Transistor gear works and sounds best when left on 24/7. Electrolytic caps kept fully charged will function perfectly well and not degrade! Long periods of unuse are to be avoided. But they can often be restored by using a VARIAC to slowly ramp-up the AC voltage (over, say, 12 hours).
re capping
I hear the phrase 'recapping'. when do you know when you should 're cap' an amplifier? I have a McIntosh mc602 amp that sounds fine to me. I also have a McIntosh mx132 that works ok for me. I also have a bose 901 series 2 active equalizer that seems to work ok. the 'red' on light kinda flashes now and then. if my system sounds ok, should I worry about my units?