I recently purchased an Insignia NS-55DF710NA19 and I’ve connected it to my Cambridge Audio receiver via HDMI and Optical but I’m getting no option to route my sound to the receiver. When I go to audio output in settings, it just gives me the options to turn off my TV speakers and change the digital audio format. I’ve searched high and low for an answer but haven’t come up with anything so I figured I’d give this a try.
The tv should automatically be outputting opitcal audio 24/7. You need to make sure your receiver is set to the correct input. To verify unplug the optical cable from your receiver and leave the other side connected to the TV (with it on) and put the tip of the cable up to the palm of your hand. If you see a red light (you can also look down the tip) then it's outputting normally. If you have no light check the cable and then the tv. You shouldn't have to change any settings except the audio mixing if your receiver is a 7.1 output. Let us know how it turns out of if you need more help.