C-Buffer in 535Q Wah and a question

faramir

Member
Putting an LED in my 535Q wah was the first project I attempted. I followed this example, and did a pretty crappy job.


As I got better I decided to clean it up and at the same time use the C-Buffer PCB to move my buffer pedal inside the wah and free up space. I actually put a compact stomp switch on it too which didn't technically fit the C-Buffer pcb but did with a little bending of the tabs on the switch. All that works great and looks much neater now.

To do all this I removed the original Dunlop switch which had a little pcb on the back of it. I've always wondered what that thing did. It has a bunch of components on it so clearly its more than just a tidy way to wire to the switch. However, it seems to make no difference when it's removed.

So, I traced the thing out to see what it was, and I'm still not any closer to understanding it! Any electronics whizzes out there have any guesses?

I'm not exactly sure what pin 6 is but it measures 2V when the pedal is on and it doesn't change with any of the wah settings.
 

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Hmm. Did you add an on/off LED as well? I believe that can cause popping. You can use some resistors and a capacitor to fix it:

 
@faramir I realized I did not wire the pcb directly inline, and flipped leads 1 & 2 on the 3DPT. Just fixed it, wiring it in identical to the pcb and the pop is gone and no odd issues with the faint led. Not sure if this helps explain whats going on with leads 5 & 6 but it seems like an obvious solution. Here’s some pics, Cheers!

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