The second version of the Electro-Harmonix Big Muff Pi is commonly called the "Ram's Head" version. Featuring a different circuit design from the first "Triangle" version, the "Ram's Head" offers the traditional Big Muff Pi knobs for Volume, Tone, and Sustain. In order of production, the "Ram's Head" design can be further subdivided into "47", "73", and "Violet" models.