MkI on tagboard with an additional Bias knob.

MkI with an additional Bias knob on tagboard (left) and veroboard (right).

A clone of the Sola Sound Tone Bender MkI which first came out in 1965 as the first of the company’s Tone Bender series. Developed by Gary Hurst, it’s a classic 3 transistor fuzz with a circuit based on Gibson’s Maestro Fuzz-tone. The original units used a mix of OC75 and 2G381 germanium transistors and produced a sound which was reminiscent of the Fuzz-tone’s with subsequent units becoming louder with more sustain as the pedal was developed. Famous users included Jeff Beck of the Yardbirds, Rubber Soul era Beatles and Mick Ronson circa Spiders From Mars. It can be quite a time consuming circuit to tweak and bias which is probably why there are not many mass produced clones on the market today. Even original units can sound slightly different to each other, due to each one having to be tuned individually.
Knobs are the standard Tone Bender Level and Attack (sustain) controls. They can be built on tagboard or veroboard, modified for extra output and fitted with an additional Bias knob/trimpot which allows the user to control the amount of gating in the sound. Transistors used are usually a mix of OC45/71/75 or AC125/128 and shielded cable is always used on the in/out signal paths. As it’s a positive ground circuit, I usually build them without a DC power jack, as it would require its own supply, but one can be fitted on request. A voltage converter can also be fitted on request (veroboard only) to allow daisy chaining of the supply with regular negative ground pedals.


Price: €110.00 (add €10 for tagboard build, €5 for voltage converter).

Comments are closed.