Why did my amp blow????

[shaneb 10+ year member]

wait so if your never supposed to run an amp without a load how are you supposed to set your gains with a dmm? i thought you were supposed to unhook the subs and then hook up the dmm? and i have a mbquart 4.100 and that thing gets pretty warm also

I doubt it takes very long to do what you are doing when tuning.

Sounds like he was driving around without it hooked up, for some period of time.

But he also said he had the sub turned off on the HU. I dunno...

 

[IDSkoT 5,000+ posts]

so you were playing music with the amp hooked up but no sub?
If thats the case what happened was the rail voltage built up without a load and cooked your MOSFETS on the output stage.

You should never run an amp without a load hooked up.

x3

With an input signal, the voltage just builds up with no way to discharge it until the MOSFETS melt.

Get some allen wrenches, take your amp apart, and check. You should see burn marks on the board.

wait so if your never supposed to run an amp without a load how are you supposed to set your gains with a dmm? i thought you were supposed to unhook the subs and then hook up the dmm? and i have a mbquart 4.100 and that thing gets pretty warm also

It's technically not supposed to happen period. But it does, but only after long periods of time with out a way to discharge.

As for the amp getting warm, it all depends on the power of the amp, the size of the heat sink, how well it's heat sinked, what resistance it's working at, and where the amp is. An amp at .5 ohms will run A LOT hotter than the same amp with the same electrical running at 4, 8, or even 16 ohms.

 

[Trey803 5,000+ posts]

yes my amp took almost a month to blow....and I even noticed it getting hot but did nothing about it. It will not blow if you are simply setting your gain with a DMM and you will feel it get very hot if it is about to go

 

[Trey803 5,000+ posts]