Hi Guys, I have a Cambridge Audio 640c CD player linked to a Marantz SR5200 HC receiver and Mordaunt Short Premier speakers. Using my Sharp DV 740 dvd player for movies, the amp and speakers are great except I think I am losing out on CD sound quality with the CA player using the Marantz and front two MS's. Where would I benefit most from an upgrade, receiver to stereo amp or new stereo speakers? I have £500 budget. Thanks, Phil.