No sound for DVD, Blu-Ray, or Cox via digital.

OK going back to "bypass" I would then bet the 'bypass' is for music, allowing all the video stuff etc to be bypassed. Well, I then guess 'bypass' is two channel, and for only stereo in your unit? Then it also probably only allows a PCM (two channel) digital input signal. Probably you need to NOT use the bypass! to allow the multichannel signal to be processed. It is most likely a design in the Lexicon logic system Lexicon does not want to/can't fix.
I would think they feel if you want multichannel, you would not use the bypass (which was probably designed for a pure two channel use?)
This is all conjecture, as I do not know your Lexicon device. But from what has been said, and other products with bypass features.. this is what it seems to be.

Then, on the other hand it may be the Sony is screwed up. No way to know which product is not sending the signal?
After all, SACD will not transmit via digital output, and you BluRay IS a Sony... 8^)

It's not the Sony. Coax and Toslink just don't have enough bandwidth for hi rez audio. HDMI will pass the signal of both SACD and DTS HD etc digitally. And the processor must be able to decode the signal.

As I said, the TOSlink input is working and should be able to handle DD, dts and regular PCM/stereo. Since it is not, I would suspect that the sources are not set up properly. If they have HDMI outputs, they probably default to sending the audio to HDMI and not to the digital coax/TOSlink outputs. Check the setups for the BR player audio and the cable box.

Kal

Thanks very much for the replies. Based on the troubleshooting I've already done, the suggestions to set up the sources properly have a real ring of truth. I'll embark on that project asap and report back. Many thanks!