Help connecting audio to Yamaha receiver from Android Streamer

[PapaFlorida]

I have an android streamer (Pinwheel z4) that I connected to my Yamaha RX773 receiver via HDMI. I have sound but was told to improve the sound (not getting 5.1) to connect a digital cable from the Android Pinwheel box via the SPDIF on the Pinwheel box to the Yamaha receiver.
I do not see an SPDIF connection on the Yahama 773 and was wondering where I would connect the SPDIF cable to on the Yamaha. I see under AV4 an optical (TV) and under AV1 I see an "optical" connection under component video. There is also a connection for "AV" on the back of the streamer but I was told SPDIF is better. Is the correct?
Can someone steer me in the right direction. What cable is best to use? Also is this the best way to set up my sound for the set up I have?
Thank you for any help!

 

[americanaudiophile]

SPDIF refers to the standard for consumer optical and coax digital audio. You have two inputs of each on the receiver. They can have to be assigned to an any input (such as aux) in the input set up menu. Check the manual.
Coax digital us usually better than optical. Digital is usually better than analog.
I don't think there will be any difference between HDMI and either SPDIF connection. In fact HDMI may be better.