I have a sony amp that I bought about 2 months ago brand new. It was working perfectly fine up until last week where any time I turn the music up past a quarter of the way, the amp blows a fuse. Im using the stock size fuses, nothing bigger or smaller and like I said...it just started to do this and its pretty much brand new. Its under warranty and Im gonna take it back for a new one but I was wondering if anyone knew what causes this so that I can keep an eye on the new one I get. I checked all electrical connections and everything is perfect. Checked to make sure power, ground, and rca's didnt have any cuts or tears in them and they're good to go too.

 

Taking it back is your best option, if you have checked to make sure of your workmanship first. There should be less then .5 ohm between a random ground bolt on the car and the amplifier ground terminal. Also, make sure there is at least 1, 2, or 4 ohms (whatever is the stable rating on the amplifier) on the two leads which go to the speaker(s). Both measurements should be taken with the car and amplifier in the off position.

 

Also, make sure the gain isn't cranked up. Alot of people use that knob like a volume knob, but it's not.

 

If you turned it up to a point where the output were greater than the rated power of the amp, probably due to a too-low impedance speaker, I'd say look for it to happen again. That said, sometimes electronics just fail by themselves.

 

lol. Up the size of the fuse. Its under warranty.

Actually your problem could also be from a blown voice coil in your sub. I ran into a problem like that awhile back and it only happened when I hit a certain volume level on the radio. Replaced the sub and problem solved.