So, yes, any electronic component ages quicker when you power it on and off, espeically very quickly, when the capacitors couldn't discharge yet. Some solid EE can surely explain this better. Also, all Hi-Fi stuff I got has a standby.
As to quality, the only difference I realized is on the poweramp and I keep it up all the time unless I go away for 2-3 days. Even class A today is mostly A/AB biased so it only burns 20-30Watts with no signal. That's just like leaving a light bulb burning, no big deal. My amp needs 3-4 hours to suck up enough into its capacitors and if run cold, I realize it's kind of 'restricted', bass is a little back and on acoustic peaks, it's not as clear as I'm used to. There is a simple explanation for the fact, I have about 250000mF [when turned of, the Odyssey logo still stays lit for 15mins or so ;-)] in my monoblocks with peak of 60Amp per channel. Normally, 20Amp fuses are max in apartements, so the amp needs time to suck up the capacitors full to be able to push the peaks. That takes time.
