[nyanpasu64]

I didn't realize the filter leaked this much AC until I had been using the "working" board for weeks, without audible distortion (but it's still theoretically there). And I'd have to run another power cable to the filter board, since 3.5mm doesn't supply power. It's possible the cable would result in distortion/radiation in the MHz range if the filter isn't located near the chip, but I don't know if this is a problem in practice. It might be something to work on in the future?