2. amps-preamps
  3. 1230699199

Tube Life: 6SN7, 6DJ8, 12AT7 et al.

Does the rate of decline increase with age or is it linear?

Assuming a new tube had a reading of 107/107 which for the sake of this example would represent 107% of new stock specification and it was sold after considerable use with readings of 102/102. Can the purchaser assume that for all intents and purposes that the tube will last as long as a brand new tube that specs 2% over new spec?
anacrusis

Showing 2 responses by anacrusis

anacrusis OP
69 posts
 
Thanks for your comments so far. I guess the real question is that if all parameters are equivalent, same tube tester, same amp, regardless of tube make or model, does the rate of decline tend to remain linear or does it increase with usage? If the rate increases will it do so even if the tube still specs at over NOS readings even if the original specs were higher? If again the rate tends to increase, is the rate of decline relative to the factory fresh readings or the NOS specification?

I hope I'm making myself clear, I think it's a very important question.

Thanks,
anacrusis OP
69 posts
 
My strong guess is that volume is not a factor and that less heat and resistance might even be realized at full output.

Thanks for the really good points presented. I guess the question can't be answered in absolute terms, but I do have a better feel for how I might approach a tube purchase.
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