[amol]

I switched the opamps as i mentioned on the M audio revolution with AD8620s, but is the difference that i am noticing is just placebo effect or is it really that the vocals seem totally non fatiguing now, i can listen to the music for almost 3 hours non stop.

I would like to hear your reactions.

 

[Mindless]

Yes. They are just like tubes, different characteristics on all models.

 

[fewtch]

Quote:

Originally posted by amol I switched the opamps as i mentioned on the M audio revolution with AD8620s, but is the difference that i am noticing is just placebo effect or is it really that the vocals seem totally non fatiguing now, i can listen to the music for almost 3 hours non stop. I would like to hear your reactions.

I've found there to be a difference, but it's not as big as people's posts seem to suggest. Like most differences in the audio world (aside from transducers) they are pretty subtle, and it's assumed around here that people know that the differences are subtle.

I think the tendency toward subtlety (combined with exaggerated talk) is what makes some people wonder if the differences exist at all. All that can be ultimately said is -- listen and decide for yourself.

Edit -- or believe only measurements and conclude there are no differences... doesn't really matter either way. But what would a person who believed only measurements be doing on a board like this anyway...

 

[john_jcb]

I totally agree with Fewtch, the differences between different op amps are indeed subtle. I have found that devices seem to have a certain character if they are from the same manufacturer and the differences are more pronounced when you switch brands. For instance changing from a AD to a LT device will be more significant than changing part numbers within the AD line.

 

[kwhead]

I've only tried comparing op-amps in a limited case and it made no difference. I'm planning at some point on doing some blind tests with a "blameless" output stage at some point just to see if there is any difference. Roughly one can conclude:

- If the op-amp itself is driving the headphones then you'd certainly expect audible differences since their output stages vary a lot.

- If the op-amp is only a gain stage with some sort of output buffer driving the headphones you should hear almost no difference unless you are trying for real low power and have traded off op-amp specs for that or the circuit presents unusual impedances to the op-amp.

So in short, don't be surprised if you hear no difference!

 

[PinkFloyd]

Quote:

Originally posted by fewtch I've found there to be a difference, but it's not as big as people's posts seem to suggest. Like most differences in the audio world (aside from transducers) they are pretty subtle, and it's assumed around here that people know that the differences are subtle. I think the tendency toward subtlety (combined with exaggerated talk) is what makes some people wonder if the differences exist at all. All that can be ultimately said is -- listen and decide for yourself. Edit -- or believe only measurements and conclude there are no differences... doesn't really matter either way. But what would a person who believed only measurements be doing on a board like this anyway...

Subtle differences between op amps from the same manufacturer yes but I have found there are quite substantial improvements if you replace a dual chip with two singles on say a browndog adaptor.....

2 single OPA627's on a browndog, for example, sound way better than a dual OPA2107 whereas swapping out a 2132PA for a 2227PA is "marginal"

Just "rolling" in an op amp in place of another is not enough..... the circuit has to be optimised to get the best out of each particular op amp....... unlike different brands of valves (tubes) which can be rolled as direct replacements.

There is no such thing as a "drop in" replacement op amp each op amp exhibits different characteristics and the circuit needs to be optimised to get the best out of each amp.

Pinkie.

 

[averydonovan]

Like others have mentioned, the differences between opamps are pretty subtle, but it can make a difference. And Pink Floyd mentioned an important point, the circuit needs to be optimized for the opamp. If you like the basic way something sounds but want to tweak it, then an opamp roll can help. If you think something sounds bad, an opamp roll isn't going to suddenly make it sound spectacular. The differences between opamps require a little bit of training of your ears. You have to listen to each one for a few hours to truly be able to hear its character to compare to other opamps. And a good way to tell whether an opamp change is good is the fatigue factor. If you can listen to something for longer than before after you roll opamps, then it was a positive change.

Pink Floyd, does the OPA2227 sound a bit different from the OPA2132 to you? To me the OPA2227 and OPA2228 sound somewhat similar, but the OPA2132 has a sound distinct from those (much darker and smoother). The OPA627 sounds like a combination of the best traits of the OPA2132 and OPA2228 to me.

 

[puppyslugg]

amol,

Have you tried changing out the output caps? Or tried using film cap bypasses on the stock caps?

 

[amol]

Not yet. I heard it makes the sound very bright and makes the sound with a frequency cut off at 15khz.

 

[Iron_Dreamer]

Quote:

Originally posted by john_jcb For instance changing from a AD to a LT device will be more significant than changing part numbers within the AD line.

I agree. The difference between the LT1122 and any of the AD chips in my RME is readily apparent, whereas the difference between the AD797 and AD8610 is very very subtle, and the AD8065 is a little more apparent, but still very subtle, The OPA627 also sounds quite different from the AD chips (in a good way IMO).

 

[Karlosak]

As it was said, the difference between op-amps is quite subtle. But it surely won't be difficult to find great amount of much smaller "subtleties" in the world of Audio.

To my ears, the difference between op-amps from different manufacturers (e.g. AD8610 x OPA627) is more evident than contrasts between for example cables (but this one is close), caps, lead-tin/silver solder, precision/generic resitors and so on... [going down the list the first derivation is quickly approaching zero...

]

 

[DeimosHG]

Quote:

Originally posted by Karlosak As it was said, the difference between op-amps is quite subtle. But it surely won't be difficult to find great amount of much smaller "subtleties" in the world of Audio.

For example I maintain a totally different audio system for each decile of relative humidity. I have hudistats everywhere and whenever it switches from, say, the 40%s to the 50%s, I grab my cd and set up my 6th decile system. True I rarely get to use my 1st, 2nd, 8th, or 9th decile systems, but when the humidity gets up there or down there, damn do those systems sing

 

[Glassman]

Quote:

Originally posted by DeimosHG For example I maintain a totally different audio system for each decile of relative humidity. I have hudistats everywhere and whenever it switches from, say, the 40%s to the 50%s, I grab my cd and set up my 6th decile system. True I rarely get to use my 1st, 2nd, 8th, or 9th decile systems, but when the humidity gets up there or down there, damn do those systems sing

I do it exactly the same way as you! but I've never been brave enought to bring it to the public

YOU ROCK!

 

[aos]

I think differences between opamps are not quite as subtle. It depends on the particular design though, in some cases the sound really won't change much. Then you have devices which can change quite significantly when you swap the opamp. E.g. put in AD8066 and suddenly the piano sounds synthetic. My ears aren't actually that good, and I can barely hear differences between cables and that only after a long comparison, but I can more easily hear the opamps. I'd like to think that I'm quite sensitive to colorations and that I get easily bothered with anything that doesn't sound neutral. Though overall the differences aren't that great, it depends on what music do you listen to. If it's something that only has bass and midrange (e.g. vocals) then you might not notice if you change AD8620 to AD8065, but if you listen to piano or violins you will. Also I've noticed big differences in bass with some opamps. Replace AD's with OPA2227 and it's like you added a subwoofer to the system - it was quite dramatic. Most of my listening is with speakers though so it might not necessarily be directly applicable to headphones.

 

[ppl]

aos> if you like the OPA-2227 for the Bass you might consider the AD-845. also while I also find the AD-8065 somewhat metallic sounding on strings and Keyboard this quality is very recording dependent and i am starting to think the AD-8065/66 may be so accurate that it is revealing the natural coloration of the recording.

I would expect an Op Amp to impart a more noticeable change to the sound than say cables, Resistors and caps since the Latter are Passive while the former is an Active device and as such would stand to reason that active devices would affect more of a sonic change than a purely Passive device.

Electromechanical transducers like Phono Pickup’s, Microphones, Loudspeakers and Headphones to have the most change.