I have used an Ayre KX-R with a krell 403E for the past couple of months and it sounds really good. In general, Krell evolution amp works well with Lots of preamps. I have used Pass labs, Audio Research ref5se, and ref6 as well.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.