Goliath FX Vintage Components Silicon MKII Tone Bender

The Goliath FX Vintage Components Silicon MKII Tone Bender is a fuzz pedal built around the MKII Tone Bender circuit, using silicon transistors where the 1960s originals used germanium. Guitar Pedal X's Stefan Karlsson, reviewing it in March 2025, called it "Goliath FX's Silicon MKII Tone Bender take" on that circuit¹.

Controls and dialling it in

The pedal carries three knobs: Volume, Fuzz and Bias¹. Karlsson's review walks through a range of settings: he found a decent sound with everything at noon, a killer sound with everything at 3 o'clock, and what he called a totally next level result with the Fuzz at 3 o'clock and the Volume and Bias at 4 o'clock, with relatively mild compression at those dial-in settings¹.

He also describes his best combination of harmonics and sustain as coming with the Fuzz control locked at 3 o'clock, with settings above that not sounding as good to his ear¹.

The circuit it comes from

The MKII Tone Bender traces back to the Sola Sound design of the 1960s. The conventional "large board" MKII built between 1966 and 1968 used a mixture of germanium transistors and parts². One of the best-known versions of that pedal is the Vox Tone Bender Professional MKII, supplied by Sola Sound via Macari's Musical Exchange, with earlier examples of the later version carrying a triplet of Mullard OC75 transistors and slightly larger value input and output capacitors³. The shift from OC75 to OC81D transistors seen across these pedals also appears in MKIIs supplied to Marshall and Rotosound³.

The Goliath FX pedal swaps those germanium devices for silicon, which is what its name signals. Karlsson named it his favorite silicon Tone Bender variant in his March 2025 review¹.