dude, i think i finally solved the noise issue on my mixer. i need to test it in action a bit more when it isn't super late at night, but i found that the LEVEL setting introduces noise and the GAIN setting doesn't on the microphone channels. i honestly don't fully know how this shit works so maybe that was obvious, but i've basically had gain at like 7 o clock and level at 1 o clock this whole time and i'm thinking maybe that should get reversed now. i've just always heard that you should aim for a low amount of gain otherwise you'll get distortion, but i guess i never really tested how far i could push it without it distorting. it does make sense that adding volume to a microphone before adding the microphone to the mix would result in less overall noise, i suppose? don't know why i never figured this out tbh.