I'm not sure Krell is the best answer. Their integraded amps, especially, the 300i series is a little mellow to begin with, a little rolled-off up top. It has a nice sence of flow and presents music as a piece, but if you are looking for agressive it is not your answer. Try Bryston.
Rotel RA1070 vs Krell300il/Krell 400ui Intgr amps
I am currently using the rotel ra 1070 with a pair of Vienna Acoustic Beethovens. Am thinking of change to Krell due to seemingly passive/nuetral nature of speakers. Great speakers though they seem to need a more agressive source of presentation. Can anyone help/make suggestions? The Krell amps have been suggested,