amp or preamp to extend upper end


I went from a fantastic little Krell integrated amp to a Musical Fidelity M6 amp and preamp. Found that the high end is a bit rounded off -- that amazing detail I had on the cheaper Krell is lost. My dealer said that the owner of Musical Fidelity designs his equipment for this sonic signature intentionally. Maybe I just got to used to an over-emphasized high end.

Question: would replacing the amp or preamp have a more noticeable impact on extending the upper range (assuming the new equipment can do so)? Any suggestions? Speakers are Vanderteen 3s.
evolving
06-09-15: Evolving
Rleff I did try almargs suggestion and it actually helped. Although I only had to go up by about 1/2 db.
Good! For the record, though, my suggestion essentially just seconded a suggestion that was made earlier in the thread by ZD542.

Regards,
-- Al
Yeah, the Quattros, 5's, and 7's are much better speakers than the 2's and 3's. For their prices they'd better be! Brooks Berdan was a long-time Vandersteen dealer (until he was seduced by Wilson---the money?), and I've heard the old models a lot. The new ones not so much, but enough to know how much better they are.