How long can a tube amp be left on without causing problems?

TheGoodTexan

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I just noticed this afternoon... that my tube amp has been on since the last time I played... almost 48 hours. Not in stand-by... but ON.

I plugged in and it sounded fine.

Did I just cut the life of the tubes some?
 

RubyRae

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I think at some point we all have done this, at least I know I have.
Most of the times were just 24-36 hrs. or so, and I think yours will be fine.
The one time I left a HRDX that I kept in the garage on for much longer, and the tubes were fried...not sure if anything else was damaged, but it still worked fine after a re-tube. Tough amp! I always feel terrible when it happens, like the 'bad parent' syndrome. Just rub the tolex and tell her you're so sorry, it will never happen again. lol.
 

getbent

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I've done it and suffered no noticeable ill effects (and left one on for a week) I kind of shuddered at the potential fire danger, but, in the end... no big deal...
 

jh45gun

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Look at it this way back in the old days Radio's and TVs were left on all day and half the night every day with no issues. Them old Tube PA heads were left on for hours every day in schools and where ever else PA gear was need for announcements any time of the day or night. A good guitar amp should take the 48 hours in in stride.
 

tele0053

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I sold a 65 or 66 BF Fender Showman to a friend years ago and he called me about
about a year later and told me that he had found the amp head behind some stuff turned on and if I remember correctly... no speakers plugged in!
It gets better...he then said that it had probably been sitting on for a couple of months!
He turned it off waited a day or so and hooked it up.... and low and behold the damn thing worked!
I think he said the tubes were pretty much shot, but when replaced them it worked fine.

That's one for the books I guess...
 

printer2

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Had a Scott tube amplifier in my bedroom on during the winter for weeks on end. Warmed up the room a bit which was a good thing. No problems.
 

T Prior

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radio station transmitters from years back used tubes, they never shut them off..

whats the question ? I think we sometimes get caught up in the "Tube" thing.. Tube amps require maintenance, so if you leave your tube amp on for extended periods it will require maintenance sooner, such as tube replacement and possible PS filter cap maintenance. The heat buildup from the tubes stress components so they will begin to breakdown sooner rather than later, but we are talking years here.... TV sets ran on tubes, our family TV back then was on everyday from early morning 'till late night .. Sure every now and then a tube would flutter and need replacement but it was years in between...

Think of it this way, a tube amp will offer excellent service for XXX amount of hours. XXX amount of hours can be 1 year if you leave it on for the whole year or 10 years if you only use it now and then... it's the XXX amount of total hours that matter. There is no danger leaving a tube amp on unless it is in a very confined area such as in a box or up against a wall with no rear ventilation. The heat must disperse.
 

Wally

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That was probably better than if you had turned the amp on and off 10 times during those 48 hours, The Good Texan.
 

Jimmyspaz

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It stresses the components much more to turn your amp on and off than to leave it hot. Actually better for the the tubes because of not heating and cooling. Will use more electricity though,,,,,,,,
 

charlie chitlin

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I used to visit a luthier who used to turn on his Vibrolux in the morning, and turn it back off in the evening.
For years.
It was a great sounding amp!
 

Middleman

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It's fine until either smoke comes out of it or the light goes out. In fact, sometimes just before it dies, an amp can have the best sound ever then pffft. Had that happen a few times over the years.
 

frankie5fingers

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Yes, you've used up some of the life of the components (like tubes) that degrade by exposure to heat and current, although components that degrade through the passage of signal have had no effect (like speakers). That said though, I wouldn't get the Sawzall and turn it into firewood just yet. A good older, American made tube will last several thousand hours, in fact, some of the older higher end ones will last around 10,000 hours. Current production tubes last only 20 - 30% as long as those, but are cheap enough to replace. Like others have said, not the best idea, but no real damage. (ever leave the garage light on over the weekend?)
 

SoK66

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Back when audiophile stereo was virtually all tube the common practice was to just leave it all turned on. Same with tube amps. The real stress on tubes is the warm up / cool down process. Studio owned tube amps may run for days on end and some of them are the best sounding amps you'll ever use.
 




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