On the Warm up question: Had an interesting one on a recent Sansui 2000A score. I habitually check DC offset on every system that I bring home. This one was NOT like most Sansui Gear I have brought home. It was very high, around 250mv, where every Sansui I had brought home was 25 or less, usually much less. Then I noticed it was dropping. I decided to let it run a while, and when I came back it was within specs. Tried it again later thinking possibly it was old caps not fully charged after how many years of setting, but other than a slightly lower start point, same deal.
Transistors in particular are not created equal, and can change in performance from cold to hot. (Ask any EE) between that and old caps, I think the warm up is able to affect the audible performance for better or for worse. (I could see a unit starting within spec and falling out after warm-up easy)
Speakers I am morally certain (after reading the article more than certain) that they need break-in. Tubes, probably “benefit” from it (As well as warm-up) since some hours of running will change the surface finish of a new, unused tube to some degree, and that surface dictates its performance. Caps I’m insure of, for both warm-up and break-in, but what about reforming old caps? That seems to have a basis of reality, and perhaps on net performance.
Is psycho acoustics real? I believe so. Hearing something for a period of time does make it “sound” better. As proof, how many have listened to a song for the first time and thought it stunk, or at best were unimpressed? After listening to it more, sometimes much more, it grows on you. The record companies don’t pay for play time for nothing. Soda companies used to give away free samples to try hooking people on the taste, as people like to get things free, and they acquire a taste for it. (Does ANYONE ever enjoy there first taste of scotch?)
Wow, had no Idea I had so much to say on this. Better stop now!