Gigabyte GA-X99-SLI User Manual page 22

Line Out (Green)
The line out jack. This jack supports audio amplifying function. For better sound quality, it is recommended
that you connect your headphone/speaker to this jack (actual effects may vary by the device being used).
Use this audio jack for a headphone or 2-channel speaker. This jack can be used to connect front speakers
in a 4/5.1/7.1-channel audio configuration.
Mic In (Pink)
The Mic in jack. Microphones must be connected to this jack.
The audio jacks can be reconfigured to perform different functions via the audio software (supported
functions may vary based on hardware specification). If you install a Side Speaker, you need to
retask other audio jack to be Side Speaker out. Only microphones still MUST be connected to the
default Mic in jack.
Wi-Fi Antenna Connector Holes
Secure the antenna connectors, washers, and nuts onto the holes.
Hardware Installation - 22 -