The fuzz Mechanic Logo

Owner’s Guide

This isn’t just another fuzz box — it’s your personal fuzz workshop. Pop the hood, swap some transistor, and get your hands greasy with tone.

Changing Transistors

What you’ll need: A small screwdriver, steady hands, and curiosity.

Steps:

  1. Unplug everything. Safety first, even for cats.

  2. Remove the back plate with a 3mm hex key.

  3. Locate the two socketed transistors labeledQ1 and Q2.

  4. Gently press the orange clips to release and remove the originals.

  5. Insert new NPN silicon or germanium transistors — double-check their pin layout (C-B-E).

  6. Power up and fine-tune the internal Bias Trim VR1 with a small screwdriver until it purrs just right. Note: VR1 adjustfirst transistor’s voltage while bias knob adjust second transistor’s voltage.

Fuzz Mechanic - Fuzz Transistor diagram

Changing Transistors

What you’ll need: A small screwdriver, steady hands, and curiosity.

Steps:

  1. Unplug everything. Safety first, even for cats.

  2. Remove the back plate with a 3mm hex key.

  3. Locate the two socketed transistors labeledQ1 and Q2.

  4. Gently press the orange clips to release and remove the originals.

  5. Insert new NPN silicon transistors — double-check their pin layout (C-B-E).

  6. Power up and fine-tune the internal Bias Trim VR1 with a small screwdriver until it purrs just right. Note: VR1 adjustfirst transistor’s voltage while bias knob adjust second transistor’s voltage.

Fuzz Mechanic - Fuzz Transistor diagram
Fuzz Mechanic Logo
Yellow caution sign with black border and exclamation mark in the center.

Diagram shows NPN transistor pin configuration

Only for NPN transistors only - always check polarity before powering up.

available Fuzz transistors and tone character

Tonal variation

Q1 Q2 Resulting Character
BC108 BC108 Balanced, punchy
BC109 BC109 Vintage grit
2n5088 2n5088 Modern sustain
BC108 2n5088 Modern vintage
BC108 2n1306 Soft, creamy midrange Ge only in Q2
2n5088 2n1306 Modern sustain with creamy Ge midrange

available transistors and tone character

  • BC108 - Classic Silicon fuzz tone – balanced, punchy, and familiar.

  • BC109 - Vintage Silicon grit – sharp, edgy, and biting.

  • 2N5088 - Modern Silicon – higher gain, rich, and sustaining.

  • 2n1306 - Vintage Germanium – soft, vintage clipping; creamy midrange.

Configuration Possibilities

Q1 + Q2 silicon: Mix & match BC108 / BC109 / 2N5088

Examples:

  • BC108 + BC108 = Classic fuzz

  • BC109 + 2N5088 = Vintage grit with modern sustain

hybrid mode (Germanium + Silicon)

Creates a silicon + germanium feel: soft, warm midrange with smooth clipping

Examples:

  • BC108 (Q1) + 2N1306 (Q2) = Classic fuzz with vintage warmth

  • 2N5088 (Q1) + 2N1306 (Q2) = Modern sustain with creamy Ge midrange

Note: 2N1306 (Ge) can only be used as Q2 (second stage).

Yellow warning triangle with a black exclamation mark in the center.

Config notes

Hybrid mode: 2n1306 Germanium is optimal when use in Q2 output stage.

Two germanium transistors are not possible in this circuit design. Germanium’s low gain and leakage make biasing unstable if used in both stages, resulting in low output and unpredictable tone.

Bias VR: When using Ge to reach sweet collector voltage half supply.

Q1 Selection: Determines input gain and attack.

Q2 Selection: Determines fuzz texture, midrange, and clipping character.

Sound Suggestions

Fuzz Clean-up mode
Fuzz - Distortion mode

Clean-up mode

Roll your guitar volume down for a crisp, glassy edge — think vintage Fuzz Face dynamics.

Distortion mode

Bias it hotter for a thick, sustaining fuzz that roars with midrange growl

Fuzz - Synth mode

Synth mode

Starve the bias for gated, 8-bit glitchy chaos — perfect for experimental tones.

A yellow guitar effects pedal labeled 'The Fuzz Mechanic' with blue knobs labeled 'Fuzz' and 'Bias', a volume knob, and a graphic of a black cat in a blue hoodie. Also included are small tools and a carrying case.
A yellow electric guitar effects pedal with blue knobs, a silver switch, and a cartoon sticker of a character in blue holding a fishing rod, with the text Fuzz Mechanic on it.
A metal box labeled "Mechanic's Stash" with small tools inside, placed on a black notebook with an L-shaped hex key in front, on a yellow and beige striped fabric surface.
Close-up of an electronic circuit board with various components, including a blue resistor, a yellow capacitor, and a sticker that reads 'TUNED BY TONECAT' with a cartoon cat character.
A yellow guitar effects pedal labeled 'The Fuzz Mechanic' with control knobs, a footswitch, and a sticker of a black cartoon character on the side.
A small metal box labeled 'Mechanic's Stack' with blue lock clips, an open metal container holding electronic components with black foam padding, a small blue-handled screwdriver, and a black cloth on a yellow and white checkered tablecloth.