You want an amp that does not interact with your speakers. This mean a high damping factor. You want a flat frequency response and high enough power to not clip - probably a couple of hundred watts a side. Distortion doesn't seem to be very important or people wouldn't like tube amps. Of course this description includes everything from an old Phase Linear you could get for a few hundred bucks to multi-thousand dollar amps. If two amps really sound different then at least one of them is malfunctioning.
Amp suggestion for Legacy Focus
I have started upgrading my system and would like some suggestions on amps for the Focus. The amps I'm interested in are, not in any specific order: 1.Jeff Rowland Model 2 (this would probably be bi-amped). 2.Classe CA-200S. 3.Marsh A-400S. 4.Bryston 4BST. I'm actually leaning towards the Marsh. As of right now my system consists of: Yamaha line of 1000U components (amp, pre-amp, cd, tuner). My turntable, which will be staying, Denon DP2000 with an SME series III tonearm and Denon 103S cartridge. Legacy Focus speakers (my first upgrade from Infinity Kappa 8's).Interconnects are Monster's Reference line. I have built my own speaker wires, which are 12gauge fine copper, terminated with banana plugs (which are crimped and soldered with high silver content solder), which will be staying also. We listen to primarily rock, but also classical, jazz, big band, orchestral, no opera... yeeeesh. If anyone has any other suggestions they are definetely welcomed. The upgrade after the amp will be the pre-amp, and so on back through the chain. Thank you in advance for any help.