Code
LibreELEC:/ # aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Set [C-Media USB Headphone Set], device 0: USB Audio [USB Audio]
Subdevices: 0/1
Subdevice #0: subdevice #0
As noted, my speakers are connected to the stereo jack of above listed USB audio. The sound issue is reproducable whether RetroArch is started through Gamestarter or IARL. The sound in Kodi works without issues (and has been working through all the trial and error I've done).
Since there is really no other audio module listed any more, I'm not sure what else to try. retroarch.cfg gives me
as selected through RetroArch. But I've tried all kinds of alternatives through the frontend and direct cfg editing, too.
I especially tried everything here: No sound on RPi3 with LibreELEC · Issue #39 · bite-your-idols/Gamestarter-Pi · GitHub
Thanks and cheers,
rien