If tube rolling doesn't do it DNM Reson ICs and a SS Icepower amp would be reasonable priced things to consider from my experiences. These two components in combo with the wide range Walsh driver in my OHM speakers have delivered clear and uncongested midrange to die for along with a powerful and tight, harmonically rich low end. Similar if perhaps not quite as coherent overall results with my Dynaudio monitors. The ARC tube pre-amp is a major factor in this as well.