Rega IO Amplifier Teardown

[restorer-john]

Do you know of any comparable measurements that show such as most measurements I remember from magazines of the day didn't show any such trends?

I have the actual HiFi Choice reviews here for the two amplifiers concerned. I could scan them. There's full 8/4/2R single and both channel tests in most cases. More comprehensive than anyone does these days.

 

[thewas]

I have the actual HiFi Choice reviews here for the two amplifiers concerned. I could scan them. There's full 8/4/2R single and both channel tests in most cases. More comprehensive than anyone does these days.

For which exact amps and do they confirm this statement?

In reviews and measurements of more recent Rega amps I rather see them collapsing at complex loads compared to other amps, see the "power cube" charts below:

https://studio-hifi.com/images/2010s2d-AUDIO%202017%2004.pdf

https://www.tad-audiovertrieb.de/sites/default/files/220_transistor-vollverstaerker_rega_elicit_mk5_audio_2022-09_lowres_pdf.pdf

https://www.tad-audiovertrieb.de/sites/default/files/rega_io_-_audio_10-20_-_test.pdf

 

[restorer-john]

For which exact amps and do they confirm this statement?

We were talking about the vintage JVC amps as mentioned a few posts up.

 

[thewas]

We were talking about the vintage JVC amps as mentioned a few posts up.

The questions though remains if this can be generalised to other Japanese amplifiers and if Rega or generally British ones costing similar were better, which I personally doubt. To me such stories remind me of typical anecdotal Hifi dealer myths that Yamaha amps sound bright etc.

 

[restorer-john]

The questions though remains if this can be generalised to other Japanese amplifiers and if Rega or generally British ones costing similar were better, which I personally doubt. To me such stories remind me of typical anecdotal Hifi dealer myths that Yamaha amps sound bright etc.

Personally, I would say that around the era of the JVC units we were discussing, pretty much all Japanese brand amplifiers were significantly better in just about every parameter.

I've worked on and tested more gear from that era and into the 1980s/90s than any other era and UK made stuff was pretty ordinary at the time.

I'll try to get some time to scan a bunch of reviews Japanese and UK from that time so people can see themselves the inconsistencies in 'recommended' vs not.

 

[DSJR]

Do you know of any comparable measurements that show such as most measurements I remember from magazines of the day didn't show any such trends?

I simply don't have the time to scan but if you can find a mid 80's 'Choice book of amp tests (there were several) authored by Martin Colloms, you'll see tech measurements (the first Choice amp book (not Colloms) had graphic distortion plots showing many with rising THD and IMD artefacts with increasing frequencies going out to 100k I seem to recall without digging them out. Current output was also measured and it's this that showed up the weaknesses in the cheaper models. Sadly looking back, the subjective side took over more and more and increasingly, US valve such as ARC, Quicksilver and CJ and some solid state (Krell obviously) became the reference, sinad in the former seriously low and 2 ohm drive in the latter seriously high In fairness, Martin Colloms' reviews were often written where 'characterful' but market-popular products such as Naim were pretty fairly described but not criticised as they would be here. I suspect JA walks a similar tightrope in Stereophile.

One thing that comes out in many of the 'Choice tests is that what 'we' would call neutral performance is their 'thin, 2-D and lean toned' although two Sony ES amps which look to be beautifully crafted were hammered for their disc inputs - you need to see the sources and speakers used in the preface.

Back on topic, I wonder how this Io amp would perform if laid out in a wider case as Rega's older amps were, transformer and power switch on the left, output stage and heatsinking in the middle and input stages on the right along with selector and volume control? Rega do follow their own insular path I must say...

 

[thewas]

One thing that comes out in many of the 'Choice tests is that what 'we' would call neutral performance is their 'thin, 2-D and lean toned' although two Sony ES amps which look to be beautifully crafted were hammered for their disc inputs - you need to see the sources and speakers used in the preface.

The problem of such reviews is that these typical sound descriptions were never verified in blind listening tests were suddenly those "cold" Japanese amps sound the same as well engineered (so with high enough damping factor and low enough distortion) ones from other countries which were supposed to sound more "musical".

 

[DSJR]

The questions though remains if this can be generalised to other Japanese amplifiers and if Rega or generally British ones costing similar were better, which I personally doubt. To me such stories remind me of typical anecdotal Hifi dealer myths that Yamaha amps sound bright etc.

Such was the market in the 80's, the only Yamahas that were tested seemed to be the cheaper ones and in fairness, they didn't do badly at all, but yes, I recall the 'tone' was deemed a little 'bright.' In the 90's, I was given a mint CA1000mk2 that I sold to a gent in '76 who became a friend. Got to say I found it a bit underwhelming to listen to music through (I was using AVI pre-mono's by that time shortly before going fully active - the CA1000 didn't work well as a preamp driving several metres of cables to remote amps sadly, at least not for me. To further muddy the water in terms of vague and untrustworthy subjectivism in audio, a friend's CA800 sounded lovely used in Class A mode (better reproduction of reverb and venue atmosphere) despite the low power output.

As I've said before with great sadness, the later top-model far eastern products rarely found their way to the UK. Luxman went through bad patches and by the time they turned good again, they were all but gone from these shores until a few years ago. Accuphase has some form of distribution now after being basically 'one man with a fat cheque book travelling to Germany' to load up every so often I gather) The new Technics amps got a 'Meh' reception and not sure how many higher end dealers stock and demonstrate the Yamaha models over the 801.. And still ARC bring out an ever more expensive 'Reference' preamp every eighteen months or whatever when a single or dual op-amp and simple clean power supply can do better technically This is before looking at the new Schiit Kara model which is very interesting to me.

Not comfy here, still straddling both 'schools' of subjectivism and objectivism. In my case, thank the good Lord for the used market which has all but killed off the lower to mid market here I mean, talking of Yamaha, I wonder how well a 596 amp with similar power amp chassis would compare to a current 701 or 801 for example? I remember one or two of the c2000 Technics integrateds 'sounding' very good indeed when brought to the dem room for a speaker purchase and I had a MASH CD player of theirs from similar times which 'sounded' absolutely fine and was a delight to use and see working (Philips based drive but super smooth drawer assembly).

All this crap I'm spouting just shows how bloody flawed subjective vibes and memories can be as time and learning can modify all these old impressions!!! If I/we knew than what I/we know now

 

[audio_tony]

We sold dozens of the JAS11G I remember and the JAS 22 model was 'recommended' in a group test book.

Back then, many of the *cheaper* far eastern amps were rated as powerful, but no current seemed to be there the more difficult the load became. The subjective result with music was a thin weedy tone into real speakers.

Looking back, some other far eastern models were very good indeed, so maybe I'm criticising the bottom-barrel models that we seemed to have in the UK. Our way became the tone control-less amps where the money saved went into the power supply and the traditional full feature amps became less and less I remember.

D

My JAS22 had no issues driving a pair of Realistic Mach One's when I did a disco for my Mum's girl guide troop in a large hall.

It could in fact go alarmingly loud with no loss of "drive" - bass remained firm and loud.

This particular amp used the much maligned STK modules (STK 0050) which in this case were a 'darlington power pack' the rest of the power amp section was made up of a conventional input pair etc.

The phono stage wasn't half bad either - and this essentially was only a the next model up from absolute budget if my memory serves me.

It had the added delight of VU meters too!! Decent tone controls (they only allowed for +/- 6dB adjustment) and a good range of inputs.

Far superior to any British offering of the time, and inherently more reliable too, compared to the so called "high end" offerings from Naim and Exposure.

And let us not forget the much lauded Crimson Elektrik amps of the period - which were British made but based on an up to date version of the original RCA design (and essentially the same topology as most Japanese amps of the time) - and yet the Crimson amps were highly praised! Why? Because British!!!

The UK HiFi press had the same attitude to Japanese turntables - the direct drive turntables that supposedly suffered from 'cogging' effects (and 2 decades later, Origin Live +others now claim they're magical..) - and of course the Linn Sondek was THE ONLY turntable to own - nothing else would do...

Back then, the UK HiFi press was hugely responsible for the spread of misinformation - and those magazines that went out of business deserved everything they got.

I have in fact just dug out a 'HiFi Review' magazine from 1987, where they compared a NAD 1300 / 2600 pre power combo to an Exposure VI/VII/SUPER VII and Naim 62/HICAP/90 - needless to say - the NAD was not well received.

I had the Exposure VIII power amp for a while - it was nothing special compared to my NAD2200 and Rotel power amps I had at the time.

P.S. apologies for the long post.

 

[DSJR]

This is where the whole blasted 'musicality' thing crops up and that review amp choice was a bit of a mess really for various reasons. Best stay shtum on that though

 

[thewas]

I mean, talking of Yamaha, I wonder how well a 596 amp with similar power amp chassis would compare to a current 701 or 801 for example?

I doubt anyone would be able to hear a difference between then, I had recently both an older AX-1070 power beast from the 90s and a current A-S701 and they both had no "sound signature" as any decent amp should be.