When to Poweroff amps and preamps

I apologize if this has been asked before but I haven’t been able to find it.  What is recommended for when to turn off the power to amplifiers and preamps?  What if you’re going to be using the equipment within a day or so...power it off completely, put it on sleep if that’s available, leave it on?  What if you’re not going to use  it for a longer time...a couple of days?  A week?  Are there different recommendations for solid state and tube equipment? I’m interested in both getting the best sound and prolonging the equipment life. 
I turn both my SS Pre & Amp off. If that is what you decide to do then this is what I found out here. Laughing Our Faces Off. This refers to the Amp, L & O = Last ON
F & O = First Off
This made sense to me as my last system, Infinity Kappa 8's with an Adcom 555II amp. This set up for 15 years did the same thing every time when turning off in this way with the volume turned down all the way down. For 15 or so seconds the speakers had a popping noise, then I turned the Pre off. 
Exposure to continuous heat will reduce the life cycle of electronic components. There is little to no argument most folks turn off their tube gear after each listening session.

This same argument applies to SS devices as well. Resistors and capacitors will deteriorate when exposed heat over time. So after use, it is recommended you turn off your SS amps and pre-amps. There is an argument from some quarters that turning devices on & off reduce the life cycles of electronic devices. However, damage due to heat would be much worse. Modern SS amps/preamps warm up rather quickly as in 20-30 mins. So the wisdom of leaving SS amps/preamps 24/7 is highly questionable.
My two cents.
I asked service tech at Mark Levinson on my 532H and he recommended to leave on. 
Mine are all SS, i leave them on 24/7-the amp in stand by. If i leave over night  i unplug from wall.
heavy - is your MC240 stock ? Mine is 1961 and super modified.... sweet amp for sure.


All 5, MC225,2x240s,275, and a pair of 60s are all stock, I have all the parts for PS, upgrades and pio caps, and a pair of 24k cases for the 60s.
The one 240 though has EU caps in it, so they didn't self destruct, like a lot of the other bumblebees. It is VERY special, indeed.
 I did mod up a 275 GG, that I managed to blow up a while back, (cable drop), it's quite a bit better than stock. Still it's a KT88 unit.. Not my favorite valve. I'm a 6550, El34, 6L6,  guy these days.. :-)

Summer/Winter, wahoo, night and day where I live. 33-35 is considered cold here, and it is, if you get caught in it. But I've seen, 45 at night, and 105 in the day, two days apart. Tube gear is not real partial to a REAL cold starts. My Cary stuff can pop a fuse with a real cold start too.