Quote Originally Posted by Charlie View Post
What are you using to connect to the jacks, how far apart are they, what does the board layout looks like, is there a ground plane, is there a decoupling cap on the PIC, how does the 9V ground relate to whatever you have connected, and probably a few more questions once you answer these. There are pretty sharp edges on the steps, so you may be generating RF that is rectified by whatever you are using to listen to audio.
I'm using a small bread board. The PIC and power supply are on one side of the bread board. The jacks are on the other side. The jacks are your typical enclosed 1/4" stereo jack like a Switchcraft 112BX. I'm using some higher end shielded instrument cables to connect to a guitar and a little test amp on my bench.