I've gleaned a lot of good info from this site, asked some questions and got some answers and have yet to be flamed by anybody so I thought I'd post this to help anyone else who intends to implement a similar lash up.
I recently picked up a Samsung DVD-VR330. I got it so that I could transfer recordings from my Motorola DCT6412 III's DVR to DVD (i.e., declutter the DVR) and transfer old VHS tapes to DVD also.
I have a Sony HT-7000DH HTiB that consists of an AV Receiver, upconverting DVD player and the requisite speakers for a 5.1 system. The AVR (HDMI pass through) has 2 HDMI inputs and 1 HDMI output. My set-up up to now, which works just fine, has been as follows:
Motorola DCT6412 III >> HDMI >> AVR
Motorola DCT6412 III >> Digital Audio Optical >> AVR
DVD Player >> HDMI >> AVR
DVD Player >> Digital Audio Coax >> AVR
AVR (MONITOR OUT) >> HDMI >> Samsung HL-S5086W
Anyway, after reading the manual and checking WikiBooks and some AVS threads for info on the VR330 and Moto DCT6412, I figured the following set-up should work:
Motorola DCT6412 III >> S-Video >> VR330 (S-VIDEO IN)
Motorola DCT6412 III >> Red/White Audio >> VR330 (AV 1 IN)
VR330 (DIGITAL AUDIO OUT) >> Optical Cable >> AVR
VR330 (AV OUT) >> Red/White Audio >> AVR
VR330 (COMPONENT OUT) >> Component Cable >> Samsung HL-S5086W
With this set-up, I played back both VHS tapes and DVD videos so I knew that much was OK. I also recorded (on DVD-R) and replayed a few minutes of a non-HD program that is on the DVR so that worked too. I must admit it took a couple of tries. I succeeded only AFTER I realized that I had to choose "SUPER" with the INPUT SEL. button on the remote (is that what the S in S-video stands for?? DUH!). The next things will be to finalize a DVD and try to play it on the upconverting DVD player and my computers and transfer some VHS tapes to DVD.
I currently don't plan to record via the VR330's tuner so I don't have a coax hooked up to the ANT IN JACK. If I decide I want that capability later, I think I'll use a cable splitter where the RG6 comes out of the wall.