Try an OTL for great bass and treble as well as a superb midrange in a tube amp. Atma-sphere does the entire spectrum very well. Bass is not "Krell-like" but is deep and tuneful. Highend shimmers and the mids are what you expect from tubes. Add a fast rise time for a great transient response with the OTL configuration and you get a great all around amp.
A question regarding "tubes"
This may me a dumb question but does all tube products (amps, CD player and pre amps) roll off, or softens the highs and gives up some bass slam.