So amps and the cold weather

not_the_dj

What the forum wisdom on moving and using amps in the cold weather?

I assume the risks are with hot valves and sudden temperature changes.

I generally load mine into the car last from home, and it lives in it's padded cover then a put a blanket over it in the car boot. I then try to bring that into the rehearsal room or venue first so it's got maximum time to acclimatise (still with it's cover on).

Reverse when packing away, after switching it off it'll sit there inside while I load the rest of my gear out so it's got maximum time to cool before getting outside and back in the car.

ICBM

It won't make any difference going from hot to cold. It's the other way round that's the risk - cold amp going into warm/humid venue. Condensation is the problem, not temperature change by itself.

I have seen a slightly greater incidence of dead (cracked) valves when kept in year-round unheated conditions, but that's only over the very long term and it's probably not a very significant proportion.

not_the_dj

ICBM said:

It won't make any difference going from hot to cold. It's the other way round that's the risk - cold amp going into warm/humid venue. Condensation is the problem, not temperature change by itself.

Oh ok, so keeping it wrapped up in the car to make sure it doesn't get too cold is the right thing to do. Thanks.

ICBM

If your amp has a standby switch, it's also a good idea to turn the amp on and on standby (ie muted) as soon as you can after you get into the venue, and leave it on standby for as long as possible before you play. The heat from the valve filaments will help drive off any condensation before you turn on the full HT voltage which is where the biggest risk of arcing is.

Danny1969

My amps live in a cold van all winter, only coming out for gigs. I do what ICBM suggests, on standby as quick as poss and don't turn the HT on till soundcheck which is generally a good hour after load in 

ecc83

All good advice but do remember valves were used for decades in planes, car radios (in the engine bay!)

Many a freezing garage had an old Cossor radio on the wall. PA amps were valved and wheeled out from vans to tents for point to points. 1000s of KT66 equipped Vortexions  sat on freezing factory walls till 'foreman came in to turn the heating on!

If modern valves/kit suffer due to modest temperature changes or condensation I was not aware of it as a teenager learning the trade.

Dave.

ICBM

Most of that old kit was built without PCBs with their small inter-trace separation, board-mounted crappy plastic valve sockets and other modern arcing hazards though!

ecc83

ICBM said:

Most of that old kit was built without PCBs with their small inter-trace separation, board-mounted crappy plastic valve sockets and other modern arcing hazards though!

Well, maybe but I would say the amount of ***t that built up in a garage radio or a factory PA would be at least as damaging! Din't happen though!

Then, post "red E series" valve radios used PCBs . Mind you, the later valves, ECH81, EABC80s etc were not nearly so reliable and of course NOTHING lives as long or puts up with abuse like an old 6V6!

Dave.

ChrisMusic

I used to sit in a cold loft for hours as a kid (that may explain a few things, hmmm), listening to radio transmissions on obscure wavelengths from around the world, on an old Lancaster bomber transceiver.  All valve, including the PSU.

I don't know what the operational ceiling for a Lancaster was back then, but I'll bet it was bloody cold up there in the middle of winter.  That kit just had to work, cold, vibration and all.

I do understand what ICBM is saying about modern (penny pinching) production techniques though, which is perfectly correct.

Aye, but they new how to build a bit of valve kit properly back then...

Cirrus

ChrisMusic said:

I used to sit in a cold loft for hours as a kid (that may explain a few things, hmmm), listening to radio transmissions on obscure wavelengths from around the world, on an old Lancaster bomber transceiver.  All valve, including the PSU.

I don't know what the operational ceiling for a Lancaster was back then, but I'll bet it was bloody cold up there in the middle of winter.  That kit just had to work, cold, vibration and all.

A bit over 20,000ft I think.

And that is a cool story!