[mintzar]

From what I've been reading on this thread, the consistent notion is that the reason for the change in sound is the change in resistance on the cap.

Changes in resistance cause changes in heat. Changes in heat then would cause the expansion/contraction of the capacitors. It may not change the capacitance value by much, but just the resistance change will cause a change in sound.

My guess is that the changes are tiny and probably not measurable individually, but when you place a capacitor in a circuit it's not just that capacitor that's breaking in. You have changed the circuit by changing the capacitor and the entire circuit must then re-adapt.

[Æ]

Ah, you are thinking coefficient of resistors/resistance. sensitive.
Yes, I know all about coefficients. I have helped college students and worked in a college lab setting.

Capacitors also change value due to expansion/contraction, thus temperture sensitive.

We are concerned with percentage change, no matter what the cause. The experiment demonstrates how little change is necessary to perceive a change in sound.

Cheers.

Still though, this thread is about 'burn in" not temperature coefficients. Is "burn in" a real phenomenon? If so, can it be measured, graphed with time? Is it repeatable? Can it be verified?

[Steve]

You are correct, Mint, plus more. I had the occasion, years ago, to discuss the problem with a scientist who used electron microscopes in his work, and he could actually see the changes in molecular structure. So it is a fact that the molecular structure changes.

Cheers.

[Mitsuman]

Ah, you are thinking coefficient of resistors/resistance. sensitive.
Yes, I know all about coefficients. I have helped college students and worked in a college lab setting.

Capacitors also change value due to expansion/contraction, thus temperture sensitive.

We are concerned with percentage change, no matter what the cause. The experiment demonstrates how little change is necessary to perceive a change in sound.

Cheers.

Can you please post some of the technical articles that you've published, so that we can all speak in absolutes the way you do on these topics? If you've posted them here, or linked to them, I must have missed them. Please do so, I can quit reading what other "experts" are saying.

Cheers,

Craig

[mintzar]

This would then be along the same lines as the theories regarding cryo-treatment. Bringing metals down to those extreme temperatures changes the composition of the material in some way.

I imagine with the right test equipment you could graph the change in a capacitors temperature over time as current flows through it. I wouldn't know how to do it... but I'm sure there's a lab somewhere that could.

It would just need very high precision to measure the change in heat, resistance, and probably various other factors across several different capacitors over time. Then compare and find similarities. The reason for one capacitor breaking in would, in theory, be the same reason that another breaks in. Certain capacitors may just take longer than others to go through their "changes". These may be small or large changes. Then there's other variables like film vs electrolytic, dielectric material, capacitance value, tolerance, etc.


At the end of the day the fact is that none of us have done the tests. We don't have anything proven as to why a capacitor breaks in. We all just have our own theories that we are discussing based on what we've experienced here or there. So ragging on a theory doesn't add to the discussion a whole lot. Incidentally, through much of this ragging, we are still starting to come to SOME similarities in our ideas.

But that comes from saying "it can't be this concept because this is how it really works," not from saying "you don't know what you're talking about." Competing for who's right doesn't teach us anything.

[Steve]

Still though, this thread is about 'burn in" not temperature coefficients. Is "burn in" a real phenomenon? If so, can it be measured, graphed with time? Is it repeatable? Can it be verified?

"Burn in" can be from a variety of sources. Whether it is basic changes due to molecular structural changes, relieved stresses, changes in capacitance, changes in distributive capacitance/inductances etc.

Cheers.

[Æ]

"Burn in" can be from a variety of sources. Whether it is basic changes due to molecular structural changes, relieved stresses etc.

Cheers.

Come on now, we're not talking about entropy. Everything changes with time, not always for the better either. Simply put, a mechanical item can "break in" which is understood to mean that it is getting smoother, performing up to its ideal. But does "burn in" equate to this? A mechanical item will break in and then eventually break down. What about capacitors? Do they burn in and then eventually burn down?

[Æ]

"Burn in" can be from a variety of sources. Whether it is basic changes due to molecular structural changes, relieved stresses etc.

Cheers.

So, next time I'm enjoying several beers, relieving my stress and. . . No officer, I wasn't drinking, I was burning in, why did you pull me over?

[mintzar]

Capacitors break down just like everything else. Places like Mouser and Digikey have lifespan ratings on all of their capacitors as far as I know. Better construction, like with anything, lasts longer. That's why there was a period a number of years ago where capacitors kept going bad because manufacturers tried to cut corners and make things cheaper. It was called the capacitor plague.

I think "burn-in" is an audiophile term that you're getting hooked on AE. It's the 'concept' of burn-in that we're discussing, not the word itself...

[Mitsuman]

So mintzar and Steve, both of whom sell audio equipment, share in the opinion that higher priced capacitors are good. (just reading what has been posted and from their websites) But I'm still missing the part about how the "concept" of "burn-in" is defined/proven by that premise. 

Don't get me wrong, quality is important but not just for the sake of spending more money without a tangible reason as to why.

Cheers

[mintzar]

I don't sell capacitors. And I don't sell my products based on how they burn in. Do I think higher-priced capacitors are better? Depends on the purpose and application. Using 100 modest smaller capacitors sounds better than using 1 "expensive" capacitor of the same total price.

But I wasn't intending to argue this cap is better than that, or that it's more important to use so-called higher quality caps. I was merely relaying the FACT that not all capacitors have the same build quality. Lesser build quality then explains why some go bad sooner than others.

This has nothing to do with the sound.

[JohnR]

A person can't be an engineer AND audiophile?

One would hope so.... Thanks Davey 

Personally, I go for the "plausible possibility" approach. Without the inclination, time, and money to test every possible hypothesis, I'll accept that a plausible explanation "might" exist and leave it at that. Given that ESR does vary with temperature, I don't think it's entirely implausible that there might be some change in the measureable parameters with "break in", if anybody would be bothered to actually measure them. I'd see that as much more likely with a cap with significant field across it, such as an output stage coupling cap in a valve amp, than something with zero DC across it as in a speaker crossover.

Really, I think an honest answer to Rclark's question "What is happening to a capacitor when it burns in?" would be "nobody knows". The posts in this thread so far seem to support that answer. Anyone can theorize until the cows come home to explain their subjective observations, but that is rather different from knowing the answer to a question like that. I might as well say that I believe that a million tiny tiny eggs inside the capacitor film hatch into tiny tiny little spiders that take each poor helpless electron by the arm and guide it through the treacherous molecular maze to safety on the other side. Hey, it's a theory, and it's about as good as some of the others I read.

But, in the end, I think I could care less, if it's not something I've heard for myself in my own system (which I haven't). I think a more interesting question would be "Why do people care so much about the answer to a question like this?"

[Speedskater]

In "Linear Audio" magazine/book Volume 1 (the first issue was #0), Doug Self has a 5 page article "Self-improvement for Capacitors" The Linearisation of Polyester Capacitors.

http://www.linearaudio.net/current.php?volume=Volume%201

[Davey]

But, in the end, I think I could care less, if it's not something I've heard for myself in my own system (which I haven't). I think a more interesting question would be "Why do people care so much about the answer to a question like this?"

Very well put.

The interesting part of this query is that Rclark is a young fella who's experiencing his first set of decent speakers.  So, he's made a large, recent change to his listening "baseline."  The supplier of his crossover tells him the capacitors might require some highly variable time to "break-in"......on the order of hundreds of hours.    I don't believe anybody has the auditory memory to identify this "break-in" point (if it even exists) after many, many hours listening to a "new" set of speakers.

These type of threads are highly predictable and always veer off into the weeds.  I knew it would happen after reading just a few posts.

Cheers,

Dave.

[BPoletti]

Capacitor burn-in is similar to vacuum burn-in.  Both require that the bad electrons are filtered to keep the capacitor or vacuum clean and without contamination.  Vacuum that is stored in a liquid state is much easier to clean using anti-vacuum scrubbers than liquid capacitor film since anti-electrons are difficult to store in the presence of 4-polyvinylbutylcarbinol.  Further, to achieve it's liquid state, vacuum must be chilled to -6 degrees Kelvin, much lower than the 2-2-1 trichlorofractinate film component can tolerate.  Therefore, it is much better to use vacuum capacitors than film capacitors.

Original vacuum, that special old stock that is more than 1.7 billion years old, is much better than the synthetic vacuum used in many of the cheap tubes and vacuum capacitors from the western Egyptian factories. 

Vacuum burn in, whether in a vacuum tube or a vacuum capacitor, helps guide the high-frequency electrons along a smoother path relying on the Klefting Principle of Static Flow.  The low frequency electrons are absorbed by anti-electrons that circulate freely in old stock vacuum.  Break in also helps develop the low-frequency electron reserve area.  It should be obvious that periodic cleaning and refresh of the vacuum is needed to replenish the anti-electron supply and empty the low-frequency electron reserve area. 

The values for cleaning and replenishment can be computed using the Wingstran / Janus variation of the Allison Effect equation. 

Audible Skin Effect is negligible in both vacuum and film capacitors due to the resulting high relative exponent of 1/F x (C1^4/R1 * L1^2/R1) / 1.414.  The keeps any load-bearing signal trapped in the low-frequency electron reserve area balanced between cleaning. 

CAUTION!!!!

Do not attempt to clean vacuum!!  Special cooling facilities and vacuum centrifuges are required.  Use of these at home can cause a catastrophic implosion. 

Next topic:  Quark Effect in short-length silver-platinum interconnects 

[Ethan Winer]

Wow, I didn't know you posted here.

I haven't posted anywhere for the past ten months because I was writing my Audio Book. But I'm done now, and finally have time to post again. As for Poppy Crum, I haven't seen her since our AES presentation.

--Ethan

[Ethan Winer]

Just to keep this on the topic of capacitor burn-in, I don't think it's unreasonable to first confirm that any physical changes observed are actually audible. Test gear can measure level changes of 0.001 dB, at frequencies a thousand times higher than anyone can hear. If you play the same music source ten times in a row, it's common for people to report hearing a difference even though nothing changed.

The March issue of Tape Op magazine will have an article I wrote explaining that hearing perception is the last frontier for understanding what affects fidelity. Just because something can be measured doesn't mean we can hear it. It's impossible for our ears to focus on all aspects of complex music at once. So on one playing we might notice the tone of the electric bass, and next time we'll focus on the cymbal. Is that delicate cymbal ping really clearer after letting a new capacitor "burn in," or does it just seem that way?

Related, I'm not aware of anyone being able to hear level differences smaller than 0.1 dB, so reports of hearing changes 1/100th that amount are surely due to hearing frailty rather than reality. Once everyone understands this, I think a lot of these topics will go away.

--Ethan

[BPoletti]

Related, I'm not aware of anyone being able to hear level differences smaller than 0.1 dB, so reports of hearing changes 1/100th that amount are surely due to hearing frailty rather than reality. Once everyone understands this, I think a lot of these topics will go away.

--Ethan

If you're actually writing an audio book, then you should do a bit more research.  Listening acuity is much higher than you assume.  Differences as small as 3 millibels have been repeatedly detected in otherwise identical equipment. 

[Steve]

Differences as small as 3 millibels have been repeatedly detected in otherwise identical equipment.

Even less than that B. Even changing the amp input Z from 50k to 20k, with 10uf preamp cap, is less than .006 db. Typical audio Dbt/abx tests are skewed because they do not address all the variables, Medical science for instance, just sight and manufacturer.

Cheers.

[Ethan Winer]

Differences as small as 3 millibels have been repeatedly detected in otherwise identical equipment.

Link please.