Ralf Stocker
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Highest price, lowest quality. Now you know why the Amazon boss is so rich.
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Rega IO Review (stereo amplifier)
- Thread starter amirm
- Start date
5% tolerance on what metrics? Can you link me of an Audio Analyser that specifies a 5% measurment error? As far as I know, you can have an accuracy spec in dB, which determine the precision but thats not a Tolerance, it's simply the smallest step, and you of course have the limitation of self noise and distortion, but 5% is huge.
@sam_adams Nice. I'm confused as to why Rega would design it this way. argh I had no idea the audio world was such a minefield!
OP
- Thread Starter
- #64
Company was quoted to say that they started with class D design but after two iterations gave up and switched to class AB.
bidn
Active Member
Well they have too, else everything would have five stars, so that even the more gullible readers would realize that the reviews are fakes, or at least would no longer be interested in the magazine : how would they be helped in making a choice if everything gets the same mark?
So they have to give some devices less than five stars (though I am not sure they give less than three, which might alienate some companies), probably to devices from companies not paying them or less than those companies to which they give five stars.
It is indeed huge. I used that value to show that even if they had such a high tolarence, the audible result will not matter. Follow the thread to see the context of my reply.
Stop right there. You effectively learnt something.
DanielT
Major Contributor
I'm not an EE either, but a Class AB with a big transformer in a small amp is probably always wrong. A big class AB amp must be cooled.
An EE can better describe that with: relation with power, watts combined with class AB efficiency in %, how heat must be dissipated, how large size heat sinks are then needed.
Or big or big. It will be as big and heavy as it needs to be based on its effect.
(I exclude fans for cooling, then it will be about another weight)
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I wonder what the problem was with class D? Too expensive?
No, it is a matter of the design work. I designed and built this small class AB amp with LM3886 chips in 2009 (photo attached below), it had low idle consumption and quite nice parameters. 2x50W/8ohm, 2x65W/4ohm. You can make good or bad design in either class of operation.
The amplifier in this current review is really not good and the reason is a poor design.
DanielT
Major Contributor
There is nothing wrong with the new tpa3251 or 3255, hypex or Icepower. But before that , some solutions didnt sound as good as good class A/B . Especially not in the treble.
My guess is that many english manufacturer are gonna use class D in the near future.
Any euphonic coloration can easily and cheaper be done in the preamp section.
It can also be that they wanted it to sound in a certain way, maybe soft in the treble ?Thanks for clarifying PMA.
Maybe they didnt reach for ”a straight wire with a gain” ?
OK, but let's just say, in the "context" of ASR, 5% difference on some metrics is enough difference to be the difference between recommended and unrecommended. Why are we even here? As for the "context" of the thread? I fail to see where it's obvious that you where discussing human audibility accuracy. I thought you where replying to me, I generally tend to think that when my comments are quoted before a reply.
There is a big problem of frequency response that heavily depends on speaker impedance frequency plot. In some cases of speakers, it easily makes 2dB at 10kHz and starts to deviate above 5kHz. And it is audible and distinguishable even in an ABX DBT test. No, these chips are not usable in a "serious" design.
NCore and Purify are OK. And even UcD seems to be OK, as its frequency response is independent of load impedance curve. Soon I will review UcD180HG HxR module.
A SINAD about 80 in power amps is probably enough for serious listening. In dacs with volumecontrol maybe a SINAD of 100 is good enough to be transparent in home listening. But why be satisfied with less, if you can have a SINAD at 115 for less money ?
It's a loaded question, it can also be turned around, we shouldn't side track too much on this, this is not related to this review, we can also say, why would a manufacturer spend engineering ressources on something that no one can possibly hear? I generally think that SINAD at 1K metric takes too much importance here, especially for amps. this 80 dB you mention, I'm not sure where it comes from, that's not how I assess the value in dollars of an amplifier so I can't answer.A SINAD about 80 is probably enough for serious listening. But why be satisfied with less, if you can have a SINAD at 100 for less money ?
Isnt it a bit different if you know the loudspeakerdrivers impedance in an active design where you can compensate ?
But you are right that there is a problem that the tpa3255 gonna sound slightly different with speakers with different resistance load in the treble area.
Looking forward to your test of Ucd180hg , it gonna be interesting reading, I have been reading all of your tests.
The UK has a history of half width mini amplifiers, class a/b to about 50 Watts. Naim nait, various Rega, cyrus, onix, avi. Its been a solid package in terms of sales over the decades and one that brands seem keen to keep going, they just need to update to modern tech. The issue is most of them prefer to build class a/b on- site using discrete parts rather than bought in class d boards.
The UK press is in bed with them so it'll take a long time for them to come to their senses.
The UK press is in bed with them so it'll take a long time for them to come to their senses.
KEFCarver
Active Member
Just kinda eyeballing the Phono response from 20hz- 20khz gives me a flatness of about 1.8dB, which does not seem very good, unless that is due to measuring at the headphone output.....
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