I believe that the 7300 OSD will only work over a 480I connection, thus the need for a composite or S-Video output. If you're just talking about setting up the sound levels maybe you could run a composite to a smaller or portable tv if you have one to see the on screen display.

2xM80 VP180 2xQS8 2xM3 HSU STF3 LG 60PS11 Denon 3808 ATI 1506 LCR 2xATI 1502 Oppo BDP-83