StarTech.com USB External Sound Card Adapter Instruction Manual page 5

Front View
Headphone: Connect to headphone.
Line In: Connect to tape/CD/DVD Player, or other audio sources for
output mixing and/or recording.
Front Speaker: Connect to Front speakers (via external amplifier).
Surround Speaker: Connect to Surround speakers while in 4/6/8
channel modes (via external amplifier).
Center/Bass Speaker: Connect to Center/Bass speakers while in 6/8
channel modes (via external amplifier).
Rear Speaker: Connect to Rear speakers while in 8 channel mode (via
external amplifier).
Rear View
S/PDIF IN: Connect to the digital optical output of external audio device
via a Toslink cable. The signal only passes through to the S/PDIF OUT.
S/PDIF OUT: Connect to the digital optical input of an external audio
device via aToslink cable.
USB Connector: Plugs into the system's USB port.
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