Sound card - Wikipedia
Spdf - S/PDIF Digital Converter - Boredbrain Music
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Infrared (IR) Remote Control Repeater Kit (TAA Compliant), Remote Control Extenders, AV Control Devices
Is digital audio output the same as optical? - Quora
S/PDIF - Wikipedia
Coaxial SPDIF experiment
Is it worth trying to split S/PDIF output (and what do I need to do so?)
Douk Audio & Nobsound, Amplifier, Preamp, DAC, Audio switcher, vu meter