stupid tube question of the day

Good question I think.
I would guess that for my Class A running amp it does not matter because they're full on at all times. But PP class A/B?My guess is that the bigger the input signal the more work they're doing and the faster they wear out.

Generally, tubes do indeed get consumed just being turned on. There MAY be a tiny difference in consumption between classes of operation.

I do NOT leave my tubed equipment turned on. If one does, three- to four-thousand hours of goodness get used in half a year.
.

i run my tube amps 4 hours max. if i want to keep going, i turn them off for 30 minutes then back on.

G_m_c

Why is that?

Tubes are slowly wearing themselves out as soon as their powered up. The circuit design has a big influence on tube longevity and NOS tubes aren't getting any cheaper. No sense in taking a chance on leaving tube gear powered up other than an hour prior to a listening session & then should be turned off when your done.

When powered up, I would think that when tubes are driven by an audio signal as opposed to no signal at all would in fact reduce their life span, especially in tube amps. I have had very old tube gear that still works with their original tubes. Maybe low usage could of contributed to this or again it goes back to how the tube circuit is designed or maybe both.