Wiring Of Volume Pedal Potentiometers

Dennis Manuel · From: Quesnel, B.C., Canada

Apparently there is more than one way to wire potentiometers. I currently use the method suggested with the Clarostat potentiometers that are packaged by Geoge L. Does anybody else use an alternative method? Also, there is coax wire running from the guitar to the pedal, from the pedal to the amp. and normal wire soldered to the potentiometer inside the pedal.
Could this be some of the problem associated with hum and possible loss of signal?

------------------

[This message was edited by Dennis Manuel on 18 February 2000 at 07:04 AM.]

Michael Maese · From: Fayetteville, AR

Dennis,
The wiring scheme furnished with the George-L pots is correct for an audio-taper pot. The resistance element in the pot has more of its resistance concentrated at one end than at the other. This means that if you set the pot at mid-rotation and measure resistance between the center terminal and each of the outer terminals, one of the readings will be larger. Normally, switching the outer terminal wires causes the pot to change its sense of rotation. With an audio-taper pot, reversing the wires also causes the pedal to make the signal loud a lot quicker than in the properly wired pedal.
Many volume pedals are shielded just by the way they are constructed, and others are fairly open with the wiring exposed to view. The hum problem is usually due to magnetic induction, and coax or unbalanced shielded cable will not protect you from that. The shield will minimize electrical interference (RF, switching, lightning, etc), but only a balanced cable (two center conductors with shield like mic cable with XLR connectors) used with common-mode rejection circuitry can make magnetically induced hum go away. Minimizing hum with unbalanced cables is a challenge. It helps to keep the cable runs short, and avoid running near other cables (especially power cables) and wall-warts and transformers used with a lot of electronic equipment.
Also a long cable run will attenuate the signal by some amount per unit length. If the cable is picking up hum and attenuating signal, a long enough cable can deliver a weak signal with a large hum - definitely a problem at the amplifier. Hope this helps.

Forum Index > Electronics		Next oldest topic :: Next newest topic

All times are GMT - 8 Hours	Jump to: