Aragon 4004mkII OR Adcom GFA 555 II

Another amp in that price range I would recommend would be the McCormack DNA-0.5.

I used one with Thiel 2.2's and liked everything about the amp, sound, build quality and great support from Steve McCormack.

Ive owned both. the aragon wont be in your face as much as the adcom. Much more refined sound, its a great amp comparring to more expensive amps, Be careful its very detailed so if you have hot highs already it might put things over the top.

This is a lateral move.

Try A Odyssey Stratos.

The Aragon is definately the better of the two; actually as bigger powetred amps go ... a great amp at used prices. More resolution, finesse, and .... more transparent for the buck.