Gigabyte GA-8IG1000MK User Manual page 74

Advanced 6 Channel Analog Audio Output Mode (using SURROUND-KIT,
Optional Device):
(SURROUND-KIT provides Rear R/L and Center/subwoofer)
SURROUND-KIT access analog output to rear
channels and Center/Subwoofer channels. It is the
best solution if you need 6 channel output, Line In
and MIC at the same time.
STEP 1 :
Insert the "SURROUND-KIT" in the back of the
case, and fix it with the screw.
STEP 2 :
Connect the "SURROUND-KIT" to SUR_CEN on the motherboard.
GA-8IG1000MK Motherboard - 70 -