We’re all pretty much aware of how guitar made a huge impact on modern music, drastically changing the standards in the industry by invading countless genres over the decades. But the most noticeable change – and arguably the most famous one – came with the development of guitar distortion. There were many ways to achieve this, from pushing tube amps to their limits, using faulty preamps, to slashing and poking speaker cones to achieve this effect. It took some time for the big companies to begin producing compact distortion and fuzz pedals, with the first one being Maestro FZ-1 Fuzz-Tone. But these effects that we all love and adore all sound different and they’re categorized into boost, overdrive, distortion, and fuzz. While you heard the differences, maybe you wondered what made these effects so distinctive. Well, in this article, we will be diving into this topic and explaining the difference between boost, overdrive, distortion, and fuzz.

But first…

Before we get into any of these, we need to understand the meaning of terms like “clipping” and “headroom” and “distortion”. The clean guitar tone can be represented as one continuous sine curve.

When we amplify the signal in any way, we’re making the wave bigger, or its peak to peak amplitude. However, while you’re pushing more into the signal, you’ll be reaching the threshold of your guitar amp or any other device that you’re playing through. This threshold clips your signal, making it fit into the limits of what you’re playing through. Whenever the waves reach this limit, they get cut off or clipped, thus the word “clipping”.

The room between the signal’s peak and the amp’s threshold is referred to as the “headroom”.

There are some different types of clipping. So-called “soft clipping” clips the signal gently, with waves still looking smooth. On the other hand, we have the “hard clipping” that trims of the excess signal radically, giving it rough edges.

Boost

The purpose of a simple boost device is to push your signal without doing any clipping itself. These are often referred to as “clean boosters”. Back in the early years of hard rock music, the ’60s and the ’70s, there were some treble boosters that helped push the signal and add additional high end into one player’s tone.

As mentioned, these boosters, whether they’re treble or full-range, do no clipping on their own but just push more power into the signal and enlarge the peak to peak amplitude.

HOWEVER, the amp that you’re playing through has its threshold and by boosting the signal before the amp you’ll be hitting the amp’s limits. This way, you can achieve the “organic” distortion on a tube amp and that’s something that many guitar players have been doing over the years.

In short, the boost pedal sets no threshold but relies on hitting the threshold of the amp, achieving that “natural” distortion that’s desired by many guitarists out there.

Boost pedal examples:

Overdrive

We’ve all heard the difference between the overdrive and distortion, and there are even some pedals like the Boss OS-2 that let you choose and blend between the two. The softer sounding overdrive is achieved by (as you probably guessed it) soft clipping.

The overdrive does this soft clipping on its own, setting the threshold in the pedal itself. At the same time, they do this without hard hard clipping. The softer-cut waves, that we mentioned above, will do less tone shaping to your guitar’s natural tone.

But just like with boost pedals, overdrive will push the signal that will hit the threshold of your amp, ultimately letting it do some additional harder clipping on its own and trimming some of the wave’s ends. The resulting tone is softer, slightly crunchy, and is dynamically responsive. By playing harder, you bring in more power to the signal, thus allowing your amp to do additional tone shaping in those fortissimo parts.

In order to achieve this soft clipping, overdrive pedals do this in a 2-step process. First, the guitar signal is boosted using the integrated circuit operational amplifiers. Then, in the second part of the process, the diodes in the pedal do the soft clipping while adding just a little bit of that harmonic content.

The clipping is done with two diodes – one affecting the top and the other one the bottom of the wave. Most of the overdrive pedals have two of the same type of diodes, while, in some cases, pedals might have two different diodes that create what is known as “asymmetrical clipping”.

Famous overdrive pedals:

Distortion

Now we’re getting into the territory of some really heavy and – dare we say it – “fried” tones. However, it is important to do this the right way and end up with a great sounding distortion and not just a muddy mess.

As you might assume by now, in contrast to overdrive, distortion features hard clipping. The waveform is cut sharply and abruptly at the threshold. In addition, the distortion adds more gain, yet it manages to remain more or less articulate.

The result is the tone we’ve heard so many times, mostly in hard rock and heavy metal music. You can find various distortion pedals out there, some even specialized for metal music and its subgenres.

However, hard clipping the signal, the distortion also does compression, thus making the effect less dynamically responsive. The waveform of a distorted signal resembles the one you’ll see in compression and limiting effects. In addition to this, distortion is way more saturated than overdrive, making it difficult to play more than two notes at the same time without sounding muddy.

Distortion pedal examples:

Fuzz

Dating back to the earliest days of rock ‘n’ roll music, fuzz got its name due to the obviously “fuzzy” overtones. The earliest examples of the fuzz effect were thanks to some happy accidents from back in the day. One of the early famous examples comes from the early 1960s when guitarist named Grady Martin recorded on a song “Don’t Worry” by Marty Robins using a faulty preamp. Later on, he recorded his own music using this same exact preamp.

The first commercially produced dirt box was the Maestro FZ-1 Fuzz-Tone which became popular after Keith Richards used it on “(I Can’t Get No) Satisfaction.”

But what makes this fuzzy tone so special is that it takes hard clipping to a whole new level. The fuzz pedals achieve this by implementing transistors without op-amps (operational amplifiers) which are lo-fi.

The result? The signal is turned into a square wave and has a whole different mash of harmonic content. Playing through a fuzz pedal sounds as if you’re playing through a faulty amplifier, giving that extremely oversaturated, sharp, and distorted tone.

They’re usually used for lead sections or single note riffs that don’t include any kind of chords. They’re not as big and popular as overdrive or distortion pedals, but they have their own following among blues and stoner rock players.

One of the best-known users of a fuzz pedal was Jimi Hendrix with his famous Dallas Arbiter Fuzz Face. The pedal originally featured germanium transistors in the first few years of its production. These are still produced by Dunlop, although they feature brighter sounding silicone transistors.

While germanium transistors have been praised for their better and warmer tone, they tend to heat up and make the tone less consistent over time. Silicone transistors tend to pronounce the higher end spectrum a bit but are significantly more stable.

Fuzz pedal examples: