Thanks Lou, I had found the DHS article already and it helped some, but didn't answer all my questions. I'm pretty sure that my TV has a headphone only type of jack whose volume can be controlled with the TV remote, but it is likely an "unamplified" signal, incapable of driving the DHS system. That's what I tried at first and could barely hear the output. The DHS amp also has a left and right "speaker level" input, but I think the TV has only a single speaker and not twins, although I may be wrong. In any event, that'll require more wires from the TV to the DHS amp and I'm not sure it is worth it. Also thought about a small 12v stereo amp to put some "guts" into the TV signal to drive the DHS, but that TV input is mono, so I need an amplifier/mixer arrangement to take L and R channels and mix them, then amplify.
I'll also do some searching on the RV forum for older posts. Personally, I'm not as pleased with the new search software as I was with the old.