# Stupid Amp (user) question



## BlueRocker (Jan 5, 2020)

I recently left my amp on for about 24 hours (an EL84 based 30 watt tube amp). Not in standby, but on and ready to go. Got to thinking, back in the day all kinds of tube based products would have run for long periods of time, but it still made me feel a little queezy having left it on. So, does it hurt anything to do this? Not that I intend to repeat it anytime soon.


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## Chito (Feb 17, 2006)

I've done that numerous times for even longer periods of time. Last week I had my Fender Princeton on for a week. Probably lessens the life of the tubes, not sure. I've done that with my Peavey Classic 30 too. Numerous times and I haven't changed tubes on that one for years. I wouldn't be concerned.


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## Dorian2 (Jun 9, 2015)

My understanding is that the tubes may wear out a bit quicker, but that's about it. I wouldn't worry about it too much. I've done it a few times with no issues. I'm sure one of the amp guys here can expand on this though.

EDIT: Posted about the same time as Chito haha


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## Paul Running (Apr 12, 2020)




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## player99 (Sep 5, 2019)

When I got my Fuches amp they recommend putting it in standby to stage the cooling down before shutting it off. I don't know how many times I notice hours, sometimes the next day the amp is still on standby. It really pisses me off when I do that.


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## Paul Running (Apr 12, 2020)

Like headlights for the car. There were no auto shut-off circuits back 30 years ago. Now there's a gimmick you could market to tube amp users...auto shut-off.


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## KapnKrunch (Jul 13, 2016)

player99 said:


> When I got my Fuches amp they recommend putting it in standby to stage the cooling down before shutting it off. I don't know how many times I notice hours, sometimes the next day the amp is still on standby. It really pisses me off when I do that.


This should only piss you off slightly, as that is what standby is for -- saving your power tubes.

@BlueRocker the only time leaving an amp on has ever really hurt me was when I returned to find the basement full of acrid smoke. A transformer burned up in an old Garnet because the previous owner had put in the wrong fuse. Maybe it had nothing to do with tube destruction, just sayin' -- not a good practice at any time to leave a live amp unattended for too long.


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## loudtubeamps (Feb 2, 2012)

BlueRocker said:


> I recently left my amp on for about 24 hours (an EL84 based 30 watt tube amp). Not in standby, but on and ready to go. Got to thinking, back in the day all kinds of tube based products would have run for long periods of time, but it still made me feel a little queezy having left it on. So, does it hurt anything to do this? Not that I intend to repeat it anytime soon.


Short answer ?....no.


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## Paul Running (Apr 12, 2020)

Yeah, if you burn the house down that would be traumatic not to mention the toxic substances generated from a cooking TFM.


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## Hammerhands (Dec 19, 2016)

Hmmm...did I leave my amp on...


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## DaddyDog (Apr 21, 2017)

BlueRocker said:


> does it hurt anything to do this?


As per Skip Simmons with 40 years of amp service experience, and "star" of the podcast The Truth About Vintage Amps... no.

Maybe if you had the cover on it, or something not allowing it to vent.


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## dtsaudio (Apr 15, 2009)

KapnKrunch said:


> the only time leaving an amp on has ever really hurt me was when I returned to find the basement full of acrid smoke. A transformer burned up in an old Garnet because the previous owner had put in the wrong fuse. Maybe it had nothing to do with tube destruction, just sayin' -- not a good practice at any time to leave a live amp unattended for too long.


I had a customer do that with his vintage stereo amps a number of years ago. Left them on to warm up, and went for a walk. Came back to find his basement full of smoke from a fried power transformer.
While this is the exception to the rule, and these amps were in rough shape. I don't recommend leaving an amp on unattended, especially if it is an old one.

Paul, that's an interesting chart. Notice how filament life is extended with them left on. 
I was just working on a stereo tube preamp where the filaments are on as soon as you plug it in. The power switch only turned off the high voltage. 
Talking to the designer, he says it extends tube life dramatically. Then, he's an old TV tech.
Personally, after 30 years of doing repairs, I can probably count the number of times a filament has failed on the fingers of one hand.
Although recently I got a good one. Stereo amp (very expensive stereo amp) powered up, but no sound. I noticed none of the filaments were lit (4 EL34's , and 4 12AU7's). The manufacturer wired all the filaments in series. One EL34 died, so none would light. Remember the old Christmas lights? 

Back to the thread. You won't really hurt anything.


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## jb welder (Sep 14, 2010)

Paul Running said:


> View attachment 341942


Paul, can you tell me the source of this graph? I'm wondering if it may be more for transmitter tubes?


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## Latole (Aug 11, 2020)

BlueRocker said:


> I recently left my amp on for about 24 hours (an EL84 based 30 watt tube amp). Not in standby, but on and ready to go. Got to thinking, back in the day all kinds of tube based products would have run for long periods of time, but it still made me feel a little queezy having left it on. So, does it hurt anything to do this? Not that I intend to repeat it anytime soon.



No
Yes ; Only if output tubes are biased hot , like class A amp are .
Or AB amp with wrong ( very hot ) bias . 

Wich amp ?


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## Paul Running (Apr 12, 2020)

jb welder said:


> Paul, can you tell me the source of this graph? I'm wondering if it may be more for transmitter tubes?


It is from an early RCA Application Note...allow me some time to find the exact number. If I recall it applied to power tubes.


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## Paul Running (Apr 12, 2020)

I believe it originated from this this thread at DIYaudio:





__





Heater Wiring - the Good the Bad and the Ugly


Hi While all you are saying is basic and true, you do not know enough about tube amps to really write a tech article ....




www.diyaudio.com


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## Lincoln (Jun 2, 2008)

when I build a new amp, I usually leave it on for a couple hours. I don't normally go too far away though. I've left an amp on overnight by accident (got side tracked) with no problem.

Back in the day, I was using a Nikko Audio Alpha 440 power amp. (stereo) If a record stopped playing and I didn't remember to shut the amp off, I'd come back to the "protect" light on. Fried the output transistors every time. I'm thinking it needed a fan......or two


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## BlueRocker (Jan 5, 2020)

Latole said:


> No
> Yes ; Only if output tubes are biased hot , like class A amp are .
> Or AB amp with wrong ( very hot ) bias .
> 
> Wich amp ?


Fender Bassbreaker 30R


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## player99 (Sep 5, 2019)

I started using a little crappy Fender SS amp for practicing because I can turn it on and off with impunity.


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## Frenchy99 (Oct 15, 2016)

I heat the house with my tube amps in winter !


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## cboutilier (Jan 12, 2016)

I've left Class A amps on overnight on a few occasions, with no issues to date.


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## gabriel.335 (Nov 26, 2020)

I smoked a 1969 Traynor YSR-1 recently by leaving it on for a coupe of days. Only knew it was on when a very loud noise came balsting out of the basement. Still haven't figured out what it was, not the tubes. Blew up one of the electrolytic caps. Replaced it, still no workee.


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## Okay Player (May 24, 2020)

BlueRocker said:


> Fender Bassbreaker 30R


How do you like the amp?


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## laristotle (Aug 29, 2019)

Frenchy99 said:


> I heat the house with my tube amps in winter !


Are they hooked up to each other?


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## BlueRocker (Jan 5, 2020)

Okay Player said:


> How do you like the amp?


I've owned the *Bassbreaker 15 and also have the 007 head. I think the 30 is the best of the series as far as flexibility of tones go, with reverb and a footswitchable channel. Clean channel is not that "Fendery". Haven't had it long enough to form a full opinion. It does sound pretty large through a 2x12. My shop / studio is getting a bit chilly so I've mostly been using an AC10 lately - definitely a keeper. Need to spend more time with the Fender yet. It was surprisingly difficult to find one.*


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## butterknucket (Feb 5, 2006)

Probably not. Tubes wear out faster from thermal cycling (turning them on and off) and running them hard, or banging them around when they're still hot (let the amp cool down before you pick it up and move it). So, you probably didn't do anything major. In my experience, most modern EL84's last about two years on normal to moderate use anyway.


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## Okay Player (May 24, 2020)

BlueRocker said:


> I've owned the *Bassbreaker 15 and also have the 007 head. I think the 30 is the best of the series as far as flexibility of tones go, with reverb and a footswitchable channel. Clean channel is not that "Fendery". Haven't had it long enough to form a full opinion. It does sound pretty large through a 2x12. My shop / studio is getting a bit chilly so I've mostly been using an AC10 lately - definitely a keeper. Need to spend more time with the Fender yet. It was surprisingly difficult to find one.*


Thanks for the info. I've heard they're pretty "Marshally", but most Marshall fans get very defensive at the thought so the idea doesn't get a lot of room to breathe.


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## BMW-KTM (Apr 7, 2015)

I think I would be more concerned about heat rising into the amp circuit than the life of the tubes.


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## cboutilier (Jan 12, 2016)

BMW-KTM said:


> I think I would be more concerned about heat rising into the amp circuit than the life of the tubes.


You should feel my Twin Reverb after a 4 hour outdoor gig, in the sunshine!


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## juiceboxjosh (May 25, 2016)

I didn’t read all the comments so it’s possible somebody already mentioned it but I remember reading this very famous guitarist (The name escapes me) back in the day would literally never turn his amps off because they sounded better very hot haha


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## player99 (Sep 5, 2019)

laristotle said:


> Are they hooked up to each other?
> View attachment 341989


I've seen band using the cabs like that as shipping containers for all their gear, and they make great stage show pieces but most are actually empty. They only mic a couple of amps there, but who knows these guys may all be real, on and cranked.


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## Frenchy99 (Oct 15, 2016)

laristotle said:


> Are they hooked up to each other?
> View attachment 341989



Love it when you post pics of my basement !


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## butterknucket (Feb 5, 2006)

cboutilier said:


> You should feel my Twin Reverb after a 4 hour outdoor gig, in the sunshine!


I have an old Tweed. The back panel gets very warm after it's been running for a while.


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## butterknucket (Feb 5, 2006)

juiceboxjosh said:


> I didn’t read all the comments so it’s possible somebody already mentioned it but I remember reading this very famous guitarist (The name escapes me) back in the day would literally never turn his amps off because they sounded better very hot haha


Hendrix


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## butterknucket (Feb 5, 2006)

player99 said:


> I've seen band using the cabs like that as shipping containers for all their gear, and they make great stage show pieces but most are actually empty. They only mic a couple of amps there, but who knows these guys may all be real, on and cranked.


I've seen a wall of dummy Marshalls on stage, and a single Tweed Deluxe mic'd up behind them.


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## BMW-KTM (Apr 7, 2015)

butterknucket said:


> I've seen a wall of dummy Marshalls on stage, and a single Tweed Deluxe mic'd up behind them.


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## Latole (Aug 11, 2020)

player99 said:


> When I got my Fuches amp they recommend putting it in standby to stage the cooling down before shutting it off. I don't know how many times I notice hours, sometimes the next day the amp is still on standby. It really pisses me off when I do that.


There is no need to do that.

I repair amps since 15 years, mostly vintage tube amps.
I never need to replace a tube because heater failure. Most of these amps have 50 years old tubes.
Tubes are not a bulb lamp.


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## Latole (Aug 11, 2020)

cboutilier said:


> I've left Class A amps on overnight on a few occasions, with no issues to date.



On a class A amp, power tubes may work at 100 % and more of their power dissipation. 
Playing it or not. 

More hours ON= less power tubes life.


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## player99 (Sep 5, 2019)

Latole said:


> There is no need to do that.
> 
> I repair amps since 15 years, mostly vintage tube amps.
> I never need to replace a tube because heater failure. Most of these amps have 50 years old tubes.
> Tubes are not a bulb lamp.


I've talked to Fuchs about it, he seems to think it's a good thing. He also has a cooling fan mounted on the back.


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## Latole (Aug 11, 2020)

You did not say all. 
With a cooling fan, it is another story . 

No cooling fan, no need to keep on stanby


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## player99 (Sep 5, 2019)

Latole said:


> You did not say all.
> With a cooling fan, it is another story .
> 
> No cooling fan, no need to keep on stanby


I was recording so I sniped the fan wires. I need to reconnect them again.


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## Mooh (Mar 7, 2007)

How many of us just checked to see if our amps were on?


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## Latole (Aug 11, 2020)

An amplifier, like any electronic device, can stay on all the time without any problem.

As mentioned the class A amps are prone to have the power tubes wear out faster than the class AB amps which are more popular. 

Personally, I prefer to turn off the devices that I don't use.


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## loudtubeamps (Feb 2, 2012)

Frenchy99 said:


> I heat the house with my tube amps in winter !


I do....seriously! I have a small work room ( 10 x 12) door closed, amp and soldering iron on for the day...I'm toasty!


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## butterknucket (Feb 5, 2006)

player99 said:


> When I got my Fuches amp they recommend putting it in standby to stage the cooling down before shutting it off. I don't know how many times I notice hours, sometimes the next day the amp is still on standby. It really pisses me off when I do that.


Putting the amp in stand by leaves the heaters in the tubes running, so that doesn't really make any sense. The purpose of the stand by switch is to keep the tubes hot to prevent thermal cycling, because thermal cycling wears the tubes out faster.


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## Paul Running (Apr 12, 2020)

So, like an internal combustion engine you want to keep the engine warm with the ignition off...a block heater metaphor. A warm cycle, involving efficient heat conservation of the chassis/cabinet would help, during operation thermal release is controlled to maintain a constant ambient system-temperature...the temperature that tubes feel comfortable in. This would improve the life of the tubes however, be careful of temperature constraints of the passive components.


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## Ricktoberfest (Jun 22, 2014)

I watched a video on the EVH Fender Amps where they apparently tested them by putting them in an isolation box at full volume for a month. (During prototyping). 

Unless there is something else wrong with your amp a few hours here and there is nothing but a bit of heat (like that 100 year old light bulb that everyone always talks about, no start/stop cycle, no wear)


Sent from my iPhone using Tapatalk


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## Paul Running (Apr 12, 2020)

Yup, breadboarding and prototyping that's when the fun begins...love it.


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## ezcomes (Jul 28, 2008)

Don't many manufacturers do this after the amp is built? Burn it in to ensure everything works properly?


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## Latole (Aug 11, 2020)

ezcomes said:


> Don't many manufacturers do this after the amp is built? Burn it in to ensure everything works properly?


I'm sure at 100 % they not do that and don't need.
Receipe to built a amp is not rocket science since 70 years


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## ezcomes (Jul 28, 2008)

THought i remembered MESA doing this...dont care to look


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## Markus 1 (Feb 1, 2019)

Lincoln said:


> when I build a new amp, I usually leave it on for a couple hours. I don't normally go too far away though. I've left an amp on overnight by accident (got side tracked) with no problem.
> 
> Back in the day, I was using a Nikko Audio Alpha 440 power amp. (stereo) If a record stopped playing and I didn't remember to shut the amp off, I'd come back to the "protect" light on. Fried the output transistors every time. I'm thinking it needed a fan......or two



I still have one of those.
Great amp actually. I have it in a console cabinet and if I use it without a cabinet door open for ventilation it does the same


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## Lincoln (Jun 2, 2008)

Markus 1 said:


> I still have one of those.
> Great amp actually. I have it in a console cabinet and if I use it without a cabinet door open for ventilation it does the same


They were a great amp. I still have it. Member Paul Running was nice enough to send me a schematic for it and a shop manual too. I'm going to open it up one of these days and see what's cooked.
It got fixed many times under warranty.


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## Ricktoberfest (Jun 22, 2014)

At 11:20 he talks about this “crash testing” an amp leaving it on full for a month. 


Sent from my iPhone using Tapatalk


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## jb welder (Sep 14, 2010)

Lincoln said:


> It got fixed many times under warranty.


A lot of them did.  Not the most fun thing to work on either.


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## Lincoln (Jun 2, 2008)

jb welder said:


> A lot of them did.  Not the most fun thing to work on either.


That sounds like the voice of experience!


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## jb welder (Sep 14, 2010)

Lincoln said:


> That sounds like the voice of experience!


If I recall correctly, they were not all that different from a lot of other companies designs, just everybody else running that kind of power used fans.


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## ezcomes (Jul 28, 2008)

Ricktoberfest said:


> At 11:20 he talks about this “crash testing” an amp leaving it on full for a month.


Cool..must be fake news though...they dont do that, right @Latole ?


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## High/Deaf (Aug 19, 2009)

That 'fragility of tube equipment' ** mindset causes over-anxiety (although it is fair to say better safe than sorry). Things like leaving the power on, using a mismatched xformer tap or even a quick burst without a load (speaker) hooked up are not immediate catastrophes and cause for a trip to the amp tech. 

** exception being new manufactured tubes, which IME aren't as well made as the tubes from 50+ years ago.

For the most part, tube gear is built pretty well, better than most average consumer grade SS stuff. Even the cheap tube stuff years ago could be left on or abused. The tubes were usually the only thing that failed - and they were sacrificial anyways. You'd do more damage / wear-and-tear playing cranked regularly through a load box or re-amper than leaving it on for a week straight.


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## Paul Running (Apr 12, 2020)

jb welder said:


> Paul, can you tell me the source of this graph? I'm wondering if it may be more for transmitter tubes?


Not the same graph or from the same tube manufacturer...from a Mullard publication. Figure 3 in the article is indirectly similar to the #4 post, as the heater voltage will determine the cathode temperature...some specific information on the SQ qualifier, I have noticed some ambiguity about SQ with some venders of tubes.


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