Rich and DelD,
I didn't intend to mislead you. What I meant was that with the up-conversion of the H/K Faroudja, you could, for example, run a lower-grade composite video source through the H/K and look at the results (through a component-video connection from the H/K to your HD set) or you could bypass the receiver entirely and connect directly to the composite video input of the HD set and view the results.
Now, I may have to do more research here, because it is my understanding that if the H/K or outboard tuner/converter outputs a signal in the native format of your HD set, the set's internal line doubler etc, does no further conversion. For example, if my Samsung's native resolution is 1280 x 720p (that is the TI chip that it uses), then if the HD cable box is set to output 720p, the cable box will convert everything to that native format and the Samsung will do no further conversion.
There are special proprietary circuits that are defeatable on some sets (the Samsung has something called DNle, which adds edge definition, gooses contrast, etc.); sometimes they make the image look worse, other times they improve it.
Using a DVI connector from a cable box or DVD player will avoid an additional analog/digital conversion, which is why the DVI or HDMI image shows improvement.
I'm still sorting through various connection options with my HD DLP set and checking image quality, so stay tuned. . .
Regards,
