Chaos Machine - rate and frequency knobs aren't working

[doubledre]

I'm having issues with my Chaos Machine build. I'm gettting signal and it works for the most part, except for the rate and freq knobs which don't do anything when adjusted. Previously, when I had expression jacks wired in, the freq knob was working but I decided to remove those wires from the PCB to see if that was affecting the rate knob issue. When removed, the freq knob suddenly stopped working as well. Do the expression jacks need to be wired in for the rate and freq knobs to work or something? And if so, is there a good wiring guide out there I can follow? I came across various posts about it and some seem to be showing different information on the wiring.

Any help would be greatly apprecaited! thanks!

 

[Cybercow]

If you re-examine the build docs, you will see that when NOT using the expression jacks, there are jumpers that need to be placed.

 

[doubledre]

thank you for pointing that out for me.

I wired up the expression jacks again I followed this diagram as a guide. But both freq knob and Rate knob are still not functioning. Any ideas what it could be?

 

[katheudo]

Found this thread while troubleshooting my own Chaos Machine, which had the exact same issue! I found that while it wasn't visually obvious, the contacts weren't touching on the switched jacks. So even if there was nothing in the expression jacks, the rate and frequency pots were disconnected from the circuit. Discovered this by doing continuity checks between the normal and switched sides of the jacks, and fixed it by giving them a little squeeze with the pliers. And be careful how you do those continuity checks, because if you put the multimeter probes in the wrong spot you'll push the contacts together and get a false positive, ask me how I know!

Everything works great now, and I'm filing this one away in my brain for future projects using switched jacks because it took hours to figure out and seconds to fix. The pedal is great, I love the textures it provides on subtler settings.