Tube power amp - keep on continually?

As others have said, being on all the time ages the tubes prematurely, but on/off cycles are probably harder on them than just being left on.

I compromise - I turn my system (amp, pre and DAC - all tubed) off every night during the week, but I leave them on all weekend. I figure this works out best, since I often don't listen for a couple of days during the week. This regime minimizes the on/off cycles and the amps are always up to speed when I want them on the weekends. While the power tubes only take about half an hour to warm up most of the way, the amps really only sound their best once they'be been on for an hour and a half or so.

DO NOT LEAVE TUBE POWERAMP ON UNATTENDED!
TURN IT OFF WHEN YOU LEAVE LISTENING ROOM.
TURN IT ON AND LEAVE FOR 15...20MIN TO WORM UP BEFORE LISTENING.

Thanks for all the advice. I will turn it off when it is not in-use.

Alan

I agree. Do NOT leave tube power amps fired up unattended. Proper use calls for a warm-up time ( 5 - 15 minutes depending on design ) prior to use and then a "heat-down" time prior to shut-off. Cranking signal from the tubes before they are fully warmed and / or turning them off before they've had a chance to cool off causes extra thermal stress on them, which leads to premature failure. Sean
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Sean can you explain cool down time before shutting the amplifier off? Like how long to wait? Never heard about this before? Would this apply to a class A triode tube amplifier also?