Amp — Leave on or turn off

@soix You can look up ripple capacitor ratings yourself.  Also, McCormack doesn't care if your caps are shot or not lol.  He's in the business of selling amps.  The degradation is gradual so you probably won't realize it until they bulge and blow a fuse.  But I've repaired around 50 amplifiers at this point so I have seen it all.

I'm an electrical engineer who designs amplifiers, among many other circuits.  Contrary to some other comments about power cycling, that's not the main issue with solid-state amps.  The primary failure mode are the power supply electrolytics desiccating.  When the amplifier is on, these capacitors must charge and discharge 432,000 times per hour.  In high-bias amplifiers these capacitors have an exceedingly tough life and only last around 2000 hours.  I've seen some Class A amps with them failed at 1200 hours.  The best quality caps rarely last more than 5000 hours regardless.  So I generally do not leave my amps on when I'm not listening to them.  If I know I will be having a listening session on a Saturday morning, I will sometimes leave it on Friday night, but that's about it.

@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.

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.

@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.