logitech z-5500 connections

hi havin trouble connecting devices to my amp. i have the amp set on 1-3 so i can have digital inputs. wen i do the sound test i get fuzz from all the speakers and the sub. i have a y connecter (lead phono to 2 rca) connect my dvd recorder and i only get the front (1), rear (2), centre/sub (3) whichever phono port i choose. any help will be appreciated. cheers