When do preamp tubes start sounding aged?

[thegame]

In other words, if a (less than ANOS) tube tests about 90% of life/strength remaining, will it perform essentially as new? Or at what approximate percentage of it's lifespan will a preamp tube begin to loose definition, sound dull, become noisy, etc? I should know this by now doh! If there is any audible degradation there, I'll notice it as my hearing is very acute. This will be invaluable to know if shopping for ANOS tubes or ones that test close to those standards. Thank you kindly.

 

[SoooRad]

This will vary by individual piece. One tube may still sound "good" at say 89%, and another may sound "bad" at 91%

You are way overthinking this, IMHO

 

[thegame]

This will vary by individual piece. One tube may still sound "good" at say 89%, and another may sound "bad" at 91%

You are way overthinking this, IMHO

Well I'm considering a purchase so I want to get my money's worth. I should specify I'm only considering vintage tubes of 60's, 70's, & 80's production.

 

[ZEN Amps]

There's no answer to that I'm afraid - ANOS is all about buy, try, cross fingers.

 

[thegame]

One more bump to gather more opinions. So far it seems like it's a risky crap shoot, much more than true NOS.

 

[panhead]

When they start crackling

 

[PurityS.L.G]

Usually fuzzy and undefined gain. No sustain. Crackling. Loss of volume.

 

[That1Guy]

There's no answer to that I'm afraid - ANOS is all about buy, try, cross fingers.

This. Buy & try

 

[stephen sawall]

I have hundreds of preamp tubes. Some from the 60's thru today. Near as I can tell it's a roll of dice.