I listened to these numerous times on both headphones and computer speakers. Any differences were minuscule as far as I could tell. On phones there was one sample I think I liked less than the others, on speakers I could hear no substantial differences, certainly not enough to state a clear preference for one them. In the absence of a clear preference I haven't actually voted.
But surely this is the wrong test? Would it not be at least a step in the right direction if we could also hear the original wav file to hear if the opamps have changed the sound in any way, i.e. so we could determine which opamp is most accurate.
Still, I'll be interested to see which opamps were used. It will be a scream if one of them is really the original...
But surely this is the wrong test? Would it not be at least a step in the right direction if we could also hear the original wav file to hear if the opamps have changed the sound in any way, i.e. so we could determine which opamp is most accurate.
Still, I'll be interested to see which opamps were used. It will be a scream if one of them is really the original...
Okay, I finally downloaded the files. See they are 16/48 format. Has anybody warned Windows users about the automatic SRC in shared mode that most audio apps use? If not, some people are probably listening as much or more to Windows lousy realtime sample rate conversion, as compared to the sound of different opamps.
EDIT: Too bad the record skipped. It's kind of annoying.
EDIT: Too bad the record skipped. It's kind of annoying.
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In my cheap but very optimized second system (with KEF Q100 speakers -cheap tweaked by me) the differences between aa and the others are not minuscule. The aa file does not have "life", "magic"...
And also the source directly, with no op amp, loaded with a resistor of the same value
as the other circuits' input impedances.
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In that case no, but you are making out an over exaggerated test which is NOT what is being carried on today.
In case you missed it :
What kind and level of audible differences would you expect in that case?
Specially after digitizing, up/downloading, decoding/playing back through listerer´s soundcard / amplifier / speakers ?
Some Forum Members would also add: power cable, oxygen content in copper, capacitor colour/brand/vintage, mains plug wiring, PT secondary phase, etc.
That´s why I compare such "Listening Tests" to touching some cloth for smoothness ( what the OpAmps would do) .... at the other side of a wall (everything between "there" and our ears "here").
EDIT: just saw this:
That´s what I meant .
That alone added a couple inches thickness to my proverbial "wall" .
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For people who know about Windows sound, or use ASIO drivers, no problems.
For non-inverting opamp circuits, opamp common mode performance may be an issue. Some opamps can invert the output if common mode signals are too high, some other opamps become more nonlinear and more likely to exhibit audible effects, and of course some still perform pretty well. Since we don't know which opamps and what signal levels, it's still quite possible for there to be audible effects.
Also, I gave an extreme example to make clear there are a whole range of possible effects depending on the circuit an opamp is put in. The effects can vary from small to medium to large. And when I gave the extreme example, the actual circuit had not yet been posted by PMA. His post was after mine.
Finally, regarding the proverbial wall, a number of people have listened to the files and don't think all the files are indistinguishable. To suggest without listening that flipping a coin would be as good as anything seems rather presumptive.
For non-inverting opamp circuits, opamp common mode performance may be an issue. Some opamps can invert the output if common mode signals are too high, some other opamps become more nonlinear and more likely to exhibit audible effects, and of course some still perform pretty well. Since we don't know which opamps and what signal levels, it's still quite possible for there to be audible effects.
Also, I gave an extreme example to make clear there are a whole range of possible effects depending on the circuit an opamp is put in. The effects can vary from small to medium to large. And when I gave the extreme example, the actual circuit had not yet been posted by PMA. His post was after mine.
Finally, regarding the proverbial wall, a number of people have listened to the files and don't think all the files are indistinguishable. To suggest without listening that flipping a coin would be as good as anything seems rather presumptive.
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Driving op-amps into known pathological situations or putting ridiculous loads on them just makes the comparison a waste of time.
I'll give it a try, but I'm downloading them to an external SD card player with no Windows issues at all.
Scott, please give me a break, I just like to make my examples interesting. Obviously, there are various degrees of, or levels of demand, that can be placed on opamps. I don't think it would necessarily be fair to only show them off in their very best light. That's something a marketing person might be inclined to do.
In addition, when we know nothing or little about test, it could potentially be anything. At the time I suggested the most extreme possibilities, PMA had not posted the schematic. And it might not be a waste of time, it could turn out to make a good, million selling guitar pedal. Who knows.
Also, it's easier for me to explain to someone that the opamps could be working hard than to explain that I can hear all sorts of things that are wrong/distorted in the files as they are. If I say that, then I may have to fend off audiophile accusations that I don't like as much or more than you don't like treating opamps unfairly.
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He had already said:
Who needs a schematic for that?
I know only one way to do that, which is to connect OUT to -IN and feed signal to +IN .
If you know 2 or more ways to do that, please post schematics so now I can worry: "oh my God, oh my God, I can´t sleep!! WHAT kind of circuit might Pavel have used?"
Otherwise, the circuit used was already on the table, from post #14, no need to wait for post #38
In any case, he had already excluded Op Amps with any gain, not even 10X , let alone 10000 .
Digging a little deeper, and with due respect to Pavel, this is not a very useful test for 2 main reasons:
1) a unity gain buffer is not a very useful building block.
Now if the test had been (hint, hint
) , say, a 10X to 100X gain stage, then we are talking.2) even worse, there is the certain possibility that in that specific task (unity gain buffer) , and that task only, *other* kind of ICs (Video buffers come to mind) might work better than regular Op Amps !!!!
Is that useful to us Audio buffs?
Okay, in that case I plead guilty to not reading more carefully. Sorry.
However, I still feel the cloth through the brick wall analogy is overstated. I'm not aware of anyone who is able to do that. And I still think the comments peppered with asterisks are pretty exaggerated. Maybe that's your sense of humor, I don't know.
I do believe people can hear differences between some of the files, so I would hope people don't take some of the exaggeration too seriously and not bother to give listening a try.
Maty, there are a lot of things you can hear in a sound. But most people can only perceive subjective sound pressure. When the sound pressure is low, the sound tends to have "no life". But the most accurate sound tend to have less pressure due to nonexistence of harmonics. So the "most lively" is not always the "most accurate"...
And liveliness and accuracy are only a few. There are more other properties of a recorded music...
shc, how are you listening? With speakers or headphones, your computer sound card or some other playback system, etc.? If using speakers, what distance and volume do you use?
I ask because I'm trying to better understand why some people report different listening experiences with some of these listening tests. Also, if we knew more about your listening situation, maybe we could figure out how to improve the chances for hearing some of the differences that others have described.
I ask because I'm trying to better understand why some people report different listening experiences with some of these listening tests. Also, if we knew more about your listening situation, maybe we could figure out how to improve the chances for hearing some of the differences that others have described.
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Yes I know Samuel Groner's work, great job on opamps measurements and finding differences.
However, the difference found at high noise gain by measurements, and the possible or rather certain audible differences with such high noise gain may disappear in a low-gain circuit. As opamps are often used as unity-gain buffers (and their sound in such circuits is reported), I wanted to make a test in such arrangement, rather than using a magnifying lens of high noise gain.
I think we are saying the same just in other words.
Very interesting thread, will listen over the next couple of days.
However we should all remember the above. So people can discern sounds better than others, like some people can discern different subtle types of of wines (to me a good wine is a good wine) but CD/computer files can never get close to LP playback.
Will let you know my impressions
Cheers
What? It sounded to me like the source for the listening test was a LP, and it has at least one loud pop in it. Also, it is well known there are many sources of distortion involved with records. So, it might help to understand what you mean if you could explain a little more about computer files verses LPs.
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