I run devil Soundbar/Sounddeck streaming via HDMI/Optical on the TV. The source (TV) is selected, but I hear nothing or it hums/hisses.

Possible cause: TV sound output is not set appropriately.

Solution: In the TV menu, set the audio output (sound output) to the "PCM" or "Stereo" format. The exact name of the option may vary from manufacturer to manufacturer.