Equipment Break-in: Fact or Fiction

Ok, since many of the "believers" seem to want to lambast us skeptics here is my reason for being skeptical, or at least attributing the bulk of the effect to the brain of the listener.
I have two systems, one in England (now in my parents' living room) one in the US where I have been "temporarily" living for 5 years. When I visit the UK, roughly every 18 months, for the first day or two my old system sounds bass heavy and lacking in detail. After a few days it sounds thoroughly enjoyable. When I return to the US my US system sounds detailed, but lacking in rhythm. After a few days my US system sounds very enjoyable.
Both systems cost about $3k, and a mix of new and used. I believe both are at comparable performance levels, and both represent pretty much the pinnacle of a $3k system. However both have different strengths and weaknesses. The US system excels at chamber music and light jazz. The UK system excels at rock, particularly live rock, but handles classical very well.
I believe that over a period of time, measuring days, my brain becomes attuned to a particular tonal balance. Since both systems don't contain a single component less than 5 years old (some are >10 yrs) burn in is not possible. Both are left permanently switched on.
Since I'm an open-minded EE I'm prepared to accept that there might be minor changes in sound over time due to many different second-order effects. However I also believe that these changes are swamped by the adjustment of ones brain to a new tonal balance, based on the experience I have just outlined above.
I also believe that to strive for the "perfect system" is something of a wild-goose chase, since I have found that I can live very happily with many different systems, provided that I have time to attune to their particular sound, and provided that they are reasonably good systems to begin with.
Hey, don't flame me ... I offer a sincere opinion, with evidence upon which it is based !

It should be failry easy to test this hypothesis. All we need is just a blind test of the same equiptments with diffrence burn-in time (may be 5 of them: brand new, 10, 50, 100 and 500 hours burn-in time?). Actually, I wonder why those audio magazines do not try this kind of test? If the majority of the well respected testers can't ID the equiptment correctly (or at least be able to group them), that should indicate something.

My 2 cents again.

PS I think we should call it truce. If you don't believe in burning in then don't do it and go enjoy the musics!!

Ake

There are somethings that happen in audio that science or theory can't explain. Power cords is one of the biggest mysteries to me with no explaination of why they do what they do. In "theory", they should make no difference. Go figure.

Will the sun shine tomorrow? Components definitely break in.

One explanation of why power cords make a diference is because all of your components are giving off RF & EMI and this gets into unshielded power cord while the shielding on better cables helps prevent this hash from entering via the AC. Could be a bunch of voodoo though. All I know is I'm not going back to stock cords any time soon after hearing the difference a good power cable can make.