Leave tubes on all the time?

I've turned my CAT amps on after a few minutes of being shut off, never a problem. Turned guitar tube amps on and off and on, never had a problem, ever.

 

I only wait a few minutes myself. I was talking about some much shorter interval, like when someone switches out an interconnect or a tube. Whether or not one will have problems is also dependent on the specific piece of gear. Just because you have not gotten cancer from smoking does not mean smoking is not a potential hazard for some people.

 

I think it may be more of a design issue. If a tube amp is designed and built well it shouldn't blow up switching it off and on.

 

I haven't had anything blow up, but, my friend's amp did make a BIG racket (through the speakers) and the rectifier flashed quite a bit from such a short cycle. It is otherwise a pretty rugged amp, considering that it has been around for sixty years, most of it in commercial use.

 

What kind is it?

 

I think what happens when you switch tube amps on and off and on and off again quickly once they've warmed up is that the tube filaments are already fully warm, so each time you're switching it back on all the tube are instantly pulling full current and you can get things like the aforementioned arcing rectifier tubes, or you can blow a fuse, or pop some kind of safety circuit.

 

the resistance of the filament is lower when cold so there is more current flowing at that stage until normal temp is obtained.