Three Chip Amp questions. Best device/Configuration and ultimate sound quality.

[Mooly]

Curiosity is getting the better of me here so though I would seek some opinions.

1. What device is considered to have the best sonic attributes (if any). And the best for driving more "severe" loads too.

2. Why do we never see chip amps in virtual earth mode (inverting configuration), discounting the obvious phase issue ? For me it's the preferred opamp configuration.

3. Just how good sonically can the best designs be ? Forget "on paper specs" and slew rates etc, can a chip amp sonically rival the best discrete designs in a blind test... or not.

Thanks for any opinions.

[ratza]

1. It depends on taste.
2. I don't think that the 180 phase shift is an issue, this can be ignored completely. The "problem" with this configuration is - or some people think that is - the low input impedance, requiring capable preamplifiers.
3. My opinion is that two well implemented amps with the same specs will sound just the same. In this point the speakers will make the difference.

Not 100% ontopic -> I made alot of comparisons between my two amps which managed to survive the ear test and not getting dismantled after initial run: 2x30W OPA2134/LM3886 and 1.5W SE with E88CC/EL84 (triode mode). Although the tube amp is not spectacular at all in reproduction fidelity, the timbre and the dynamics are simply astonishing, despite the low output power. It really sings, voices and acoustic intruments are very nicely reproduced. The LM3886 on the other hand has a better frequency response, is more precise and usually it amplifies also the stuff you don't want to hear. Actually, this is the drawback of the transparecy. Unfortunately it lacks both the dynamic and the timbre of the tube amp.

In audio we are all put in the situation of choosing between something that does everything but nothing great and something that does a small part but simply beautifull. This is one of the reasons I have two amplifiers. As you see, there is no perfect amplifier, only the one that suits your needs best.

[Mooly]

Originally Posted by ratza

Not 100% ontopic -> I made alot of comparisons between my two amps which managed to survive the ear test and not getting dismantled after initial run: 2x30W OPA2134/LM3886 and 1.5W SE with E88CC/EL84 (triode mode). Although the tube amp is not spectacular at all in reproduction fidelity, the timbre and the dynamics are simply astonishing, despite the low output power. It really sings, voices and acoustic intruments are very nicely reproduced. The LM3886 on the other hand has a better frequency response, is more precise and usually it amplifies also the stuff you don't want to hear. Actually, this is the drawback of the transparecy. Unfortunately it lacks both the dynamic and the timbre of the tube amp.

Hi Ratza,
That's the kind of info that's really important... I know just what you mean by that too re the timbre and dynamics. That's exactly how I feel with the Lateral FET design I use, it has a magical quality about it somehow.

So the big question is, whether it's possible to get better subjective sound from the chip amps by perhaps going away from the text book implementations.
Have to admit I have never built a chip amp for serious listening.

The TDA7293 ? seems to be one of the better specced devices from what I see.

Thanks

[ratza]

Originally Posted by Mooly

So the big question is, whether it's possible to get better subjective sound from the chip amps by perhaps going away from the text book implementations.
Have to admit I have never built a chip amp for serious listening.

The TDA7293 ? seems to be one of the better specced devices from what I see.

Thanks

Of course it's possible. Even more when you know what you are doing
You just experiment untill you get what you like, that is the real fun of DIY. I haven't worked with TDA7293 but I put one of my friends' TDA7294 amplifier on the blind test. Sounds similar with LM3886, but a little bit softer. We had different setups though, power supply approach, gains, internal wiring and so on; the kind of things people usualy do not pay too much attention.

[Mooly]

Hmmm... very interesting
I might stick a couple on the next order to have a play around with.