Opamp distortion tests posted

[sendler]

http://www.sg-acoustics.ch/analogue_...distortion.pdf

Great article. Especially for any one considering active crossovers such as the Orion. It is interesting that the tests don't favor my favorite, the LT1360. I have evaluated Burr Brown OPA134 (Over hyped de facto opamp in high end audio equipment. Not nearly as transparent as the LT.)and OPA627 (much better but not quite as good as the LT, a little distant and not as dynamic, and way over priced), Analog Devices AD811 (very good. Warmer than LT but too fussy about power supply design) and my absolute favorite, The LT1360 (Explosive and transparent) which sounds very close to the AD811 and has proven to be indestructable. The real, not surprising loser, is the OPA604 which must have gotten some good marketing because it has seen quite a lot of use in high end source equipment but is well known to be upgraded by the 134.

I have compared all the previously mentioned opamps in various applications. Output driver, unity buffer, gain stage at 6-18db, I/V converter, dc servo, inverting stage, differential amp, etc. The sonics of the LT1360 are in general the best. Several steps ahead of the OPA134. Why the LT13xx family isn't more popular I have no idea. I have been raving about them for years. They drop into any application and sound better than whatever you took out and stand up to incredible miss use. The AD amps sound very good as well but are very fussy about implimentation, I have had two of them fail, and somewhat pricier so I have given up on them. I don't find much advantage to the even faster 1364 so I just prefer to play it safe and stick to the 1360/1361. The 134 is a good amp and will be a nice step up from the TL071 that was ubiquitous in the 80's ( A great invention in it's day but is now a dinosaur, very opaqe in comparison. Responsible for the bad rap opamps get that lingers to this day.) but I find the 1360 sounds more open and see through. These studies are now 5 years old so there are some newer amps that I should try such as the AD797.

[Pan]

Hi!

Did you perform your tests blind and levelmatched?


Thanks!


/Peter

[sendler]

Sighted and level matched.

[Pan]

Thanks!

Have you done some/any tests blind?

Reason I ask is I have listened to gear that has several op's cables, connectors, resistors and so on without detecting a difference.

People I know have performed blind tests on linestages and come to the conclusion that it's not very hard to make it transparent.


/Peter

[Cauhtemoc]

This has been mentioned already:

Amazing opamp measurement shoot-out