I've recently built a bartop arcade running from a pi 3, everything was running great except that audio via the in built jack was terrible. I've installed a usb audio interface and got it up an running by changing the default sound card in the alsa.conf file.
I'm using attract mode as my front end and when i boot up everything sounds great, I can scroll through my games and all the previews play fine and the sound is perfect but when I try to load a rom it just goes to a black screen for about 10 seconds before returning to the game menu. As soon as I return the default audio back to the onboard sound the roms load fine.
Has anyone else had this issue when using a usb interface? I'm running mame4all.