Games don't seem to have analog audio out

[Ulugbeg]

Version (or build number)

0.2.0

Platform (Pocket or MiSTer)

Mister

Steps to reproduce

With an analog I/O board, play a game, for example, mario bros, and connect speakers/headphones to the analog audio output.

Expected Behavior

Hear sounds through the speakers/headphones

Actual Behavior

I hear nothing through the headphones

Additional Context

Love this core, brought back so many great childhood memories! Hopefully, analog audio out can be added :) Thanks!