New (used) Tube Amp Question

Is it safe to leave a tube amp out in the garage overnight if it gets below freezing? I was thinking about getting a small, cheap tube amp to replace the nice, much more expensive big one I just sold...

Reading about how others are doing things like this with their acoustics, given the current climate & state of affairs—leaving it sit for a few days, etc.

Just don’t have any idea if there is a danger to the tubes (or anything else if the temp drops below freezing at night, or during the day with windchill)? Thanks everybody! :)
 

SFIV1967

Venerated Member
It depends how fast you want to use it again! :
"Tubes are not harmed by cold weather as long as they are allowed to warm up and cool off GRADUALLY. That means when you bring your amp inside from five hours in the back of a sub-zero truck you need to let it warm up to room temperature before applying power (this is basically true of all electronic equipment). If your amp is in a road case I would recommend (if you have time) letting the case warm up a while before removing the amp. Just break the seal on the case and let it warm up gradually. In some cases the tube sockets are more fragile than the tubes. They can get quite brittle when cold. Be careful about condensation too. It can accumulate around tube sockets, which can be fatal for the equipment. If you notice any condensation in or on your amp DO NOT TURN IT ON. Wait for it to evaporate or dry it out with a blow dryer (which is no doubt carried by your lead singer)."

Also read here: https://www.gearslutz.com/board/geekslutz-forum/25983-tube-amp-amp-freezing-temp.html

Ralf
 

AcornHouse

Senior Member
The cold wouldn’t be the issue for me, just follow Ralf’s quoted advice. The real dangers are mice and damp. Amps make lovely nesting places with yummy wire insulation. And dampness/humidity can corrode metal parts and rot wood and tolex.
 
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jp

Senior Member
I agree with everyone above, and Chris is absolutely right. Critters and moisture are enemies of electronics. Avoid them if possible.
 

Nuuska

Senior Member
Hello from Finland

We have usually cold winters - we have thousands of bands - and hundreds of guitarplayers use tube amps. And winters do get cold here every now and them. And many bands keep their stuff in vans or trailers between gigs.

I would not be that worried of temperature - reason being that it's not that big difference, if it starts from -10C 0r +20C - while after the tubes are warm, the temperature is really high - I ca not find any exact figures. But anyway - the temperature rise is due to amp tubes gradually warming up and eventually radiating their heat around. A quick rule of thumb is that 10W amp produces 30W heat.

Humidity then - like Ralf wrote - is downright dangerous - when you bring a cold amp into warm room, there is potential of condenced water - and the idea of carrying a hair-dryer is excellent. But this is not to be exaggerated , either. Ih you see water drops on or in the amp - THEN use the hairdryer. If it is just that tolex cover feels a bit moist, then there should be nothing to worry.

Guitars and some drums are cracking their finishes when opening a cold case - because wood and surface materials / finishes have different temperature coherent - they shrink and expand differently - so slow temperature change speed is essential.

On amps and loudspeakers there are none of those issues - we are not talking about schlepping exquisite hi-fi-gear around - so nothing will break when you take your amp from behind truck - where it has spent last two weeks - but keep eye on if or not the units are getting wet.

My writing is based on over 40 years on the road plus as roadie/FOH-engineer - plus repairman between gigs.
 

Quantum Strummer

Senior Member
I presume you're referring to letting a shipped package sit "in quarantine" for a few days after it arrives before bringing it inside the house. IMO this is the right approach. I wouldn't worry about the temperature. After you bring the package inside let it sit overnight so the amp can warm up.

-Dave-
 
Bingo! :)

I presume you're referring to letting a shipped package sit "in quarantine" for a few days after it arrives before bringing it inside the house. IMO this is the right approach. I wouldn't worry about the temperature. After you bring the package inside let it sit overnight so the amp can warm up.

-Dave-
Thanks as always everyone, I learned a ton! I probably knew about 20% of what was written. And by 20%, I mean closer to 2%... So, thank you! I’m going to order it— :D
 
Hi all!
So, I’ve got it... & quite naturally—I’ve (already) got a question. Now, I’ve had a lot of tube amps over the years, yet I know almost nothing of their maintenance. I’ve never even retubed an amp, outside of an initial pro jr that came in “near mint” cond. but sounded like it was possessed form the moment you turned it on. Once the shop took care of that (new tubes), it worked fine: actually, it took two attempts as the first set they slapped up in there made the problem somehow even worse! My local shop did the repair; I’d ordered it from another across the county...

I either, have never played them hard enough (most were either purchased new or in very great shape), or sold them beforw needing such things. Most recently, I had a Mesa combo & as I understand it, you don’t even need to rebias those, so long as you use their brand—&id has that one fro about 5 1/2 hrs (I guess I did replace the power tubes once, just to see what would happen - Id been given a free set with a prior purchase that turned out to be a defective amp/& though a different model, they were the same tubes, and seemed to function fine or the same once this was done).
Now onto — finally — my most recent acquisition: it is a 15 yr old hybrid Marshall (which I believe means that the preamp, or possibly distortion/od channel is tube). So, when you turn it on, it makes a continuous noise. That were I turning the volume up loud enough, or not using any reverb at all, or playing only on the clean channel (solid state, I think), it would be very minimal, if not go all the way away. What I am wondering is, will changing the preamp tube eliminate this annoying noise which is so nuisance inducing, at least to my overly sensitive ear, that I cannot think when playing (outside of it: the buzz). It is there when turned on. It stays there when played. It gets better if you dial the reverb back all the way off / to zero. If you disengage th e od (overdrive channel), it gets better, too. I’d almost say that each of these two things comprise about 50% (apx.) of the noise. If however you put it on the clean channel and turn both volume & gain dials (what this amp labels “pre-amp), up close to noon, you will still hear it some. This is one of those valvestate 200 avt models. I had one when new, but that was so long ago I don’t know if this was present then. And it might i to have bothered me that much when I was younger, and likely to be playing at much louder than middle of the night, bed/living room volumes. It kind of sounds like if you see footage of an old fender amp that’s dimed on stage—& they go to switch it on : that hum or whatever you want to call it, or similar to a fender Mexican strat with the single coils activated exclusively on certain amps (positions 1, 3, & 5?)...

I don’t know, maybe it’s normal. Shops bit responding to inquiries; but I guess that’s to be expected given the current climate and conditions. I’ve had two or three jcm 2000 dsl 401’s (none of the ones that melted from the tubes!); all used come to think of it... & none of them encountered such a thing. I don’t know anything about scratchy pots , or anything, or even if this has those! ;) Sorry for the novel, and thanks if you’ve got any ideas. :)
 

AcornHouse

Senior Member
No, it’s not normal. You can try changing the preamp tube; you won’t hurt anything, and there’s no biasing/adjusting to be done.
But, while that might take care of it, I think there’s more going on here. Which means amp tech. Personally, if you just got it, I would return it. There’s plenty of other amps out there. My Vox Valvtronix 2X12 hybrid, that I’ve had for years, is dead quiet. I have vintage amps from the 60s, 50s, 40s, and 30s, and, when serviced, they are (mostly) quiet.
Noise is an indication that something is not right. The trick is figuring out what is not right.
 
Hey, thanks a million AcornHouse! I really appreciate it... I never knew any of that, so very very helpful to someone like me. It’s quite embarrassing, actually, how little I do know relative to how long I’ve been playing (though exclusively solo). I always feel like such an imbecile or a dummy posting these kinds of questions on here! I can just hear people’s heads shaking across their screens... maybe if I wasn’t such an idiot w/the internet I could solve many of these dilemmas myself (or at least in most instances). But thanks again, truly! I mean it—already sent out the box to recycling; so, I’ll have to go the “amp tech” route. Fortunately, I think I’ve got a good one—from what I’ve heard and understand. The local guys at my local shop are quite knowledgeable and well versed in all things this & that! With plenty of experience even in gigging (one guy goes way back; I mean all the way to the 70’s possibly even 60’s, I know you must think I’m making this up!). ;^D
 

JohnW63

Senior Member
Keep in mind if your single coil guitar is any where close to the amp, you WILL hear hum. If it's making noise with nothing plugged in, you do have a problem.
 
It improves only slightly when walking all the way to the opposite side of the living room and turning around (& I’m talking maybe 5% noise reduction). Yes, the sound begins before you even plug your guitar in. It was from a nationally reputable dealer, who in terms of being full service, probably is in the running for biggest—at least in terms of sheer volume of inventory turnover. It was listed in ‘very good condition’ & their ratings are said to be reflective of the Reberb definitions. But I could see how someone could just fire it up for 5 minutes while testing it out in the shop and possibly not notice a thing (especially when considering how they may have played it: perhaps exactly the opposite of how i currently am)... Or something changed during the shipping. By the way, it only sat about a day and a half in the garage as the show began to melt, and then water deep into the floor (luckily I colaught it befor it reached the box the amp was sitting in). And it wasn’t actually even as cold as I had anticipated beforehand - don’t even think it got down below freezing, with or without windchill, at any given pint. If nothing else—it serves as a nice stand for my small fender amp, which I enjoy playing, but don’t crank loud enough to really properly distort! ;)
 
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