Dunlop Wah GCB-95 rev C

[AntKnee]

I was given a wah that someone had sloppily attempted to mod and I'm trying to clean it up and make it right. They had added a 12 position rotary switch, of which they only used 5 positions, and was running differnt caps through the switch in parallel with the 33k resistor. I've removed their sloppy additions and replaced the resistor and now have the wah back to stock. I think.

Right away, I wanted to replace the 1/8" dc jack with a 2.1mm boss style dc jack, which I did. I installed it in the horribly drilled hole the previous owner was attempting to use for his switch, after I redrilled it to make the hole an actual circle. When I hook up the pedal, I get buzz and no sound. I do get sound in bypass, and I do get effected sound when I use the battery. I only have a problem with the power jack connected. I verified that I do have the wired attached to the jack correctly. In fact, I even tried switching the battery and dc positive wires to make sure it didn't somehow work that way. I also replaced my dc jack with another to rule that out.

Once I get this figured out, I'll move on to other tricks.

[AntKnee]

More information from Dunlop, if it helps...

"There are two different AC adapters used on our wah pedals: the ECB-02 and the ECB-03. If your pedal has a female AC jack, it requires the ECB-02 (a 3.5mm plug); if the AC jack has a pin in the center of it, it requires the ECB-03 (a 5.5/2.1mm coax plug). Any versions of our wah pedals that support AC adapters require the following power parameters: anything greater than 20ma, 9volt. The ECB-02 is positive tip polarity, and the ECB-03 is positive outside polarity."

So, there is probably some compatibility problem in switching to the 2.1mm coax. I think I need to add a small board or filter to fix it. If anyone knows of a layout, let me know please.

[Stomptown]

have you checked to make sure the wiring to the input stereo jack is correct?

[marmaliser]

I did one of these years ago and I think I had the same problem.  IIRC it was a grounding issue

[AntKnee]

I think I'll probably just put a weener in there and be done with it. Can't beat a free enclosure!
Anyone know how to test an inductor? I may try to reuse it if its worth it.