stupid tube question of the day

What about taking steps to cool the tubes down while they are in full operating mode? Such as running a small, quiet fan toward the tubes. Say one of those super silent computer fans, or A.T.M.fans (Active Thermal Management)? Could providing a cool breeze or flow of air directed toward the tubes be a solution? Extend tube life? Or would that not matter?
As we all know-Heat is not our friend. Most tube amps and alot of tube Pre's generate significant amounts of heat which can't be a good thing, right? If one could lower the ambient temperature in and around the proximity of the vacuume tubes, wouldn't it stand to reason that life span and efficiency would increase? What good is all that generated heat doing anyway? Please advise.

Most commercial and military tubes were designed with a 10,000 hour operating life. This life expectancy can be shortened by primarily two activities: 1- frequent power cycling, On/Off [if you are planning a day of listening and want a few hour break, go take your break, but leave the equipment on]; 2: High Bias/hard use- if the B+, or Bias is at or above the design threshold, then the tube(s) will be driven 'harder' which will cause the plate to off-gas, which in turn will eat up the getter, and in short shorten the tube life. There was an amp in the late '80's/early '90s that used 8417 power tubes at Very high B+, and the tubes would only last about 3,000 hours. I have both AI pre-amp (M3) and MR power amp (RM-9MK-1) and have re-tubed each once - after ~10 years of use. The getters were pretty transparent - more like ghosts, and the 9-pins were getting noisy. They (the tubes) are designed to be replaced, and a prudent owner of tube equipment will have spares...
Happy listening

6bq5 -- I can't speak to other tube makes or gear, but in the case of ARC, the factory recommends that power tubes in more current models, such as 6550Cs, be replaced every 2000 hours. These particluar tubes bias at 65 mV. ARC has replaced the 6550C in some amps with a new tube, the KT-120, which is supposed to be more robust. Time will tell if service life will be extended. However, in the case of pre's and other input gear, such as phono pre's and CDPs, the more recent models use 6922s and 6H30s. ARC advises that these audio/signal tubes be replaced at 4-5,000 hrs. Certainly in the case of ARC gear, I am not aware of any tube, at least in current models, that has a 10,000 service life. Perhaps, longer tube life might be found in gear from other companies.

I think the question at hand is whether there are suggestions or recommendations out there in audio-land that can help extend, or at least not shorten, tube life -- whatever the factory's recommendations might be. I think you put at least 2 recomendations out there in your post. Thank you. Your advice makes a lot of sense.

Two things. ARC wants to maximize the listening pleasure of it's owners, without much regard to the cost of tubes.
So they want to be certain the tubes in use are always going to be excellent, and never 'wearing out'.
Thus thier recommended replacement intervals.
No problem in my mind with thier philosophy.

Another thing is the preamp tube, and the power tube are really two very different animals as far as tube life.
Power tubes are run hard, and wear out pretty fast, and when they fail, it can be fireworks. So you want to replace power tubes when recommended.
Preamp tubes (depending on the usage and design) can last a very long time. And never do any explosive things. (well possibly, but i never heard of it) A few designs do run preamp tubes hard, some notorious preamp designs went through 6DJ8 tubes fast! So preamp tubes (and preamp type tubes in an amp) can be used until they start getting bad/noisy.
You do NOT want to leave a power tube running without a person present. the exploding/fire etc possible distructive death of a power tube is real. And so its the fire hazard.
Not so for a preamp tube.

I leave my VAC Standard preamp on 24/7 with a pair of 12ax7 and a pair of 12au7 in there, and a sealed case, (separate SS power supply) with little generated heat, I expect them to last pretty long even on 24/7 (as i listen over ten hours a day average anyway)
And finally playing music or idling. Preamps are mostly class A 100% so the tube is run at 100% at idle, and actually less when playing music.
Power tubes can be anywhere in the class "A" to class "AB' spctrum, and depends on how they are biased etc.

Cd player tubes are in there as a preamp tube or tube buffer. and are not stressed much. They should last a long time also. ditto most headphone tubes.
A few BIG headphone amplifiers use real amp tubes though.

Great responses, and all very helpful!

Much appreciated.

Thanks all,

--dan