I’ve owned tube preamp for 25-30yrs now. Do not worry about your tubes, they will last a lot longer than you think. I use mostly expensive highly sought after vintage tubes in my preamps and in all these yrs, only 1 tube has went bad. I use 20 tubes total in my 3 main preamps. AR SP11 mk 2, Marantz 7 and CJ PV5. When I’m listening to one of my systems, I turn the preamp on about 12 noon and do not turn it off till 12 midnight. I have 3 tube testers in house, and like I said, all these yrs, only 1 tube went bad. Whatever system you want to use to “save” your tubes is fine, but the point I’m making, don’t worry about them so much, they’re gonna last a long time in your preamp unless 1 or 2 fails.
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?