I put together the VFE Blueprint project, got it working. If I so much as look at the Echo knob, it sends the effect into pretty extreme oscillation, distorted repeats with each one growing in volume and distortion until I zero the Echo knob or shut off the pedal. Thought it might be a bad PT2399, but I've swapped at least 6 times with no change, so it has to be something on the board. Anyone experienced this or have any idea what could be the cause?
Crap, I think I just figured it out. Looks like I accidentally swapped the Time and Echo pots. That would do it.
Nevermind, that actually made it worse.
Without seeing any close up pictures of the back, it sounds like there's either a solder bridge or an incorrect resistor value.