What speakers are you using? That might help us to provide you with better suggestions. Also, any particular reason you feel the need to upgrade from the Lexicon - not enough power, not the sound you like, etc.?? Any interest in the LX series?
Anthem is one worth looking at. Their P5 and P2 (5-channel and 2-channel) are 325w/ch and should provide more power than you'll need unless you have very power hungry speakers. They also have the A5 and A2, but I'm not sure if you would consider those an upgrade from your Lexicon. Theta is certainly another company to consider.
