Yes, thank you for reframing my exact question! I think no one may actually know the answer because there are too many variables for a "rule of thumb" guideline. Lots of well intentioned responses. I'm going to turn it on a little before or concurrent with my listening, and leave it on the rest of the day, turn it off when I head to bed. Done! I'm over it!! Thanks!
rule of thumb: how long do you leave a tube preamp on versus turning it off then back on?
I just upgraded to an Audio Research REF 10 with 12 tubes and I am wondering how to best preserve the tubes. How long sitting turned on is equal to the wear and tear of turning it off then on again? I had a Rogue RP 7 with just four tubes so I didn't worry about this issue so much, I just turned it on when I began to listen then off at the end of the evening. Now I'm wondering where the sweet spot is? Away for a hour, two, three, turn it off when? Am I over-thinking this issue?