Quick question about amplifier smoking.

[Lime]

Hi all.

So I believe that I understand what the problem here is, but I would just just like a little input on the situation.

I've had a sub/amp combo going for about two months now, and it's been working perfectly up until this point. Today I removed the sub from the back because I needed the extra trunk space, but I just left everything else all plugged in, including the amp. I drive for about ten minutes playing music at pretty high levels (with my sub still not plugged in) and I see smoke coming out of my head unit as it turns itself off. I check out the amplifier under my seat and I realize most of the smoke is coming directly from it. Now my amp seems dead and won't turn on. The head unit seems to be fine, though.

So my question is...

It only did this because I was a tard and played my amp at high levels without a sub as an output for the power, thus overheating the amplifier, correct?

[Rocko]

Your audio system appears to be suffering an allergic reaction to the shitty music you're feeding it.

[Lime]

Super fucking helpful.

[Kwinnie Bogan]

It is unfortunate that we don't all know as much as Munkey, Seph (where is she?), Phwemorp, or HLC etc when it comes to car audio, and as such can't always give you that quick answer.

I did some googling in the meantime on your behalf, and from what I've gathered the answer may just be a "Yes/no". I think that there may be faulty components in the amp. ..faulty before the meltdown . Did it ever used to make noises, humming or buzzing? It may have been a shit capacitor. But that is one of a number of possible causes.



A humourus post is about all most of us can do without ignoring the thread altogether.

[Eskorbuto]

Signal flow.

Too much power fried something somewhere. Not sure how you had your shit connected, can't help you if you're so vague.

[MunkeyQ]

Originally Posted by fsk-&t

Signal flow.

Too much power fried something somewhere. Not sure how you had your shit connected, can't help you if you're so vague.

Fail. Ignore this douche.

Anyway, as stated in another greasemounkeys thread, I'm far from sober. Will post in the morning when i have half a brain.

Your amp needs a load to drive. Cheaper Class D amps don't like driving a load of infinite resistance (i.e. no speaker) and will overheat the switching chokes very rapidly indeed. This is much like the transformer coupled tube amps of long ago, which would pop their output xformers when run without a load. However, most modern amps will have protection to kick in and mute the supply in this event, stop[ing damage. I'm guessing your protection circuit died...

[MediumD]

Originally Posted by Lime

It only did this because I was a tard and played my amp at high levels without a sub as an output for the power, thus overheating the amplifier, correct?

More than likely, yes. It could also be possible the wires to the sub shorted to ground somewhere if you weren't careful...

You see, electronic circuits are basically a bunch of tiny tubes that transfer smoke between components. When that smoke leaks out of the circuits, things don't work anymore...

[Professor_Skullsworth]

^And once you've let the factory smoke out, you can never get it back in.

[MunkeyQ]

Originally Posted by MediumD

You see, electronic circuits are basically a bunch of tiny tubes that transfer smoke between components. When that smoke leaks out of the circuits, things don't work anymore...

Magic smoke theory!

Anyway, if the sub output shorted across, most car amps are designed to either crowbar or shut down without damage. There's a chance the protection circuit didn't work though...

To elaborate on running switching Class D amps without a load, it's a pretty complex thing which I don't fully understand, but it's related to a resonance building up in the output filter. By design, Class D amps have a bandpass filter on the output to block harmonics and artefacts from the pulsing process. In its simplest form, this is simply an LC filter - but when the filter is driven with enough power, the inductor goes into saturation since the load is taken out the filter equation. Saturating an inductor means its value changes significantly, altering the filter point. It is then possible for a resonance to build up, and if that matches the switching frequency, Bad Things happen and current flow in the filter goes through the roof. Chances are the smoke was coming from the filter components...lacquer burning off the inductor or something.