People aren't thinking in that direction. They are asking why some things seem to sound better after some time passes. Some of it may be due to actual burn-in, and some of it undoubtedly has to do with psychological adaptation. But, I don't think we can prove it all has to do with the latter.
Regarding capacitors and burn-in, at least we could do some experiments to find out. Let some listeners adapt over time to some burned-in caps, then swap out the caps with new ones. Since we are starting from a long term listening condition (listening for awhile to burned-in), any small audible changes due to unburned-in caps should be as noticeable as they ever will be. That's when human perception should be most acute. (Have to make sure the caps have the same measured values, of course)
In addition, it's been known for a long time that arguments about what should or shouldn't happen are no substitute for experiments to determine truth. Not that the found truth never changes, but it's the best we know how to do and its part of the process of science. That is, science is a process and not a result.
Also, as long as people hear effects that are of unproven origin they will have an interest in finding a cause. If they can't find out the truth, many or most will construct the best story they can and believe that. True if a scientific sounding story or a supernatural one.
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Do you recall other's subjective evaluations/descriptions of this audibility ?.
Reprints of TAA article ?.
IME seemingly 'same/similar' construction PP caps can each have pleasant characteristic 'flavour', subtly different but present.....are all PP films the same and what about metalisation process differences.....and lead out material and platings.....and..... ?.
Other dielectric types and associated constructions each have their own nuances IME and these may be or may not be pleasing.
And with modern economic ic/opamp do-ability win/win....why not ?.
How about, how tightly they are wound? Dimensional stability under electric field forces is necessary for constant C.
Scott,
As usual, if you set your input coupling capacitor to equal the input resistance at 20 hertz what do you think the phase shift is at 20 hertz? (Trick question.). Now with much musical energy at 50-150 hertz what is the phase shift there?
Linear means the graph is a straight line. But as everyone likes to use different definitions....
Fair enough, but that still doesn't solve the intriguing fact that everybody always reports that things improve after 'burn in'. Never 'after burn-in it really sounded horrible, as if a veil was put in front of it'.
That's curious, and points to an overwhelming psychological effect.
Jan
One cap manu tested this with a laser interferometer and found the changes in dimension less than an atom of the foil material. It's a non-issue.
Jan
A psychological effect could be reluctance to talk about how it sounds if it sounds worse. People don't always like to make public admissions if they made a mistake buying something. Sometimes they do, it depends.
Also, we may not pay much attention to somebody who says they didn't notice any difference. What attracts our attention tends to be reports of sensational results. Then we are affected by availability bias, more striking memories come to mind more readily, and the heuristic for what is more believed to be more common or probable is based on what comes to mind most easily. That is, the ease of recalling a few cases of sensational reports makes it seem like almost all reports are sensational. Things that take more effort to recall tend to be judged as less probable or less common.
There a lots of ways for bias to work, and all of them are always in play.
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Ed we were talking the deviation from ideal due to DA. Give up on the linear thing, you were wrong so what move on. I would never attempt to comment on your PA business.
There are many mathematical systems that rely on linearity and time invariance. There is an accepted definition of a linear process it has nothing to do with straight lines.
That is if you decompose a signal into its Fourier components and individually pass them through a linear process and recombine them you get the same answer as passing the whole signal through the same process. This is not true of a nonlinear process. It is true of an ideal R/C filter.
Mark, you know that does not work like that. You know that the way it works is that they ALWAYS feel like it sounds better, looks better, is better because they sunk cost into it.
That is at the root of the phenomena that after burn-in, it ALWAYS sounds better. Psychology 101.
Jan
Thank you Mark for your intelligent posting.
Over time further differences get noted and same deal, psychological adaptations are not universal.
That said, education/indoctrination/hypnotism can cloud terms of reference of 'scientific' investigation.
I have done enough subjective AB experiments to verify to my satisfaction the proposition that some wires/cable assy's can be directional, whereas standard theory holds this to be impossible AFAIK.
Standard scientific testing denying this finding will then preclude inclusion of wire/cable direction as a variable in experimental testing and measurement.
IOW scientific explanation is as good only as the inclusion of input variables considered.
Deliberate or ignorant exclusions can cause obscuration of truths.
It matters zero if the repeatable subjective/observed effect concerned is 'explained' in snake oil terms, the interest is in the physics why.
Dan.
Most certainly there is the former, and the latter is not universal.
Yes, such step change is when fine differences immediately get noticed, and repeated fast/instant AB comparisons hone discrimination of and identification of differences.
Over time further differences get noted and same deal, psychological adaptations are not universal.
Yes science is a process of rigour, be it in observation or in experiment to determine outcome of predictions.
That said, education/indoctrination/hypnotism can cloud terms of reference of 'scientific' investigation.
I have done enough subjective AB experiments to verify to my satisfaction the proposition that some wires/cable assy's can be directional, whereas standard theory holds this to be impossible AFAIK.
Standard scientific testing denying this finding will then preclude inclusion of wire/cable direction as a variable in experimental testing and measurement.
IOW scientific explanation is as good only as the inclusion of input variables considered.
Deliberate or ignorant exclusions can cause obscuration of truths.
I treat these stories as allegories, describing observed effects with a semi 'plausible' explanation.
It matters zero if the repeatable subjective/observed effect concerned is 'explained' in snake oil terms, the interest is in the physics why.
Dan.
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Thanks, I/we know that already, and thanks for saying so.....is that the only difference between on first inspection 'same' caps ?.
Dan.
Bragging rights. Some even go as far as putting their car in orbit around the sun! All for a good story! 🙂
Jan
There are plenty of boutique/classic/collectible pedals commanding extreme prices.....these are coveted because of definite audible characteristics.
Expensive/particular caps may or may not be involved.
Dan.
IIRC, maybe it was DF96 or jneutron, who pointed out at high enough frequencies cables may appear directional to some extent due to various factors, but what theory tells us is that at anywhere near audio frequencies, and especially for short cable lengths there is no known justification for believing cables ought to be directional. To be directional, there would have to be things like dimensional variations in cable construction on the order of significant fraction of a wavelength. At audio frequencies cables and cable terminations dimensional variations are much, much, much smaller than audio wavelengths of interest. Up at GHz frequencies, audio cables would also be very lossy due to complex dielectric constant of insulation, there would be all kinds of quirky resonance modes, etc. Those things just don't happen anywhere at all like that at audio frequencies. No comparison.
People also talk about OFC verses normal copper wire as though it should make a difference. The thing is current flow and electron flow are two very different things. Current flows much faster than electrons hop along. To make a water pipe analogy, its like you had a water pipe 20ft. in diameter and you want to move one cup of water per minute. How fast does the water have to move in the pipe in miles per second? Of course, because copper wire has resistance which causes heat, if you tried to get most of the electrons moving at once, it would get quite hot, but not for long. 😉
(Add usual, include disclaimer about analogies being imperfect)
A Tube Screamer pedal or clone thereof doesn't cost $200. Most of the cost is for the rugged case you can step on all you want. Inside is an op-amp, some diodes, a few other parts, and variable bandpass filter using tantalum caps. It sounds better with tantalum, they give a little swish to the sound as the amplitude changes. Those pedals have been used on lots of records, they sound pretty good for a bluesy lightly distorted effect.
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