Yep, that's my site! The trimmer version uses variable resistors instead of fixed value. Its something I put that together at the request of another customer and it allows you to fine tune the Y/C signal a bit. In my experience I've had no problems using the fixed values, but I figured I'd leave the option in there.

Oh, and my previous comment about grounding would only apply if using a separate s-video jack, which in retrospect would be a silly thing to install