Wednesday, November 04, 2009

Taking the Scratch out of the Snarling Dog

My Snarling Dogs Whine-O-Wah started to "scratch" when I engaged the wah pedal. It would make a "scritch-scritch" sound whenever I moved the pedal up or down. This was a classic case of a dirty pot.


Most of the time, the usual fix is to apply some contact cleaner and work the pot until the dirt is worked out. It made sense to remove the pot from the pedal to provide access. In addition, the inside of the pedal would stay clean and free of contact cleaner. Here are the step to access the potentiometer and apply contact cleaner:


1. Flip the dog on it's back and remove the machine screws that hold the rubber feet on the bottom plate. It might be helpful to also remove the battery cover to have something to grab onto to pull off the bottom plate.




2. Carefully lift off the bottom plate. You'll want to be careful that you don't lose the lock washers between the bottom plate and the pedal housing.




3. From the topside remove the nut and lockwasher that hold the switch in place. Flip the pedal over on it's back again and remove the footswitch. Use a flat head screwdriver to work off the pinion gear from the pot. You can then loosen the 1/2 inch nut, the lockwasher and the flange that hold the pot into the housing.



4. You now have clear access to the pot. I put a paper towel behind the pot when I sprayed the contact cleaner into the pot at the shaft. Then I worked the pot and removed the excess grimey grease from the pot. Here I was able to plug in the pedal to a guitar and amp. I had to repeat the process a few times until the pot was cleaned out and wasn't making a scratching noise.



5. The only real trick to reassembly is to get the shaft in the proper position relative to the rack. Loosen the screw that holds the rack support in place. The support is the white plastic thing against the rack. Rotating the support out of the way allows you to move the rack around and get some clearance. Now put the pot back in place with the flange, the lockwasher and the 1/2 inch nut. The pinion gear can go back on with some help from a screwdriver. Turn the pot completely counter clockwise. Then put the pedal in it's fully forward position bringing the rack into the housing.




6. Put the rack support back in place, as shown in the photo below. Put the switch back into the top of the housing. Last thing to do is reassemble the bottom plate.




7. Time to WAH!!



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