the 100w amp gives that extra, even on 50w speakers used carefully. For most Domestic Uses you don't really need more than 40w-50w in a typical UK sized room, if you have a Huge USA Basement then you'll need 95dB speakers plus the 50w amp to do justice.

Four 1965-73 Amplifier Phono Stages Tested.
To try these amps for their Phono stages using the amp & play on Headphones. All amps have been recapped & upgraded. Similar tests as on the Turntables-Phono page, to use our Technics SL-120 & SME and Goldring G-850 that suits Mono vinyl well as it's a 1970 cartridge using a Conical stylus. We need Treble Gain on all amps, if leaving Bass flat plus Mono switch. The Four Amps include 2 we have for Sale currently, 1970 Akai AA-8500 and 1973 Trio KR-6340 as a customer asked for a compare & to add the 1965 Sansui TR-707A and 1973 Sony TA-1140 to give a better comparision. To pick two 1960s singles to test with, Loud Cut ones need a good Phono stage as per the earlier test. Tracks we choose from stock: 00165 Cops & Robbers 'Just Keep Right On' a midtempo track that has a 'recorded live' sound & 00272 Peter Fenton 'Small Town' that is recorded loud with high treble to need good resolution. The Reference is our own Valve Phono design in the Luxman LX33 that resolves these tracks beyond any Domestic Hifi. So to try the Sony TA-1140 first, the C&R one sounds nearly as detailed as the Valves, similar on the PF, both sound very decent for a Transistor amp. Depth & detail not as deep as Valves but impressive. Further compares suggest this amp isn't true to RIAA as it's too Trebly, perhaps it's been altered if we've not taken much notice of the Phono beyond recapping. Sansui TR-707A next, this is similar to the Sony if detail is better focussed on both tracks, it's also a bit upfront lacking some depth & sweetness to the sound as confirmed playing a few other 45s. We remember the Fisher 1960s Phono stages were similar, a bit hard if detailed, making Headphone listening less pleasing than the Sony here. Again this doesn't sound like a True RIAA Phono stage, it's more trebly & seems peaky on midrange. Now the Trio KR-6340, a 4ch amp if Phono is 2ch if has 4ch decoders. After the upfront 707A sound this is less defined, upper bass a little thick compared to the Sony sound. Not a bad sound but a little blurred on resolution that loses the PF record's bright trebly sound. Akai AA-8500 next, similar sound to the Trio. Phono is better focussed than the Trio on both records. This is more true to RIAA as is the Trio. Conclusion. The Sony is brighter on Phono & from playing many amp Phono Stages this isn't strictly the RIAA sound curve as treble seems about 5dB brighter than typical amps which the Trio & Akai are more like. To us RIAA is less trebly than the 'Sound' we like, our Valve Phono is designed to a sound we like that suits 1960s Vinyl. The 1960s Phono stage on the Sansui is found to be a bit hard. Phono Stages do vary a lot in Tonal Balance, they all Claim to be ±0.5dB accurate to RIAA, but in NFB Phono Stages it varies a lot on the design. Even heard from a Hifi shop dealer saying post 1972 records have Different RIAA, which is true in the idea there is the first RIAA from about 1954 & an 'improved' one that gives a slightly different response more suited to later records. RIAA EQ has always been a rather varying sound on Amplifiers. Oddly an earlier section on the Sony TA-1140 said we thought it sounded dull which the TA-2000F stage does, perhaps the TA-1140 has been altered to sound brighter? In General the Tonal Balance can be sorted with Tone Controls, the Qualifier in a Better Phono is how focussed the sound is on playing detailed music. Phono Stages are very varying & from trying on a Sony STR-6120, to try to get the Valve Sound as our MP3 samples on the Sales Pages show, to design Transistor that good is very hard & we've not tried since which was about 2003. Design Values. The Akai uses a typical EQ circuit that is familiar from later amps, the 0.0068 & 0.0022 are commonly seen. The Trio uses Phono for Tuner, Phono & 4ch Matrix with non standard values. Sony uses very similar value to the Akai so has to be altered to be that Trebly. The Sansui values are very different. The Akai balance is more true to RIAA & would suit users of later amps better, for a more familiar sound. These values can be tweaked to the sound you like by experimenting.

This Continues with July 2019 on a New Page HERE.