Sorry, there is one glaring resemblance: neither the LF356 or the AD711 was in particular designed for audio applications.
The fact that the AD711 guarantees the distortions in the data sheet (typ. 0.0003%), while the LF356 data sheet is mum about, is of course irrelevant for the High End Audio priests.
True, all amplifiers with the same slew rate are, for all High End Audio purposes, identical.
Why would I want to use either of those opamps, really? Neither have that great of appeal -- no slight to the AD711, just you can do better nowadays.
I would not use an AD711 for just about anything today, but it was OK for servos back in its day. The AD797 is pretty good, in fact, excellent for instrumentation, but too expensive for most audio projects. I don't use any Analog Devices IC op amps at this time, except for the AD825 which I designed into a power amp. I like this op amp.
Jack Bybee sold his Bentley, so Richard is the only other guy left who I've known who ever had one. Nice car.
For the record, I pointed out the AD711, because it would be close in performance to the LF356 in the TIM test that I posted in Graph 1.
I thought that Scott should know where he would approximately place on the graph, if his op amp was tested in the same way, under the same test conditions. uA741? We don't use those anymore, but they were very popular back then, in the middle 1970's and they were much cheaper to buy than the LF356. The LF356 sounded better than the uA741, even in guitar amps. But that is another story. '-)
I thought that Scott should know where he would approximately place on the graph, if his op amp was tested in the same way, under the same test conditions. uA741? We don't use those anymore, but they were very popular back then, in the middle 1970's and they were much cheaper to buy than the LF356. The LF356 sounded better than the uA741, even in guitar amps. But that is another story. '-)
Daniel, this is something what I do not understand as well. I started my professional career in 1979/80, after graduating from technical university. Even in those years I needed to use much faster parts, like uA715, or LM318. I would never ever consider using those funny parts like 741 for professional instrumentation purposes. 741 had been obsolete even in 1979. Maybe audio designers had a different view.
Yeah, a lot.
BTW, you avatar is misleading and indecent. That finger should point to a Bentley.
The funny thing is a AD744 with a push-pull buffer sounds the same as a JC2 line amplifier. I got the circuit from Walt Jung's opamp booklet.
Attachments
Reminds me Burr Brown parts available in 1980's. Almost everything debated here already resolved.
For example BB3554
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Is that the one that bypasses the output stage? I brought out the extra pins because for a while we used them in hybrids with external PNP's.
That was directed at the audiophool industry in general, I have complimented your designs here numerous times. Why you side with folks obviously selling products with fraudulent claims I don't understand.
Back on the slew rate during mistracking graph John showed Shure was claiming 35cm/s at 1kHz for the V15II back in 1971. Why did people stick with MCs that tracked like a Lincoln town car handled?
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