I'm pretty sure it's not a counterfeit amplifier, I am fairly certain it's just a bad repair. As I mentioned before the subwoofer worked great for many months before an extreme circumstance caused it and my Carver amp to both shut off. Only difference is the Carver came back on, the M&K did not. After the repair the subwoofer was ran for a day and it fried again (due to improper fuse size) and they "repaired" it again. That time they put the correct fuse value in, but it was still sensitive enough to blow without much output comparitive to the first time it blew.