From PS Audio...
Is it better to leave equipment on or off?
Sonically, it's better to leave equipment on. The problem is tubes. While tube gear certainly sounds better after it's been on for a while, tube life will be shortened if it is left on all the time.
With solid state gear (transistor), it is best to leave it on all the time, but a lot of people are afraid to leave their power amps on for fear of something happening that might blow up their speakers or amp or both.
I recommend leaving everything BUT your power amp on.
Also, bear in mind, anything with a remote control is probably not off anyway. It certainly isn't COMPLETELY off; if it were, there would be no way for the signal from the remote control to be read.
Tubes: leave it off and warm up about 30 minutes before use. Transistors: leave it on always, unless it's a power amp.