I own an SA-ST7, but can't find an owner's manual (with any degree of useful information) on-line that gives me some guidance on how to set up Chromecast audio. I see lots of info on HT-ST7, but not on an SA. What is the difference between the SA and HT? I was thinking of plugging the Chromecast into OPT 2 using a TosLink cable, but perhaps there is an easier way to get Chromecast to work. My config is Google Home and Sony XBR-65X850B, in addition to the SA-ST7.