Equipment Break-in: Fact or Fiction

When I bought my last amp I kept my other amp for a while so I would have something to compare with. The new amp sounded so different after about a month anyone could hear the change. Sloppy bass had tightened up and closed in highs opened up. This was with my other amp that was very good in both respects a four cable swap away. Im sure its not my imagination, my wife heard the change and she dosnt mind telling me when something does not sound good. In my system this -was- a silk purse from a sows ear. I could also hear a big change when I broke in my Totem Ones.
I dont know about cable break in. If it happens its too subtle for me, but these changes were obvious to me and my wife.

I tend to agree with Stehno but I also agree that my speakers did indeed change during the first 300 hours or so. I am somewhat confused about what is really happening, even as an electrical engineer doing circuit design. I don't know much about voice coils but about transistors and wires, I feel rather confidant and I cannot think of exactly what parameters are changing. The Si doping has most of the influence over a devices character and it does not change with time (but does with device temp - hence why I agree with Stehno). On the other hand, dealers are always telling me that burn-in is critical but everything they have me audition has barely 2 hours on it. If burn-in for circuits is true then I cannot believe what I hear at the dealer. Catch 22 - oh well.

HEAR US NOW AND BELIEVE US LATER!! -Hans & Franz.

Truer words were never spoken. Equipment break-in is real. Apparenly your ears and mind haven't fully broken-in yet. ;-) Otherwise you would have never posted the question.

We're dealing with humans here, and I believe the actual truth of this debate is lost among the BS. Perhaps there is a small sound difference between components before and after they've "burned in". But it is no doubt overshadowed by the human listener's ear changing over time. If you walk into a loud disco, 15 minutes later the disco doesn't sound loud anymore. The disco's amp did not "burn in" to this lower volume, your ears adjusted. I'd also like to point out people will describe their artwork and mattresses very differently after owning them a year, and it's not because either of these "burned in". Give me a break.

I'm told all the pieces need time to "burn in". Perhaps someone can explain what the heck this means. Burn in? How come my computer doesn't need time to "burn in". I don't notice my hard drive speeding up after 100 hours of use. I'm not ruling out the possibility that the components actually do sound better over time, but I'd at least like to know some physics-based explanation why it's so.

Those of you who believe everyone's claims that their components "open up", "burn in", or otherwise improve over time could use a brushing up on the well documented social psychological phenomenon called positive test bias. I guarantee it's orders of magnitude stronger than the changes in electrical properties.

From my experience, after about 20 to 30 hours what you hear is what you are (stuck?) left with. I agree with Marakanetz - the sound does not magically improve after a "break-in". What I noticed, whether source, amp or speaker, is only the imaging and soundstage pulling together; the song remains the same.