No need for Surround. Only Stereo.
The sound is more open via my HDMI. More explosive. More details.
If you have Tidal, this is an excellent song to hear the differences:
https://tidal.com/track/58099923
(Count Basie from 1958, Moten Swing No 1)
Maybe it's just the cheap optical cable. That's why i'm asking here.