Well, we could talk about opamps in circuits such as the one in the attached image. Sounds great for many things and is quite famous.
Also, notice the .22uf tantalum capacitors in the tone circuit. Gotta love that sound!
Back to back diodes and a distortion pot, and the stupid comments about the sound of each op-amp in that socket will still ensue.
The thing is, if you change the op-amp, it will usually sound different. If you change the diodes, maybe or maybe not. Going from 1N914 to 1N4007 doesn't sound much different to me. LEDs usually change the sound some, as might be expected.
That being the case, it's not clear why one would say that comments about changing the op-amps are stupid. Why would talking about a real effect be stupid? Just because nonlinearity is being exploited?
Real? By what process, this case stretches the imagination to the limit. It's an effects box, driving an amplifier outside its specified operating range has nothing to do with with its intended use. 1N4148's as clippers sound different than 1N34's who cares? What does an effects box have to do with amplifying a signal as a precision instrument would?
It's not the same as a precision instrument, obviously. It's a musical sound effect, which is a perfectly legitimate application. Even so, if whoever designed the thing never anticipated it's usefulness for that purpose.
Somehow, after having designed such things for precision instrumentation and similar applications, you seem offended that someone would use it to make music in a way you didn't intend. Are people only supposed to do what you want them to or what?
It's like a guy who makes cowbells for cows being offended that someone would use one to make music.
Somehow, after having designed such things for precision instrumentation and similar applications, you seem offended that someone would use it to make music in a way you didn't intend. Are people only supposed to do what you want them to or what?
It's like a guy who makes cowbells for cows being offended that someone would use one to make music.
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Thank you, Ed. My MA1458 (should be repeated that it is a dual 741) used in the test was produced about 1980 - 1985. Yes, not 50+, only 30+ years old sample
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A 20dB line stage or phono pre-amp is usually not designed as an effects box. With respect to music I have no intent, if you want distortion I don't care, I suspect everyone would tweak the pots to a different place. If you want to distort the signal provided on a tape, CD, or LP to your taste these discussions have little point.
Although some people may like a very small amount of distortion in a music reproduction system, it's not a preference here.
But, I do like electric guitars and the classic effects used to make the music I listened to when I was growing up. In that vein, guitar and other musical effects circuits seem fun and interesting. Don't know how everyone else feels about it though.
But, I do like electric guitars and the classic effects used to make the music I listened to when I was growing up. In that vein, guitar and other musical effects circuits seem fun and interesting. Don't know how everyone else feels about it though.
Well given that the challenge was if anyone could detect their preference with foobar ABX, carefully setup to prevent the cheaters that often appear it is right of Pavel to point this out. Zero positive ABX results. This in itself is important, even with the limited set of results. If there was a clearly detectable signature there would have been at least one result surely?
One can argue that Foobar ABX is not up to the task, but it seems to allow flexibility for the user to run it the way they want. Not AES grade, but certainly good enough to make the point.
Bill, I have to disagree about Foobar. It's fine for demonstrating detection of more obvious differences, ones that are distinctive enough to memorize for a little while.
But for detection of very, very small complex differences, which are not especially memorizable, it is completely unsuitable, IMO. Lots of people have said more or less the same thing, including people like Bob Lugwig, and many others. After my recent efforts, I will add myself to the list.
I did say I thought if Foobar had a loop feature it might help a lot. I would have to try it and see. Otherwise, I would suggest someone write a sorting test program, with looping, and with security features for results verification.
To make an analogy, and yes I know all analogies fail at some point, suppose you have an oscilloscope program that works with your sound card and you use it for lots of stuff. But one day you build an amplifier that may be oscillating at 400 MHz. Someone may insist there cannot possibly be an oscillation because the oscilloscope shows no such thing.
The main difference between the analogy and Foobar testing, is that we know all about oscilloscopes, what they can and can't do, and what it means to have a 400MHz oscillation.
When it comes to Foobar, we don't know the limits of what it is good for testing. We might imagine it should work for anything and everything, but that is just imagination. There is no study or science to support that view.
Where are we with the science for measuring ability to detect small differences in distortion? Not very far, I would say. I have some personal experience that sorting with looping is more sensitive than Foobar ABX. But, it's only one anecdotal report. It needs to be studied more carefully and extensively if we are serious about developing technology for measuring limits of listening brain DSP.
That's my opinion.
But for detection of very, very small complex differences, which are not especially memorizable, it is completely unsuitable, IMO. Lots of people have said more or less the same thing, including people like Bob Lugwig, and many others. After my recent efforts, I will add myself to the list.
I did say I thought if Foobar had a loop feature it might help a lot. I would have to try it and see. Otherwise, I would suggest someone write a sorting test program, with looping, and with security features for results verification.
To make an analogy, and yes I know all analogies fail at some point, suppose you have an oscilloscope program that works with your sound card and you use it for lots of stuff. But one day you build an amplifier that may be oscillating at 400 MHz. Someone may insist there cannot possibly be an oscillation because the oscilloscope shows no such thing.
The main difference between the analogy and Foobar testing, is that we know all about oscilloscopes, what they can and can't do, and what it means to have a 400MHz oscillation.
When it comes to Foobar, we don't know the limits of what it is good for testing. We might imagine it should work for anything and everything, but that is just imagination. There is no study or science to support that view.
Where are we with the science for measuring ability to detect small differences in distortion? Not very far, I would say. I have some personal experience that sorting with looping is more sensitive than Foobar ABX. But, it's only one anecdotal report. It needs to be studied more carefully and extensively if we are serious about developing technology for measuring limits of listening brain DSP.
That's my opinion.
Every analogy is off track at some point.
We were trying to pin down if people can actually hear differences between opamps in a particular circuit. To make detection harder for the listeners, the signals went through less than the best A/D conversion after passing through the opamps. Before you scoff, one A/D has a lot more going on in it that one non-inverting opamp buffer. To think that the opamp buffer might add some distortion but the A/D wouldn't would seem quite unlikely.
However, despite the handicap there were still detectable differences.
I could sort the files pretty well, but could not do pretty well with Foobar. In fact, I get negative correlation with Foobar which is not an indication of guessing, because it's not random.
Between my results with sorting and with Foobar, as far as my opinion goes, we have prima facie evidence that there is some problem with Foobar that is not present with sorting.
The only real thing in favor of Foobar is that it already exists, it's free, and it has some anti-cheat features. Well, that makes it look pretty perfect if that's all one happens to care about.
But there is just one nagging problem, multiple people rated the files with some correlation or reverse correlation relative to the opamp measurements.
Oops! Well, let's just ignore that little inconvenience and brush it under the rug. After all, Foobar is free, has security, and its easy to imagine that it should work (like someone could unwittingly imagine a limited bandwidth scope should work).
What me worry? - Alfred E. Neuman
We were trying to pin down if people can actually hear differences between opamps in a particular circuit. To make detection harder for the listeners, the signals went through less than the best A/D conversion after passing through the opamps. Before you scoff, one A/D has a lot more going on in it that one non-inverting opamp buffer. To think that the opamp buffer might add some distortion but the A/D wouldn't would seem quite unlikely.
However, despite the handicap there were still detectable differences.
I could sort the files pretty well, but could not do pretty well with Foobar. In fact, I get negative correlation with Foobar which is not an indication of guessing, because it's not random.
Between my results with sorting and with Foobar, as far as my opinion goes, we have prima facie evidence that there is some problem with Foobar that is not present with sorting.
The only real thing in favor of Foobar is that it already exists, it's free, and it has some anti-cheat features. Well, that makes it look pretty perfect if that's all one happens to care about.
But there is just one nagging problem, multiple people rated the files with some correlation or reverse correlation relative to the opamp measurements.
Oops! Well, let's just ignore that little inconvenience and brush it under the rug. After all, Foobar is free, has security, and its easy to imagine that it should work (like someone could unwittingly imagine a limited bandwidth scope should work).
What me worry? - Alfred E. Neuman
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Is that preference based on the samples provided by PMA or some previous experience? Did you listen to PMA's samples and vote in the poll?
Am I mistaken in my understanding that most people cannot detect the insertion of an A/D-D/A loop in their playback system? It is my impression that this has been tested many times. (OTOH sighted listeners regularly hear a difference when they *think* an A/D-D/A loop has been inserted, even when nothing has changed.)
Why is that a problem? Whose problem? Wasn't that the point of the test?
It wouldn't be surprising if many or most people can't or don't notice some A-D-A loop. But, some people can. It can take some practice to learn what to listen for. Besides practice, it may take good enough playback system, and near field monitoring.
In case the discussion involving a problem was not clear, some people seem to have correctly correlated the op-amps with their measurements, so yes, that was the point of the test. However, nobody produced a Foobar ABX result making the same file differentiation. If one has strong faith that Foobar ABX is well suited for measuring the limits of human listening perception, then there would appear to be a problem. How can people differentiate opamps in pretty good correlation with their measurements if those same people can't score high on a Foobar ABX test? And why do some people have a reverse correlation with Foobar? They must not be guessing because guessing is random, and reverse correlation is not random.
Markw4, what I don't really understand is why you are insisting ABX test. uu is not obviously different from the other files for you? It should be.
If one can hear the difference, he can choose whatever he wants choose. We can't control someone's personal taste, even it is not correlated to the measurement. I personaly thought uu is the best in this selection, and I don't see any reason that I have to change my preference after I know it is 072.
If one can hear the difference, he can choose whatever he wants choose. We can't control someone's personal taste, even it is not correlated to the measurement. I personaly thought uu is the best in this selection, and I don't see any reason that I have to change my preference after I know it is 072.
Then it's a good thing that nobody made that claim.
Not sure what you mean by reverse correlation. Do you mean in this test or some others? Do you mean that listeners consistently identified the unknown "X" sample with the wrong source? How would you explain that? If we accept the evidence, and I see no reason not to, then can you conceive of any reason why that might happen? I can think of a few, but I'm sure you are far more capable than I in these matters.
The differences aren't that obvious to me now. They probably would have been at one time. It's that I'm getting old, have hearing loss (can't hear HF), and have some tinnitus (ringing in the ears). While I can hear differences, it's much easier if I can pick a spot here or there in the files to concentrate on.
Why bother with ABX? (1) At face value, it seems like it should work, even though there seem to be problems with it in practice. I would like to better understand the science behind that. And, I am still curious to find out if it can work at all for the differences in question. (2) People around here who claim to be able to hear things like the differences have been confronted with heavy skepticism at the least, and at the worst may have been forced to shut up or leave. I have wanted to see that situation improve, which it has, but there is still is little more room to go. (3) People who claim that there are no audible differences tend to be supported by prior published research, and I think it is probably time that the literature on this subject be updated and corrected. In relation to that, I want to encourage calm thoughtful discussion of the subject in a way that is respectful of all views. Among other things that means that concerns of more skeptical people should be taken seriously and an effort made to try to find ways to prevent cheating and exaggerated claims. Therefore, finding a way to make Foobar ABX work, or to provide some equivalent means, is necessary to address legitimate concerns.
Okay, maybe that was about a little more than the question of why try ABX? But, hopefully you get the idea. Somebody needs to figure out how to make it work, or figure out why that it can't.
One of my conclusions with this test is that I will not use foobar2000 again for any future tests in my second system (with PC).
With J River Media Center 22 I was able to detect high frequency distortion with the TL02, while with foobar2000 it was the audio I liked the most.
Also it is logical, JRMC 22 is the player that I use to enjoy the music, except for SACD ISO because they sound better with foobar2000 (with SuperAudio CD Decoder, well configured).
With J River Media Center 22 I was able to detect high frequency distortion with the TL02, while with foobar2000 it was the audio I liked the most.
Also it is logical, JRMC 22 is the player that I use to enjoy the music, except for SACD ISO because they sound better with foobar2000 (with SuperAudio CD Decoder, well configured).
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