The USB thing has me somewhat confused, I went to great lengths to download directly from original CD's, at 320 Kbps on an AAC format, via Itunes. I was under the impression that the UBS would allow the 2150 to process the info, but I can still control volume, bass and treble through windows. Maybe this does not matter, but I am wondering what these levels should be so that I am optimising the capabilities of the 2150. Any thoughts, maybe I should go back to the CD player, but I like the convenience, also a number of people complained about the sound quality when using the USB port, is that perhaps because they are downloading the music with a greater compression, mine seems to sound fine, but I do not have a CD player right now, so it is difficult to compare, as an aside does anyone have Axiom speakers I just ordered some M80's and would appreciate some feed back.