Tone Pot Wiring
A tone control is made up of a capacitor and the potentiometer.
The capacitor sends certain high frequencies to ground causing the sound of the guitar played through the amp to sound warm and jazzy.
The range of frequency that is sent to ground is determined by the value of the capacitor. The potentiometer controls how much signal
passes through the capacitors. This means that the tone controls the depth of the effect.
Capacitors used in passive A.C. circuits such as guitar wirings (unless the guitar has a battery in which case it is active) work by only allowing certain parts of the frequency to pass through it (electrolytic capacitors are an exception and are mostly used to filter D.C. current in power supplies).
The great thing about capacitors is that capacitors in the range of .001 mfd (micro farad) to .1 mfd take out parts of the frequency that often yield a pleasant result. The .1mfd capacitor will sound very very muffled and the .001mfd will be hard to even notice. The most common values found in guitars are .022 mfd and .047 mfd capacitors. Here is a guitar mod of mine that lets you choose 6 different capacitors on one guitar.
The Potentiometer With The Capacitor
Below is a diagram of how a tone control is wired. The positive (hot) wire should be connected to the center lug of the volume pot. It could also be connected to the third lug of the volume pot. This is because both of those volume pot lugs are positive (refer to wired volume pot diagram above if confused). The ground wire from this tone pot should be wired to the metal shell of the volume pot. The result of this is that the potentiometer controls how much of the signal will be routed to the amps gain stages and how much will be routed to ground through the capacitor.
The diagram below is a nice way too visualize how a tone control directs the audio signal. The high frequencies are represented by the orange arrows heading through the pot and capacitor to the black ground wire. The rest of the audio signal still makes it to the amps gain stages.