I second the KILLER amp response. The Aragon is a fairly "polite" amp overall with an iron fist on the bottom end like my Krells. Very hard amp to beat even in todays market. Keep in mind some 4004's were factory upgraded to MKII status when the actual MKII version came out. Probably doesn't matter and I'm not sure how you can tell the difference internally, just figured I'd mention that fact. Keep us updated on your decision. Dave.