I recently got a used Exposure Super XV integrated amp. It would not turn on, so I had it repaired at a stereo repair shop. It turns on now and plays music, but immediately after powering on, even without music playing, it emits through the speakers a horribly loud, constant buzzing/humming sound. Loud enough that it actually hurts my ears (i.e. not a slight background noise). I tried moving around the cables some; making sure the power cord does not touch the speaker wires, but it had no effect.
Any thoughts? Perhaps the amp is still broken or they did not fix something?