This may or may not be a freak occurrence ... I finished up my ZP mini and had no modulation. Eventually I found that pins 6 and 7 were connected; I scraped away the coating and there was an actual trace under there. Once I cut it things worked fine.
Just putting this here in case anyone else can't get the modulation to work.
On IC3? I haven't built mine yet, but I just looked at the board and there looks to be a narrow stray trace between pins 7 and 8 on IC3 that I think shouldn't be there. I checked it with a continuity meter and pins 7 and 8 are connected. Mine doesn't have a connection between 6 and 7 though.
I'll take a look at some of the boards today. Hopefully these are just isolated instances of a manufacturing error but I will see if I can find any others.
RobA - Any chance you can get me a close up pic of what you are seeing?
Unfortunately I can't get a clear shot with my crappy camera. You can just make it out in this blurry shot. The trace is about a fifth to a sixth of the size of a real trace and it starts in about the middle of the seventh pin's hole and angles down towards the inside of the 8th hole. It does stay above the ground plane but gets pretty close near the 8th hole.
(http://www.musicunfolding.com/graphics/bad_trace.jpg)
I wish I could get a better shot but I hope this helps.
Yup, definite manufacturing error. Go ahead and cut that thin trace with an exacto knife or razor. The pads should not be connected.
I just checked the remaining boards and found about 10 like that. I'll post some more info on it in a bit.
Here's the post I just made in the errata section: http://www.madbeanpedals.com/forum/index.php?topic=8451.0
Thanks for bringing this to my attention.
Mine had the trace as well. Thanks for the heads up :)
Also,stay away from the brown acid!