There have been several queries about using HDMI output butgetting the sound via the 3.5mm socket.
A configuration change was posted this week in the Rool Forum.
The original source was -
formatting link
I have just tested it and it works OK, stopping sound via the HDMI connector and enabling it via the Pi's 3.5mm Skt. Video is not affected.
Add this line to the "CONFIG/TXT" file (inside the Loader Directory)
hdmi_ignore_edid_audio=1