stupid tube question of the day

Ckoffend, your comment is consistent with my thoughts too. However, I am not an electronics techie, so I have no real basis for formulating a view, ergo why I asked the question.

There are a number of A'gon members who are heavily involved in tube based electronics. To be courteous, I will not mention names or their A'gon handles, but perhaps if they catch this thread, they will chime in with some recommendations and guidelines that are based on their considerable knowledge and experience.

No matter what you do, tubes will eventually wear out and that is a fact of life. The most important thing is just be reasonable and enjoy the music. If you plan on listening to music on any given day, leave it on for that day. I believe too that cycling tube gear on and off several times during a day can be more harmful than good in regards to tube life. A case in point is that Audible Illusions believes this is true and design their tube preamps where the tubes are always lit even when the preamp is powered off. But now I'm just talking tube preamps only.

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.