There's no way to pass regular nes roms through the FDS RAM Adapter by any chance it there? Doesn't the FDS Ram Adapter output it's own audio when plugged in, or does it combine it's own audio with the NES & combine the two? Sorry if that's a confusing question.
As far as audio options I just took a look & a question hit me. Why are some of the audio channels set to 1/4 volume by default? Shouldn't Square 1,2,triangle, etc, bet set to 80 like the other channels so they're equal?