Allan,

Just something to think about - but if you are satisfied with your AVR 4000 for movie playback, and not music - what makes you sure that the source of your problem is your amp? If you are already achieving an acceptable amount of performance through your current amp (which I am assuming is a receiver/processor/amp combo) from DVDs, maybe the problem is the source that the music (CDs?) is coming from.

If I were you I would at least audition a new CD player. Plus keep in mind (in my experience) the quality level from one CD to another varies more greatly than from one DVD to another (maybe I've just been lucky with my choices in DVD).

Food for thought,
Don