On or Off - On or Off - Audio Electronics

If I go away for an extended period I unplug the units.

Also since it's OK not to care about the environment anymore I'd say go nuts leave everything on as long as you want.

Some manufacturers will tell you.  I always insisted it was put in manuals of stuff I designed.

Someone succinctly summed up what I believe to be the general rule:  Solid state gear on all the time - except for power hungry power amps. They will both sound better after somewhere between 20 minutes and 8 hours of warm up, draw little power and will last longer (less shock on components).  But power amps can get hot; and having them on when there are power interruptions might subject your speakers to abuse.

Warm up is not a controversial topic in sophisticated electronics. Mots delicate lab gear is not even in calibration when its cold.

For power stages of high power amps (all my designs actually have standby in which the power-draw electronics never go off) I generally find the first hour delivers 90% of the benefit, and the subsequent 8-24 hours the remainder.  So I turn my power amps on ~ 30 minuets before I plan to listen seriously.

Isn't there a big difference between switching into standby mode, switching off at the wall, and switching off by removing the plug from the wall?  Only the latter protects from lightning-induced surges.

in general, any unit without an easily accessible front switch should be left on. Most user manuals also tell the owner to unplug when the equipment will not be used for long periods.

My class A solid state amplifier is only on when I need it, or the room needs extra heating.

Many years back when I listened to my system several times a week every component was shut down after each use. I had to replace power switch on preamp twice in 40 years then recap at 40. Still have pre amp going on 45 years. 

Maker of my now Odyssey amp Klaus  said to leave it on 24/7 but weekend evenings are my usually listening time so power up all components friday morn before work to warm up system for evening then power down sunday.

Tube dac powered down after each use as that seems to be the thing to do.

For the last 30 years I've turned off my system (including a tubed preamp) only when leaving for extended periods of time (vacation). Never had the slightest issue.