Leaving my amplifier on ok?

@minorl I think I kinda misspoke — I meant that every time you turn your system on the temp of the internal electronic components go from cool to warm/hot, and then when you turn it off the reverse happens.  This is the temperature fluctuation I was referring to, not some constant fluctuation during operation.  Just wanted to clear that up and sorry for the confusion. 

No worries.

we are on the same page.

Thanks,

enjoy

1) Valve amps should not be left on since the life dependancy of the tubes
is affected.

2) Class A amps should not be left on due to the wasted energy and heat
that they generate.

3) The rest depends on whether your amp has an inrush current limiter or not.
- If it does (your lights do NOT dim when you switch it on), then turning it
off would be ok.
- If it does NOT however (your lights DO dim when you switch it on) the
amp should be left ON all the time since considerable stress occurs at power up.

In the Link is the comments made on a Respected Amplifier Manufacturers Web Site.

https://support.hegel.com/product-articles/frequently-asked-questions#can-i-leave-my-hegel-amp-on-all-the-time

Off course in relation to this Brands advisory, such guidance can be overlooked by the owner of a product, and the guidance discovered within a forum can be the one chosen.  

@highend64, like most things in audio, it depends.

Obviously class A amps will run hot so best not to leave on but Class AB can and IMO should be left on all the time.

You'll probably remember the old incandescent light bulb that mostly failed on switch on because the filament is cold and at its lowest resistance and pulls most current = blown.  This is stressful for amps at switch on.

When a hot amp cools down there is condensation so the PCB is contracting in the presence of moisture providing the ingredients for failed solder joints and corrosion on anything with some ferrous content. Class AB in its quiescent state draws very little power and does not get hot so just leave it on.

Of course if it is to be out of use for a long period then best to turn off.

Valve amps can also be left on if HV to the power tubes is interrupted by relay and the heater voltage to driver is reduced to 2/3 of nominal. So 6.3V can be reduced to about 4.2V via a standby switch thereby avoiding cathode poisoning. Flipping from standby to on will very quickly bring the heaters up to nominal V while the HV is delayed for 20 to 30 seconds before connecting.

Some but not many commercial tube amps provide this feature. Easily done using an LM 317 adjustable voltage regulator for less than $2