DPH:
Well otoh you might be unable to hear... or it might just be a mass delusion.
And quite the contrary I am NOT looking to find a difference at all.
I'd prefer to NOT find any.
That I do find one is both confounding and frankly a pain-in-the-rear.
Your projection of what I think or am "looking for" is asinine, frankly.
For the record, what does your "reference system" consist of?
I'll actually post should I be able to measure oscillations, clipping or for some strange reason a "current overload".
So, let's just get on the same page here, how would an op amp current "overload" when driving a 25kohm resistive load via low capacitance cable?
Clipping? On the output of a DAC where the nominal "0" level is <2.0v?? Really?
Now oscillations - definitely possible. We can see that with a scope, IF it were there.
Or do we need another means of detection?
However, how would these translate into a a change in tonal quality in a 4th order LP filter at say 75Hz. IF any were present?
Explain.
Well otoh you might be unable to hear... or it might just be a mass delusion.
And quite the contrary I am NOT looking to find a difference at all.
I'd prefer to NOT find any.
That I do find one is both confounding and frankly a pain-in-the-rear.
Your projection of what I think or am "looking for" is asinine, frankly.
For the record, what does your "reference system" consist of?
I'll actually post should I be able to measure oscillations, clipping or for some strange reason a "current overload".
So, let's just get on the same page here, how would an op amp current "overload" when driving a 25kohm resistive load via low capacitance cable?
Clipping? On the output of a DAC where the nominal "0" level is <2.0v?? Really?
Now oscillations - definitely possible. We can see that with a scope, IF it were there.
Or do we need another means of detection?
However, how would these translate into a a change in tonal quality in a 4th order LP filter at say 75Hz. IF any were present?
Explain.
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Those are some of the problems I have had to deal with using very sensitive condenser mics in conjunction where very accurate electronics. I once put a very fine condenser on a tambourine. You could hear each individual tin disk rattling, including that they were out of tune with each other, and they had warbling, dissonant overtones. It sounded awful. Off came the condenser, which was replaced by a $79 dynamic mic. It sounded much better then, and that's what we used for the final recording.
There is a fly in that ointment - that is the super-ultra low distortion opamps seemingly would not benefit from a pull up or other "class A" bias scheme for the opamp's output. How could they?
Been in the same boat too but when I was recording it was all tape. I can see how that would drive pro tools, or some such, crazy. But really, the more optimum solution would have been to get a better tamb. Or try some notch filtering, tube compressor with EQ'd side chain before the $79 mic. But I know how it feels with session time ticking away and musicians getting tired and such.
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I don't know what mechanism would cause an opamp used in a well designed circuit to make such distortion, but I know how such a thing could end up in a commercial recording. Read about the Aphex device here:
https://en.wikipedia.org/wiki/Exciter_(effect)
Long story short, this thing adds harmonic distortion (with before-and-after filtering, compression, and who-knows-what to make it less gross, more subtle and more "interesting") to the signal. I understand this was used mainly on vocals at the time, but since then I wouldn't be surprised to hear what all this and similar effects have been used on, including the two-track master.
But at least one group publicly disclaimed using the device (going against the grain of others' liner notes listed in the Wikipedia article), as the liner notes for this album explains:
https://www.discogs.com/Eagles-The-Long-Run/release/408432
Of course, the engineer's goal is to make it most pleasing to his ear, or what he thinks is most pleasing to the buyer's ear (mixing often involves sound checks with inexpensive speakers and/or in car stereos to make sure it sound as good as it can in lower-end equipment).
I've even heard (okay, read on rec.audio.pro) of several "pop music" processes (various effects added, editing together several performances to make a mistake-free "perfect" performance) being done in jazz and classical recordings, so it can be hard to know what was done to the original recording.
I don't know because I don't bother with them. All the ones I see in that category are too slow. How are you going to really know at 20v/us and some so-so power supply. That's what most are doing! 😉
Let me requote this because you're not getting your own gist. Or have a hard time seeing the trees for want of the forest.
CM distortion, well, pretty much any distortion in a relatively modern opamp running in it's well behaved region (as mentioned before, if it's the wrong opamp for the job, fine, pick the right one and fix your circuit, too), are SMALL. Go ahead, go look at Samuel's very excellent data. How far down are these errors on 1000x noise gain? How big are the differences in absolute terms? Relatively (%age wise) the best vs the worst is huge (100x better, what have you). But 100x smaller of a small number means the change is, on an absolute basis, small (e.g. a distortion that is -60 dB is 1/1000, so if you improve to -100 db, you're now 1/100,000; now, how much has it changed? 999/100,0000, or ~1/1000. Small change.). And when you're wanting the absolute best or need it for a highly demanding application, fine, that's cool. Line-level audio isn't a highly demanding application, phono/mic/I-V as I mentioned are the weakly arguable exception.
What you're describing above is tone control material--not opamp rolling differences. Unless, as I said, your opamp is misbehaving, in which case it IS a tone control. It's these sensational analogies that are just unbelievable, not "I tried a couple opamps at this location and they scoped out okay; think I heard a little difference and ___ makes me happier".
Unless, of course, you have the most magically exquisite ears and brain to hear differences orders of magnitude below our present understanding of "what matters" would suggest. (Yes, Mark, I am using magically exquisite in a pejorative sense. 😀) I'll stick to expecting horses when I hear hoof beats, not zebras.
You keep saying that, and yet, somehow, you *seem* to always find these differences. When does that protestation stop?
You know you've lost an argument when you try ad-hominem attacks to discredit someone else? Please start digging upwards. I suggest in a stair-like pattern so it makes it easier to get out.
Please register for your local community college's "intro to circuits" or similar title. It seems you could use a refresher, and I'm sure your classmates would appreciate your understanding of the universe.
Understood. Sometimes just one line transformer added between the preamp and ADC can work as a fix, by adding a little coloration to the sound (not too hi-fi of a transformer, that is, we want just a touch of audible distortion for this case). Anyway, the $79 mic was an SM-57, which is actually a very good mic, that just happens to be inexpensive. Also, it does need to be loaded correctly at the preamp to sound it's best.
So what is your "reference system"?
Please tell us so that I will try to believe that you are speaking from real experience, not some on-paper engineering perspective.
Anyhow, you've fastidiously avoided my specific questions. Good work.
Explain how an AD797 and an LME4563 can possibly sound any different from each other. They can't right?? Well perhaps used in some situation where one or more of the parameters are challenged - but not as an output buffer on a DAC.
According to what you seem to espouse, the 5534 ought to sound the same as the two mentioned above, yes?? Not enough difference to hear.
Your assertion of "tone control" would show up in a simple frequency response. Right?
Somehow I doubt that you've ever tried any of this yourself. Have you?
Why not tell about it?
And, I don't need to have "magic" ears - just about ANYONE can hear this, anytime.
Now as far as the power supply regulation purity, suggested by Moronix (I think) I'm ok with that, and should applying maximal power supply purity means render the differences between "good" opamps minimal and the sound then being "better", great. But again, this implies that the PSRR figures, which are generally very good, are not good enough and that the difference can be heard - which again flies in the face of what DPH asserts. It's too small to make a difference!!
You have contentless questions that are there for begging a question and validating your world view. I refuse to participate. I thought you were on better behavior, but no, you're still being pugnacious and obstinate. Carry on.
Sure.
You tell me to go to a community college for an intro to circuits course?
But you refuse to say anything about your self, your listening experience, your system or if you have ever actually tried any of this yourself??
You cite possible causes of opamps not working properly - all well known - and stop right there. That's all you bring??
You call me pugnacious and obstinate? Pheh.
Why bother to participate in such a thread, when your viewpoint is essentially that everything sounds the same unless the implementation is flawed?
You're one of these "participants" who snipes, makes negative statements and never takes a position, so that they never have to take a stand, get questioned or find out that they are not always in possession of the "truth". Holier than thou, never a good way to present oneself, but at least back it up with something very solid. Peh.
You tell me to go to a community college for an intro to circuits course?
But you refuse to say anything about your self, your listening experience, your system or if you have ever actually tried any of this yourself??
You cite possible causes of opamps not working properly - all well known - and stop right there. That's all you bring??
You call me pugnacious and obstinate? Pheh.
Why bother to participate in such a thread, when your viewpoint is essentially that everything sounds the same unless the implementation is flawed?
You're one of these "participants" who snipes, makes negative statements and never takes a position, so that they never have to take a stand, get questioned or find out that they are not always in possession of the "truth". Holier than thou, never a good way to present oneself, but at least back it up with something very solid. Peh.
I think there has been a miscommunication, Mark. You missed that possibility.
Thank you very much. Psychology is my interest, as I have told you before, which generated funny replies from Jacco 😀
Hi, thanks. I have bookmarked the website.
I'm using FoobarABX because there was a blind test thread on this site which promoted the use of it. Yes, I found that using digital files to understand the sound of distortions is useful.
That's interesting. I need to know what a 0.25dB difference is like 🙂
That's confusing. Of course it is possible because I found that -54dB (0.1995%) was very easy to detect. But some members here found that they couldn't detect that. -54dB was the limit in Klippel distortion test: Listening Test
I have years of activity listening just by ears. Of course it is 100% peeking but I'm 100% sure that I'm not imagining things. Otherwise, how can I have wasted my time to create the best sounding circuits that way (when I can simply measure or simulate)? I think it is not that -100dB that we hear...
Max,
I know you understand that different cables can give different measured impedance, inductance and capacitance, so why is it so hard to figure out why your could hear differences in playback? Now if you said you were using two identical cable types and the sound was different I would question your conclusion, but you just told us a real measurable component that can be quantitized.
I know you understand that different cables can give different measured impedance, inductance and capacitance, so why is it so hard to figure out why your could hear differences in playback? Now if you said you were using two identical cable types and the sound was different I would question your conclusion, but you just told us a real measurable component that can be quantitized.
My question about this talk of hearing a difference between two tracks one .25db different or even 1db of difference is are we talking about a difference that is across the entire FR and exactly the same over the entire bandwidth or are we talking about high "Q" peaks or 1/4 or even 1 db differences which I can totally understand being able to quickly identify? And at what reference level are you doing these tests, at 85db or at 100db a very different type of difference based on our hearing acuity at differing spl levels.
As I hear it, the mechanism is simple. But I can assure you that it is a subjective preference, not absolute. For most ears, yes, that is the case, but for better ears, the opposite is true.
When distortions are added to a signal, the signal will appear to have higher SPL. You can hear a "wide" sound that tricks the ears as if you can hear a lot more details. A clean signal OTOH, will sound like a needle, the (natural) harmonics of the sound are almost undetected.
The distortion seems to fix the problem with human ears to hear such harmonics that should available with natural sound, but there is trade-off. The sound will lose its quality. Easy is when you hear human vocal. If you can focus your ears to listen to the micro details of the vocal, you will found out that high distortion vocal doesn't sound like human. Or, another way I do it in blind test is, I will perceive as if the singer cannot sing well.
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