Tube amp on/off: best practice?


My main system, with a tube integrated, is in my studio where I work 10-12 hours a day, interrupted by the occasional offsite meeting or errand.

What's the best practice/rule of thumb for powering it up and down as I duck in and out of the studio? Just leave it on all day?
How long do I need to be away for it to be better to power it down?

Right now I'm firing it up and cooling it down about 3x a day, running it a total of 6-8 hours a day.
soundgasm
My thought is off, but tube sales people encourage you leave them on. The advice I have always received is Solid State stay on and Tube off. You will undoubtedly get a mix of responses, I will be interested to see the opinion of majority.
WhenI leave I shut the amps off!!! The preamp is also shut down. Two weeks ago I had a tube start going bad, if I wouldn't have been there.........?????!!!!!! Now I don't like to leave the room for an extended time, I'm a little paranoid!! If I have to turn everything on and off two or even three times in a day I'll do it, no more running down the street to the post office etc......
Samhar, turn the preamp ON first then the amp. When shutting down turn the amp OFF first then the sources and preamp.
Why put extra hours of usage on your tubes? My amp sounds fine on start up and gets optimal after 10-15 minutes.Just my thoughts.
I was under the misconception (?) that the power cycle was hard on the tubes, shortening their lifespan.

Also, Samhar, I thought tubes just went quietly into the night...at least that's how they've failed for me so far. But yikes - is there a fire-hazard variety of tube death I don't know about too?

Thanks for your thoughts and expertise.
I had a Winged C EL34 go bad on a power amp and it looked like it was shooting sparks inside the tube. It was crazy. I'm glad I was there to cut it off immediately.
Polk432
That's how I do it.

Soundgasm
The 9 pin tubes stay on all the time in my amp and on standby in the preamp, it's been the "big" power tubes in the amp where I've had problems. The last power tube that failed, a 6C33CB, started to glow cherry red, and the one before that started arcing. I haven't had anything catch fire and don't intend to tempt fate anymore even though my amps take 1 1/2- 2+ hrs to hit their stride, "settle in" and start sounding very good, at 3+ hrs the magic really starts to happen!!!
I would say since you a leaving and then coming back I would power off just in case of a problem devolping and you are not there to resolve the problem.
The on/off is supposedly harder on the tubes than just leaving them on. However, a tube blowing is scary too. You are in a "no win" situation.
For that same reason I went with solid state in my office. I just leave it on all week now. If that were tubes and they were totally safe, you would still be stuck retubing once or twice a year!
Save the tubes for home or serious listening only.
I agree with the above about not leaving the room when tubes are on, they most certainly don't always go quitely.
The best advice by the tube sellers I buy from is to conserve tube life by turning the amp off. I also asked about the power up cycle as potentially leading to excessive wear on the tubes. The answer is that most amps nowadays have a soft start cycle to blunt whatever the power surge may damage. The other concern for me is that I am fond of old stock tubes which as everyone know have become scarcer and scarcer. Therefore I really do my best to preserve them.
Generally speaking, unless a tube amp has a sentry circuit that automatically shuts down tubes in the event of tube failure (very few tube amps have such a circuit), it is not a great idea to leave a tube amp unattended, as the above posters are correct - output tube failure can resemble the 4th of July in a worst-case scenario. My tube amp has a sentry circuit and I generally leave it on all day, and at times unattended, if I intend to listen at various times during the day.

Regarding the specific question of whether tube life in tube equipment is best extended by 24/7 operation or turning it on and off, this subject has been discussed in great detail in many threads. The short answer is that tube power amps should be turned off when not in use because output tubes (the big tubes) pass a lot of current, which is hard on them (cathode stripping). The answer for small-signal tubes (i.e., the little tubes found in preamps, DAC's, and the little driver and splitter tubes found in tube amps) is more complicated, but I generally advocate leaving them on 24/7. This very recent thread about two high-end preamps includes many of my thoughts on the subject, as well as those of the founders of Atma-Sphere and BAT, but you need to read through the entire thread because the discussion of how best to extend tube life is not the actual thread topic:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1282891541&openfrom&1&4#1
Turn tube amps of when not using them in general. If you're going to space listening sessions by 30 minutes or so, best to leave the amp on. Tubes have a finite life. In a perfect world, you'd leave them on all the time...but it's not a perfect world.

Sequence- in "Get Better Sound," Jim Smith is pretty emphatic about "amplifer ON last, OFF first." Something about getting any junk out of the system by turning tube components other than amps on first and off last.....
I agree with Elevick completely. I've had many tube amps over the years. One of which had a output tube go bad. Music was not playing, but there was a god-awful screech coming out of the left channel, then I saw a red flame shoot up through the top vent, followed by smoke. Thank god I was home. I lived in a condo and I don't want to think what could have happened to the seven other families in the building. I've been using digital amps for a while now.
ok, so here's another reason I don't want my lovely wife reading Audiogon.

Thank you guys for the reality-check.
I leave my pro-ject tube phono preamp on all the time. Is this ok?

Rest of my system is Audio Refinement SS gear.

TIA,

Scott
If you listen all day, and turn it off at night, that's fine; but it's realy not good turning tube gear on and off like you describe, and I forget why or why not.