Why do I get a nasty hum when I use my wah pedal?”
Inductor based wah pedals are very sensitive to EMI (Electro-Magnetic Interference) due to the fact the inductor itself is senstive to EMI. Fans, compressors, computer monitors and wall warts are all things that can make your wah pedal hum. It can become really apparent when you are using a high gain distortion pedal. Unfortunately, the only thing that really eliminates it completely is more distance between the wah pedal and the source of EMI. This is because it is actually magnetically coupled. The only real solution is to get it as far away as possible from the offending source of noise. “An inductor with a low DC resistance sounds better.” An inductor with a lower DC does resistance result in a higher Q factor. In a wah pedal circuit, the DC resistance is of little consequence until it gets up to several hundred ohms. Then you might be able to hear some differences, but they would be subtle. In new manufacture wah pedals, the resistor that is in parallel with the inductor reduces t
