Do we break in our componets or do our componets ?

Hardly a new idea, though. We adapt to most stimuli. Our hearing changes under different conditions and throughout our lives and yet we are rarely aware of it. Just think about how protective mechanisms change hearing in response to high level sound which some people like to be subjected to.....

Uh, gee, hate to say it but Pbb shared some truth. Lak nailed in perfectly though. Break in is a real deal but usually not making huge differences. I do believe some pieces make break in an agonizing affair though my equipment hasn't done that to me. That being said, the cryo'd outlets are a real break in nightmare. The music changes daily. Getting better, then horribly worse, then better again and again. It will take about a month for things to settle in. You would need to be deaf to not hear this phenomenon.

Digital stuff really does benefit from being left on so it is warm - that could be a significant source of what you report. Also, when I bought my sony 777 sacd, it didn't sound any better than the (much cheaper) digital front end I had, but over the next 10 days (this player is notorious for lengthy break-in) it improved to the point of being considerably better. In other words, I had the benefit of a constant (the existing front end) to use as a comparison. It wasn't just psychological (at least I think it wasn't...)

I agree with most posters above and think it's all the above, changes in AC coming thru, the system getting all charged up (my Quads do it) and you getting accustomed to the sound in your room again. What a relief it's sounding better too, eh? Please come back in a month and tell us how your system is sounding.

Pbb, wouldn't there have to be a point where the ear/brain just throws in the towel and says, sorry, I can't fill in all the holes? I am thinking specifically at a local Best Buy, playing some black cube type HT speakers (the company headed by a Dr. B.) where I had to literally duck to prevent the thin, peaky, beamy sound from assaulting my ears. So bad, I stopped looking for CDs early than I wanted. Simply put, COULD my ears EVER get used to that??
Or should I buy 'em and try 'em at home?

Anyone denying the effects of break-in should try a new (if you can find one) Sony NS-500V SACD player. Out of the box it sounded okay, then it got increasingly awful - one friend said he literally couldn't stand to listen to it -- and gradually it "recovered" and ultimately became downright musical. My second SACD player, a SONY XA777ES, went through the same metamorphosis although not as dramatically. Again, I was not the only one to hear it happen. The whole process took a long time, at least 100 playing hours and probably much more. I've had other break-in experiences that were equally real but not as marked.