It's not a different discussion at all. You're claiming a difference in the sound after some so called "burn-in" and I'm simply asking what exactly changed. Something must have changed if there is a difference. So what was it?
Initial aging often proceeds at a rapid pace for some period time then slows down until EOL approaches, whence it may speed up again. Maybe similar to a "bathtub" curve.
If there are many devices, then there may be many aging processing going on at once.
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If it sounds better after burn-in, then count yourself lucky.
😉
😉
I've always been very lucky. Don't recall ever having the sound go the other way, but it's not impossible.
Certainly I've seen people get all excited about a new component, and then have that enthusiasm fade after a while.
JGH was kind of known for that, bless him. But I don't think it was the bathtub curve doing that.
He was basically an optimist, but was too often disappointed.
Certainly I've seen people get all excited about a new component, and then have that enthusiasm fade after a while.
JGH was kind of known for that, bless him. But I don't think it was the bathtub curve doing that.
He was basically an optimist, but was too often disappointed.
But to the engineer who designs them they are not just black boxes.
They are, in fact, very well understood circuits whose performance characteristics can be predicted with great accuracy. And nowhere in these predictions is there any indication of the sound output being affected by the power supply filter capacitors. Their purpose is simply to smooth out the AC ripple that rides on top of the DC voltages generated by the power supply.
Even if a small variation in capacitance occurred over time it would be insignificant relative to the overall capacitance and there is no path through which the listener would know the difference. None.
Fine. Explain then in engineering terms how a filter capacitor in a power supply can change enough with so called "burn-in" to actually make a difference in the sound output of the amplifier.
Or if it's not the power supply that is changing what is.
Or if it's not the power supply that is changing what is.
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I find burn in is complete when the wife walks past your new piece of kit and no longer says "that cost you how much?"
If someone believes we know how to measure everything we can hear with common audio measurement instruments, there is a lot that person doesn't know. To start off, how does one measure sound stage depth, and lateral localization?
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Then there is the long list of stuff ESS talked about, some of which do not show up in standard measurements.
From the ESS Hyperstream Modulator presentation:
There is a slide which initiates discussion about audiophiles with the words, "Understanding what audiophiles are hearing."
"The surprising reality is that sigma-delta DACs can be audibly distinguished from a conventional DAC despite measuring very much better than that DAC."
"...an important point: The human ear detects signals well below the noise level of the DAC."
"The ear is exquisitely sensitive to "unusual" noise sources. Your ancestors camped out by a waterfall (white noise) and yet their 'ears pricked up" when they heard a hint of a predator moving in the undergrowth. (The equivalent visual phenomenon is "seeing something out of the corner of your eye). Noise, to a large degree, can be accommodated by the ear and is not troubling, but the tiniest "anomalous" noise is raised to the conscious level."
"Sigma-delta modulators create non-periodic steady state noise (non-PSS) artifacts..."
"Periodic Steady State analysis is common in RF circuits. It means that the system is forced to repeat a pattern of behavior over and over again with a certain time period. Any artifact is presumed to also repeat in this time period."
"Audio measurements such as THD and DNR are done in the Periodic Steady State. Therefore, they will not activate non-PSS noise. You will not find non-PSS noise by looking at THD, DNR, and SNR."
"As the audio signal moves, the noise does not remain the same."
"Non-PSS noise is the biggest issue, but experiments suggest there are more problems. For example: Audiophiles rate as inferior systems that have variable excess phase noise."
"We find that an unconditionally stable loop sounds better in listening tests."
Link to Yumpu Presentation:
https://www.yumpu.com/en/document/read/23182504/noise-shaping-sigma-delta-dacs-ess-technology-inc
"WHY AUDIOPHILES KNOW BY LISTENING IF ITS A SIGMA-DELTA DAC" starts on page 28 of the yompu presentation.
At ASR:
https://www.audiosciencereview.com/forum/index.php?threads/ess-thd-‘hump’-investigation.5752/page-5#post-134135
Additional info at 6 Moons:
Where ESS talks about doing MANY LISTENIG TESTS.
https://6moons.com/audioreviews2/resonessence/2.html
More at ASR about ESS and TI paper on modulator idle tones:
https://www.audiosciencereview.com/forum/index.php?threads/ess-thd-‘hump’-investigation.5752/post-150331
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Then there is stuff about noise and distortions in dacs that are not really noise nor really distortion from a nonlinear transfer characteristic. They just look that way on FFTs.
https://www.diyaudio.com/community/threads/return-to-zero-shift-register-firdac.379406/post-7636229 and
https://www.diyaudio.com/community/threads/return-to-zero-shift-register-firdac.379406/post-7686002 ? Or rather the discussion about partly passive filtering?
We have a very-low-level frequency-modulated tone added to the audio signal with some modulator types. As its carrier frequency is very close to zero, it looks like harmonic distortion on a DFT plot until you zoom in. It is in fact due to intermodulation between quite-high-level frequency-modulated tones around half the DSD rate.
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Then there are the infinite number of types of white noise:
So long as we are on the subject of noise, hopefully we are all up to date on the nature of white noise, and its appearance on a typical audio FFT.
There is a graph of white noise types in this article, which may surprise some people:
https://www.edge.org/response-detail/11715
It turns out that noise can look white on an FFT, and even if at a very low level, it may or may not be audible. It all depends on the process producing the noise and its probability distribution (which is related to the phase distribution of the noise).
In the most extreme case white noise can be in the form of a Dirac Function (impulse).
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In terms of electrolytic caps, their storage capacity, DA, etc., can change from one day to the next depending on their recent history. There was some data about that around here very recently. Have to see if I can find it. Whether or not it can be heard depends on the non-ideal PSRR of the circuit its powering. Nothing new about that.
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The point of all this is to make clear that simplified models of how audio circuits work and how we measure them are something of a engineer-created fantasy. In fact, the IEEE book, "Grounds for Grounding," makes that very point about the concept of ground. Here is what they say: "An “Ideal Ground” is a very convenient fantasy invented by engineers to simplify life but, like other fantasies, does not exist in reality."
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In science, students begin with oversimplified ideas because they lack the foundation to understand
anything more complex. But as one progresses in a scientific field, far more depth and complexity is found.
Attempting to answer a single question will open up many further questions, and so on.
The measured performance of audio equipment is the engineering part, but there is more to it than that.
Despite what some may say, we do not know everything, or even close to it. As Newton said, "I do not know
what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore,
and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary,
whilst the great ocean of truth lay all undiscovered before me."
Parts in the schematic work perfectly. The ones soldered into your circuit do not.
Engineers stopped having to build their own parts a century ago, thank goodness.
You just select and buy them, and use them according to the data sheet.
Otherwise you could have rather drastic consequences, such as fire, loss of job, lawsuits, etc.
That doesn't mean the chosen parts are perfect, just that their particular imperfections
are acceptable for the application, within the constraints that you have.
But using one's judgement dealing with the imperfections and their impact on the final sound quality is art.
This art cannot be easily taught, but rather must be learned from direct experience over a period of time.
And, of course, some artists are better than others.
anything more complex. But as one progresses in a scientific field, far more depth and complexity is found.
Attempting to answer a single question will open up many further questions, and so on.
The measured performance of audio equipment is the engineering part, but there is more to it than that.
Despite what some may say, we do not know everything, or even close to it. As Newton said, "I do not know
what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore,
and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary,
whilst the great ocean of truth lay all undiscovered before me."
Parts in the schematic work perfectly. The ones soldered into your circuit do not.
Engineers stopped having to build their own parts a century ago, thank goodness.
You just select and buy them, and use them according to the data sheet.
Otherwise you could have rather drastic consequences, such as fire, loss of job, lawsuits, etc.
That doesn't mean the chosen parts are perfect, just that their particular imperfections
are acceptable for the application, within the constraints that you have.
But using one's judgement dealing with the imperfections and their impact on the final sound quality is art.
This art cannot be easily taught, but rather must be learned from direct experience over a period of time.
And, of course, some artists are better than others.
Most of what you wrote above is perfectly fine but has nothing to do with the issue at hand. Namely, does so called "burn-in" significantly change the sound of an amplifier. Or even change it a little bit.
With regard to electrolytic capacitors, it is not possible for their storage capacity to change in any major way from day to day. Over long periods of time, many years, yes changes do occur. But from day to day, no.
Finally, you have provided no scientific evidence or testing reports from studies that burn-in makes any difference in the sound whatsoever.
But really grips me are sentences like this:
"The point of all this is to make clear that simplified models of how audio circuits work and how we measure them are something of a engineer-created fantasy."
You have that completely backwards. Engineers do not live in a fantasy world, but quite clearly some of the people here that think burn-in changes what you hear from an amplifier do live in that world.
Remember, these are the same engineers that designed the equipment in the first place. They understand how it works far better than the burn-in pundits here.
rayma,
What you said in Post #31 is all well and good. But it has absolutely nothing to do with the subject of whether "burn-in" makes any difference to the performance of an amplifier. You have shown nothing to support the idea that it does.
What you said in Post #31 is all well and good. But it has absolutely nothing to do with the subject of whether "burn-in" makes any difference to the performance of an amplifier. You have shown nothing to support the idea that it does.
So what does the engineer who designed the equipment say,
since he understands how it works far better than the burn-in pundits here.?
since he understands how it works far better than the burn-in pundits here.?
Of course there is not published research on every possible thing. Never will be. It almost seems surreal to have say that.
Anyway, there is some info on electrolytic caps in my collection maybe some people here aren't familiar with. What exists will have to do for now.
Anyway, there is some info on electrolytic caps in my collection maybe some people here aren't familiar with. What exists will have to do for now.
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Burn in is a major issue for high end manufacturers, even high quality parts including semiconductors need burn in in a very short time
Poor quality parts may never burn in and may start off with very high glare, brightness and harshness in the ultrasonic range, these reach very high spl with very little power consumption
Have a look at this https://www.diyaudio.com/community/threads/break-in.415795/#post-7751295
Poor quality parts may never burn in and may start off with very high glare, brightness and harshness in the ultrasonic range, these reach very high spl with very little power consumption
Have a look at this https://www.diyaudio.com/community/threads/break-in.415795/#post-7751295
I used to watch a lot of Paul McGowan but stopped a few years ago when he posted a video touting the benefits of cable risers. That destroyed any credibility he had had with me. So, I completely ignore him now.
Also keep in mind that as an equipment manufacturer he needs to run all new products for a long enough period to find any early component failures, which do occur. Don't confuse that need with the so called "burn-in" period.
Aging capacitors and transformers create new challenges and problems, so when going vintage replace everything or buy new. Powering on without even connecting speakers is enough to detect a potential problem
I not able to open those attachments with my browser. If you could provide actual URLs I would look at them.
Now hold on ... I know what you're saying, but we don't need to know what's inside to test how much this burning-in phenomenon affects the amplifier.
Get two brand new amplifiers, put one in the closet for a while, and run the other for the 100 or howevermany hours burn-in. Get the other one out, connect them up so the speakers can be quickly switched between the amplifiers. For those who have experienced burn-in as a real phenomenon, which amplifier is "new" and which was burned in should be quickly and easily identifiable.