What Would Be A Step Up

Hi Guys:
Currently using an Arcam A85 and P85 in a bi amp mode this combo sounded OK with my Monitor Audio silver 5i's. However just purchased a pair of Castle Conway 3 and the sound even though is loud with a good soundstage as lost the sweetness in the highs. Would this be because of the speakers are not getting enough power or what? Cables are all the same all around. Do I get new gear or should I sell the Castles. What would be a step up from the A85, P85 combo.
Thanks for taking the time to help