Amp — Leave on or turn off

I always turned my Benchmark AHB2 amp off after use every night. After all, why is there an on off switch on the front panel if not to do that? Last night I accidentally left it on. This morning, when I played my first record, I couldn’t believe my ears. The same record I played last night sounded infinitely better. I tried a second record and that, too, was much better.
I know there’s a debate on the question of leaving an amp on all the time.
I now know where I stand!


I usually leave the amps on most of the day, but I do turn them off late in the evening. With the high price of energy these days I need to be aware.


I like my Hegel 390 to be on for about 1 hour before listening.  I don’t like the idea of on 24/7. But I also feel like excessive on and off isn’t good either. So I have it set to go into standby after an hour if no signal. 

A local dealer leaves their amps powered on 24/6. they shut down on sat nights. on monday AM opening the store the sound is noticeably off compsred to days after they were left on. the main rep says it takes two days for some of them to sound their best!

My incidences tell me they sound best after 45 minutes or so

I am not leaving my amps on 24 /7.  I have a 40 year old pioneer receiver that still sounds great.  i doubt it would be in the same condition being left on for 40 years.  

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.

Contrary to some other comments about power cycling, that’s not the main issue with solid-state amps.

@aball What’s your evidence to support this? Steve McCormack advises to leave his amps on (again, not Class A SS amps) to the point when they do their amp upgrades they decouple the power switch so it’s just attached to a dummy light so the wife knows it’s on. If it’s plugged in, it’s on. My McCormack amp was powered on 24/7 for 20 years with no problems other than a fuse, which is pretty damn strong evidence. It defies logic/common sense that constantly cycling electronic components from cold to warm doesn’t put stress and wear on them.  And what makes you smarter than Steve McCormack?