Connectivity Problem Soundsync A3341

I have the A3341 and am trying to play Spotify from my iPhone through the Anker to my Onkyo AV receiver TX SR601 vis optical cable for the best connection. I can connect my phone to the A3341 but it does not play over the receiver to my speakers. Current connection is from the SPDIF RX on the A3341 to my receiver optical in. The A3341 is switched to RX.