George i run an ADCOM 555
I agree with sunshdw it has enough wattage at 200w into 8ohm, but they don’t really muscle it into 4ohms only adding another 100w, the 2ohm figure would be a bit worse again and blew it’s fuses when ask to do it.
And the Ren 90’s hits 2ohms EPDR and lower from what I’ve been told by a tester of them.
They’d like a more Krell early amps of 200w or 300watters, which have more low impedance balls than the Adcom
Cheers George