I posted previously that running the Retropie mixer at 44 (or 80% in GUI) allowed the Picade to run at full volume without hanging the controls and dragging the power down. However, after much testing I have found that you have much better quality audio (with disable_audio_dither=1 in \boot\config.txt) if you set the audio mixer to have a dB gain of “0” or as close to as possible.
If you do this the audio is much improved but you MUST turn the Picade volume down to prevent lockups when it needs more power. A volume limited Picade firmware would help loads in this situation as you would then be able to max out the Vol+ button.
Monkey