Definitely use the HDMI-ARC feature to connect your TV to the 976. It is true that professional installers from the 1990s would use the toslink or digital audio but the audio processing codecs are way beyond that now and HDMI will handle all of the signals. That way if any of the programs or apps on your TV are able to output discrete audio you would be all set. At least part of the techno advantage you are paying for is the HDMI-ARC feature so you might as well use it. As far as the Chromecast it connects to your system as a two channel source through a 3.5 mm jack. You would need an RCA splitter to connect to one of the 976 analog inputs.

Thank you Helson and XenonMan. I'm not sure why the advice I was given was for digital audio. I thought maybe since I have only three speakers it didn't matter whether hmdiarc or digital audio was used.

And to confirm... Is that two Hmdi cables one for set up and one for arc connections or can I get the job done with just one connection, if we are talking the 976? And, XenonMan, I'm not sure I get your chromecast info. My chromecast hooks into an hdmi port on my tv as well as a power plug to a power strip.

Just the single HDMI cable. It would need to be connected to HDMI out #1 for the ARC feature which would also be for the on screen display menu.
I think what Xenonman is talking about is 2-channel PCM from the Chromecast.

I was looking at the older model which just had the 3.5mm connector. How do you plan the connect it to your system, at the TV or with the 976 directly.

Should I wind up with a 976, I guess I would inquire here if anyone had suggestions what would be best, or if it even matters. Do you know if there would be a benefit connecting one way or another? It's not the latest chromecast, nor the chromecast audio. But as mentioned it has an hdmi connector. I don't use it often but on occasion will cast a movie to the tv.

Connecting it to the 976 would allow all the Dolby and DTS surround matrices to be used to change two channel to surround sound . I don't think a TV will do this for you but it may just pass the signal through the ARC to allow the 976 to come into play.

Once again, thank you Helson, thank you XenonMan.