how long do preamp tubes last on average?

[Acquiescence]

a buddy of mine says he hasn't changed the preamp tubes in his mesa for like 4 years.... is that possible?

[omg_otters]

The preamp tubes in my traynor have been in there for over 30 years.

[Pope on a Rope]

Yes it is possible. The tubes' lifespans are determined by how hard you drive them.

[Armitage]

There's no problem having quality preamp tubes for 10-20 years, even longer. The ones in my 5150 were old when I put then in... in 1993.

 

I've had JJ preamp tubes last less then a year though... they sucked anyways.

 

Unlike power tubes, preamp tubes aren't much affected by how hard you drive them.

[Captain Commie]

mine have been in the same amp for 30 years. In fact my amp has known no other tubes...

[iansmitchell]

Average lifespan of a 12ax7 under normal conditions is approximately 700 hours.

 

"normal conditions" is likely the preamp of a fender twin reverb with no pedals in front of the amp, but still, that's what they used to say.

[butterknucket]

Preamp tubes can last for decades.

 

I have two amps...one is 40 years old, the other is fifty years old, and they both have the original preamp tubes and they work fine.

[wagdog]

I gig once a week, band practice once a week and I play at least 15mins, sometimes an hour or more a day (usually w/an amp). I replace my tubes (all of them) at least once a year, sometimes more.

[Wyatt]

The guys are right, preamp tubes don't see the same heat the power tubes do. So, they last several times longer. Some of the better made old American tubes easy last 10 years plus. Modern tubes are far less robust. Complaints about modern preamp tubes lasting one a couple of years are also normal. Still a set of preamp tubes (not counting the PI) should last out 3 or 4 sets of power tubes.

 

So, 4 years on a preamp tube can be just fine and dandy.

 

In hi-fi applications, where power tubes aren't run as hot, it isn't unusual to get 10-20 out of a power tube as well. To same is true of guitar amps that aren't pushed. A casual hobbiest who plays a Twin Reverb set on 1 or 2 for only a little while each week may see 10+ years of performance out of their power tubes.

[iansmitchell]

 

I gig once a week, band practice once a week and I play at least 15mins, sometimes an hour or more a day (usually w/an amp). I replace my tubes (all of them) at least once a year, sometimes more.

 

 

Can I have all your old tubes? I'll pay shipping.

[asatnutz]

I change mine every 3000 miles.

[wagdog]

Can I have all your old tubes? I'll pay shipping.

 

 

I keep 'em, for backups, that I never seem to need.

[iansmitchell]

I keep 'em, for backups, that I never seem to need.

 

[f13ndus]

I've only got 1 in my most-used amp (Gibson Gibsonette). I've changed it... twice. Both times I'd been using old USED, not NOS (one from 1960s, one from 1950s) GE tubes, and I guess gratuitious Big Muff application made them decide to finally bite it. So much fun, though...

 

I've since put in an RCA grey plate 12AX7 and it sounds as good as the day I got it in the mail. NOS, so since the other ones were good after 40-50 years, I think it'll last a while. Depends how much Muff I throw at it, I guess...

[hecticone]

I change everything once a year.And for those guys that say they have had their tubes in for years. Why?

[Armitage]

Why change something the hasn't even been used for 1/20th of it's life?

[jrockbridge]

Preamp tubes can last a long time. Change them if they become microphonic or if you want a different sound. Otherwise, enjoy the ride.

[C-4]

I use NOS Mullards, Telefunkens, RFT's, and Bugleboys.

The manufacturers have stated that these tubes may last up to 10,000 hours.

Who am I to question them?

If a tube works fine, I am certainly not going to mess with it.

I only change pre-amp tubes out depending on how I wish to voice the amp.

[goodwater]

I'd say anywhere from 1 hour to 100 years...maybe longer

[strtdv]

I have a couple of old Brimars that are original to my Orange (1975), that I now use in my Laney, and I also have a late 60's Mullard ECC82 that I use as a phase splitter in my Orange.

 

The reason to keep them; they sound better than any current production model I have come across (although the Groove Tubes Mullard reissues sound pretty good too).

 

OTOH, I change power tubes yearly. I find they lose their sparkle over that time.

[tlbonehead]

I usually change V1 about once a year. The others not too often.

[Lucio]

Depends on the position of the tube in the circuit.

[Wyatt]

 

Why change something the hasn't even been used for 1/20th of it's life?

 

 

Modern tubes don't last as long. But a reason to replace them systematically, instead of at fail is reliability.

 

If you gig regularly, you want to do preventative maintenance to make sure you don't have a meltdown on stage.

[Dave L]

I

[charveldan]

I'd put my NOS Blackburn Mullards up against any current tube made today, some of them are more than 40 years old still got that upper register detail, clarity, chime and complex mids....beats a 10 dollar JJ or chinese tube, a few of the russian tubes i'd take if I had too. Current made tubes aern't made as well as NOS so they won't last as long.