Can you do anything to make power tubes last longer ?

Put the Mullards XF2 in. Great tubes, probably need a little of burn in time. So much better than SEDs. Hold the bias perfectly. Should’ve bought them when I bought the amp. Noble, balanced sound.

When I don’t listen to music, all power off.

Power on, standby, etc...., I don’t do that.

When I want music, I just all power on. After 5 minutes, almost full performance comes out.

24-hour-on mode does not give much better performance than 5-minute-wait mode.

If you doubt it, just do the both ways. You will realize my opinion is CORRECT!

I'd say, in the case of my VAC it is 10 minutes of warm up minimum, I usually do a little more than that for critical listening. And VAC's manual says the same - 10 minutes before tubes warm up fully, especially if you want to check the bias before you go.

This is a situational maybe.  In South Florida especially during hot weather in densely populated areas we experience fairly large voltage fluctuations.  During peak demand hours at my location voltage can range from ~105-120 VAC.  Power tubes were constantly needing to have bias adjusted.  Like weekly.  I bought a power regenerator, originally a PS Audio P10 later a P20.  Tube bias requirements dropped almost to nothing, like once every 6 month I check but almost never need to adjust, and tube life at least doubled.  So if you live in an area with high peak power demands and consequent voltage fluctuations taking steps to regulate your power supply could extend power tube life.  

@billstevenson -good point. In Austin, we get 110F for days and weeks on end in the summer. The utility sends out constant warnings about potential rolling black-outs as a threat to turn down the A/C and conserve power. I simply don't turn the big system on during the summer, not b/c of the heat indoors- we are well insulated and have very efficient new HVAC, but because of power quality issues. 

I thought about buying a pair of Valvets (solid state amps) to use in lieu of my Lamm SETs, but everything else in the chain is tube as well (except a modest digital front end and the woofers/subwoofers and turntable). So, the idea of regeneration might make good sense. I haven't heard one since they were first introduced. We had very "clean" power here even without the big Iso transformer (10Kva) I installed as p/o an electrical subsystem for the main hi-fi, but given the growth and power demands, I consider it a risk to play this gear when the grid is "iffy." When I was in NY, along the Hudson, we had very antiquated power infrastructure, and could lose power easily. 

I'm thinking I might take up ice sculpture or some other hobby during the summer, which is brutal. (Though right now, the weather is perfect, the blue bonnets will soon come out and there are an awful lot of great things about living here).  I guess no place is perfect. 

We aren't constrained to live here, I'm retired, my wife will retire in a few months. And I may have one last move in me, but that's a constant topic of discussion-- where?

(to be continued, perhaps in another thread).

PS: I'd live abroad for no reason other than the excitement, history and challenge but that's a hard sell to my spouse. She loves traveling, but also likes being in proximity to friends. I'm different: I could live out of a good hotel in a safe place that had good food, a village or town full of life and proximity to the things needed- health care, an airport and a little culture. I did so for many years when I was on the road.  Oh, and no more winters, which is why I'm here, rather than the NE.