Does dust affect amplifiers?


2005-07-15 7:14 pm
Over the past 2 months, i've blown 2 amplifiers. Not like fuses or shorts or anything. They catch on fire and my car fills with smoke. I own the A8002T Audiobahn 800 watt Intake Series amp, which has the cooling fan on it. Its mounted in my trunk and i was thinking, my trunk isnt all that air tight, and allows dust in through it. If the dust were you get inside the amp from the fan blowing it in, would that cause my current problem? I'm thinking yes, but i dont have a whole lot of expirience with this sort of thing. Any help would be appreciated.
It's likely that the power supply failed. When the power supply FETs fail, they often make a mess. At the time when they fail, there may be visible flames for a second or two but as soon as the FETs open, the flames are gone. It may take a couple of minutes before it stops smoking (unless the fan was in operation at the time).

It's unlikely that dust had anything to do with the amplifier failing. Even if there is no air flow, the amp should have simply shut down (all amps have thermal protection).

If you've blown 2 amps and you're running it into a safe ohm load but you were running the amp hard when it failed, you may be asking for more than the amp can deliver. If the amplifier was not being run hard when it failed, there may be some underlying problem (intermittantly shorted transformer, defective insulator, broken leg on FET, shorted speaker wire...). These can result from poor installation, poor amplifier design or simply bad luck.

Before you install another amplifier, you need to check all of your wires for shorts. Use an ohm meter to be sure that each individual voice coil is OK. They are likely to read ~10-15% less than the rated impedance when using an ohm meter. If all of the speakers are identical, the reading should be very close on each. If you get one that's significantly higher or lower than the others, that speaker needs to be replaced.
As for the dust,I can see it being a problem,if there's alot of it.
I've had my PC go crazy from being dusty inside,a good blast (or 10) of air to clean it all out,and it's fine again. It was pretty dusty inside. ;)

But I don't think that's likely to be your problem.. :hot:
Check the wiring,make sure the power and speaker wires are large enough,all terminals/connections are tight,etc.and maybe try turning the volume down a tad? :D
I've experienced a lot of mild problems with dust in potentiometers and switches of amplifiers placed in dirty trunks (bricklayer cars, etc...). However, I've never ever seen such a catastrophic failure. Huge amounts of dust and moisture are required in order to cause trouble in low voltage applications.

Your failure is probably due to anything but dust.

Also, don't trust Audiobahn at all, here in Europe some of their products appear to be sold under different names and logos. This means that they are just buying ready-to-use stuff in China like many others (no R+D).
I don't think the dust would be a problem. it wou take a lot of dust to stop up the airflow (and even with a ton of dust, there shoul still be some flow. The thermal cutout should have saved the amplifier before it caught on fire. But Then again, I have very very little faith in car amplifier "engineers" to produce a working protection circuit. Personally, I think there was either a problem with your install, a defective amplifier (were these two different Audibahns, or was the first one repaired?), or a design flaw in the amplifier?

I would check the instal for the following:
1. proper load for the amplifier
2. speakers/subs are working
3. power supply wiring and power system is decent
4. amp is mounted correctly, not exposed to excessive vibrations, and the fan and vents (and possibly any other heatsinks) had ample ventilation
5. no power wires are frying or shorting
6. was the amplifier being overdriven and clipped often (get a bigger one or moreefficient speaker boxes)

If you ae owrried about dust, you can just blow it out every once in a while with some canned air. But I've seen some fan cooled electronics get extremely dusty and still work. look at computer power supplies and TVs.
When you changed the first Audiobahn for the second, did you change anything else about the install, or did you just plug in the new amp? Maybe there's a short circuit somewhere that's causing super low resistance on one of the channels, maybe a speaker wire connection that's touching the ground or touching another connection. I'd go through all the wires and connections and make sure they're well insulated.



2004-11-26 3:15 am
At work(Futureshop) we had a kenwood amp 7201 I think ~450Wrms 2channel. And If you hit the case the fan blew out a bunch of dust everytime. It worked mostly fine and was normally run 2ohms mono though when it hit clearance(discontinued) I found it with the fuses blown and non functioning. I dont think it was necessarily because of the dust though. Kinda makes me happy though mine have no fans.