I also have the 3805 Denon with a 5.1. Atlantic Technology 4200 speaker system + I just added two old Cerwin Vega speakersw on the back wall and the 7.1. sound is jawdropping Anyway back to your question I hooked up my Denon 2910 d.v.d. player using componit vidio cables and the picture was very poor, So I bought a 4" d.v.i. to h.d.m.i. cable, since you are running your sound thru optical connections d.v.i. and h.d.m.i. make no difference Anyway there was a huge difference in picture quality using a h.d.m.i. cable So buy one and if it doesent work well you may take it back good luck stewart