hi idk what's wrong with the amp but I think it would be a simple fix, the RIGHT A AND B still work fine but the LEFT A AND B doesn't and when all the channels worked and u put that loudness setting on, this thing is loud and beautiful and puts out more bass to your speakers than you would ever expect ur speakers to output, I still used it a few times by using the mono setting and using the right channel a and b, you can also wire a active subwoofer to this but only do that if all channels are working.
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