My Comcast cable is connected to HDMI 1 and my TV picks up Dolby 5.1 and sends the audio to my AVR via tosklink cable from my TV...no problem. When I use the HBO Go app on my TV I can watch a movie and the Dolby 5.1 is sent to my AVR via toslink cable...no problem. However, my Roku which is connected to HDMI 3 on my TV... and when I watch a movie on HBO Go via the Roku HBO Go app, the audio coming from my TV to my AVR is only PCM and not Dolby. I configured the audio settings in my Roku to Dolby and Dolby Plus...but only PCM comes over. I ordered from Amazon a HDMI Audio Extractor which should arrive today...perhaps that will solve my problem? I am just curious why I can receive Dolby from my TV HBO Go app and can receive Dolby from my Comcast connection to HDMI 1 but I can't receive Dolby via my Roku which is connected to HDMI 3...only PCM comes over to my AVR. Please advise. Thank you.