Sumo 9+ Class A Differential Power Amplifier. Right channel has primary issue but both channels will likely need a repair. Fuses blowing on operation. Great cosmetics and the rest of the internals internals seem generally good. this would make a good platform for a custom modification or rack power amp as well. The case looks fantastic and has a nice edge to it with the angled rack handles. A real bold piece. We've seen new ones go over $1000. Customer sold to us because they did not want to go through with the repair and just buy a new unit.