In this tutorial, I'll demonstrate the process of designing and constructing an electric guitar with a fuzz pedal.

The instrument will feature six strings and a custom-made pickup. It will be connected in series with the pedal, which will be assembled using analog electronic components. The signal will then be routed through a 6.3mm jack output

Supplies

For electric guitar building:

2 wooden boards 1,4x10x100 cm
.010'' string pack [Ernie Ball 2221]
Bridge (Hardtail in this case)
6 guitar pegs (recommendation: locking tuners)
20 guitar frets
Nut for electric guitar
6 magnets ø 10 mm
Copper wire ø 0,065 mm

For fuzz pedal building:

Perforated PCB board
2 BC109 transistor
10 nF ceramic capacitor
22 uF electrolytic capacitor
2.2 uF electrolytic capacitor
100 kΩ resistor
33 kΩ resistor
8.2 kΩ resistor
330 Ω resistor
470 kΩ potentiometer
4.7 kΩ potentiometer
6.3mm mono female jack connector (I used a stereo)
9-volts battery

Step 1: Electric Guitar Design

After considering several prototypes, I opted for the last one. It is the most affordable and straightforward to execute. However, it necessitates a durable base to withstand the tension of the tuned strings. As a remedy, I elected to place a double board, being cautious not to exceed 1.4 centimeters in thickness for the headstock.

The strings have been tuned to the equal temperament system. The interval between frets is a semitone. The semitone interval is the twelfth root of two in this system.

The strings are tuned to E2, A2, D3, G3, B3, and E4.

I employed this diagram to position each fret. This fret placement diagram will assist us in calculating the phase speed of each string (c), the distance between each fret and bridge (L), and the tension of each string (T)

To calculate the phase velocity, I utilized the third formula. For this equation, you'll need the distance between the first and second frets (L1 - L2) and the fundamental frequency (first mode) of the note (f1). Once the velocity is calculated, you'll use it to calculate between each fret and bridge. To do this, I employed the first formula.

Note: Both the first and second equations can be used interchangeably, provided that you are selective about the frequency you employ.

To calculate the tension of each string (T), the previously determined phase velocity of each string (c), the density of the material (µ), and the radius of each string (r) are required. The radius can be obtained from the diameter or gauge of the string.

All the findings of these computations are documented in this spreadsheet.

An electrodynamic pickup is a transducer that converts the vibrations of a string into an electrical signal. It consists of permanent magnets and a coil of copper wire wrapped around them. The theoretical explanation for this phenomenon is that the copper coil is positioned perpendicular to an electromagnetic field. The vibration of the string causes the field to fluctuate, and this movement induces an electrical current in the copper coil. The amount of signal generated is determined by the number of turns of the coil around the magnets.

Step 2: Electric Guitar Build

I created boreholes of 8 mm in the wood to accommodate the pegs.

Additionally, I made some apertures of 2 mm in the bridge region to accommodate the strings.

Notice: It is preferable to make the holes smaller. I had to glue the end of the strings to the board to prevent them from going through the holes when tuning.

To assemble the pickup, I secured the bottom of the magnets to the wooden surface and the top to a plastic base. Subsequently, I wound the copper wire around the magnets.

Both the nut and the frets were affixed to the wood.

Note: To secure the strings to the pegs, I utilized screws. To further secure the rope, anchor it to the peg and at an intermediate point.

Step 3: Fuzz Pedal Design

For the pedal design, I have taken this image as a reference.

There is another model of fuzz pedal that replaces the NPN silicon transistors with germanium ones. The sound they produce is different. Germanium transistors have an internal parasitic capacitance that acts as a "high-pass filter". While the model with silicon transistors produces a sharper sound, the germanium transistor model has a cleaner and more musically pleasing sound.

Note: The input signal is the electrical signal generated by the coil of the pickup.

Step 4: Fuzz Pedal Build

As a DC power source, I have employed a 9-volt battery. To incorporate it into the circuit, I have utilized a compatible battery holder.

As an output, I have incorporated a 6.3mm female jack connector. Since I was working with a mono jack connector, I soldered the ground wire to the connector's ground terminal and the input wire to the connector's tip terminal.

All of these components have been soldered to the perforated printed circuit board (PCB).

Note: The coil is connected to the input of the circuit by a conductive wire. Two terminals exit the coil, one for the signal and the other for the ground.

Notice: Be cautious while soldering. Maintain sufficient separation between components.