Tube stuff gets shut down when I'm not near the room or ready to go back; some solid state stuff needs to be plugged in for a long while before it comes on song.
I used to have a Lamm L2- two chassis line stage with a solid state audio path and tube rectification. Vlad said to keep it on all the time, which I mostly did (in NY) except during fierce electrical storms. It took days to come back on song from a cold start.
There's a piece by Sear of Sear Sound about shutting off recherché gear. You should be able to find it on the open web.