I think he can't imagine them sounding different in a circuit like that, so assumes if they do sound different, the only explanation would have to be that they are somehow misused.
(maybe someone should start by telling Jay that the lowest discernible difference in SPL depends on the medium, not his ears)
Different opamps require different treatment to work properly (or optimally). Some say that opamp rolling (into fixed circuit) is wrong because one circuit may work for one but not for the other...
Hence the point: build a proper circuit for opamp A and build a proper circuit for opamp B.
I guess output buffer is less challenging for most opamps. Of course some opamps cannot be easily used for gain=1 but most of good ones can.
Toole & Olive was using pink noise with 5kHz resonance and Q=1. The threshold was 0.25dB. For music they said, it should be higher than that.
Yes, I believe I can do better than that. How much better, it depends on whether you want to setup the test or not 😀
Why I'm sure I can do better? First, I have passed a test similar to their distortion test and I could pass the threshold very easily. Of course, I have my own empirical threshold number but even I can't be sure if the number is correct (it looks ridiculously low) but at least I know that my threshold is lower.
Second, similar to the above, I have my own empirical threshold number for the sound pressure (at ABX normal listening level). Yes, it is below 0.1dB. I don't want to assume if the number is properly measured or all the controls are properly in place.
You know, my hypothesis is that human are so poor in utilizing their brain. They have very poor ability to perceive differences such as in ABX while I believe that their brain can do it at sub-coscious level...
I believe that human potential for things like this is very high, much higher than realized.
Oh by the way, Jacco... I can pick at least 3 persons at my work (and they are above average) who believe that I can blindly guess the card they take from a deck only by using my "imagination" (it is as if the card show up in my mind). Of course, everyone will not believe it at first but in the end they have to say "Okay, now I believe you. I'm truly convinced" 😀😀😀
Okay, that's a joke (I'm afraid that's too hard) 😀
I could tell, but then I'd have to kill you all.
Signal embedded noise triggers/moderates system noise, good for creativity, not good for playback.
Gear signature is due to system internal noise mechanisms and consequent noise spectrums which alter envelope behavior, the elephant in the room that our ears are critically sensitive to, and this envelope sensitivity increases with age/hearing loss/experience.
These inherent system noises are signal dependent, and cause a pseudo random cloud of modulation/intermodulation products which causes masking and additionally, perceived distortions, ie system noises are not good noises.
That said, these system noises have signal dependent spectral behaviors, and can constitute the subjective signatures that separate similar measuring very low distortion gear.
This signature can be deliberately or inadvertently tailored by component choices, but this direction is just 'bending' the system complex noise behaviors.
My direction is in essentially removing signal dependent system noise behaviors and I believe I have achieved this.
The result is that just about any analogue audio device sounds 'correct', no embellishments, no reductions, just matter of fact clean, clear, detailed real sound.
Digital is a whole other subject.
Dan.
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0.1 dB is relative. If output voltage or SPL, then it's 1.2% difference. If it's output power or intensity, then 2.3%. Either way, 0.1 dB is > 1%. In other words, 0.1 dB isn't as little as it seems. dB SPL difference is also different for different frequencies.
Honestly, it seems 0.1 dB is completely arbitrary.
If I was listening in a completely controlled environment and changed the *level* by 0.01 dB, I'd probably say I heard the change. Placebo.
Just to make sure we're on the same page, here I have 2 files (Change ASC into MP3). What is the difference between these two files in 2 decimal places?
And may I add, whichever one you listen to second will sound slightly louder because the clip starts off loud and the average volume decreases until the end.
Interesting. Once I thought it was up and down and up and down.
But that's not going to make an ABX any easier, is it?
When mixing two tracks in a song and trying balance them perfectly, I have found 0.2 db discernible, but not quite 0.1 db. This is according to the digital mixer display. The smallest resolution it allows is 0.1 db, so I don't know exactly where between 0.1 and 0.2 my absolute best might have been. Even then, 0.2 is quite tiny. And without the two tracks to minutely compare when I adjusted one of them, I don't think I could have done 0.2.
You know, I've supported the fact that it's possible to probably hear a difference between op amps. But you're just throwing yourself into a hole.
Byte for byte, those files are identical.
static void TestFiles(string file1, string file2)
{
byte[] file1Data = File.ReadAllBytes(file1);
byte[] file2Data = File.ReadAllBytes(file2);
int differentBytes = 0;
for (int i = 0; i < file1Data.Length; i++)
{
if (file2Data.Length <= i)
{
differentBytes++;
continue;
}
if (file1Data != file2Data)
{
differentBytes++;
}
}
Console.WriteLine("There are {0} bytes difference between the files", differentBytes);
}
An externally hosted image should be here but it was not working when we last tested it.
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