The Zeta Distortion/Sustainer is a pedal that is based on the Colorsound Jumbo Tone Bender and Supa Tone Bender, which were silicon successors to the classic Macaris germanium fuzz pedals from the late 1960s. The Zeta is actually a completely different circuit adapted from the Electro-Harmonix Big Muff Pi, despite sharing a name with the earlier germanium Tone Benders.

The main differences between the Zeta and the earlier Tone Benders are that the Zeta has had the clipping diodes removed from the second stage and the post-tone gain recovery stage has been dropped entirely. The Zeta circuit was sold by Colorsound under various names such as Tone Bender Mk. IV, Supa Tone Bender, Jumbo Tone Bender, and Fuzz Unit (produced for Barnes & Mullins). The last of these pedals were produced in late 1980.

In the 1990s, Colorsound also created a vintage-inspired semi-reissue called the Bass Fuzz. Although they never had a vintage product called the Bass Fuzz, it is essentially the same circuit as the 1970s pedals, but with all the capacitor values doubled.

The default parts list for the Zeta is based on a 1976 Jumbo Tone Bender, but component values are provided for each of the other variants. The PCB allows for building any of these variants, and there is a switch that can be used to increase the gain of the first stage and change the frequency of the tone control. More information on this can be found in the build documentation.

Summary created by AI from the original source.