Normally the bottom right or number one lug on the potentiometer is grounded to the case of the pot. The center is the # 2 lug and the bottom left lug is # 3. Connecting a .001mfd., 25 volt capacitor between the #2 & #3 lug will allow a smoother taper when the volume is turned up, and it helps retain the brightness in a pickup as the volume is turned down. By adding various value resistors can also change the value of the potentiometer. It is common for many companies to use a 150 Ohm, 1/4 watt resister to make the potentiometer more compatible to the output of a pickup