switel TV-L2BT Mode D'emploi page 19

Please note that only one input (either analogue audio input or optical
input/TOSLINK) must be connected. If both the analogue audio input and
the optical input/TOSLINK are connected, the priority use is analogue
input.
Using the optical TOSLINK digital audio cable
If your audio source has an optical audio output (TOSLINK/S-PDIF), connect the
two devices with the included optical TOSLINK digital audio cable. This
connection offers a higher transmission quality and a lower susceptibility to
electrical and magnetic interference.
Please make sure the optical TOSLINK digital audio cable does not get bent or
folded! Avoid tight bending radii.
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