Turn off or leave on?

@kgbspy,  (putin, is that you ???)

makes me wonder if any of you got electronics training

Ok you can climb down from your pedestal now and go ... well go somewhere.

If the component is solid state and does not consume huge amounts of power when in its quiescent state then better to leave it permanently on, unless it's not going to be used for a considerable period.

Those who remember the old incandescent light bulb will know that 99% of the time they blew at switch on. The filament is cold, its resistance at its lowest and is when it draws the most current. POP.  Same with the solid state component. When on it warms up and then cools again when powering down, there is expansion and contraction on the PCBs and also condensation. You have now unwittingly provided all the ingredients for failure. Left on the device stays gently warm and should last decades.

For tubes that are permanently on their life will be shortened but there is a work-around. Some amps that have a standby switch just turn off the HT but leave the heaters/filaments on which will, over time, lead to cathode poisoning, however if the cathode voltage is reduced to 2/3 voltage, that is 4.2V instead of a 6.3V supply, all is fine and stripping is no longer a problem.

 This feature is not often found but I use it on my DIY stuff. When coming out of standby I arrange for the heaters to come immediately to design V and use soft start for the HT. There is little or no warm up needed as the amp is always and safely warm. 😎

I leave my TT, network streamer, and power conditioner on 24/7x365.  I will turn them off in an electrical storm (even though I have a whole house surge protector) and when on vacation.  I turn my hybrid preamp, hybrid power amp, DAC and phono pre "off" - they go into standby mode.

In my two systems the transistor gear (one amp, one tuner, one disk player/dac, one separate dac stay on, or at most I may turn off the transistor amp overnight.  The tube gear (amp, preamp, headamp, tuner) goes on a half hour before listening, and gets turned off when done listening.  Optimum life for all, sound enhancement at least 99%+ of being on all the time.  When the equipment is new I hear more change when violating this routine, but with time I can hear no difference.

My experience - I could leave my solid state amps on, or on standby, with no problems (like the Krell FPB600) over several years of use. My Atma-sphere MA1 tube amps are another matter - I turn them off, after use, to preserve tube life. My Io phono preamp, also using a lot of tubes, is another matter. I fell in love with how good the Io sounds, fully warmed up, so I left it on, all the time. Not a good idea. Not just because it took tube life, but also because some components - including crackelating soldering - did not like it. Also, I used to have my Einstein The tube preamp on, most of the time, and when I sent it to service, recently, several components (capacitors, mainly) had to be replaced.

A main rule becomes clear. Regardless of the cost in tube life. How components react to "always on" depends on time x heat. With more heat, e g restricted air flow above the component, the problems increase over time, the longer you leave it on.

TURN OFF!!!  We're killing the planet enough already... you can wait a stupid 30mins to reach your audio nirvana for the sake of our future.... which of course is screwed no matter what we do now...... but still.....