Work in Progress: "Fuzz Face" Effects Pedal Construction

A metal enclosure and various electrical components.

Many electrical components will be used in constructing this guitar effects pedal, as well as one metal enclosure and two gold knobs.

Isaac Levine and I have immersed ourselves in the troubling yet rewarding world of guitar effects pedal construction. What began as a short project designed to bolster our knowledge of circuitry in musical instruments has now turned into a lengthy trek to explore the instructional resources of the internet, the inventory of the North Campus WorkBench, and the variability of the electrical components required for guitar effects pedal construction.

This project was founded upon the intersection of personal interest, intrigue for further education in a given subject, and the capabilities of the Design Lab’s resources. Both local musicians and guitar players, Isaac and I discovered a shared interest in the DIY fabrication of guitar effects pedals, understanding the burdening costs of expanding one’s personal pedalboard. Additionally, I felt the urge to expand my experience with soldering, schematics, and other spheres of electrical fabrication, which paired well with Isaac’s electrical engineering knowledge gained from his time in the undergraduate Performing Arts Technology program here at the University of Michigan.

We began by locating sufficient online resources that could guide us through the process of DIY guitar pedal effect construction, since we were both beginners in this field. First, we came upon DIYstompboxes.com, which provided a welcoming array of different pedal schematics to choose from. We landed on the decision to build the Fuzz Face—a guitar effects pedal made famous by legendary musician Jimi Hendrix—which produces a muddy fuzz tone that immediately invokes the famous sound of Hendrix’s guitar playing. As beginners in DIY guitar effect pedal construction, we chose this pedal because it appeared to be the most doable based on the simplicity of the schematic, and the amount of electrical components we had available in the WorkBench. The website provided the schematic, as well as a brief description about how transistors made of different materials can influence the outputted sound of the pedal.

The construction of a guitar effect pedal requires a series of various resistors, transistors, capacitors, LEDs, and potentiometers. Other components include input/output sockets, knobs, a power jack, battery clip, foot switch, and the enclosure that houses all of the electrical components. The electrical components of a given guitar effect pedal determine how the sound is outputted after the input signal is processed from the guitar, and the materials of the transistors and capacitors are especially important to the texture of the sound—they can influence the formation of the entire schematic based on which material is used. For example, with the Fuzz Face pedal, we learned from the schematic description that germanium transistors were used in the original Fuzz Face pedal, but that silicon transistors (specifically, 2N3906 silicon transistors) had proven to recreate the sound in previously completed projects. Germanium transistors produce the consistent, muddy fuzz tone that the pedal is known for, and the silicon transistors tend to be less consistent, oftentimes producing a sound that is less full and occasionally clips the signal (that is, if they were not 2N3906 transistors). However, the schematic provided was based on the use of 2N3906 silicon transistors, so we chose to go with those.

We began to compile a list of electronic materials and structural components to purchase from Tayda Electronics. The structural components add a layer of creativity to guitar effect pedal construction process, allowing the builder to choose from different styles and colors of knobs, and dress up the enclosure with any colors or images that may suit the sound effect of the pedal. We chose a white enclosure because it would be easy to paint over, and a collection of gold, silver, and purple knobs to honor the regal and psychedelic style of Hendrix.

After using the electrical components made available in the WorkBench and the Design Labs, and ordering items that were not available from Tayda Electronics, this project cost us only about $15 per pedal, including shipping. However, after our first couple days of building the pedal on a breadboard (to avoid needless soldering mistakes on a perfboard, where the circuit would eventually be transferred to the enclosure)—during which we had built a circuit that we believed to be complete and correct—we realized that some of the components we had ordered (the output socket, one of our potentiometers, and our switch) were impeding us from producing the fuzz tone that we were looking for. So, we sought out a new online source to help us figure out why we were not producing the tone we expected, and found General Guitar Gadgets.

In contrast to the website we had been using, here we found DIY pedal project descriptions that included not only schematics, but extensive and specific lists of materials to order, as well as a wiring diagram for each pedal. Luckily, they had the Fuzz Face pedal project available, and we began to discover that some of the electrical components we were using would not give us the tone we were looking for. So, we made a second order through Tayda Electronics, adding on $7 to the cost of each pedal, and now feel that we have the necessary components to get the right fuzz tone. Additionally, the wiring diagram on the website will be a huge help when transferring the electrical components from our breadboard onto a perfboard, once we have completed our circuit.

The next steps will be completing the circuit on our breadboard with our new components, and then eventually soldering our components onto a perfboard to be housed in our enclosure, which will require the drilling of holes into it to give access to two potentiometers, the input and output sockets, the LED, the footswitch, and the power jack. More to come...