control increases signal saturation, leading to harmonic distortion. Electrical Engineering Stack Exchange 2. The Tone Stack (Equalization)

The first stop for your guitar signal is the preamp.

Guitar amplifiers are sophisticated electronic devices designed to take the faint electrical signal from a guitar pickup and transform it into a powerful sound wave capable of filling a room. Whether you are a musician or a hobbyist, understanding the fundamental electronics behind these "tone machines" is the first step toward mastering your sound. The Three Pillars of a Guitar Amplifier