Leave tube amps always on?


Mark, the owner of Linear Tube Audio, suggested I leave my tube amps on all the time 24/7 if im listenting every day, and to turn them off if not using for a period of time, a few days or for example we go away.  His reasoning was that it uses considerable more energy to turn on/off on a regular basis. 

Do others agree?  Kinda risky since these NOS Mullard tubes ain't cheap and will soon be gone forever.   
aj523
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.”