How do guitar pedals work?
After picking up a guitar and tweaking your amps settings to get that tone you’ve been searching for, the next logical step is to think about where else you can take your sound. This is where guitar pedals can step in and take your guitar sounds to places not possible with most on board amp controls. Guitar pedals work by taking the signal produced by a guitar and modifying it before passing it on through the chain, whether that be on to more pedals or to an amplifier.
The signal can be manipulated via analog or digital means. With analog pedals, different sounds are produced by passing a guitars electrical signal through transistors, resistors, capacitors, diodes and more, depending on the sound the pedal is trying to produce. Digital pedals on the other hand work by taking your guitars electrical signal, sampling and converting it into binary code which is altered with by an effects algorithm before being converted back to an electrical signal and sent on.
Guitar pedals will typically have at least one input and output, a power source and an on/off switch. From there, the number of knobs to control the aspects of the pedal can vary greatly. Guitar pedals are designed to be placed on the floor to be controlled by a guitarist’s feet, and normally receive their inputs from the right, sending the output out from the left. Although running pedals from right to left may seem confusing, the reasoning for this is simple. Most players (up to 90% according to Fender) play right-handed guitars, meaning that from a playing position the guitar cable will leave the guitar from the right. Having a guitar pedals input also on the right means that the cable won’t run in between the player and their foot pedal.
There is an enormous amount of different foot pedals available on the market that add a huge variance in the sound your guitar can produce. With that can come confusion, so let’s take a look at the main categories of pedal and how they effect the sound of your guitar.
This group contains pedals that don’t add effects at all, such as tuning pedals, switcher pedals or expression pedals. Tuning pedals are used to help you tune your guitar, a must for every musician. Switcher pedals are used if you’ve got multiple signal paths that you’d like to send your guitar signal to, jumping between each. Expression pedals can be used to control the effect of another pedal with your foot, without the need to get down on your hands and knees to adjust knobs.
These pedals offer further control which generally effects the processing of a guitar’s volume. Pedals in this category include compressors, limiters and noise gates. The technicalities of what each of these do can get quite complex, so it is worth researching each of these to fully understand how they effect your guitar’s signal.
On many amplifiers you’ll see knobs that control ‘bass, ‘middle’ and ‘treble’. Each of these knobs targets a frequency range across the audio spectrum, allowing you to adjust each to your liking. Different amp manufacturers will tailor these differently, meaning that each will target different frequencies within that range. Equalisation pedals take these basic controls to a more granular level, in some cases allowing you to tune specific frequencies to your liking, allowing you to mould your guitar tone. Envelope filters and wah pedals also fit within this category and, like the pedals in the dynamic section, are somewhat complex to explain but essentially make specific adjustments with EQ to create unique sounds.
There are 4 main effects styles that fit into this category that, in the following order, essentially perform the same function but to greater effect. These are boost, overdrive, distortion and fuzz. Each of these pedals work by increasing the volume of your guitars signal, while ‘clipping’ it to create a more distorted tone.
Modulation foot pedals are those which control a variation of the signal over time with slight adjustments that alter the resulting tone. Effects that fit into this category include chorus, vibrato, tremolo, phaser and flanger. Some of these have similar properties on first listen, but closer inspection reveals unique differences.
Finally, time-based pedals are those which take the guitar signal and multiply it over time. Effects in this category include reverb, delay and loop pedals.
Although these categories contain most effects you’ll find available in guitar foot pedals, it is certainly not exhaustive. There are a number of different effects available that do not fall easily into the above and help to create an even broader scope of sounds available.