Leaving an Amp on Standby for a Long Time

Brent Hutto · May 5th, 2008, 06:58 AM

I accidentally left my 8W 1x12 combo amp (single-ended 6L6GC) on standby instead of turning it off for about 10 hours last night. This amp uses the switch on the center tap of the power transformer standby design.

Does that do more wear-and-tear, less wear-and-tear or about the same as leaving it all the way on, including the high voltage, for the same length of time? It has NOS rectifier and output tubes so it's no big deal burning through ten hours of an expected service life that's probably in the thousands of hours. I just hope having filament and no HV isn't an extra-bad way for a tube to spend time. It is an indirectly-heated Bendix rectifier if that matters..

Joe M · May 5th, 2008, 07:47 AM

Even though that has never happened to me, I've read of many people doing that very thing, for even a longer period of time with no damage at all. It would just take some tube life off, just as if you had been playing for a real long gig. I wouldn't worry about it.....

rhomco · May 5th, 2008, 08:05 AM

AC-15 on standby for two months! It did not damage anything except my pride & ego!

Rob

JimiBryant · May 5th, 2008, 08:25 AM

Rob beats me, but I once left an amp on standby for two weeks while I went to Japan!!

Brent Hutto · May 5th, 2008, 08:40 AM

OK, sounds like I've didn't screw up too badly. That's a relief...

I had to do some experimenting to find a set of tubes I liked that didn't go all microphonic on me (the power tube sits like 1/2" or less from the magnet of a Jensen Neo 12") and I'd hate to think I just burned through ten year's life in one night. I'm hoping I can use this sucker every day for a couple years without having to change a thing.

bradpdx · May 5th, 2008, 09:33 AM

In Standby there is no B+ applied and so no power dissipation beyond the heater filaments. Any tube wear would be minimal at best.

If it helps, consider that back in the day of all-tube recording studios much gear was left in standby forever - filaments were never turned off in order to maintain a consistent temperature and thus reduce noise (no temperature changes to generate noise).

There is even an old-school of thought that believes that tubes are generally happier when the filaments are always on. I won't go into a technical definition of "happy" here, but I think you get the drift.

So, no worries.

boris bubbanov · May 5th, 2008, 11:59 AM

Quote:

Originally Posted by rhomco

AC-15 on standby for two months! It did not damage anything except my pride & ego!

Rob

Thanks for reminding me again that I really need to buy a bulb for my Twin. What you describe hasn't happened yet to me but it will.

One good thing about the Custom Vibrolux Reverb. You know when that sucker is on.

Dennis68 · May 5th, 2008, 12:08 PM

10 hours shouldn't hurt your amp, especially since others here have said they have gone with it like that for far longer. I keep my amp on a HD surge strip, and strip gets shut off after the amp. Sort of a ritual I do when I finish playing.

Chito · May 5th, 2008, 12:32 PM

Shouldn't be an issue. I just left my Traynor YCV50 on from Wednesday afternoon till Saturday morning. Haven't noticed anything wrong with it. I've done this a few times now.

Frontier9 · May 5th, 2008, 12:51 PM

I know this is off topic a bit, but this thread reminded me of the time I left my college roommate's turntable running over Christmas break. He came back after 3-4 weeks and found the needle counting off the miles in the runoff groove.

trag-o-caster · May 5th, 2008, 01:46 PM

Quote:

Originally Posted by Frontier9

I know this is off topic a bit, but this thread reminded me of the time I left my college roommate's turntable running over Christmas break. He came back after 3-4 weeks and found the needle counting off the miles in the runoff groove.

That's gotta be good for the stylus, I'm sure!

Who was the person that returned from their winter home, to their summer home to find that they'd left their tube amp turned on, and on standby for about 6 months with no damage? I always liked that story!

6942 · May 5th, 2008, 04:52 PM

The first radio station I worked in (early 70's) used mostly tube gear.
The chief engineer left them on 24/7.

Steve

garytelecastor · May 5th, 2008, 04:53 PM

You didn't do any damage at all.

65flh5326 · May 5th, 2008, 05:48 PM

I dont know if this is relative to amplifiers. I have used metal cutting lathes that have tube controlled DC variable speed drives.
Upon start up, the main power connector is engaged, the tube filaments are warmed by timer for one minute, then the control button lights and the machine can be set in motion.
In practice, if the machine has set unused for a period of time, the tubes should be at standby for 15 minutes. The thought is, some of the gas in the tubes can turn to solid, by warming them, the gas in the tube is restored.
Experience has shown that to be true, as cold starting reduces tube life. Also its well known that if the machine is to be used off and on through the day, its better to leave the machine on standby rather then cold start it for each use.
Retail price for the 3 power tubes is $4100, but if lucky, they can be found for $750 each for the two beer bottle sized ones.
Since using these machines for 35yrs, I have done the same start up with my tube amplifiers with great results, I seldom have had problems.

Thanks,
Don

EdMax · May 5th, 2008, 08:15 PM

Quote:

Originally Posted by Brent Hutto

I accidentally left my 8W 1x12 combo amp (single-ended 6L6GC) on standby instead of turning it off for about 10 hours last night. This amp uses the switch on the center tap of the power transformer standby design.

Does that do more wear-and-tear, less wear-and-tear or about the same as leaving it all the way on, including the high voltage, for the same length of time? It has NOS rectifier and output tubes so it's no big deal burning through ten hours of an expected service life that's probably in the thousands of hours. I just hope having filament and no HV isn't an extra-bad way for a tube to spend time. It is an indirectly-heated Bendix rectifier if that matters..

Back near the end of the Tube TV set, they used to achieve the instant on effect by leaving all of the tube filaments on 24/7. ( basically in standby mode)

I can remember going on 2 week vacations and coming home and having the TV smelling of heat and vaporized dust.

I left my Seymour Duncan on 8 days once, melted a module casing on a pre-amp module but still worked great with no issues.

backalleyblues · May 5th, 2008, 09:30 PM

Quote:

Originally Posted by 65flh5326

I dont know if this is relative to amplifiers. I have used metal cutting lathes that have tube controlled DC variable speed drives.
Upon start up, the main power connector is engaged, the tube filaments are warmed by timer for one minute, then the control button lights and the machine can be set in motion.
In practice, if the machine has set unused for a period of time, the tubes should be at standby for 15 minutes. The thought is, some of the gas in the tubes can turn to solid, by warming them, the gas in the tube is restored.
Experience has shown that to be true, as cold starting reduces tube life. Also its well known that if the machine is to be used off and on through the day, its better to leave the machine on standby rather then cold start it for each use.
Retail price for the 3 power tubes is $4100, but if lucky, they can be found for $750 each for the two beer bottle sized ones.
Since using these machines for 35yrs, I have done the same start up with my tube amplifiers with great results, I seldom have had problems.

Thanks,
Don

It's funny, but I've done the exact same thing, let the amp sit on standby while I finish setting up (guitar check is always last) usually 15-20 minutes before cranking it up. Didn't know about the gasses in tubes solidifying, but it kinda makes sense. BTW, I also shut down the amp first and let it cool down before moving it-this helps with tube life too...

Franc Robert
Back Alley Blues Band

eugenedunn · May 5th, 2008, 09:36 PM

If I start playing either one of my non-standby equipped amps (69 Princeton Reverb and 79 Champ), and then get called away or distracted, I'll just leave them on, but volume knob turned down to nothing. I figure it's easier on the whole amp if I don't power-down and then up again if I'm gonna return in an hour or so. It's kind of like a long set break during a gig.... When I return, the amps are warmed up and sound great right away.

From everything I've read or heard about operating tube amps, it seems like the potential for most shock and instability all happen in the first instant when power is applied.

Wardpike · May 5th, 2008, 09:41 PM

You never have to worry about leaving an amp on standby for an extended period of time unless there are heat buildup problems.

Heat in general should be your biggest cause for concern.
Either
1. Overheating whilst the amp is on, standby or in use...you need proper ventilation and perhaps a cooling fan if this is an issue
OR
2. Not cooling down your amp before you move it. After you finish a gig or rehearsal, you need to turn OFF the amplifier and let it cool down almost completely before moving it as sudden jarring movements can seriously reduce the life of your tubes when hot.

I hope I've been helpful,

Ward

EdMax · May 5th, 2008, 10:04 PM

Quote:

Originally Posted by 65flh5326

I dont know if this is relative to amplifiers. I have used metal cutting lathes that have tube controlled DC variable speed drives.
Upon start up, the main power connector is engaged, the tube filaments are warmed by timer for one minute, then the control button lights and the machine can be set in motion.
In practice, if the machine has set unused for a period of time, the tubes should be at standby for 15 minutes. The thought is, some of the gas in the tubes can turn to solid, by warming them, the gas in the tube is restored.
Experience has shown that to be true, as cold starting reduces tube life. Also its well known that if the machine is to be used off and on through the day, its better to leave the machine on standby rather then cold start it for each use.
Retail price for the 3 power tubes is $4100, but if lucky, they can be found for $750 each for the two beer bottle sized ones.
Since using these machines for 35yrs, I have done the same start up with my tube amplifiers with great results, I seldom have had problems.

Thanks,
Don

Were those by any chance Mercury Vapor rectifier tubes?

I know a lot of audiophile guys use those and are extremely careful to allow proper warmup before use. Seems I read a couple threads where guys had exploded them by starting them cold. Mercury is not exactly something you want leaking in your home or workplace.

65flh5326 · May 5th, 2008, 10:09 PM

Good points on letting the amp cool down before transport and using a cooling fan in warm conditions or extended use. I glued a hook on a small fan and hang it on the back panel of my old Bassman and Hiwatt head.
I managed to get a reasonable supply of NOS tubes years ago,but I suspect the prices of the real good tubes to climb out of sight in the future.
Example, I used to buy these 5665 tubes for $100 in the late 70s, found this one on ebay, and thats a good deal!

http://cgi.ebay.com/NATIONAL-ELECTRO...2em118Q2el1247

Thanks,
Don

No, thankfully they are not mercury filled! They have been known to blow, they intake 600v with alot of amps, and put out 220v with 7.5 KW for motor power.

klasaine · May 5th, 2008, 11:01 PM

I regularly have tube amps running and/or in standby for 8, 10, 12 hours straight sometimes at sessions. Basically all day. No problem. I don't how true it is but many amp as well as other electronic equipment manufactures 'claim' to burn in gear from 12 - 48 hours(?). Seems reasonable as a lot of defective parts will "fail" quickly.

65flh5326 · May 5th, 2008, 11:42 PM

With the tube powered industrial equipment I described, it takes about 48hrs of use on a new set of tubes before they stabilize.
On the control module, there are pots to adjust top speed and speed compensation. The beauty of the tube drive is, the machine will maintain the exact set speed under varying load.
As the new tubes burn in, they put out more power and the adjustment pots have to be turned down to maintain the balance. If everything is kept in check, the tubes can last 30yrs, some examples over 50yrs.
The main problem with this equipment is heat buildup from the filter on the cooling fan getting plugged and moron operators abusing or overloading the machine, then the tubes are toast.
I own two of these and maintain 5 others for another company. These are hand built to custom order one at a time, and are considered the best on the planet.
I wish I could play guitar like I run these. Tubes rule!
http://s170.photobucket.com/albums/u...ent=Don006.jpg

Thanks,
Don

May 5th, 2008, 06:58 AM	#1 (permalink)
Brent Hutto Tele-Holic Join Date: Dec 2006 Location: South Carolina Posts: 606 6 Photos	Leaving an Amp on Standby for a Long Time I accidentally left my 8W 1x12 combo amp (single-ended 6L6GC) on standby instead of turning it off for about 10 hours last night. This amp uses the switch on the center tap of the power transformer standby design. Does that do more wear-and-tear, less wear-and-tear or about the same as leaving it all the way on, including the high voltage, for the same length of time? It has NOS rectifier and output tubes so it's no big deal burning through ten hours of an expected service life that's probably in the thousands of hours. I just hope having filament and no HV isn't an extra-bad way for a tube to spend time. It is an indirectly-heated Bendix rectifier if that matters.. __________________ Lazarus, Lazarus, How did it feel When you left this mortal world

May 5th, 2008, 08:05 AM	#3 (permalink)
rhomco Tele-Holic Join Date: Oct 2004 Location: Crowley, Texas Posts: 678	I left my Vox AC-15 on standby for two months! It did not damage anything except my pride & ego! Rob __________________ If I won the Lotto.... I'd just build guitars and sell them till the money ran out

May 5th, 2008, 08:25 AM	#4 (permalink)
JimiBryant Tele-Afflicted Join Date: Sep 2007 Location: Chicago Chicago that toddlin' town Age: 46 Posts: 1,296	Rob beats me, but I once left an amp on standby for two weeks while I went to Japan!! __________________ I am very proud of the fact that I'm so humble!

May 5th, 2008, 08:40 AM	#5 (permalink)
Brent Hutto Tele-Holic Join Date: Dec 2006 Location: South Carolina Posts: 606 6 Photos	OK, sounds like I've didn't screw up too badly. That's a relief... I had to do some experimenting to find a set of tubes I liked that didn't go all microphonic on me (the power tube sits like 1/2" or less from the magnet of a Jensen Neo 12") and I'd hate to think I just burned through ten year's life in one night. I'm hoping I can use this sucker every day for a couple years without having to change a thing. __________________ Lazarus, Lazarus, How did it feel When you left this mortal world

May 5th, 2008, 09:33 AM	#6 (permalink)
bradpdx Tele-Holic Join Date: Jul 2006 Location: Portland, OR Age: 50 Posts: 569	In Standby there is no B+ applied and so no power dissipation beyond the heater filaments. Any tube wear would be minimal at best. If it helps, consider that back in the day of all-tube recording studios much gear was left in standby forever - filaments were never turned off in order to maintain a consistent temperature and thus reduce noise (no temperature changes to generate noise). There is even an old-school of thought that believes that tubes are generally happier when the filaments are always on. I won't go into a technical definition of "happy" here, but I think you get the drift. So, no worries. __________________ ---------- Tech Geek and Sensitive Artiste String bender ordinare!

May 5th, 2008, 07:47 AM	#2 (permalink)
Joe M Moderator Tele-Afflicted Join Date: Mar 2003 Location: Michigan Posts: 1,020	Even though that has never happened to me, I've read of many people doing that very thing, for even a longer period of time with no damage at all. It would just take some tube life off, just as if you had been playing for a real long gig. I wouldn't worry about it.....

May 5th, 2008, 12:08 PM	#8 (permalink)
Dennis68 Tele-Holic Join Date: Oct 2003 Location: Hudson Valley Posts: 757	10 hours shouldn't hurt your amp, especially since others here have said they have gone with it like that for far longer. I keep my amp on a HD surge strip, and strip gets shut off after the amp. Sort of a ritual I do when I finish playing. __________________ -Dennis

May 5th, 2008, 12:32 PM	#9 (permalink)
Chito TDPRI Member Join Date: Jan 2007 Location: Ottawa, Ontario Posts: 67	Shouldn't be an issue. I just left my Traynor YCV50 on from Wednesday afternoon till Saturday morning. Haven't noticed anything wrong with it. I've done this a few times now. __________________ www.mosayk.ca

May 5th, 2008, 12:51 PM	#10 (permalink)
Frontier9 TDPRI Member Join Date: Dec 2007 Location: Sunny New Jersey Posts: 79	I know this is off topic a bit, but this thread reminded me of the time I left my college roommate's turntable running over Christmas break. He came back after 3-4 weeks and found the needle counting off the miles in the runoff groove.

May 5th, 2008, 04:52 PM	#12 (permalink)
6942 Tele-Afflicted Join Date: Apr 2006 Location: Western Maryland Posts: 1,362	The first radio station I worked in (early 70's) used mostly tube gear. The chief engineer left them on 24/7. Steve

May 5th, 2008, 04:53 PM	#13 (permalink)
garytelecastor Friend of Leo's Join Date: Sep 2006 Location: Minnesota Posts: 3,084 18 Photos	You didn't do any damage at all. __________________ éí 'aaníígÓÓ 'áhoot'é Redd Volkaert is a Jedi Knight at one with the Force!!!

May 5th, 2008, 05:48 PM	#14 (permalink)
65flh5326 Tele-Meister Join Date: Jan 2008 Location: walla walla wa Posts: 155	I dont know if this is relative to amplifiers. I have used metal cutting lathes that have tube controlled DC variable speed drives. Upon start up, the main power connector is engaged, the tube filaments are warmed by timer for one minute, then the control button lights and the machine can be set in motion. In practice, if the machine has set unused for a period of time, the tubes should be at standby for 15 minutes. The thought is, some of the gas in the tubes can turn to solid, by warming them, the gas in the tube is restored. Experience has shown that to be true, as cold starting reduces tube life. Also its well known that if the machine is to be used off and on through the day, its better to leave the machine on standby rather then cold start it for each use. Retail price for the 3 power tubes is $4100, but if lucky, they can be found for $750 each for the two beer bottle sized ones. Since using these machines for 35yrs, I have done the same start up with my tube amplifiers with great results, I seldom have had problems. Thanks, Don

May 5th, 2008, 09:36 PM	#17 (permalink)
eugenedunn Tele-Holic Join Date: Dec 2006 Location: Sacramento, CA Age: 54 Posts: 606 33 Photos	If I start playing either one of my non-standby equipped amps (69 Princeton Reverb and 79 Champ), and then get called away or distracted, I'll just leave them on, but volume knob turned down to nothing. I figure it's easier on the whole amp if I don't power-down and then up again if I'm gonna return in an hour or so. It's kind of like a long set break during a gig.... When I return, the amps are warmed up and sound great right away. From everything I've read or heard about operating tube amps, it seems like the potential for most shock and instability all happen in the first instant when power is applied. __________________ Ono Boy says "good n' swampy....."

May 5th, 2008, 09:41 PM	#18 (permalink)
Wardpike Tele-Holic Join Date: Feb 2008 Location: St. John's, Newfoundland Age: 43 Posts: 585	You never have to worry about leaving an amp on standby for an extended period of time unless there are heat buildup problems. Heat in general should be your biggest cause for concern. Either 1. Overheating whilst the amp is on, standby or in use...you need proper ventilation and perhaps a cooling fan if this is an issue OR 2. Not cooling down your amp before you move it. After you finish a gig or rehearsal, you need to turn OFF the amplifier and let it cool down almost completely before moving it as sudden jarring movements can seriously reduce the life of your tubes when hot. I hope I've been helpful, Ward

May 5th, 2008, 10:09 PM	#20 (permalink)
65flh5326 Tele-Meister Join Date: Jan 2008 Location: walla walla wa Posts: 155	Good points on letting the amp cool down before transport and using a cooling fan in warm conditions or extended use. I glued a hook on a small fan and hang it on the back panel of my old Bassman and Hiwatt head. I managed to get a reasonable supply of NOS tubes years ago,but I suspect the prices of the real good tubes to climb out of sight in the future. Example, I used to buy these 5665 tubes for $100 in the late 70s, found this one on ebay, and thats a good deal! http://cgi.ebay.com/NATIONAL-ELECTRO...2em118Q2el1247 Thanks, Don No, thankfully they are not mercury filled! They have been known to blow, they intake 600v with alot of amps, and put out 220v with 7.5 KW for motor power.

May 5th, 2008, 11:01 PM	#21 (permalink)
klasaine Tele-Afflicted Join Date: Nov 2006 Location: los angeles, ca Age: 46 Posts: 1,203 3 Photos	I regularly have tube amps running and/or in standby for 8, 10, 12 hours straight sometimes at sessions. Basically all day. No problem. I don't how true it is but many amp as well as other electronic equipment manufactures 'claim' to burn in gear from 12 - 48 hours(?). Seems reasonable as a lot of defective parts will "fail" quickly.

May 5th, 2008, 11:42 PM	#22 (permalink)
65flh5326 Tele-Meister Join Date: Jan 2008 Location: walla walla wa Posts: 155	With the tube powered industrial equipment I described, it takes about 48hrs of use on a new set of tubes before they stabilize. On the control module, there are pots to adjust top speed and speed compensation. The beauty of the tube drive is, the machine will maintain the exact set speed under varying load. As the new tubes burn in, they put out more power and the adjustment pots have to be turned down to maintain the balance. If everything is kept in check, the tubes can last 30yrs, some examples over 50yrs. The main problem with this equipment is heat buildup from the filter on the cooling fan getting plugged and moron operators abusing or overloading the machine, then the tubes are toast. I own two of these and maintain 5 others for another company. These are hand built to custom order one at a time, and are considered the best on the planet. I wish I could play guitar like I run these. Tubes rule! http://s170.photobucket.com/albums/u...ent=Don006.jpg Thanks, Don