[PROBLEM] Video's output audio to DAC

[teekay]

The Atolls are external boxes with coax/optical SPDIF input.

The best thing you can do is to get a HDMI audio extractor. The Ligawo devices are known to work well for this. There is a version with optical and coax SPDIF out for around 50€, and a version with optical SPDIF and analog RCA for around 35€. The digital does 5.1, analog is 2.0. Here is a description from a German reseller.