Samsung TS-H492A-WBGH - Manual (Page 12)

Setup
Connect a jumper to the rear side of the COMBO.
If the jumper is connected to MA (Master), it will work in the Master mode.
If the jumper is connected to SL (Slave), it will work in the Slave mode.
If the jumper is connected to CS (CSEL), you can control the device by using the host interface signal
CSEL. (In general, connection to MA is recommended.)
Connecting the audio cable from a sound card
Connect the 4-pin audio cable between the sound output terminal on the Optical drive and the audio
input terminal on the sound card.
For clearer sound, use a digital output terminal.(Available only for the CAID that supports digital output)
This may not be available for general sound cards.