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 ?
No doubt real for transducers.

Less certain about the rest but not impossible.

I have the same observations with my Stax headphones.
Sorry Donjr, but I'll be happy to demonstrate cable break-in with my Audiodharma Cable Cooker any time you'd like. The difference isn't subtle.
I'm not a cable skeptic, but I trend, with Doug and Al, to being a break in skeptic (with the already noted exception of transducers).

The reason is that the experience of components improving with time is predicted by several well known psychological effects, which collectively suggest that much of the "break in effect" is mostly what people here have been calling "psychological accomodation."

1. The "mere exposure effect": people tend to prefer familiar stimuli. Thus, the more you hang around your component, the more you can, all else equal, be expected to like it.

2. The "mere ownership effect." People tend to prefer things that belong to them, even over *identical* items that do not belong to them. Thus, you can be expected to like what you own.

3. "Self-enhancement." People tend to find ways to view themselves in the most favorable light. You're not the kind of bozo who would drop a ton of coin on a marginal improvement (or step backward) for your system, are you?

4. Self interest. No fancy name needed here. Dealers and manufacturers have a strong interest in promoting the "break in effect"; it makes a good answer for the disappointed customer who might otherwise want a return, and buys time for the psychological processes noted in 1-3 to do their work. Try calling a dealer and saying the item you just bought underwhelms you, and then ask about break in. Do you think the dealer is likely to say "break in is a myth"?

This is not to say that break in is never a factor, and still less to say that people cannot properly appreciate big, and even small, differences in gear. (Bring those big Rockports or Wilsons over, and I'll likely prefer them to my more modest speakers, ownership be damned.)

It is to say that the psychological evidence suggests people would experience the "break in effect" *even if there were no objective improvements in gear over time*. So I would like to see very compelling evidence before attributing the experienced improvement to the gear rather than the listener. (Note that the experience itself cannot be such evidence; it's not the experience that is at issue, but its source.)

Nice post! I agree with your observatons/conclusions.I believe there is some level of psychological accomodation but if something sounds truly poor time won`t change that perception. Break in is real based on my experiences. Sound quality can and has evolved and changed over time towards improvement.There does seem to be a maturing/curing aspect to materials and various parts to reach an optimal performance level.