When to power off a tube amp?

Hopefully Ralph (Atmasphere) or Gary (Hifigeek) will weigh in. My practice, FWIW, is that I will leave my amp on unattended for up to 4 or 5 hours -- never if I am out-of-town.

Seem to recall that it's a bad practice to shut a tube amp off and then restart it unless waiting for at least 5 or 10 minutes. The "wear and tear" of a tube as I understand it is the tube's innards responding to hot and cold, which in turn, causes the innards to expand and contract.

Tube failure also occurs because of arcing. I do not know what user-related factors (if any) cause arcing. I for one would love to hear back from Ralph or Gary.

Bruce

George, what you say sounds reasonable, but I am not EE savvy. I can barely tell the difference between the front and back of the amp. :( Further, any mods to the amp's circuits will adversely affect its resale value.

My linestage and amp have a 12 volt trigger connection. The trigger starts the amp within 10 seconds or so after the linestage is turned on. I suspect this is NOT the same delay circuit you described. Instead, I think delay start-up prevents a linestage turn-on thump from causing a power surge through the amp into the speakers.

Otherwise, I think you and I are on the same page about turn-on/turn-off concerns. I'm not sure if 4 or 5 hours is a good number for my rig, but it's what I have been doing. Thank goodness I never had a Fourth of July problem with my gear -- at least not yet. Hopefully Ralph or Gary will weigh in.

Cheers,

Bruce

Al, can I assume, therefore, if one leaves their amp on unattended for even a short period of time, they could learn upon resuming their listening session that not only does their amp not work, they may be minus one or two speakers as well?? Al, there is obviously no written rule out there that I am aware of, ... but at the risk of too quick a turn-off/turn-on, what's your rule of thumb about leaving a tube amp on unattended?

Thanks

Bruce

Highroller -- good question ... good questions all. Let me summarize the opinions given above. Let's see ... uuhhm, exploding tubes, out-of-control tube oscillations taking out speakers, fire hazards, shortened tube live if tubes are turned on and off ....

I finally get it. Boy am I dumb. If you own tube gear, the best way to avoid all of the these hazards and perils is simply not to turn on the system. Or, ... dump the tube gear and get a Phlame Linear 400, or just plain ole' SS gear. Anyone looking to buy ARC ref level gear??

:( :( :(

This thread gets my lowest rating. 3 unhappy faces.

Cheers,

Bruce