Check your preamp tubes.
When I received my amp the first preamp tube in mine was cracked from shipping. The tube was actually cracked in half and looked like it had white powder in it. I had a similar thing where the volume was all the way up and there was hardly any sound, except it was that way on every channel.
When I received my amp the first preamp tube in mine was cracked from shipping. The tube was actually cracked in half and looked like it had white powder in it. I had a similar thing where the volume was all the way up and there was hardly any sound, except it was that way on every channel.