Hi Wilson W/P8 owners, best amp ever to drive WP8?

I have a pair of W/P8 for over a year, used with Krell 700cx amp. The system sounds great but I crave for a little more warmth and glow in the midrange, overall airiness in the treble and soundstage plus a more natural/real presence of acoustics. I have audition Audio Research Ref210s with W/P8, love the sound but was bothered by the overly full mid bass(typical of tube amp?) and the slight loss of focus and precision when compared to my Krell amp. Well controlled bass and a tight mid bass are top priority. What amps, SS or tubes, have you owned that optimise the sound performance of your W/P8s. Thanks for sharing your experience.