Rega IO Review (stereo amplifier)

[Yevhen]

Always surprising to see how little attention is given to thermal management in audiophile products.

Guys, I think there might be nothing wrong with thermal management here. Ok, maybe Amir's hand wasn't happy with 65C on the heatsink, but the silicon dies in transistors start failing at 200C. At 150C they can easily operate for 200 000 hours. Of course, electrolytic caps will not last that long, but something around 10 000 hours.

There is a term "mission profile" in mass production. For example, it defines that the amp should be reliable enough to work for 5 years and 1 hour per day. Then we end up at 2000 hours only.

 

[pma]

Guys, I think there might be nothing wrong with thermal management here. Ok, maybe Amir's hand wasn't happy with 65C on the heatsink, but the silicon dies in transistors start failing at 200C. At 150C they can easily operate for 200 000 hours.

You serious?? Heatsink and the case is the same thing in this amp. Do you suggest 65°C as allowed operating temperature at the surface of the case of the consumer audio amplifier?? He measured 45°C at the case at a mere 2x5W.

 

[antcollinet]

At best, electrolytic capacitor lifetime will be screwed. Aprox half life for every 10C increase in operating temperature.

I think though, for the average user, probably running at an average 1-2W it won't be a big issue. For anyone wanting to shake the walls, they need a different amp.

 

[KSTR]

https://www.researchgate.net/profile/Shun-Zhang-23/publication/338507131_Thermal_Considerations_for_Information_Technology_Equipment_from_Product_Safety_Perspective/links/5ef75fe3a6fdcc4ca433c0b5/Thermal-Considerations-for-Information-Technology-Equipment-from-Product-Safety-Perspective.pdf

 

[DSJR]

I'm copying this across from the teardown thread - The 1980's was a dire time for the UK mid-market, as the far eastern amps with superb build and measurements were dismissed for 'not sounding good' and home grown products with seriously iffy performance were raved about by the then new wave of subjectivists led by reviewer/engineer/consultant/guru Martin Colloms, who was amongst the first to claim that measurements said little about perceived sound quality while recommending all manner of US made valve confections with diabolical bench performance (I could say loads more looking back but older members here will understand I think). Mr Colloms in print mentioned in speaker tests how much 'better' digital recordings were, yet to my old pal and colleague in the dealer's main store he worked at, he said a Rega 2 turntable 'sounded better' than any digital (this after we were lent a Sony 1610 AD/D-A unit wired in A-D-A mode which sounded identical on its output via a tape loop to the bypassed signal (I was later told any issues with early digital were in the workstations used back then in the days before 10 bit plus mastering, but I'm digressing again.

'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 20kHz. 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 [edit A-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 '

 

[antcollinet]

https://www.researchgate.net/profile/Shun-Zhang-23/publication/338507131_Thermal_Considerations_for_Information_Technology_Equipment_from_Product_Safety_Perspective/links/5ef75fe3a6fdcc4ca433c0b5/Thermal-Considerations-for-Information-Technology-Equipment-from-Product-Safety-Perspective.pdf

Can you give us the tl;dr?

 

[KSTR]

Can you give us the tl;dr?

No. It's right there and immediately obvious, blatantly obvious actually. I mean, really, c'mon....

 

[restorer-john]

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).

Mmm.

PM was the suffix for Marantz, not Pioneer. The PM-44se was a UK HiFi rag fav. Pioneer always has SA for "Stereo Amplifier" and Marantz used PM (in the 80s) for "Pre-Main" (as in console, back in the day).

Sony used TA for "transistor amplifier" and into the ES era, they added the "F", TA-F which meant...I don't know! Maybe fabulous?

Sony's TA-F700es was the EU/US version of the 444esX/444esXii from 1986/7/8 IIRC. I have a mint 444esXii here if you want to see it? Totally different to the TA-F333esR/TAF-730es that came two years later ( I have two here) There was of course, the TA-F555es which was a more powerful version.

 

[Yevhen]

You serious?? Heatsink and the case is the same thing in this amp. Do you suggest 65°C as allowed operating temperature at the surface of the case of the consumer audio amplifier?? He measured 45°C at the case at a mere 2x5W.

Actually, the international electrotechnical commission suggests that, not me

 

[DSJR]

My apologies for getting it wrong. The Pioneer was the A-44, in the same tests, the Marantz PM26 and PM45 were 'recommended' and the Sony's were TAF 500ES and TAF 700ES, the latter getting an 'average' sonic score (the MC RIAA had a noticeable low bass error with a lift of +2dB ar 50hz) yet distortion figures were down at -90dB or so on the line inputs and IMD even better on the line inputs. No recommendation bearing in mind the prices asked.

 

[NTK]

Actually, the international electrotechnical commission suggests that, not me

View attachment 162988

IEC 61010 (the more stringent of the 2 standards you showed) is for equipment for lab use by professionals, not for consumer use in homes where the devices are accessible to small children.

 

[antcollinet]

No. It's right there and immediately obvious, blatantly obvious actually. I mean, really, c'mon....

There is 11 pages or so there, and you've just posted a link with no reference, or even hint to the point you are trying to make. It's obvous to you because you know where you are looking, and what is in your head.

 

[pma]

There is 11 pages or so there, and you've just posted a link with no reference, or even hint to the point you are trying to make. It's obvous to you because you know where you are looking, and what is in your head.

Guys you usually talk too much without being willing to read or study anything. And you are losing time in debates then? Klaus linked this and you'll see it in seconds.

 

[Yevhen]

He measured 45°C at the case at a mere 2x5W.

Guys you usually talk too much without being willing to read or study anything. And you are losing time in debates then? Klaus linked this and you'll see it in seconds.

Is it 70C then? So almost the same as the 65C suggested from the previous table, even higher...

Again, to me, it seems like Rega is not doing anything criminal here. Apart from poor audio performance

 

[Doodski]

it seems like Rega is not doing anything criminal here. Apart from poor audio performance

The Rega IO is simply a cheesy design. No vents for heat to escape, tight dimensions inside and the layout is really questionable as has been mentioned.

 

[Yevhen]

The Rega IO is simply a cheesy design. No vents for heat to escape, tight dimensions inside and the layout is really questionable as has been mentioned.

I didn't see it live, but it seems like the bottom plate is used to transfer heat from transistors to the side ribs. If you drill the holes there, it will probably affect thermal conductivity of that path

 

[Doodski]

it will probably affect thermal conductivity of that path

Yes, I saw the thermal imaging pic. That's a long way for heat to conduct to the the sides.

 

[antcollinet]

Yes, I saw the thermal imaging pic. That's a long way for heat to conduct to the the sides.

Right - plus all along that distance, it's conducting heat to the air inside the enclosure.

 

[TimF]

I am seriously impressed with you guys (are there any women ASR members and I hope there are?) regarding your factualness and access/recall abilities regarding the long-term developments in audio reproduction technology and in the notable products that have come and gone.

 

[VintageFlanker]

I measured the IO while playing the Wharfedale 12.2 speakers at 100db. Using approximately 16 wpc at this level

What instrumentation did you use exactly, for both acoustical and electrical domains?