Leave tube amps always on?

The way I read it is his reasoning is based on environmental concerns and not the life of the tubes. I have had a Cat preamp for over 25 years and there is no difference in sound after 20 minutes of playing no matter how long it is left on. Based on that, I see no reason to leave them on for a minute more than when you are done listening for the day.

Leaving a tube amp on 24/7 implies that it will be left on unattended. If one of the tubes fails and the amp is unattended this could cause a significant fire hazard IMO. I would NEVER leave my tube amps or preamp on 24/7 under any circumstances.

I own 2 LTA amps now and I’ve also owned the LTA Ultralinear. These amps do run the tubes significantly cooler and stress them less than other amps using the same tubes. I’ve also talked to Mark several times at audio shows and he really seems to know his stuff. 

I can see why he would recommend leaving them on because every time a tube amp turns on and off, that’s wear and tear on the tube. Even if it has soft start circuitry. An example, I have an older Modwright pre amp and the on/off toggle switch was damaged in shipping. I didn’t know that and when I started using it, the on/off switch made intermittent contact and rapidly shut the pre on and off a bunch of times. That quick series of powering up and down was enough to kill the rectifier tube and also F’ed up the driver tubes. Quickly turning tube amps on and off is really hard on the tubes. 

That said, I wouldn’t leave the LTA amps on all the time either. If I’m just going out for an hour or so and I plan on listening when I come back, I’ll leave it on. But I wouldn’t leave them on for long periods if I’m not around. Too paranoid for that. They have built in protection circuits but my thought is, why risk it? I’d rather not have a fire happen that I could’ve prevented. Imagine trying to explain to the authorities what happened. “Yeah, I leave my tube amps running all the time... Oh, you don’t know what tubes are? They’re gas filled bottles that run hot and at high voltages.” 

@tomic601
Wasn’t Einstein a physicist? They know a thing or two about energy and glass tubes. ;)

No matter the built-in protection, I take the point about gas filled tubes and fires and its enough convincing for me to shut it down every night or when we leave the house. Thanks for that gloriousunicorns :)

I guess it just comes down to some daily thought around when you may use your system throughout a normal 10 hour period in that day and plan accordingly 👌 So one follow up may be if I use my system on the weekends in the afternoon, take a few hours break and then again at night --- what say yee - on or off?

As a side matter, I have left my solid state amps always on 24/7 in my home theater room since 2011. And that was on the advice at the time of just about everyone on the theory that they draw very little power when idle and not being used and there is a bigger risk with the amp breaking down with constant switching on and off.