Samsung LED 7450 E-Manual page 21

For the LED 7450/7500, 8000 and PDP 8000 series models
Refer to the diagram and connect the optical cable to the TV's digital audio output connector and the
device's digital audio input connector.
The displayed image may differ depending on the model.
For the S9 models
Refer to the diagram and connect the optical cable to the One Connect digital audio output connector
and the device's digital audio input connector.