last night i had to rehook a few wires because they were coming loose, and after i hooked them up and turned the radio on, my amp was making a buzzing noise....the amp doesnt have a fan so its not from a fan, but turned it up to see how the subs sounded and they sounded fine, but the amp making htis noise scared me so i unplugged the power....why is it making this noise and how do i fix it??? thanks