What Exactly Does "Burn In" do for Electronics?

06-18-14: Bifwynne

Btw, maybe not so crazy. I understand that low temp cryo "cooking" of metallic parts like gun barrels, engine parts and so forth changes the crystalline structure. The result is stronger and longer lasting parts, so the cryo proponents maintain.

I think cryo'ing has been overdone in audio, it's fine to do material of one substance like a gun barrel.
But when people start doing tubes, this is just not on.
As the rates of expansion and contraction of unlike materials like metal tube pins that are an air tight seal with the plastic base and the glass that is a seal with it, just think of what happens to the vacuum in the tube when this is cryo'ed.
Then lead solder on plated metal interconnects with silver or copper wire three different materials all contracting at different rates, solder is bound to get cracks in it.

Cheers George

George, I can certainly understand your concern and your analysis seems like it might hold water. The problem with your analysis is that in reality tubes are cryo'd everyday in cryo labs around the country without experiencing any problems.

"The problem with your analysis is that in reality tubes are cryo'd everyday in cryo labs around the country without experiencing any problems. "

Seldom does anything happen without some problems, except in a perfect world, so something a bit more concrete than saying it is so would be useful. Saying something is so does not make it true. Especially when there is money to be made.

Prescription drugs are marketed to us continuously these days. You get a brief summary of the drugs benefits and then you get the many possible side-effects.

At least companies that push drugs are regulated to the extent that they have to disclose pros and cons fully. No such luck with high end audio. THe stakes are just not high enough to regulate anything so its pretty much the wild wild west where anybody can claim anything at anytime with no substantiation and get away with it perhaps.

06-18-14: Bifwynne
What are your views about electronic gear? FWIW, ARC maintains that its gear requires a considerable amount of break-in.

FWIW, my instinct would be to consider their recommendations as credible, certainly for their own products. Tubes, capacitors, and (I suspect) transformers and transistors, and perhaps even resistors, can be expected to change their characteristics to an audibly significant degree during some period of burn-in. To a greater or lesser extent depending on the specific circuit design, the specific parts that are used, and on how much testing and burn-in is done at the factory.

There must be a lot of material science going on here that is way over my head. As far as cables and power cords are concerned, is it possible that running current through the cables and cords in some ways affects the metallic crystalline structure?? That is a serious question?

My feeling is that it's over everyone's head, in the sense that all kinds of explanations can be hypothesized, one of them being dielectric absorption effects which are commonly cited, but given the difficulty or impossibility of establishing (either analytically or empirically) that a given hypothesized explanation is great enough in degree to have a reasonable chance of being audibly significant, any such hypothesis is unlikely to be either provable or disprovable. Which is one reason why:

06-19-14: Mapman
... its pretty much the wild wild west where anybody can claim anything at anytime with no substantiation and get away with it perhaps.

+1

Best regards,
-- Al

Mapman wrote,

"... its pretty much the wild wild west where anybody can claim anything at anytime with no substantiation and get away with it perhaps."

The difference being I have experience in cryoing audio items, 15 years of experience. Whereas you have, uh, none. So I guess it's actually YOU. who are claiming anything at any time with no substance. Duh!

Al gets a big -1

:-)