Is noise really so very important? I personally don't listen to the background hiss with no music playing and the amp's volume set at max.
It would be kind of like smelling a car's exhaust
Kind of
I listen jazz during the night sometimes and I hate to have any background noise. Those opamps are exactly what I needed. In my system I use a gain knob with which I can select one of the following:- direct input in final stage (through volume pot);
- 10x attenuation (180k in series with 22k pot's input pin);
- 4.1 amplified and buffered signal through preamplfier.
SoNic_real_one, that NJMs is nowhere near OPA2134's performace. BTW, do you speak romanian by any chance?
I fully agree with janneman on this... I have found the inverting configuration to generally have better sonics, particularly when the op amp is correctly compensated and applied.
As to which opamp... I still like the OPA604 for it's "musicality" but I guess that is a personal choice. The distortion spectrum seems "pleasing" to the ears... mine anyway.
Peranders.... nice link re the pdf
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I agree about the OPA604. I haven't lived long with this, but it keeps being a good choice. Not LT1028-good though...
Of course (when talking about noise) I was starting from the fact that common audio opamps all have a low noise floor... really it has never happened to me to hear any background noise with the music playing, not even on headphones!! An inflated, overrated problem!?
Of course (when talking about noise) I was starting from the fact that common audio opamps all have a low noise floor... really it has never happened to me to hear any background noise with the music playing, not even on headphones!! An inflated, overrated problem!?
That's exactly the measurement shootout I was mentioning before. Great information, but in the end it's only half of the story - at best. I'd say only about a quarter, personally.Peranders.... nice link re the pdf
For instance... the LT1363 (or dual LT1364) gets trashed there, but it sounds quite good when it's not oscillating..
Hi Andrea,
Agree about the noise too. For line level inputs it's pretty much a "non issue" and a bit of white noise, tape hiss on older recordings etc doesn't distract from the musical performance... in fact it can add a "nice" bloom to the sound, I believe it helps the ear resolve low level detail better, almost like dithering a digital signal.
My goal for audio is to have a system that reproduces the majority of music well, not a system that has to have "certain demonstaration" CD's etc played to sound any good.
Agree about the noise too. For line level inputs it's pretty much a "non issue" and a bit of white noise, tape hiss on older recordings etc doesn't distract from the musical performance... in fact it can add a "nice"
bloom to the sound, I believe it helps the ear resolve low level detail better, almost like dithering a digital signal.My goal for audio is to have a system that reproduces the majority of music well, not a system that has to have "certain demonstaration" CD's etc played to sound any good.
Oh yeah, absolutely. Demonstration CD's = audiophile nonsense. 
BTW, that test doesn't even tell you that the opamp with the most perfect measured performance is clearly the best sounding... see the OPA211. I couldn't live with it, I just wouldn't enjoy music like I used to do. I preferred LT1028 (ACN8 and CS8) to OPA211 in 2 different DAC's.
Or compare the OPA132UA to the OPA827: with similar measured distortion (well referring to the OPA2132), does that very thorough measurement let you in any way expect that the OPA132UA sounds far more musical?
OPA132UA which sounds quite a bit more transparent than the dual OPA2132P, while retaining the musicality, BTW.
BTW, that test doesn't even tell you that the opamp with the most perfect measured performance is clearly the best sounding... see the OPA211. I couldn't live with it, I just wouldn't enjoy music like I used to do. I preferred LT1028 (ACN8 and CS8) to OPA211 in 2 different DAC's.
Or compare the OPA132UA to the OPA827: with similar measured distortion (well referring to the OPA2132), does that very thorough measurement let you in any way expect that the OPA132UA sounds far more musical?
OPA132UA which sounds quite a bit more transparent than the dual OPA2132P, while retaining the musicality, BTW.
Unless a given circuit is specifically designed for a specific OpAmp it's not always a fair test to just swap them around.
Each OpAmp and application has to be optimised first. Then listen
Meaning? On paper the LT1028 is the least universal, since it has such a high open loop gain and is not even specified as unity gain stable... yet in my applications it simply sounds best
While the LME49720HA is very easy to deal with, like the LME49723 and the rest of the family. Also the OPA211, OPA827 are quite well behaved opamps.
Different matter would be THS4031, THS4051 (better than the former BTW), EL2228, OPA2822, etc. These surely need some tinkering to get going (most of the time).
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Meaning in the very simplest of terms that the circuit has been tested for well behaved squarewave performance and compensation tweaked/applied accordingly. That decoupling is appropriately applied and that if needs be a small series resistor is used to isolate the output from capacitive loading effects that may cause HF/RF instability.
I like to examine every part of a full cycle with a dual timebase scope looking for any non linearities... it's surprising what that can show sometimes.
Ultimately it is what ever works for you in the end though...
I like to examine every part of a full cycle with a dual timebase scope looking for any non linearities... it's surprising what that can show sometimes.
Ultimately it is what ever works for you in the end though...
I'm not that technical. At any rate, the LT1028 is the least suitable opamp for unity gain operation on paper, yet in my DAC it sounds best. Coming to it from the OPA827 revealed the better tonal quality, insight and smoothness the LT1028 is capable of.
All "audio" opamps have well behaved square wave responses, anyway... So they tend to be pretty much interchangeable (used within their specified electrical parameters).
Instead, take the LT1363 or the LT1357 or LT1360... these indeed change a lot in sonic behavior with the circuit! No surprise, look at how 'untameable' the unity gain square wave response looks.
All "audio" opamps have well behaved square wave responses, anyway... So they tend to be pretty much interchangeable (used within their specified electrical parameters).
Instead, take the LT1363 or the LT1357 or LT1360... these indeed change a lot in sonic behavior with the circuit! No surprise, look at how 'untameable' the unity gain square wave response looks.
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BTW, I was thinking that it's funny and interesting how that guy who made the "masterpiece" opamp test treated audio and non-audio opamps all the same way... and thus got universally better results from the 'proper' audio opamps. He should've made a specific test gig optimised for each of the high-speed opamps! 
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BTW, I was thinking that it's funny and interesting how that guy who made the "masterpiece" opamp test treated audio and non-audio opamps all the same way... and thus got universally better results from the 'proper' audio opamps. He should've made a specific test gig optimised for each of the high-speed opamps!
I think that test showed clearly that there is influence from how the circuit is set up - inverting, non-inverting etc.
Don't you want the best opamp for the best application, making sure that what YOU like best also performs best in other people's application? Or doesn't anybody really care and is this thread just some anecdotal, personal stories with no real value to others?
jd
Interesting that you find/prefer the slower LME49723 to the LME49720 with it's almost order of magnitude better distortion preformance and marginally better specs, but of course that can be largely dependent on circuit design layout and such.
Personally I'm a fan of the LM4562HA (LME49720HA) but don't consider it to be the be all to end all for every circuit. indecently I can not tell the difference between these,..
As to the LT1028 I should have to try it and compare to OPA604 and LME49710 and such,... always fun.
Personally I'm a fan of the LM4562HA (LME49720HA) but don't consider it to be the be all to end all for every circuit. indecently I can not tell the difference between these,..
As to the LT1028 I should have to try it and compare to OPA604 and LME49710 and such,... always fun.
jd:
that is a trick question, right?
i'm in violent agreement with you.
i gave up when i saw op amp rollers switch between
1. super low noise bipolar-input opamps,
2. wide bandwidth video opamps, and
3. high speed, jfet input opamps
all without changing the circuit at all (feedback impedance networks and power supply decoupling, just for starters) and then expect to make fair/accurate assessments of circuit performance (sound and specs).
incredible ...
mlloyd1
that is a trick question, right?
i'm in violent agreement with you.
i gave up when i saw op amp rollers switch between
1. super low noise bipolar-input opamps,
2. wide bandwidth video opamps, and
3. high speed, jfet input opamps
all without changing the circuit at all (feedback impedance networks and power supply decoupling, just for starters) and then expect to make fair/accurate assessments of circuit performance (sound and specs).
incredible ...
mlloyd1
Fantastic suggestion , if everyone would list their info on Speakers , ancillary equipment etc when making comments , it would go along way in understanding their evaluation .....
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The LME49723 is fast and low distortion enough...
What matters for us humans is that it sounds nicer tonally and more dynamic than its more performance-tuned siblings
The LM4562 is a bit too dull and also a bit rough, to me. The LME49720NA isn't so very inviting sonically... The LME49860NA is nice but to me a bit...don't know how to put it, imperfect. The LME49722 is the lowest-distortion and most dull sounding of the series.
So I happen to prefer the LME49723MA and the LME49720HA to all the former. Of course they're only subtleties... but when it's just the subtleties that matter (didn't they)...