Amp — Leave on or turn off

Tubes: Turn off at end of usage.

SS: Leave on all the time.

@jl35 I've repaired over 50 amplifiers.  Leaving them on 24/7 definitely shortens their lifespan due the wet-electrolytic power supply capacitors failing.  Pass knows this, but the failure is gradual (takes about 2000 hours) and he figures you won't be comparing your amp to a new one to notice the difference anyway.

I understand aball, but after all these decades,  I'm going to keep trusting Pass and McCormack...

@jl35  I'm like them - we don't care if your amp is worn out. This information is for those who want to know what really happens inside.

Every piece of equipment I've had a failure with was on power up. I've found that most of the small electrolytic capacitors are what fail due to heat in my krell equipment the big power supply caps don't seem to fail as often. 

The power-up condition triggers failures due to inrush current.  In standard failure theory, the starting condition is always the toughest (it's the same for mechanical systems).  Electrolytics are typically rated for 85C, which is actually quite low.  They try to get nicer 105C rated ones for the supply.  Unfortunately many amp designers don't think about thermal management enough.

I listen 2.5-3 hrs every day for the most part...

everything stays on for me (all SS):

Power Amps

Preamp

Phono Preamp

Dac/Streamer

Master Clock Generator

Turntable ADS

Turn it off. 

Turn off if they have tubes.  For solid state, it's up to you.

I listen to my system every day for 4-5 hours and turn it off after.

Turn in on, more or less 30 min before the listening session takes place.

Some of my gear have tubes (hybrid integrated amps, preamps and dacs) and I want to extend the life of the components and save on the power bill.