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diy guitar pedal glossary

As a beginner or even intermediate guitar pedal builder, you might come across a few terms or component names that you aren’t sure of. This can prove frustrating to first time builders as they must then google the term and try to figure out what they’re working with.

This post is going to help solve that issue by providing pedal builders with a one-stop glossary page which defines and describes important terminology and components used in guitar pedal building. This glossary is by no means all-inclusive but will be updated periodically to include more terms/components.

Pedal Components

PCB

PCB stands for printed circuit board and is the piece of your pedal kit that connects all of the components together. A PCB uses conductive tracks and pads to allow electrical current to flow from one component to another. PCBs are generally based off of schematics which outline how each electrical component should connect before actually creating the PCB.

pcb

The printed portion of a PCB is actually what is commonly referred to as a silk screen. Without the silk screen, a printed circuit board would simply be called a circuit board.

Diode

Diodes are polarized components that only allow electrical current to flow in one direction. There are many different types of diodes used for a variety of purposes such as light-emitting diodes (LEDs), signal diodes, zener diodes, etc.

The schematic symbol for a diode sort of resembles a funnel shape with a line on the other end. If a signal tries to pass through the diode in the direction where the funnel is large then gets smaller, the signal won’t pass through. But if the signal tries to pass through the direction where the funnel is small then gets larger it will work as expected. Here’s a great video which helps further explain how diodes work.

Diodes are often used in fuzz/overdrive/distortion pedals to clip (or cut off) certain waves of an audio signal to create the well-known distortion effect. Remember to reference the silk screen on your PCB to identify which direction your diode should be placed. Diodes will have a single band around one end to denote the negative (-) cathode.

diode

Transistor

The basic functions of a transistor are to amplify and switch electrical signals. There are a variety of different types of transistors that can be used when building pedals and based on which type of transistor you use as well as what kind of material it is made with will produce a different sound.

transistor

Placement is also an important factor for transistors when soldering them to your PCB. With any of our Guitar Pedal Kits, you can simply reference the silk screen of the PCB and place the flat side of the transistor in line with the flat side on the PCB and the curved side of the transistor in line with the curved side on the PCB.

Resistor

Resistors are used to limit the flow of electrons through a circuit. Without resistors, certain electrical components within your PCB would simply be fried as soon as a battery or power supply was connected to them. Resistors help control the electrical current coming through the circuit board by applying resistance.

resistor

In pedal building, 1/4W metal film resistors are typically used. These resemble the resistors shown above, usually blue in color and with varying colored bands around them to indicate how much resistance the resistor provides (more on this in another post).

Integrated Circuit

Integrated circuits, or ICs, are tiny circuits made up of their own mini diodes, resistors, transistors, etc. They’re used to perform a variety of functions such as oscillation, amplification, etc. Integrated circuits have a small circular cutout in one corner to identify which pin is #1. This is important when placing the IC into the PCB itself.

It’s important to note that integrated circuits aren’t very forgiving when it comes to heat. If you’re soldering the IC to the PCB and keep heat applied to the IC for too long you could risk frying the component. That’s why you’ll often times see IC sockets being used to minimize the amount of heat transfer that the IC must incur. Simply place the IC into the socket, the socket into the PCB and solder the socket to the PCB.

ic and socket

Trimpot

A trimpot, also known as a trimmer, is used to make adjustments and fine-tune the circuit as required. Internally, trimpots work in the same way as a potentiometer however as opposed to making adjustments manually, trimpots increase or decrease resistance automatically.

trimpot

Trimpots come in a variety of styles however cermet trimpots (as shown above) are the most common type used for pedal building.

Capacitor

There are usually a variety of different types of capacitors used in any given guitar pedal kit. They all basically do the same thing the only difference being their level of electrical capacitance – the amount of electrical charge they are able to store. There are three basic types of capacitors used in guitar pedals – ceramic, electrolytic, and film capacitors.

capacitors

Coda Effects has a great post about capacitors and has included the handy guide below to show the value ranges between each popular capacitor type in guitar pedal building.

capacitor values

Potentiometer

Potentiometers, or pots for short, are used to change the resistance between the lugs or pins of the pot. All pots come with 3 lugs or pins which you should take note of when building your DIY pedal. Be sure to follow the instruction guide for your pedal and properly wire the corresponding pins to the proper pads on the PCB.

Like many other components, potentiometers come in different shapes and sizes. The potentiometers used on our pedal kits are called 9mm round shaft pots and have pins to connect wires from the pot to the PCB.

potentiometer

It’s also important to note the resistance values of each pot which should be labeled on the underside as something like:

  • B50K,
  • B100K,
  • B500K, etc.

Again, reference your instruction guide to ensure you use the proper pot for each pedal’s setting.

Footswitch

A footswitch on a guitar pedal is typically used to change the pedal from bypass to active mode. We use 3PDT, or 3 pole double throw, footswitches for our pedals, therefore, resulting in all pedals being true bypass.

footswitch

Each lug of a 3PDT footswitch serves its own purpose. Whether it be connecting to the input jack, the ground, the LED, etc each lug is important. In certain DIY pedals, you’ll need to solder a wire to each lug of the 3PDT footswitch and then solder it accordingly either to certain pads on the PCB or other hardware. However, with our kits, the 3PDT footswitch is soldered directly into the PCB and all connections are made once the footswitch is properly placed. This makes it easy for the pedal builder and minimizes error.

General Terminology

Silk Screen

A silk screen is the white printed instructions on the top of the PCB that denote where each electrical component should be placed within the PCB. Silk screens include information such as the component’s number, polarization, direction, and more. Be sure to carefully reference the silk screen of your PCB as well as follow the instructions provided for your DIY guitar pedal kit before soldering a component to the PCB. This will greatly help reduce the number of mistakes made and will overall cause you fewer headaches.

Ground

There are typically various pads on a PCB which denote a ground. In a guitar pedal, all grounds should ultimately be connected together in order to minimize any unwanted noise which can come from the circuit. Grounds help reduce the build up of static electricity which is usually the cause of any humming of hissing noises. Be sure that you follow the instructions in your DIY guitar pedal’s build guide and properly ground all components to avoid creating unwanted noise.

Schematics

Schematics are essentially the blueprint of an electrical circuit. Before a PCB is made, schematics are drawn up to outline which components should go where and how they will all connect. There are a variety of tools available to draw up schematics, one of which is 123circuits.

In a later post, we’ll outline how to read a guitar pedal’s schematic as well as what each symbol means within a schematic.

Polarity

Polarity refers to whether or not an electrical component has a negative and a positive terminal. Components such as electrolytic capacitors, LEDs, and other diodes are known to be polarized components as it is required to insert them in the proper direction within the PCB. Other components such as resistors aren’t polarized and can be soldered to the PCB in either direction.

2 Comments

  • jonathanjfann7 months ago

    Great idea and solid foundation. Might be worth noting transistors can also fry like ICs so best practice is to socket them as well. This also lets you try out different transistors to find “the one” without having to desolder it from the board.

    Also, might be helpful to note what the A/B/C’s in pots designate (linear, audio taper, reverse log).

    Also, trim pots are actually interchangeable with “actual” pots circuit-wise. Sometimes it’s handy to wire a pot in its place so you don’t have to open up the enclosure to adjust whatever it’s controlling.

    reply

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