Amp Suggestions for Harbeth C7es3

I have a pair of C7 pairing with Supernait. In my current room (8'x10' room with speakers placed against 10' side wall), the combination is a bit too expansive. I would appreciate some opinions if I were to change the amp to get a little more high frequence air and better sound stage and sound image definitions. I mostly listen to Classical and Jazz music, occasionally vocal and pop, thus I don't mind losing a bit bottom end punch, as long as the bass definition doesn't suffer. I am also not ready yet to jump to the tube camp yet. Any suggestion would be appreciated.

cheers