McIntosh MA-6100, Harman Kardon Citation 16A, Phase Linear 400 Series II, Carver M-400 (two, strapped in mono), Yamaha M-40, McIntosh MC-2300, Harman Kardon Citation 16A.. which is where I stop. Without question, the Citation 16A is the best balanced amp I have ever heard. I always end up going back to it, and it always reveals something that the other amps I have used failed to do. I know its old school, but it's got an indescribable magic to me.