analog man 12/00
Making a Speed control pedal for Original Uni-Vibe type pedal like Ultravibe or original Captain Coconut (not CC2 or ULTRA-VIBE-II which use normal expression pedals)
1. First you need a shell like a dunlop crybaby or univibe speed control pedal.
2. Take everything out of the case but the toothed rack which turns the pot gear and the bushing that presses up against it.
3. Get a pot at radio shack, part # 271-1732C Stereo Volume Control 100K dual-ganged with audio taper.
4. Grind down the shaft on the pot to make one round side flat, with a file on a vice or better yet a Dremel tool. Grind it off enough so the gear from the old Dunlop pot will just fit. You may have to remove a c-clip with snap ring pliers to get the gear off the old dunlop pot.
5. Mount the pot onto the wah case, will probably need to get some bigger, thin washers or grind down the mounting area as the mount is almost as thick as the flange on the pot. Use loctite or glue to keep it tight after it is mounted.
6. Adjust the gear so you do not run out of range on either end. Usually one tooth from max when you have the pedal pushed down all the way works best.
7. Cable: Get a 3-conductor patch cord to connect the controller to the coconut pedal, or some 3-conductor wire and a stereo 1/4" plug to plug into the Coconut and make your own cable. You can buy a wire with a plug already on it, radio shack has some in 20' lengths with another size plug recepticle on the other end. This is part# 42-2460 B, a 20' headphone cable. Cut off the 1/8" stereo mini jack and wire that end to the pot in the control pedal.
8. Wire the gear as below. Note the 2 middle lugs on the pot are connected together, and are attached to the ground lug on the plug. A jack is shown instead of a plug, but you should wire it up to the cable with a 1/4" stereo plug on the end with the corresponding wires going to the different contacts on the plug end.
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