Tube life question

[Mooncusser]

Hi everyone,

I have a tube question. Some people claim that they have had the same set of tubes in thier amp for the last 10 years.
Is it possible that you could leave tubes in an amp that long and have them still operate at acceptable levels?

I am going on two + years with mine. They are MESA 6L6GC's. They came with the amp, and it is not a mesa. I do not know much about mesa tubes, as I usually go with SED's, so I don't know anything about their longevity record in terms of quality, reliablity, and use.
I guess this is a two part question.
Thanks for your help.
Take care,
Mass

[Blue Strat]

10 years of one hour playing time per week isn't much time at all.

I has more to do with HOURS of operation than anything else.

NOS, US or Western Euro tubes made 30+ years ago, tend to last 5 to 10 times as long as new production "third world" tubes.

[Mooncusser]

Thanks for that info.
So, for someone like myself who plays 2 hours a day EVERY day, what in your opinion would be the time to change out the tubes?
I appreciate your help.
Take care,
Mass

[Blue Strat]

Originally Posted by Mass

Thanks for that info.
So, for someone like myself who plays 2 hours a day EVERY day, what in your opinion would be the time to change out the tubes?
I appreciate your help.
Take care,
Mass

Hard to say with any certainty. I'm assuming they're new production tubes in which case 500 hours seems about typical for power tubes. If they don't go microphonic sooner, maybe 2000 hours for new production preamp tubes.

[Mooncusser]

May I ask how you can tell if they go "microphonic"?
Thanks,
Mass

[Blue Strat]

Originally Posted by Mass

May I ask how you can tell if they go "microphonic"?
Thanks,
Mass

Check the FAQ on my website under Resources. There's tons of useful information there.

[Mooncusser]

That was probably a redundant question to ask at this forum...will do on the FAQ,
Thanks

[Old Tele man]

...most NOS MIL-SPEC (ie: 5XXX-series and "W") receiving tubes had projected life spans of about 10,000 hours...and NOS commercial tubes had about 50-80% of that.

...today's imported tubes, however, seldom achieve much over about 20-30% of the NOS commercial tubes...and nowhere near the MIL-SPEC tubes.

...for more info, see the MIL-SPEC vacuum tube testing document posted by Ned at TRIODE ELECTRONICS.