I have an a/d/s P-850 amplifier as my "primary" amp in the ShoWagon. (There is also a PPI PCX-280 whose job it is to run the subwoofers.)

When the weather is colder than -10 degrees F, and the car has been sitting out for any length of time, the P-850 will not run. It takes anywhere from two to 10 minutes (the colder it is the longer it takes) for it to start working, and when it does start, it fades in slowly over a 20--45 second period of time. Even in the summertime with temperatures in the 80's, that amp will take 8--10 seconds to get going. I always figured that since it was a pretty big, pretty complex amp (8 channels with separate gain controls and active crossovers on each channel pair), it just needed a bit of extra time.

The PCX-280 amp starts up immediately, regardless of temperature. But listening to Mozart through nothing but a pair of 10" subs just lacks that "concert hall" experience.

My question is: why would a solid state amplifier with no moving parts be so drastically affected by a cold environment? I always thought that with transistors and diodes and other magical stuff the colder the better.

tanstaafl.

It could be some connectors inside that would shrink when they get cold, and break the connection.

Assuming you've checked the supply & control wiring at the amp while the fault condition exists it's probably a faulty component or marginal solder joint within the amp itself that responds to temperature. It could be a defect in the amp's PCB but that's less likely in my experience.

If it were my amp, I would rig it up on a bench with a power supply and attack it with a hot air blower and a can of freezer spray. This way you should be able to carefully apply heat/cold to various sections of the circuitry and observe the fault come and go at the same time and you can narrow down where on the amp's circuit the problem lies. Once you know where the fault lies you can then inspect/resolder joints in that location, if it's a faulty component you'd need to identify it and locate a replacement. It can sometimes be a little hit and miss adopting this approach and sometimes there's no substitute for proper fault finding using conventional electronic test equipment.
If you decide to give this a go you could use a conventional hairdryer on slow speed with a home made funnel attached - you need to be as accurate as you can be with this. Freezer spray is available from electronic hobby stores but at a push you could use a can of air duster upside down!
Of course, this is all assuming you have a fine tip soldering iron and feel confident using it in your amp - it sounds like it might be a nice one and in which case you might be better off having it repaired professionally.

I've never had trouble with mine starting right up but then again it hasn't gotten quite that cold here. I have had trouble with mine overheating though and having to be shut down for 15-20 minutes to cool off and start playing again.

I'll bet that a/d/s would answer your question if you knew how to ask them. Do they have a web site?

Well if it was a diesel i would say check the glow plugs and injectors

i only say this as me car don't like the cold it is a pig to start

a/d/s website

With that hot/cold testing technique, I'd be worried about condensation forming if you're spraying freezer spray on it in a nice warm workshop.

Maybe install some glow plugs around the amp?

Might work

Dude, your avatar profile picture thingy is broken.

works for me so no idea

I don't see it either

I'm not bothered if you're not but it doesn't work for me either.

Forbidden
You do not have permission to get URL '/users/a11a965b/bc/My+Folder/penguins.gif' from this server.

ah ha i see someone knows more than i do excellent have to have a rethink

You can attach the picture to one of your posts and host it via the bbs, or email it to me and I'll host it for you.

I'm curious as to how many files have accumulated in the BBS over the years...

- Trevor

okay thanks

Just Hijacking the thread to upload my picture

About 1800 files