System warmup?

Why does it take 15-20 min. of play before system sounds best when everything is broken-in and all components are always on, not even standby?
Maybe it's not your system, maybe it's you. How long does it take for someone to sit down and relax?
Maybe it's because your system needs a signal passing through it for fifteen minutes to really warm it up.

I'm my case however, it may be more the "Human Factor" as Onhwy61 points out. My ass needs to settle in the chair before my ears work properly and my mind gets into listen mode.
I think that temperature of metal affects its conductive properties. Once it is on for a while and warms up the current runs a little bit smoother.
My system is the same way. It sounds kinda crappy when it is just turned on. It also sounds crappy after 20 minuits of use, but slightly less crappy.

upgrade bug upgrade bug upgrade bug
Slappy, Is it even less less crappy after an hour?
I would think after 2 hours of warm up it would be great as it likely ran out of crap. ( you sure got a laugh out of me on that one )
I would have thought so too. But just like my dogs and thier crap, its like jesus and his basket of fish.

This could be a troll post but here goes the 5 cent explanation:-

Electronics has always been sensitive to temp. changes & it is well-know fact that variations in temp. has a moderate/drastic effect on the perf. The moderate/drastic effect comes from how the designer implemented the circuit i.e. did he take temp. effects into account or not. As the current flows thru the electronics, the devices heat up but the ambient air around them is still cold in comparison & so during this time the perf. varies. It takes a while for the enclosed air inside the chassis to equalize in temp. Once the temp. stabilizes then there is no more heating to take place & the electronics is surrounded by an isothermal which allows the various bias operating points of the devices to stabilize. Now the devices begin operating where the designer intended them to. In ss gear this takes 20-30 minutes at a min & in tube gear it takes about 1 hr.
I'm afraid it's just the nature of the beast!