Tubes at idle

Excellent post by Larry, as always.

Regarding the original question, I'm pretty certain that Wolf is correct, and that there will be insignificant, if any, difference in preamp tube longevity as a function of whether or not the preamp is processing a music signal while it is powered up.

The current that heats the filament will not be affected by the audio. And since nearly all tube preamps operate their tubes with class A bias, the power dissipated (consumed) by the tube, and the current passing through it (averaged over each cycle of whatever audio frequencies may be present), will be essentially the same whether a signal is present or not.

Regards,
-- Al

08-21-14: Czarivey
They do not, although their life shortens by idle hours as well.

Czarivey, did you read my post earlier in the thread? If so, what is the basis for your statement that "they do not," which I presume refers to the question in the OP as to whether or not preamp tubes "get consumed at idle as fast as they do with music going through them?"

Regards,
-- Al