Something like the qed performance graphite optical is a good entry level option.
Hdmi cable with optical output.
Agptek 4k x 2k hdmi audio extractor splitter hdmi to hdmi audio converter adapter support ultra hd 4k toslink optical audio output and 3 5mm audio with optical fiber cable 3 8 out of 5 stars 85 19 99 19.
Tendak 4k x 2k hdmi to hdmi and optical toslink spdif 3 5mm stereo audio extractor converter hdmi audio splitter adapter hdmi input hdmi digital analog audio output 4 0 out of 5 stars 756 25 69 25.
Both are better than analog the red and white cables.
Agptek 4k x 2k hdmi audio extractor splitter hdmi to hdmi audio converter adapter support ultra hd 4k toslink optical audio output and 3 5mm audio with optical fiber cable 3 8 out of 5 stars 85 19 99 19.
Both can pass multi channel audio like dolby digital.
Both hdmi and optical pass digital audio from one device to another.
Agptek 4k x 2k hdmi audio extractor splitter hdmi to hdmi audio converter adapter support ultra hd 4k toslink optical audio output and 3 5mm audio with optical fiber cable 3 8 out of 5 stars 84 19 99 19.