I hope this is the appropriate forum, as I wasn't sure if this question should go here or in the Receivers/Separates/Amps forum. I apologize if this is the wrong place for this question. Here's my situation. I recently got an HTIB system for use in my apartment until I move into a house. It is the Sony HT-6600DP. Everything is working fine, but I have one question... The receiver has 3 video ins: DVD, Video 1, and Video 2. I have my DVD hooked up through component and coxial for the audio. I have my X-box hooked up to the other component input on the receiver (it does component switching) on Video 2 and the audio is through optical. The Video 1 inputs on the receiver only allow for composite or S-Video, and no digital audio connections, so I have my cable box hooked up through component cables directly to the TV, and the audio out of the TV is going to the audio in on Video 1 on the receiver. Obviously I can't get DD5.1 out of the cable box this way. Now, the receiver has a couple other optical audio connections, but they are not for any of the video sources. They are for MD/Tape In and CD/SACD In. My question is, can I hook the optical out on my cable box to one of these two optical ins, and get DD5.1 when available through cable box, or are these inputs specifically for these types of devices, and will be damaged if I hook up something other than MD/Tape or CD/SACD? Normally I'd just give it a shot, but I don't have an extra optical cable laying around, and I don't want to damage the receiver if this shouldn't be done. Thanks in advance for any information.