break-in--bane or boon ??


as a reviewer , i often receive equipment which is new and has no playing time.

i have to decide whether to break in the component and if so, how many hours is necessary.

i have often asked manufacturers for guidance.

one cable manufacturer said the cables--digital, analog and power, required no break in. another said 24 hours.

when i reviewed a mcintosh tube preamp, i was told by a technician that no break in was necessary. all i needed to do was leave the preamp on for one hour in order that the tubes were "warmed up"

can someone provide an objective explanation as to the basis for break-in and how to determine how long to break in different components ?

for example, cables comprised of different metals, if they require break in, is there a difference in the requisite time for a given metal, e.g., gold, silver or copper ?

can someone provide an explanation as to what is happening during the break-in process ?

can one devise a mathematical equation to quantify break-in hours, as a function of the parts in a component ?
mrtennis
My feeling is that there is a combination of equipment break-in, human factors and other things as well at play when changes are noticed over time.

Too complex and variable to determine anything for certain in lieu of a major research project.

My advice is to give any change some time to assess and avoid jumping to conclusions. Then things will work out over the long term regardless of what factors might be at play at any particular time.
Trelja, some interesting insights/arguments but I would not accept hand-wired/made units made over time with possible variances in wiring, solder, caps, tubes, etc. to be close to two mass-produced units. They may be made on the same template, but that hardly makes them identical. A variance in sound, nuanced but there, would be expected.

Perhaps a clarification is in order; I'm not saying that things such as wire, caps, etc. cannot change over time. I am saying that IF they change at all the human typically cannot hear it - it is beneath the human hearing threshold. IOW, it doesn't matter experientially if it is changing or not, to the ear it won't be detected. Hence, my casual comment that it is "not changing." A pair of jeans would obviously be above such a threshold.

I believe I made it clear in my article that transducers were excepted; when a physical motion of a driver is involved there obviously is a break in period.

Regarding coupling capacitors, I have not read the article/test you refer to. Are you saying, then, that the PC test of the changed cap was demonstrated to have made an audible change in the sound of a component. Or, is this an extension logically. IOW, I don't care if capactitor looks different electronically when used/broken in. I care about if the component will sound different.

In my instance of use of two different sets of cdp and integrated amp I had one set which was not burned in and one which was. I would assume the caps in the well used set would perhaps measure differently according to your illustration. However, there was no sonic change in hearing the two side by side. In the end I don't care if you show me a chart of ten things which supposedly measure differently when new vs. used; I care if the sound is changed over time/use. I have not found that to be the case.

I don't think you've made your case convincingly.

Don't lump me in with cable skeptics! I'll quote your last comment, "The subject of break in tracks much like cabling. Even today I meet so many audiophiles who maintain that "wire's just wire." I begrudge them not. Likewise, should you continue to go forth feeling that same way about break-in, I understand"

I would assert that the issue of Break In does not track much like cabling. Cabling is easily demonstrable in a good rig over a very short period of time, even a couple minutes. Break in is not. The one is a matter of swapping out parts, the other a perception based on purported changes over days/weeks/months to the same parts. That is a world of difference.

I do not see any absolute correlation between a person's acceptance/denial of cable efficacy and their perspective on Burn In. I would assume that there might be a mix of audiophiles, some who accept/reject both, and others who hold to one or the other only. In fact, the primary determinant of whether an audiophile accepts or rejects them both likely would be their hearing acuity! :)

Mrtennis, practical answers are usually straightforward. You don't need a complex test to ascertain whether you hear a difference. If the difference between used/new identical components is not discernible then you are wasting your time with Burn In. If the difference is so vanishingly small that you can't be certain it's in effect, then you are wasting your time with it.

Only if the difference would be "wow!" like a different component had been used would it be worth paying attention to. As it is, I get noticeable changes when I replace one or two power cords, or a single digital cable, or a set of ICs. When my friend and I heard the new/used comparison there was nothing different sonically. Ergo, waste of time fretting about Burn in.

The test is simple, and more people should simply do it if they are serious about getting down to the bottom of the issue. :)
I manufacture speaker cables and IC's. I cryogenicly treat them and I have to burn them in to sell them. It would be unlistenable if I didn't.
With that said, if I put a new power cord or IC etc. in my system and its bright or edgy, it's not my ears getting used to it if they break in over time and is not bright or edgy. Edgy is edgy, and there's no getting used to that.
I'm a firm believer in break in for cables, speakers and many other components that go into a system.
I know someone with a "Cable Burner" and I may borrow it and rerun the test. That would be interesting. Thanks for the idea. :)
BTW, my argument is in regards to simple utilization of a product, not use of tweaks or gagdets to enhance them; that is another can of worms. However, they could be tested quite simply as well.

I think it's time to get my hands on that Cable Burner.