How Long Do Tubes Last?

[pickinpete]

I just bought my first tube amp and I love it, even though it is my honeymoon period, I have always Known I wanted a tube amp. I just bought the Peavey Classic 30 and I think this is a good amp to start with. But of course, I have questions and you guys are great at giving answers. First off, How long should I expect before I have to replace any tubes. I play every day an hour more or less. Second How will I know when I need to retube? A particular sound or the amp just stops working or what? Is there something I need to get into the habit of doing that I didnt do with my solid state amps to make it last longer or keep it sounding its best? Is something you would say absolutely do not ever do? Even tho the pvc30 doesnt have one, What does a standby switch do? Please, educate me.

Pickin Pete
www.billsbluegrass.com

[Dacious]

Other C30 users might like to pipe up, but they don't seem especially hard on tubes. It's always a wise policy to keep a spare set and one preamp tube (12AX7) too, as you might a spare fuse; as like a fuse they should be regarded like a consummable.

How long is a piece of string? Depends on quality of manufacture, individual tube construction, where the tube is, in what amp and what it is doing. Good quality preamp tubes for example might be virtually immortal. In some positions they wear out faster than others, like the 12AT7 reverb driver in BF/SF Fenders which wears more frequently than other preamps in those amps.

Power tubes are another matter. Think of tubes as like spark plugs in your car. Lots of flat out running will wear them out faster than a little leisurely use. If you play once or twice a week at moderate volume you might get up to dozens of years. OTOH if you play ten hours a day dimed with a metal pedal through the front (any gain increasers will work the whole amp harder) you might get hours-weeks.

You should always get matched power tubes, and always replace them as a set. So you would expect to replace them sooner than say a 6L6 amp. Running worn out tubes too long, like running worn out sparkplugs, is not wise from a longterm maintenance POV. I would ask for low-current draw tubes which are more likely not to cause a problem. Getting them from a reputable vendor lis encouraged - tell them what they are going in, often the vendor builds a knowlegde of what works best. Sovtek EL84Ms don't have the best sonic reputation but they are tough tubes. JJ Teslas are another with a good rep. EIs are reputably sonically good, but maybe not so tough.

Increases in hums, or popping and crackling especially if it occurs when volumes are at zero is potentially a tube issue - swap your spares in temporarily and check. Same with noise when voume goes up - try swapping your spare preamp in to each position. If noise goes away - walla. If not, might be another issue.

Generally, if the amp starts sounding muggy, fuzzy, you notice it seems to have lost clarity and volume is a sign the power tubes are on the way out as is silence if amp lights and tube heaters aren't out. Swap spares in - if problem solved, buy in new spares, 86 the fritzed tubes. If no difference, might be something else. Often a blown fuse might indicate a tube issue - swap in spares, good? Problem solved. Not? Tech time.

To maximise life, warm the heaters up for ten minutes on standby or zero volume before playing, and leave amp on standby or volume zero'd if taking a short break of less than 30 minutes. Tubes like car engines prefer less cooling/heating cycles.

Watch out swapping hot tubes - they burn! Oven mits are good to avoid burns. Hot tubes should be handled minimally and not jarred or banged into things.

[tazzboy]

Originally Posted by pickinpete

I just bought my first tube amp and I love it, even though it is my honeymoon period, I have always Known I wanted a tube amp. I just bought the Peavey Classic 30 and I think this is a good amp to start with.

Congrats on your first tube amp

But of course, I have questions and you guys are great at giving answers. First off, How long should I expect before I have to replace any tubes. I play every day an hour more or less.

Preamp tubes tend to last long the Power tubes. Power tubes generally tend to last 6 months to 1 year depending on how long you play and how much you play. I do agree with Dacious on the Power tube needing to be match set.

Preamp tubes can last and long time unless they start to become Microphonic aka feedback going on especially when they is no guitar plugged in.

Second How will I know when I need to retube? A particular sound or the amp just stops working or what?

If it's brand new and hasn't been played in the store then listen to how the amp sounds now that is how it should when down the road it will sound dull and lifeless sounding and doesn't have the kick it once had once you bought it new.

Also nice thing about Peavey Classic 30 amps is that you can change the tubes yourself and not don't need a meters and bias control. Just take out the old tubes and put in the new tubes and you are off an running.

Is there something I need to get into the habit of doing that I didnt do with my solid state amps to make it last longer or keep it sounding its best?

Tubes amps aren't that hard to maintain just make sure that you give the amp it's normal warm time like you do with your solid state and listen carefully for things like feedback and keep and eye the tube glow as well. If you see a purple glow on your tubes then it's time to replace them.

Is something you would say absolutely do not ever do? Even tho the pvc30 doesnt have one, What does a standby switch do? Please, educate me.

Just remember to keep your eyes on tubes once in awhile and if you decide to change the stock speaker make sure you get the correct ohms (16ohms is what the internal speaker is) and the right wattage. Tubes amps are picky when comes to speaker changes.

As for Standby Peavey decided against for cost reason and something. You can log on to the peavey amp forum http://forums.peavey.com:8080/~amps

and talk to there live customer service people and other techs and what not

[Dacious]

Oh and standby lets you turn the tube heaters on without powering up the rest of the amp: the cathodes in the tubes don't like being in the circuit and subjected to plate voltage and current draw until the heaters have warmed them up.

A good startup process on an amp with no standby is to leave all volume controls on zero for some time prior to playing, which will minimise draw through the circuit.

[pickinpete]

wow, thanks guys, I sure have alot to learn (besides how to play this thing, its only been 25 years so far) I appreciate the great advice and I'll be checkin in regular

Thanks
Pickin Pete
www.billsbluegrass.com

[johnreardon]

I tend to change my valves after 18 months and then keep the old set as spares. Far better, if you gig a lot, to anticipate and avoid failures.

[6942]

Your tube life will depend on use......and luck.
IF your lucky enough to get a "good" tube....right out-of-the-box....doesn't always happen.
A power tube will (generally) have HALF the life-span of a pre-amp tube.

Steve