Why do OpAmps sound different?  

The answer is yes opamps sound different as so many, such as those in the opamp thread find they sound different. The real question should be, what causes opamps to sound different? Is it the opamp itself or the listener and their baises and expectations.

Quite a couple of designs use op-amps to directly drive the load, yet some guys "upgrade" to op-amps that are not up to the task, for example they use op-amps that have very limited output current in combination with low-impedance headphones, or that are not suitable for the given design and start to oscillate / become unstable without them even noticing, etc..

In such "broken" configurations imo it's quite possible to really hear differences.

Other than that I have to agree with Prog Rock Man.

99% of opamp comments make no sense at all. For example, many will tell you that the OPA627AP is nothing compared with the OPA627BP, despite the only difference being that the latter has better DC specs - they measure identically as applicable to audio.

Aren't they all totally different circuit designs, for the most part?

I dislike the plastickiness and artificiality of LME49710/49720/LM4562, LT opamps tend to have a strange lack of articulation to the sound, like they are trying to slur everything, plus they tend to sound green or whitish-green, which is weird and I get bored of it quickly.  I was never expecting these things when I first tried those opamps, and I was hoping that I may like them or find them interesting or something.  I usually have positive expectations.

TL051C caught my attention with the dreamy creaminess to its sound, as another example.  Very unexpected.  OPA1611 has this coloration to it and sense of "naturalness" that I can't explain, then OPA209 sounds like it is the child of 1611 and TL051, lol.  I was not expecting that in the least, and I love these three, especially 209 nowadays, with my Grados.

What's up with all this, I have no clue.  The difference they each make is small, but large enough to where it is quite fun.

When an opamp doesn't sound the same in one piece of equipment versus another, that is often because one piece of equipment provides much cleaner power (LT1363 in my desktop gear versus Minibox-E+ portable amp) and/or the other one isn't supplying enough voltage (like AD797 in my desktop gear versus my Minibox-E+), or something else about the circuit design, so I speculate.

How is it that higher grade versions of the same chip achieve better DC specs?  Mild tweaks to its circuit?  Tighter tolerances in certain aspects or something?

When I am confused is when people say things like, "but LT1677 is more 'musical'."  Sure buddy.

As always, take my opinion with a salt shaker or two, maybe a whole crate, lol.

I always wondered how one piece switched in from a device with 0.001% THD could make an audible difference.  Can people hear 0.0001% THD?  Not saying they can't since I still have everything stock in my stx sound card.

That amount of THD is far, far outside the realms of audibility. There isn't even any debate - it's like claiming you can hear 0.001db channel imbalances.

It is when people start to claim they can 'feel' the difference I get really annoyed.

Quote:

Originally Posted by Prog Rock Man 

It is when people start to claim they can 'feel' the difference I get really annoyed.

On the contrary, this might be a far more honest assessment. Feelings are (mainly unconscious) cognitive processes informed more by predetermined biases than reasoning. If someone can't quite remember the differences and report them clearly, or can't identify them to begin with, they might conflate their emotional state with a a random but identifiable factor (opamp, cable, etc.) in an attempt to rationalize their preferences. Expectation bias primes them for a specific response, they really do "feel" the difference rather than "sense" it (as in sensory input).

Quote:

Originally Posted by Prog Rock Man 

The answer is yes opamps sound different as so many, such as those in the opamp thread find they sound different. The real question should be, what causes opamps to sound different? Is it the opamp itself or the listener and their baises and expectations.

So you ask about the real question, what causes 0p-amps to sound different, fair enough!  But when you say is it the op-amp itself or the listener and their biases and expectations, that's implying one can't hear the difference.... I know several of listeners and myself who listened with me while changing OP-A sets in my DAC that couldn't believe the difference in the sounds of these different OP-A sets!  We all heard a night and day difference in the sound of different Op-amp sets... Read this link if I can post it.   By the way I'm not trying to start an argument with you or any other member of this post, but I hope most of you guys CAN hear a difference in most of these changes in our equipment..http://sound.westhost.com/dwopa.htm#rules
 

Quote:

Originally Posted by 9pintube 

So you ask about the real question, what causes 0p-amps to sound different, fair enough!  But when you say is it the op-amp itself or the listener and their biases and expectations, that's implying one can't hear the difference.... I know several of listeners and myself who listened with me while changing OP-A sets in my DAC that couldn't believe the difference in the sounds of these different OP-A sets!  We all heard a night and day difference in the sound of different Op-amp sets... Read this link if I can post it.   By the way I'm not trying to start an argument with you or any other member of this post, but I hope most of you guys CAN hear a difference in most of these changes in our equipment..http://sound.westhost.com/dwopa.htm#rules
 

 

Not disbelieving you but...

You did Blind tests right ?

You level matched to +/- 0.1db ?

You used the same track for each comparison ?

What was the switching delay ?

What were your expectations prior ?

How did you prevent opinion cross-contamination ?

Why not measure the different outputs using the different opamps that would be **much** more informative and allow detailed comparisons
 

The number of times a night and day difference disappears when cues are removed makes it certain that sighted tests have extremely limited utility for verifying if perceived differences are real or imagined, amps that are wildly different often become indistinguishable, $12K CD players sound the same as $200 DVD players, boutique DACs indistinguishable from Digital EQs - this happens again and again and again. This is why when I read night and day differences elsewhere I just ignore them. Here however we expect a greater level of evidence and sighted poorly controlled comparisons are insufficient for that purpose.

Certainly opamps measure differently, whether they are different enough to be audibly different in-circuit can only be judged on a case by case basis and with more rigorously garnered evidence.

Quote:

Originally Posted by nick_charles 
Not disbelieving you but...Thanks for that.

You did Blind tests right ?YES

You level matched to +/- 0.1db ?YES

You used the same track for each comparison ?YES

 

What was the switching delay ?How ever long it took to change the OP-A's After listening and taking notes on the sound, of each set!

What were your expectations prior ? None, Just wondering what would be the audible difference (if any)!

How did you prevent opinion cross-contamination ? Didn't have any pre- opinions of the sound differences.

 

Why not measure the different outputs using the different op amps that would be **much** more informative and allow detailed comparisons Yes it would prove the output being some what different but when you don't know what set of OPA's your buddy changed and you heard a difference, then compared your notes from previous sounds in the same song, that's all I and my partners needed to pick what OPA's fit and sounded best in my system!,  Sorry if this is not enough for you or others!
 

The number of times a night and day difference disappears when cues are removed makes it certain that sighted tests have extremely limited utility for verifying if perceived differences are real or imagined, amps that are wildly different often become indistinguishable, $12K CD players sound the same as $200 DVD players, boutique DACs indistinguishable from Digital EQs - this happens again and again and again. This is why when I read night and day differences elsewhere I just ignore them. Here however we expect a greater level of evidence and sighted poorly controlled comparisons are insufficient for that purpose.Not to be a smart ass, and dispute your words,  but I've always thought highly of your post and the help you given many  members concerning our hobbies Equipment! Haven't you ever noticed a HUGE/ or noticeable difference in any changes that you've made in any of your equipment? (Maybe night and Day) was the wrong words to use but it was clear-cut difference.

 

Certainly op amps measure differently, whether they are different enough to be audibly different in-circuit can only be judged on a case by case basis and with more rigorously garnered evidence.AGREE

nick_charles

I tried to answer your questions as truthful as I could. My answers in red type was the easiest to help you and others read my answers to your questions, which I find very pertinent to this topic.. what did you think of the web sites explanation of the difference in Op-Amps???

A smart-arse which I am not might suggest that some of the opamps you installed were inappropriate for the circuit and oscillated/were starved of current...thus resulting in audible differences. How sound signatures spring forth from opamp designs that all aim for vaguely similar things measurably seems a little confusing. I have a hard time picturing Texas Instruments engineers designing opamps by ear.

Quote:

Originally Posted by Willakan 

A smart-arse which I am not might suggest that some of the opamps you installed were inappropriate for the circuit and oscillated/were starved of current...thus resulting in audible differences. How sound signatures spring forth from opamp designs that all aim for vaguely similar things measurably seems a little confusing. I have a hard time picturing Texas Instruments engineers designing opamps by ear.

OH! OK I'm Done!  I've been in audio for most of my 58 yrs. of life and I sure don't throw pieces into a circuit that don't belong..... It's like many of the guys on this site who think just because a tube socket has 9 pins or 4 pins any tube with that amount of pins will work.. WELL That's NOT ME. OK!  If you would read my equipment, in my profile, you'll see I ask, if needed or show my best friend Chris Ivan who is a proven master of circuits and builder/repair man! My other best friend has a PHD Degree in Electrical engineering and Circuit design, so I don't just DO what MIGHT make an improvement.... Willakan so maybe direct your comments like these to some of the members that don't have a clue... If your not a smart-arse then what do you call your response  to my post.......I'm so tired of so many members putting people down to show their ass... It's sad, I thought we were all trying to help each other... PS I never said Texas Instruments design their Op-Amps by ear or any other reputable designer or builder...