How long can preamp tubes last?

LOL Fred puttin’ Dino out THEN, Dino puttin’ Fred out!
BUT Fred won’t jump back through the window, the way Dino did.
Fred was a little thick in the HEAD and bottom..

Bang Bang Bang! Wil-ma, WIL-MA!! BANK BANG BANG.

Rockport TT
Stonehenge speakers

When we were kids, ay.

I’m glad I’m NOT talkin about Steamboat Willie, 1928. vs Flintstones 1960. :-)

All kidding aside

I do have some OLD valves that work perfect. It depends the way they were used.

GE 6550s with 4000 hours and just perfect over 50% left
GL KT88 5000 hours still 40+ % left
RCA BP 6L6 5000 hours 40% left
300b with 15,000 hours.. and they were bought with 10,000 on them. 20,000 hours or a LOT more.
I herd they would go 50,000 in communication applications.. Not a big fan
All kinds of power valves with 3000 hours or more and at least 50% left

Most of my stuff was Mac with super high hours.

The problem is sometimes one side wears quicker than the other because of duty cycle and what one side of the valve does. I know, I have GEs and RCAs small valves I’ve put 10,000 hours on.. Still good! No microphonics, usually the issue with old RCA and GEs.. They go under water or echo like crazy.

Regards

It depends on the preamp.
I turn my Atma-Sphere MP-1 off and on twice a day to save the 18 tubes. Ralph says that if left on, the tubes need changing every 6 months. I try to make them last a year or more. It is on about 8 hours a day.
I think that most preamps are easy on their tubes and can last many thousands of hours.

Thank you ALL for the great inputs!
Did learn a lot and sound advice was given!(no pun intended)
Much appreciated.
Rockanroller