What is distortion? You may have heard a lot of jargon surrounding distortion: like “gain” or “drive”. Technically speaking, distortion is a type of gain, and gain pedals can generally be categorised into 4 different types: Boost, Overdrive, Distortion and Fuzz. I will explain the differences and characteristics of each so that by the end of this guide, you’ll have a better understanding of which type of pedal to go for.
What causes Distortion?
To understand what type of pedal is right for you, it’s helpful to have some understanding of how distortion works. When you strum your guitar, the string vibrations are captured as waveforms by the pickups, which are sent to your amp. However, beyond a certain point, an amp can no longer get louder as the waveforms get bigger. Once the waves exceed this point (known as the “headroom” of the amp), the peaks of the waves begin to get squashed down, or “compress”.
It is this compression that causes distortion, and how these waveforms are compressed will influence how your sound distorts. However, to get your clean signal to distort naturally from the amp may require you to turn the volume up far beyond a reasonable level. Distortion pedals can simulate this distortion at far more reasonable levels by using amplification and “clipping” circuits.
What is Clipping?
Within gain pedals, the circuits will clip the waveform as an amp would past its headroom. There are essentially 2 types of clipping: “soft-clipping” and “hard-clipping”. This refers to how the peaks of the waveform are compressed, with affects how the distortion sounds. Soft-clipping will squash the peaks just as a cranked valve amp would, whilst hard-clipping will simply cut off the signal as it exceeds the headroom, which produces a more aggressive, edgier sound.
Generally speaking, overdrive pedals use soft-clipping to get an “amp-like” distortion that is dynamic and responsive; it will generally distort more the harder you strike the strings, and get cleaner the softer you pick. Whereas distortion pedals mostly use hard-clipping to achieve a gnarlier sound. Fuzz pedals amplify and clip the signal to such extremes that the waveform becomes a “square-wave”, which can sound fuzzy and woolly, or spitty and nasty (but in a cool way), and can get wild and uncontrollable – it’s a very fun effect to try and tame!
Unlike the other types of pedals on this list, boost pedals don’t contain any clipping. As the name suggests, it simply boosts the volume of your guitar going into your amplifier. But the way it interacts with valve amps or other types of gain pedals is interesting. Using a boost pedal into a valve amp can provide enough volume boost to exceed the headroom of the valves, causing them to overdrive, creating those sweet, crunchy classic rock tones. Into a solid state amp, it will simply boost the volume without adding any appreciable amount of gain; this can be useful for a solo boost if you just need that extra volume to cut through the band mix.
But boost pedals can also be used in combination with other types of gain pedals to produce different gain levels – this is known as gain stacking, and is a great way to add more variation to your sound! Adding a boost pedal before another gain pedal such as an overdrive or distortion, will produce more gain without much more volume, while putting it after another gain pedal will produce more volume without much increase in gain. So try out both and see what you like!