Asus Xonar U3 - Connecting Speakers

5ASUS Xonar U3
2.1 Speakers
7. Connecting speakers
For Analog Spakers
2 Speakers
For Digital Speakers
SPDIF Out
Plug the optical TOSLINK adapter into the S/PDIF-Out port. Then, connect your
decoder’s S/PDIF In port to the optical adapter with a TOSLINK optical cable.
The TOSLINK optical cable is purchased separately.