Blown Amplifier: Fuse?

[cron]

I DJed a houseparty with a friend last weekend where we blew the hosts' £300 amp. Oopsie. We think we'll be using our own amps from now on.

Being completely clueless about electronics, I was wondering if it was possible that it could simply be a fuse inside the amp that has blown. We noted the 'smell of electricity' in the vicinity after it had happened if that provides any clues.

Lastly, does anybody have any hints on how to avoid this in the future? For instance, is it better to have a low input signal from our mixer and blast the volume knob on the amp, or vice versa? Are both as bad as each other?

Cheers!

[C00kie]

We noted the 'smell of electricity' in the vicinity after it had happened if that provides any clues.

In that case most likely something else than just a fuse gave way. Maybe also a fuse blew, but chances are that if you just replace that it will blow immediately again.

The unit is due for repair by an expert and that's usually not cheap since the costs are mostly labour for figuring out what's wrong. You could open it, and look for burnt items. Replacing those is a good start, but it could very well be an item that shows no visual signs.

does anybody have any hints on how to avoid this in the future? For instance, is it better to have a low input signal from our mixer and blast the volume knob on the amp, or vice versa? Are both as bad as each other?

The signal from the mixer shouldn't go into the red. Still that's no guarantee, for example if the mixer's output is at +10dBV while the amp is designed for -4dBV. Not a likely scenario, but not unthinkable...

Another possible cause is an impedance mismatch at the speaker side. Can happen if the amp can handle 4 to 16 Ohm but you've hooked up several 4 Ohm speakers in parallel per side.

Most good power amps have overload protection mechanisms. Maybe this one didn't, or it malfunctionned.