Asus Xonar D1 - Manual (Page 9)

9 ASUS Xonar D Quick start guide
English
1.5.3 Connecting 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 the TOSLINK optical cable.
1.5.4 Connecting Line-In audio sources
SPDIF Out
Line In