Rega IO Amplifier Teardown

[DanielT]

You mean by not specifying any distortion, noise, or really anything other than wattage?

I had not bought an amplifier without the manufacturer specifying level of distortion, noise.I had asked myself the question why it is not specified.I think the answer to that question regarding Rega IO can be found in your review.

With that said, Rega is not doing anything illegal. Perhaps cowardly not to specifying distortion, noise but not illegal.

I suspect that Rega probably knows its performance but do not want to report it but think that it is enough that the brand Rega itself sells. So maybe it can be?

Or Rega just ignore creating an amplifier with sensible levels of distortion, noise.

Developed construction in a hurry due to ...

One can speculate, but in the end of course I do not know the reasons why it came about that this IO turned out the way it did and yet it ended up on the market.

Edit
Additionally, I wrote this in the sister thread about IO
More information before a decision to buy is good so it is great that Amir tested IO.

So I really appreciate you testing what's related to HiFi.

 

[pseudoid]

I had not bought an amplifier without the manufacturer specifying level of distortion, noise.I had asked myself the question...

"...I won't bother unless those specs come from the trusted lab-bench of some dude w/glasses named @amirm?"

 

[DanielT]

"...I won't bother unless those specs come from the trusted lab-bench of some dude w/glasses named @amirm?"

Even better of course. However, if a manufacturer specifies something ( it does not only have to apply to Hifi) the manufacturer is aware that what is stated may be tested to see if what is claimed is true.

If car manufacturer X claims that the fuel consumption is Y, then it should all be Y (given accepted margin of error). By the way, I would not buy a car where the manufacturer does not tell you what the fuel consumption is.

 

[sarumbear]

Tracing the origins, design based on 'Wireless World magazines dating from the late 40’s to the 70’s'.

Transistor amplifiers in the 40s?

 

[restorer-john]

Transistor amplifiers in the 40s?

It's all a giant conspiracy. They existed (in secret).

Marty took a bag of modern transistors back in the De-Lorean and gave it Bardeen, Brattain and Shockley at Bell Labs in 1947. They fast tracked "their discovery" so Steve Wozniak would eventually build the first Apple in his garage and Elon Musk's mom planned it all so when he grew up, he'd become the world's richest man and eventually send humans (back) to Mars.

 

[sarumbear]

View attachment 162858

Why are those horns facing back? And, they are too close together. Staging will suffer.

 

[EJ3]

I request you fry some bacon and eggs on it.

Hashbrowns too!

 

[pseudoid]

I recall the '70s derogatory terms "Japanese Watts" after the HeathKit craze died out.

 

[DSJR]

May I suggest that 'Japanese Watts' was more about higher voltage output with feeble current. Into the 80's newer wave of 4 - 6 ohm speakers with all manner of reactance. This is one area where many UK amps could perform better, even if THD, IMD and so on went out the window,

Just to refresh our younger readers as to what was thought acceptable forty years ago - an early 80's HiFi Choice test on the UK-revered Naim 32/250 (could have been the small SNAPS preamp supply) had distortion at rated power into 8 ohms as -80dB, and -63dB at 20lHz. IMD (19 + 20kHz) was a mere -69dB. Just think what fun Amir would have tearing into one of these sets fully restored? Modern Naims are around 10 to 15dB better (and in my opinion, 'sound' a bit cleaner for it) according to Stereophile, but still....

Restorer John may remember this, but the same 'Choice book' tested a Pioneer PM 44 which measured well with claimed poor sound quality and in another issue, the two Sony ES integrateds (a 500 and 700 I think) sounded poor apparently (loose bass was one criticism). I'm starting to wonder if even by this time, reviewer ego and personal tastes were starting to heavily creep in to the judgements, unless some measurements were being left out. the followup test book left the IMD distortion figures off the reprinted Naim review for example. While I have the HFC 'Issue 50' here, the Io's distant ancestor Naim Nait (15 - 20WPC and now a quite valuable used collector's item) measured distortion at rated power as - 20Hz = -66dB, 1kHz = -72dB and 20kHz = -51dB. IMD at rated power 19/20kHz was -70dB and -52dB at '0dBW' on the phono input (RIAA was all over the place, but intentional I think and worked with the crap cartridges we used to sell back then, all with lf lift and presence suck-outs).

A Creek 4040 which in price is where the Io would be if made back then, was worse. THD ranged from -60dB, -69dB (1kHz) and -51dB at 20kHz and IMD as mentioned above was -57dB and -27dB on the phono stage, not that the latter figure mattered overmuch with the cartridges used as said above.

So, with that kind of UK spiritual ancestry, I honestly think the Io isn't 'bad' at all

 

[pseudoid]

Restorer John may remember this,

I refuse to acknowledge your assertion about the 'bad-hair day' (every day) Restorer-John being an old-fart like us.
My understanding (of what "Japanese Watts" stood for) was that they were playing the old "grosser schwantz" game and fudging the means with which they tested for power output @3% THD (<<I think and if I am not mistaken>>: rather than W/ch@1% THD).

 

[DSJR]

Not as I understood it (and restorer John, while perhaps not as old as I, knows the 80's and 90's far eastern amps far better than I believe anyone in the UK does now as we saw so few of them due to reasons already given!). I remember Sony ES models gradually thinning out each year and getting ever cheaper as the early 90's progressed. For us independent dealers, the requirement was to sell the entire range and not cherry pick as we could with Denon and even Yamaha for a time. That's why only the big chains often had these brands and even then, maybe not the top models which probably had to be ordered from Germany, the main European centre for such products I recall.

OK, do you remember the thread recently about an inexpensive Denon amp which claimed reasonable power but sounded a bit 'weedy' in practice? I can think of quite a few lower cost amps that could give good power into an 8 ohm resistor but fell down somewhat driving loudspeaker loads which were beginning to dip too much towards 4 ohms even then (late 70's onwards), probably due to marginal power supplies and over-ambitious specs as you mention above. Their top models could do very well for example and the Yamaha receiver shown tested in the proper Io test, was a seriously good 'sounding' receiver in its time and I sold a few of these, as well as the CR800 and fondly remembered if over-the-top CR1000 and the integrated amps related to these. Didn't like the *10 and *20 replacements though for some reason but that could be subjective only vibes here (the flip switches weren't as nice ).

Staying with Yamaha, one of their smaller amps (AS301) I'm certain claimed 100WPC in the UK site puff. Some delving showed this was at 10% THD. I put it at a 60 - 70WPC amp and indeed, the spec is just that - 60WPC both channels driven at 0.019% THD

A-S301 - Specs - Yamaha - Other European Countries

Designed for excellent sound quality, with a beautiful appearance.An integrated amplifier with the advantage of digital input.

europe.yamaha.com

I didn't take screenshots but currently, the spec above seems fair and it's a very cheap amp here.

Yamaha A-S301 Stereo Amplifier Black

Designed for excellent sound quality, with a beautiful appearance.An integrated amplifier with the advantage of digital input.

homeavdirect.co.uk

 

[Ralf Stocker]

These companies all have a "design philosophy". They'd better study electrical engineering.

 

[restorer-john]

Staying with Yamaha, one of their smaller amps (AS301) I'm certain claimed 100WPC in the UK site puff. Some delving showed this was at 10% THD. I put it at a 60 - 70WPC amp and indeed, the spec is just that - 60WPC both channels driven at 0.019% THD

I have an AS-300 here. Same amp without the inbuilt D/A. A solid performer, with some limitations.

 

[BicycleJoe]

Any idea what the phono section output is, my present cartridge is 3.6 mV the phono preamp I have on waitlist requires something close to 5 mV. I put $60 down on the open box IO so I'm locked in unless I want to give away $60. Can you tell me if the I/O preamp section gain?

 

[AvPioneer]

I mean...you can...but why base opinions around 4ohm stress tests when they recommend not doing that? I'd imagine we could slant a lot of products by misusing them but what would be the point or usefullness of that?

 

[Mart68]

I mean...you can...but why base opinions around 4ohm stress tests when they recommend not doing that? I'd imagine we could slant a lot of products by misusing them but what would be the point or usefullness of that?

Because why would you want to buy an amplifier that severely restricts what loudspeakers you can use with it?

If you know the amplifier will only work with speakers that are an easy load you can make an informed buying decision.

Otherwise you might buy it based only on the rave subjective reviews and then wonder why the sound is of poor quality with the speakers that you already have.

 

[audio_tony]

May I suggest that 'Japanese Watts' was more about higher voltage output with feeble current. Into the 80's newer wave of 4 - 6 ohm speakers with all manner of reactance. This is one area where many UK amps could perform better, even if THD, IMD and so on went out the window

Replying to an old thread..

I'm not sure what vintage of Japanese amps you are referring to however, back in 1979 I had a JVC JAS-22 amp. Specs stated 43w RMS per channel, and I measured it at a comfortable 50w a side (both channels driven).

I do however recall some older more feeble designs from the early 70's which were poorly specified but still (mostly) met the specified power rating.

The specs were good too.

 

[DSJR]

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

 

[restorer-john]

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

Both the JA-S11 and JA-S31 were "recommended" by HiFi Choice and at £85 and £120 list, they were a great buy over there. I don't recall ever seeing JA-S22s here in Australia- I think it came the year or two after.

But then, HiFi Choice's "recommendations" were so terribly biased toward UK products it was a bit of a joke (except it wasn't).

 

[thewas]

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.

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?