Accuphase Factory Tour

[knobtwiddler]

The firm started out as a Kenwood spinoff and has been going since 1972 - Wiki page: https://en.wikipedia.org/wiki/Accuphase

https://www.youtube.com/watch?v=upvfySyKRDs

Moments that stand out to me:

They seem to tolerate mild cosmetic imperfections… Unless something’s lost in translation (or my comprehension?). Every OEM will have a particular bar in this regard, but I am surprised at the openness of the discussion.

The amps appear to be highly traditional in their design, with toroidal transformers and class A or A/B operation (in contrast to many of the highest spec amps out there today, which are often class D types, fitted with SMPS)

Their test kit seems to be standardised across benches, mainly comprising a Kenwood scope (my Kenwood has the sharpest trace of any scope I’ve used) and Panasonic distortion analyser. I see no test kit that was made after the late ‘80s.

The firm is obviously doing good business. To my knowledge, the cheapest amp seen in the video is about £10K.

The components are fitted to PCBs at another facility. This one (and its surprisingly high amount of staff, if you consider that household names such as Sony, Technics and Nikon no longer manufacture anything in Japan) could aptly be described as a ‘screwdriver’ operation – fitting premade assemblies and testing them.

If you agree with Peter Baxandall's assertion that by the late ‘70s decent transistor amps were impossible to discern from one another when operating within their linear region, then the somewhat perfunctory test gear and old-school topology tends to paint the firm as a ‘Rolex’ outfit. i.e. their product may not necessarily be more accurate than a Casio, and they trade off the engineering quality. Nowt wrong with that, if you can afford it!

I can empathise with the fellow banging his amp up and down on the table whilst squinting at the scope!

[Craig Sawyers]

At one stage in the last 20 years I owned an Accuphase T100 tuner. And a thing of beauty it was too. Some of the illumination bulbs had blown, but someone was making LED replicas in the correct colour and physical size. I think I bought them from an eBay seller, but can't swear to that.

Eventually sold it to a guy who was trying to complete his Accuphase set up. For a surprising sum of money - a factor of several what I paid for it. He certainly drove quite a distance to collect it.

Thanks for the link - that power amp was built like a battleship. Given the monster size of the heatsinks I suspect it was Class A

Craig

[lesmw0sec]

Ye gods - did I just read 10K for an amplifier? The phrase 'fools & money' spring to mind.

[paulsherwin]

There are plenty of high end amps that cost a lot more than that.

[Craig Sawyers]

Originally Posted by lesmw0sec

Ye gods - did I just read 10K for an amplifier? The phrase 'fools & money' spring to mind.

That is loose change by comparison with https://www.dandagostino.com/products/relentless

Over a quarter of a ton weight for each

At £300k. Each. Times 2 for stereo. And £170k for the preamp

Craig

[Radio Wrangler]

Originally Posted by knobtwiddler

.....Sony, Technics and Nikon no longer manufacture anything in Japan

Nikon, by the way, make a thing about their highest performance range of equipment being made in Japan, and that includes some current camera bodies and lenses. This includes making the electronic sub-assemblies in these things. The UK Nikon Owners group organise trips to Japan for factory tours every year or two. They also make wafer-steppers and optics for semiconductor manufacture/assembly.

The deciding factors seem to be products which require skilled human hands for critical processes, and/or low turnover which would make the work in transferring maufacture to another country uneconomic. The Kensonic-Accuphase amplifiers likely are steered similarly.

David

[knobtwiddler]

Are you sure that info is current re: Nikon? My understanding is that they no longer make any bodies in JP since they discontinued the 35mm film camera a few years back. Some of the big-aperture lenses are still made in Japan.

TBH, I am a massive admirer of Japanese manufacturing. I would be happy to be contradicted re: Nikon.

[knobtwiddler]

According to This Link their $52K p/pair monoblocks generate around 0.0015% (-96dB) THD into 4R @ 10W. The 1978 Hitachi amp shown in my avatar (it runs warm, as the cat can attest) can be found for under 1/100th of that if you know where to look. Using the same machine as Mr Atkinson in the above link, I got 0.0005% (-106dB) when driving 7V into 4R with the Hitachi.

[paulsherwin]

Fundamental transistor amp design progressively settled down throughout the 70s, and by the mid 80s they were indeed all sounding very similar, even at the budget end of the market. Some people do just like to own expensive things though.

[Radio Wrangler]

The D6 is still current as the Z9 can't do some of its fast sports tricks and low-light work... and mine is clearly marked "Made in Japan"

I expect the gang may have a trip out there next year, so updates then. The top spec lenses rely on hand finishing to shape the elements as well as selective assembly. Their prices assure low turnover.

David

[Craig Sawyers]

5ppm distortion is impressive in a power amp. What frequency was that at?

Craig

[knobtwiddler]

1KHz 20Hz to 20KHz BW (same criteria as Atkinson's test I believe). It was into a straight 200W resistive load (Arcol resistors). I made a video of the test, as I couldn't believe a 1978 amp could perform that well. I dare say its performance wouldn't be as polite at higher levels, but my speakers are efficient and nerding out with power amps is a luxury activity, so I didn't take exact figures for higher levels.

The late 70s was an interesting era for battleship hifi, with Japanese titans fighting it out for the best specs. Some of the components from the era would be better than those available today, i.e. the Alps pots used in the Sony pre-Esprit range are trimmed to have channel matching within around 0.1dB. You will need a stepped switch or relays to get that nowadays.

[Craig Sawyers]

FWIW I have one of these https://khozmo.com/product/stereo-with-input-selector/ with the 64 step relay ladder attenuator, XLR balanced.

And a thing of beauty it is. The custom remote control is so hefty I swear you could drive nails with it.

I have been through a range of "passive preamps" over the years. Basically a pot in a box of varying degrees of sophistication. The main thing is that, leaving aside phono cartridges, an active preamp normally attenuates the signal on its way to the power amp; so it is not really an amplifier at all, it is an active attenuator.

The thing that active preamps are good for is providing a controlled and low impedance drive, whereas any passive preamp/attenuator has a higher and varying output impedance (or more accurately resistance). So a passive attenuators are more sensitive to high capacitance, or longer, connecting cables.

Back in the day, a preamp was really a control amplifier, incorporating balance, tone controls, filters, tape input/output, mono/stereo switching etc. Nowadays an active preamp tends to minimisation with an input switch, a volume knob, and occasionally a balance control.

Most, or all of which, you can do passively.

Soapbox mode: off.

Craig