"Burn in" Are you serious?

Jostler, It is true that people will grow accustomed to certain types of sound over time, but that does not mean that they cannot tell the difference in sound quality before and after a break in in period. Also we are not really talking about the same "people" here. We are mostly talking about a group of somewhat experienced audiophiles, as it would not even be an issue with the majority of consumers. But even an "average Joe or Jane" listening to a component or a cable before, in between and after a break in period would probably notice a difference if asked to pay attention to the quality of sound for a few minutes. I have occasionally asked my wife to compare sound, and for a non- audiophile with little patience for my my audiophile leanings, her observations are keen and are almost always similar to mine. Also, the components I have bought (DVD player, Mini Disc recorder, Reciever) showed no change at all after 10, 100 or 300 hours, but the cables I have bought did show a definite change after a while.

Sorry, guys, but the laws of nature apply to "somewhat experienced audiophiles" just as much as they do to everyone else. It is quite common to hear changes in the sound of an audio system over time. But there is no way for you to know whether that perceived change is the result of a change in the sound of the system or a change in your perception of the system. (Unless you simply assume, contrary to all scientific evidence, that your memory for sound is perfect--but that's not knowing, that's believing.)

I had the oppertunity to compare a brand new pre amp with the stores demo pre amp in my home. Although both were the same brand and make preamp there was a huge difference. The one that was broken in was more open and a lot smoother.

I think perfectimage just answered the question quite perfectly.

Hi Jostler; It took me several years to acquire "critical listening skills", and using these skills is quite a bit different than listening for pleasure IMO. Perhaps you haven't expended the time and effort necessary to learn these, but many audiophiles have. If you are going to quote scientific evidence to support your position, then please do so. So far you've just stated opinions (even about the "scientific evidence")-- like the rest of us. I would think that someone reading/participating on this site would either have a different opinion on this issue, or more specific evidence for their "contrarian" view. No? Cheers. Craig.