Please advise - power for TUBE amp?

I am uncomfortable leaving a tube amp on whin I am not in the house. I would not change back to SS but, I do have a smoke detector hanging just above my set-up....

I power up my (tube) rig as soon as get home from work and power it off before going to bed. I leave it powered off if I expect to be out 3-4 hours or more.

Normally, the worm-up of tube amp to the tube's specified operation parameters is much faster than for transistors. Tubes to some degree don't need to reach certain temperature of operation since they're not depended as much on the temperature as transistors but unlike transistors, they need to be mandatory wormed up before passing an input signal to avoid its short life.
If you plan to stay home and listen to the music, than keep it on. Turn off when you go to sleep or out of home. It'll save tube life and electric bills. If you give 20...30 min of worm-up before passing an input signal, it can be considered as normal for tubes. Non sufficient worm-up time may result on large difference in tube's operation characteristics that maybe distructive and shortening the tube life.

I'd guess it depends on the amp and circuit design, but from what I understand turning tubes on and off does put stress and wear on the tubes above and beyond leaving them on. Obviously if you leave them on for several days without listening that point is moot. The best advice I've read is; if you plan on listening on and off for a few days, leave them on 24/7. If you know you won't be listening over a period, turn them off. My 300B SET's sound best after about 2-3 hours of warmup time. I don't notice much of a difference after that. YMMV.

Marco

I don't know about your specific amp but my BAT VK-75SE takes a couple of hours to properly warm up. So I usually leave the amp on if I will be listening to it shortly. Otherwise, I turn it off (overnight, go to work, out of town, etc...).