hey y'all!
all four knobs on my 404sx are getting a bit loose from carrying it around in my bag a lot, so I was wondering: is it possible to unscrew the faceplate and tighten the potentiometers or what they're called?

Try it. I had a weird encoder on my OctaTrack that I had to tighten up several times and that was easy. I would imagine the 404 has less complicated gutzzzzz.