# The Tube Amp Warm-Up Time Thread



## sunseeker888

First off, let me say that I am a believer in warming up gear before doing serious listening. I do not want people responding if they say it is not necessary. Head-fi is full of people who believe in warming up cd players, DACs, amps, etc and I would like to hear input from them. 

 On both my speaker amps and headphone amps, I see a significant jump in SQ after its been running for about an hour. It seems as though the circuits hit a peak in performance when all is at a certain temperature. I don't think its a question of capacitors charging, since this takes a mere second or so. (I do not have multiple Farads of capacitance in any of my amplifiers' supplies)

 My question is this: For most can-amps, what do you feel is the optimum warm-up time before listening to your favorite album?


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## nor_spoon

I power on my equipment, wait 30 seconds for the tubes, put the headphones of choice on my head, and press play


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## Tridacnid

Once I can't keep licking the tubes, then I know they are warmed up 
	

	
	
		
		

		
		
	


	




 I usually just flick the amp on, then wait a minute.


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## NiceCans

Quote:


  Originally Posted by *sunseeker888* /img/forum/go_quote.gif 
_My question is this: For most can-amps, what do you feel is the optimum warm-up time before listening to your favorite album?_

 

I have a simple formula:
 1- turn on amp
 2- get appropriate liquid refreshment
 3- go use the bathroom
 4- return, sit down, and begin to listen
 5- enjoy


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## Sherwood

I only wait long enough that the DC offset voltage is no longer making sounds in my ears, but I think it takes about 45 minutes for an amp to reach thermal stability, i.e. full performance.

 That's why I leave 'em on all the time.


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## sunseeker888

Thanks Sherwood. You realize that it takes some time. I used to leave my gear on 24/7 but never tubes. Only the DAC and CD players stay on now. Interesting thoughts, guys. Keep em comin!


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## Happy Camper

Tubes are meant to be used. Military and industrial use run 24/7. And the atmosphere they are used in is often much worse than our listening rooms. Audio folk tend to be too protective of their gear. 

 An example is the TV. People pull tubes from 40-50 year old sets and the dust is major thick. Tubes work fine and we pay crazy prices for rare vintage ones. Aircraft tubes take landings, field radios take the rigors of being tossed around.

 I turn my amp on when I get home and let it run with hps through dinner and listen til bed. On weekends, it comes on Friday after work and stays on til Sunday night. If you do run your amp, always have a pr of hps plugged in or a resistor plug. Something to load the circuit.


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## n_maher

It really depends on the amp really and the tubes that it uses. The little Millett I use at work takes a minute or so, if I'm running big tubes in the Menace at home (like 6528s) it can take a half hour or more for the tube to reach its operating temp and stop making *ping* noises as the metal inside continues to expand.


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## sunseeker888

I'm a certifed old-TV tube puller. Some are dusty but test new. 

 I let my tubes run, just not 24/7 always. Like my digital stuff. I have no problem leaving the tube amps on for days at a time, but only if I'll be around.


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## wavoman

*Happy Camper*'s advice is time-tested. All old-timers follow the same drill with tube gear: turn it on Friday after work, and keep it on until you go to bed Sunday.

 (This assumes of course that you do most of your listening on the weekend).

 You will find this advice all over the web.


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## Sherwood

I frequently run tubes for months. If they burn out, they burn out. 

 I've little problem replacing tubes. My most expensive Ax7 cost $30. If I sink a few hundred dollars into one I might preserve it, but as it stands now I like them warmed up and waiting for me.








 like my women.


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## Planar_head

Quote:


  Originally Posted by *Sherwood* /img/forum/go_quote.gif 
_...like my women._

 

How'd I know you'd put that?


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## Sherwood

Because planar heads think alike (he says as he listens to his Maggie MG12s 
	

	
	
		
		

		
		
	


	




 )


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## Uncle Erik

I turn amps on 10-15 minutes before I listen and turn them off when I'm done.

 Tubes are easily replaced. Caps, resistors and transformers are not so easily replaced. They don't last forever.

 When you open up old radios, the tubes are frequently still good. Open caps are what usually puts a set in the garage. The resistors are never within tolerance, either. It's the heat that does that. Heat also melts the enamel on transformer windings.

 That's why I let my gear cool off between listens.


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## Uncle Erik

The mysterious double post!


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## sunseeker888

True, Erik I have seen a lot more blown transistors/ICs then I have tubes. This is in vintage hifi and tv's. But, I guess there should be some balance in leaving it on. I'll just use common sense, lol. 

 Mmmmm Magneplanars and women.....


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## philodox

Not sure how much is my source, my tube amp or my headphones, but I find that an hour or so makes a big difference with my rig. Because of this, I usually set everything up playing quietly on repeat for an hour or two before I listen.

 That said, after 10min it is definitely listenable.


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## Golden Monkey

I'll turn mine on and can listen after a minute or so, but there's a significant difference in sound after 45 mins or so. Better soundstage, dynamics, and no background noise. I'll turn it on anywhere form 15-60 mins before I plan on listening, and let a CD play on repeat until I'm ready.

 My good tubes, the Siemens 7308s and the Tung-Sol 7236 are dead silent from a cold start, but some of the other tubes I've gotten since are really noisy for the first hour or so. The Chatham/Tung-Sol JAN 6080 pings like it's got popcorn cooking inside, and the RCA 6080 pings so loud I can hear it across the room and is highly microphonic to begin with. My other Siemens (E88CC) tubes are pretty quiet, but slightly microphonic although they seem to settle down fairly quickly. Not quite as quiet overall or as sweet sounding as the 7308 (E188CC), but an excellent tube overall.


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## BigTony

I find my tube ping for 5-10 mins, then settle down. The sound is optimal after an hour.

 I moved my amp to a new shelf, and I tweaked all the tubes, now it pings less and sounds better! Maybe it didn't like its old home.


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## vcoheda

my G08 i leave on all the time. when i had my Apache, i left that on all the time as well. my B-52 i let warm up for a good hour if not more before listening. absolutely sounds better after a good warm up.


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## sunseeker888

Maybe I'm lucky but I own a bunch of new and old tube gear and haven't once heard my tubes ping during use. The little dot MKII does have microphonic stock tubes however, which ping after the powers turned off.


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## Happy Camper

Quote:


  Originally Posted by *Sherwood* /img/forum/go_quote.gif 
_Because planar heads think alike (he says as he listens to his Maggie MG12s 
	

	
	
		
		

		
		
	


	




 )_

 

Another weird speaker lover. Martin-Logans and women.


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## immtbiker

I turn on my gear (SS and tube) as soon as I get home from work, and turn it off when I go to sleep...with listening sessions throughout the evening.

 With women, whenever I leave the vehicle, I just tell them to keep the meter running, and get back as soon as I can.


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## Radioheadache

I usually give my tube amp about a minute to warm up before putting on my phones and turn them off when I'm done. They've generally been for 30 minute-ish sessions lately anyway.


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## Jolida302

Warming up is essential and can be very long for some electronics, the worst may be big solid-state amps and subwoofers amps, it can goes until 5h of running!!

 My excellent pure class-A Sugden "Le bijou" headphone amp (on sale) takes not less than 48h at first to be at the top (of course, it's already listeanable at 20h) and then you let it "on" all the time.


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## IceClass

My Melos SHA1 takes a couple of minutes to warm up.
 My Fisher 500-C however takes a good solid hour to get up to speed and is virtually unlistenable in under 30 minutes.

 No idea of what tubes are in the 500-C.


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## Jolida302

Most pure tubes amp are perfect at one hour.


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## sunseeker888

IceClass, has the 500c been restored (caps and resistors and selenium recitifer)? If not thats probably why. Before I redid mine it sounded crappy for about an hour also. Still takes about a half hour IMO before it really sings though. All NOS GE and Telefunken tubes FWIW.


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## IceClass

Cool; another 500-C owner!
 It's not been restored. I had been looking for either a nicely restored one or an unrestored one at a price that permits the upgrades.
 I finally found the latter; it arrived a few days ago and I've been having a blast with it.

 I instantly prefer it even to the venerable SHA1 with MDR3Ks so far.
 Beyond upgrading the caps, resistors and selenium rectifier, are there any other recommended upgrades you can think of?

 I'm also interested in trying some tube rolling with this beasty. Is it just the quad of 7591 tubes at the rear that get rolled and do you recommend any tubes in particular with the 500c?


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## sunseeker888

I love vintage Fisher too!

 Besides the necessary recapping, many guys replace their volume control since it's a combo with the switch and gets worn out easier than the other pots. But, be advised its a toughie to install since the power switch is on it. And thats the 'achilles heel' in these-- add an inrush limiter in-line with the ac cord when you update the power supply or else its almost guaranteed that the switch will toast itself eventually.

 As for tubes: See what you have already. Fisher-branded Telefunken is sweet and should be reserved for the phono section. The tuner tubes should not be swapped around as this can desensitize the tuner. 

 And the 7591 outputs: Steer clear of JJ! Best new production IMO is Electro-Harmonix, and they aren't really great in the 500-c since Avery Fisher ran the outputs at 110% of their specs. Great sound, but output tubes go quickly in a 500-c/800-c. New tubes aren't up to this task, and require a resistor upgrade to use new-production tubes most of the time. 

 I have a matched quad of GEs in mine and they sound lovely. Go for NOS sylvania, Westinghouse, RCA, or GE-- but be advised they go for BIG $. I've seen a macthed pair on eBay go for over 100 bucks.


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## jimtbaker

Usually I leave it on all the time so warm up is needed. If by remote chance it has been off then at least an hour before seious listening.
 J


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## OutdoorXplorer

My newly RSA Raptor needs approx 5 minutes.


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## TheAttorney

I used to follow the popular 1 hour warm time up for my Stax SR-007t and also always switched off the amp at end of the day. One evening I realised that I had forgotton to switch it off the previous night (too much drink?). 

 Wow! An amp upgrade for free and completely unexpected. After repeating this a few times (the drink helps!), I've convinced myself that the improvement is real and very worthwhile. Like someone wrote in an earlier post, I now leave it on all weekend when I do most of my listening. But I switch it off during week days, as I'm still uncomfortable with leaving any tube equipment on 24/7.

 I've found that 2 days warm-up was slightly better still, but I haven't explored this in depth - I'd rather just enjoy the music.

 There's more to amp warm-up than the tubes reaching optimum temparature.


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## spookygonk

Quick question from a new tube amp owner: Do you make sure you have headphones plugged in when you switch the amp on (and there's no music playing)?


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## fordgtlover

I find that my amp and ears take about the same amount of time to warm up. So, I turn on the amp, put my headphones on my head and start listening. 

 My theory is, why waste the warm up time


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## BigTony

Quote:


  Originally Posted by *spookygonk* /img/forum/go_quote.gif 
_Quick question from a new tube amp owner: Do you make sure you have headphones plugged in when you switch the amp on (and there's no music playing)?_

 

Yes, don't go running an amp without any cans plugged in, especially a tube amp! I turn the volume to zero, turn in on, then turn the volume up and let it get nice and toasty. Keeps me warm in winter.


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## spookygonk

Thanks for that, BigT.


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## Golden Monkey

I do the same thing as Tony...I always turn the volume to zero prior to shutting it off, and make sure that's where it is when I fire it up as well. Too many times in the past have I left it loud, and with the auto-resume on my CDP when I turn it on, it picks up where it left off (unless I hit stop twice)...loud volume level + "cold" ears = *!!!gah!!!loud!!!*


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## sunseeker888

Regarding the 'having headphones plugged in at all times argument' :

 If its an OTL tube amp, you haven't much to worry about. This mentality comes from the old days of tubed hifi speaker amps, which almost all used an Output transformer. If you ran those unloaded, they could melt down due to oscillations produced in the transformer. Unless you are running your tube amp at max volume for long periods of time with no load, you're fine. 

 And for sold state: These amps couldn't care less.


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## Golden Monkey

Yeah, mine is an OTL, but I like leaving the phones plugged in anyway - I have the plug treated with Deoxit Gold, and since I'm down to one pair of phones I use pretty much exclusively, F it...I leave them plugged in...


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## immtbiker

OTL or not, it is always advisable, to turn off a tube amp when changing or removing the load.
 With electrostats that are *not *hybrid, like the Stax 007t which uses a SS output, you should always turn off the amp being that you always have bias voltage to the headphones. 

 Justin, Jack Woo, and Mikhail recommend turning off the amp. It only takes a second and can remedy a hardship and $$ that can take weeks to recover from.


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