There are only so many electrons in a vacuum tube. The longer you burn the tubes, the shorter their lives are going to be. You can expect to wring about 10k hours from pre-amp and driver tubes, and about 3k hours from power tubes. An important issue is how you bias your power tubes. That will have a major effect on their longevity. Yes, a lower bias in a class A/B will create a lower transition to Class B, but you probably won't hear it at lower volumes. This is not an issue with signal tubes used as drivers and in pre-amps: they are running full-tilt all the time regardless of volume and tone settings. The volts applied to them will affect their lifespan, but that's not something you can control from the front panel.
Is it a OK to leave tube pre-amps powede up 24/7
I’m relatively new to tubes in my hifi setup. Recently went from SS pre to tube ARC pre-amp and a Croft phono stage.
I have always kept all of my SS gear powered up 24/7(and still do), but I shut down my pre-amp and phono stage now after I am done listening for the day. I power them up at least a half of an hour before I put anything into play.
I would prefer to leave my tube gear on all the time, but am concerned about premature tube wear.
What would the tube folk here think about 24/7?