Sony VGC-RA304 Operating Instructions Manual page 22

To use the digital audio output
Make connections to an amplifier with digital input, as shown below.
To OPTICAL OUT
connector
Note
When using the digital output to reproduce sound via an amplifier with digital input, leave the audio plugs
(white and red) of the audio/video cable unconnected.
22
Optical fiber cable
(not supplied)
To digital
input (optical)
l : Signal flow