Yeh after some further testing – there is little difference really – and the previous code has audio interpolation which sounds better (slightly slower, but not much).

I am going to revert back to the upstream code, but overclock your rpi more and it should be better. also you can try configuring “runcommand” from the retropie-setup setup / configuration menu and set governor to performance which might help too). If it’s fine on ondemand though leave it like that.

can also try the dispmanx video output driver. go to retropie-setup / setup / configuration menu and go to config editor. edit common options / all/retroarch.cfg and set video_driver to “dispmanx”

to improve rpi audio via jack, and remove background hiss you can try adding disable_audio_dither=1 to /boot/config.txt

overclocking more is the best bet though imho.