Leave tune powered up?

I agree that for sound quality, it is best to leave most gear powered up. This is particularly the case with solid state stuff which takes a long time to stabilize. As far as longevity is concerned, I don't think gear should be left on. It certainly is not the case with tube gear and not the case with solid state gear that runs hot when idling (biased high into Class A) -- heat is a killer of components.

Tuners and other low temperature, low power dissipation gear probably is not hurt much by being powered up all the time (aside from greater vulnerability to power surges/lightning strikes). My Dynalab tuner is actually on all of the time, even when the power switch is turned off (this only mutes the output and turns off the panel lighting). Dynalab apparently favors being powered up all the time. My CD player is also designed to be powered up constantly. My solid state preamp, a Levinson No. 32, is also designed to be on all of the time.

Thom,

Great advice all around. I found it interesting what you said about Black Gates. A dealer was telling me about a customer who had his amps upgraded with Black Gates. The customer complained that the amp sounded worse, and this made no sense because he liked the upgrade when he heard it at the dealer's shop. It turns out that the customer turns his amp on and listens for relatively short sessions and the dealer almost never turns off his amps. The customer switched back and was happier.

The safety issue is a frustrating one for me. I have a Naim CDP 555 cd player. The manufacturer's representative says it should be powered up all the time. Indeed, if it is turned off for more than a few minutes, it takes a really long time (several hours) to come on song again. The instruction manual, however, has all these dire warnings about lightning and protecting the gear by completely unplugging it.