A regular Roku (not the streaming stick) is probably the ticket here, just hook it up to the two channel input of your choice on your AVR. No AirPlay, although the Roku will work as a DLNA renderer for playing your own digital music collection. You might need to find one of the older Roku (the first gen or the Roku 2) as I believe the Roku 3 only has HDMI outputs.
Receiver: Denon AVR X3400H/Display: Vizio P65-E1
Blu-Ray: Sony UBP-X700/LaserDisc: Panasonic AG-LD20/Streamer Amazon FireTV 4K
Satellite: Dish Hopper w/Sling
Speakers: SVS Prime Tower/SVS Prime Center/SVS Prime Surround/Velodyne HGS-15