tone stack

A tone stack is the tone-shaping section of an amp or pedal circuit that filters the signal, often with controls for treble, bass, or midrange¹². In amp-in-a-box and overdrive designs, builders may include the filtering of an amp's tone stack to reproduce the amp's voicing¹³. Tone stacks vary in design and character: sources describe two-band versions for treble and bass⁴², a Baxandall type⁵, a Dumble-refined stack that yields tighter bass and more prominent mids in a Fender-style circuit⁶⁷, and British-style examples with more upper mids or a "burning-hot" midrange⁸⁹¹⁰. In fuzzes, the tone stack shapes the EQ response, affecting how scooped, bassy, or usable the controls are across the knob's range^11121314.