I bought my Harman Kardon HK6250 integrated amplifier used with the expectation of using it exclusively with my Energy C100 bookshelf speakers when it would be overkill to warm up my vintage McIntosh. It's done its job and more- I found that it pairs surprisingly well with my ATH-AD2000s. It has a clean sound but tends to sound thin (yet neutral) at times. Detail is better than the Meier Audio Headfive and dynamics are handled well. Vocals are more fluid and natural, the presentation fuller and warmer, and the soundstage deeper. Music comes alive on...