The Tone Knob (ton nɒb) on a guitar is a built-in equalizer that controls the high and low frequencies produced by the guitar’s pick-ups. Tone knobs are located next to the volume knob on the front of a guitar. The tone knob consists of a potentiometer and capacitor that combined to change the frequency of the sound produced. Guitars can have as few as one tone knob to as many as four. The higher the tone knob is set, the higher the sound frequency the guitar will produce. When the tone knob is turned all the way up, the guitar will produce a flimsy, thin or tinny sound.