I connect MiSTer to an external speaker via an optical audio cable on the analog IO board. This works perfect for all cores but Odyssey2, which is silent. Sound works fine with the same core if I change to either an analog cable or HDMI.
I suspect that it is a bug in the Odyssey2 core. Can anyone confirm the issue?
EDIT:
Looking at similar topics, it seems to be a problem for some arcade cores as well. So I guess optical audio output is a feature that is not implemented in all cores?