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How long is the life span of tube amp?

post #1 of 42
Thread Starter 
I know that SS amp probably can last for decades or longer. But tube amps are depending on the life of tubes, if those are discontinued, it's very impossible to fix it. And tubes are basically like light bulbs, so how long can they last???
post #2 of 42
Tube amps - forever.
Tubes - 1-2 years? That's why folks stockpile em. If you have an unused tube with a good vacuum, those tubes can last forever, so your tube amp will always be up and running.
post #3 of 42
Depending on how often you turn on and turn off your gear, but tubes should last about 5,000 to 10,000 hours. For most people, they only need to be replaced every 2-3 years at most. But it's good to have at least a spare set around just in case one of them decides to die on you.

Most popular audio tubes are still been manufactured in countries like Russia and China. They are just not as good as tubes that were made during the golden age of tubes (1950s - 1960s) in most applications. The market for vacuum tubes are fairly small, comprises mostly of audio enthusiasts, musicians, and ham radio enthusiasts. But the supply is fairly steady. So don't worry, they won't run out. Unless, of course, your gear uses some obscure tubes that nobody is manufacturing these days. Even that, you will probably upgrade to something else before those tube supplies dry up.

And if you are that worried, buy several sets of the tubes now and save them for later use. The price of those tubes will only go up. (Better than investing in most stocks) I have "horded" enough NOS 6DJ8/6922/7308 tubes to last me several lifetimes.

And...you can always ask Doraemon to take you back to the 1950s with the time machine and get some good NOS tubes for dirt cheap.
post #4 of 42
Quote:
Originally Posted by Jahn
If you have an unused tube with a good vacuum, those tubes can last forever
maybe i'm being a pedant, but unused tubes will eventually lose vacuum. atmospheric molecules costantly enter tubes (even well made ones), though at a very slow rate. the getter flashing, which contains barium, absorbs these molecules, but it's ability to do so degrades over time as more and more reactions occur. eventually all tubes, unused or not, will go bad. well manufactured ones will last longer than poorly made ones, however, and the time spans may be long enough as to be practically forever for current users.
post #5 of 42
Let's put it this way. You will get bored with hi-fi or succumb to upgrades and sell the amp before the supply of tubes dries up.
post #6 of 42
What does NOS mean?
post #7 of 42
Quote:
Originally Posted by ken36
What does NOS mean?
NOS: New Old Stock


Overlunge
post #8 of 42
Thread Starter 
my understanding is that you can put your spare tube in a jar and vacuum it and store it somewhere safe. Are the tubes usually socket-inserted into amp PCB or soldered on it? that will make a lot of difference. And do you turn it off when not in use? I always leave my SS amp on even not in use. I thought turning on/off makes some impact on tube but tubes can also burn out with long time use. That's a dilemma...
I am considering a Chinese made G&W2.6F tube amp, I heard it's quite good, especially with Senns cans.
post #9 of 42
Quote:
Originally Posted by EdipisReks
maybe i'm being a pedant, but unused tubes will eventually lose vacuum. atmospheric molecules costantly enter tubes (even well made ones), though at a very slow rate. the getter flashing, which contains barium, absorbs these molecules, but it's ability to do so degrades over time as more and more reactions occur. eventually all tubes, unused or not, will go bad. well manufactured ones will last longer than poorly made ones, however, and the time spans may be long enough as to be practically forever for current users.
ouch ~ I read this and can't help but feel a little depressed.

Great info.
post #10 of 42
Most tube amps are easier to fix then solid state amps.

A good tube amp will last a lifetime, granted some parts may need replacing over time for best performance (coupling caps, resistors, sockets, diodes .... all universally available parts). Solid state parts don't last an eternity either.
post #11 of 42
Quote:
Originally Posted by EdipisReks
maybe i'm being a pedant, but unused tubes will eventually lose vacuum. atmospheric molecules costantly enter tubes (even well made ones), though at a very slow rate. the getter flashing, which contains barium, absorbs these molecules, but it's ability to do so degrades over time as more and more reactions occur. eventually all tubes, unused or not, will go bad. well manufactured ones will last longer than poorly made ones, however, and the time spans may be long enough as to be practically forever for current users.
It is INCREDIBLY rare for vintage tubes to lose vacuum. I have no hard statistics, but it'd be something in the order of 0.05%. I've literally handled thousands upon thousands of tubes made from the 1930s to 1980s. No vacuum is perfect, but tubes will easily last decades (and if I can extrapolate from what we know of tubes, likely centuries) without appreciable degradation. It's nothing I'd ever concern myself about.
post #12 of 42
I'm glad i'm a patient man. There will always be a spare set of tubes out there for me somewhere...as long as there is a Reputable dealer online somewhere...
post #13 of 42
Quote:
Originally Posted by Jahn
Tubes - 1-2 years? That's why folks stockpile em.
Tubes really last a lot longer then 1-2 years. If driven within specification, you can expect most small signal tubes to last 3,000 to 10,000 hours. Some tubes like the TFK ECC803S or WE 300B will last a solid 30,000-50,000 hours. If you listen to your amp for 6 hours every day (without skipping a day), such a tube will last you about 20 years.

Modern production tubes is an entirely different story. The quality control is a farce compared to the golden era of tube production.
post #14 of 42
Quote:
Originally Posted by Len
Tubes really last a lot longer then 1-2 years. If driven within specification, you can expect most small signal tubes to last 3,000 to 10,000 hours. Some tubes like the TFK ECC803S or WE 300B will last a solid 30,000-50,000 hours. If you listen to your amp for 6 hours every day (without skipping a day), such a tube will last you about 20 years.

Modern production tubes is an entirely different story. The quality control is a farce compared to the golden era of tube production.
but my melos manual said that ECC88 tubes should only last 1-2 years in the belly of the beast! we'll I'll ride em till the glass shatters, i'm sorta cheap like that! if they are "old" the tubes still perform perfectly, up to the fizzle date right? i mean, it acts more like a rechargeable battery and not an alkaline in that respect, analogy-wise?
post #15 of 42
Quote:
Originally Posted by Jahn
but my melos manual said that ECC88 tubes should only last 1-2 years in the belly of the beast! we'll I'll ride em till the glass shatters, i'm sorta cheap like that! if they are "old" the tubes still perform perfectly, up to the fizzle date right? i mean, it acts more like a rechargeable battery and not an alkaline in that respect, analogy-wise?
Your Melos may drive the tubes pretty hard. There are a number of circuits out there that put a lot of stress on 6DJ8 tubes (in this sense, the 6DJ8 is to signal tubes what the 845 is to power tubes .... both commonly driven hard).

Tubes don't really behave like batteries, rechargable or otherwise. Once the emissions is gone, you can't really recharge it (well, there is a process called rejuvenation, but it is a short-lived fix and only works with some tube types). Old tubes will still perform "normally" (I wouldn't say "perfectly") if no catastrophic failures occur from use such as open filaments or shorts. As with anything, internal tube parts do have finite servicable lifespans, so they will eventually break. I wouldn't run a tube way over it's specified operating life or if it tests extremely poor. For starters, the sound degredation is huge and noticable. If you don't have a tube tester (and even if you do), a good idea is to swap in new tubes of the same type every 6-12 months and see if you can hear a big difference. If you can, your old tubes are probably tired and needs replacing. Running a tube too long may also damage other tubes in your signal chain or your amp if the tube should fail or not pull its weight as it is required to do (such as in push pull circuits).
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