I can only agree with the opinion that the NE5534 is duff, I've never really liked them. The TLO71 series can be surprisingly good and very cheap.
For ultimate performance I dont think there's anything to touch the OPA134 "soundplus" series from Burr Brown (Texas instruments), truly a "straight wire with gain" in my experiance.
Jez.
For ultimate performance I dont think there's anything to touch the OPA134 "soundplus" series from Burr Brown (Texas instruments), truly a "straight wire with gain" in my experiance.
Jez.
I haven't had the time or resources to do a lot of AB comparisons but I was wondering anyone had given some attention to "settling time" as a parameter that ought to be comsidered when comparing the audible qualities of amps (not just op amps). Way back in the early 70's Linsley Hood in the UK was advocating attention to squarewave performance and settling time as useful objective measurements to consider when looking for a correlation between sound and specs'.
BTW jez `it's been while since I read it but in Walt Jung's review of op amps in "AUDIO" (USA), back many moons ago, I seem to remember the TL071 series came out very favourably in listening tests.
BTW jez `it's been while since I read it but in Walt Jung's review of op amps in "AUDIO" (USA), back many moons ago, I seem to remember the TL071 series came out very favourably in listening tests.
Mike,
I'm aware of the reported differences between these op-amps according to Doug Self. I would still choose the OPA134 over the NE5534 every time without a moments hesitation though. I listen with my ears, not an Audio Precision
I see that post was from 2004....I hope that some of the op amps that have come out in the past couple of years will prove to better the OPA134. I've just had samples arrive from National Semiconductor of their new LM4562, which has most impressive specs and, so far, very favourable reports on this site as regards sound quality. I have learned over the years that relentless persuit of more zeros after the point in THD measurements is not worthwhile when it comes to sound quality (especially with power amps). In fact, if vanishingly small distortion is achieved via huge amounts of NFB it is usually to the detriment of the sound (sometimes grossly so, have you heard one of Doug's blameless amplifiers?).
Although we are mainly talking op amps here and comparatively small signal stuff, I have found that lots of feedback and 0.000etc in pre amps, line level etc does not seem to be an issue in the same way that it is with power amps, IID maybe? What do think on this one?
I'm aware of the reported differences between these op-amps according to Doug Self. I would still choose the OPA134 over the NE5534 every time without a moments hesitation though. I listen with my ears, not an Audio Precision
I see that post was from 2004....I hope that some of the op amps that have come out in the past couple of years will prove to better the OPA134. I've just had samples arrive from National Semiconductor of their new LM4562, which has most impressive specs and, so far, very favourable reports on this site as regards sound quality. I have learned over the years that relentless persuit of more zeros after the point in THD measurements is not worthwhile when it comes to sound quality (especially with power amps). In fact, if vanishingly small distortion is achieved via huge amounts of NFB it is usually to the detriment of the sound (sometimes grossly so, have you heard one of Doug's blameless amplifiers?).
Although we are mainly talking op amps here and comparatively small signal stuff, I have found that lots of feedback and 0.000etc in pre amps, line level etc does not seem to be an issue in the same way that it is with power amps, IID maybe? What do think on this one?
jez said:
I'm using two LM4562 in my preamp and the sound is superb! No weak points that I can detect. I didn't think I'd find the ideal op-amp so soon, but I feel it can be left alone now and I can focus on other things. (beats OPA2134 (dull) and LM6172 (brash) nicely and is more detailed)
Simon
I hope I have similarly favourable results when I get round to trying them
Whilst I have had superb results from the OPA134 series in many applications, there was one occasion when I used it in a line level pre amp (in which it was driving a push pull class A output stage) and did indeed find it slightly lacking....I don't know that I could describe it as dull but it was at least lacking high end detail....to the extent that when I tried a TLO71 in place of the OPA I found the TLO much better, in fact they're still in there!
Whilst I have had superb results from the OPA134 series in many applications, there was one occasion when I used it in a line level pre amp (in which it was driving a push pull class A output stage) and did indeed find it slightly lacking....I don't know that I could describe it as dull but it was at least lacking high end detail....to the extent that when I tried a TLO71 in place of the OPA I found the TLO much better, in fact they're still in there!
jez said:
True...to a point.
jez said:
Not true, as D. Self's amps do not use ''huge amounts of feedback''.
Don't like his amps., but not for the reasons you've given.
THD absolutely provides fool-proof indication of the quality of an amp provided all conceivable load conditions are catered for.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.