I have a Sony 40V300 and connecting to a Denon AVR 1508. I can't get sound out from the speakers. Looking at the quick set-up guide, it shows the HDMI connection from the receiver to the TV, and then a Digital Optical connection from the TV to the receiver. This cable I don't have and I don't see this port on the receiver, but I see the port on the TV. The receiver has OPT-1 (CD) and OPT-2 (VCR). So I don't know if this is the reason I don't have sound out of the speakers.

If you are using the Sony HDTV as the source (internal DTV tuner), in theory the HDMI connection could pass the Dolby Digital signal to the Denon receiver, but I'm guessing the Sony HDTV HDMI connection is one way only; for use as an input from the Denon receiver. Use the Optical out of the HDTV to the Denon, and it will not matter which input you use, either OPT-1 or OPT-2.

Thanks for the response, I give that a try. Its interesting why system manufacturers don't include necessary cables.