What's the difference between overdrive, distortion and fuzz pedals?
According to 
Alan Ratcliffe, all three are technically the same thing — distortion, i.e. clipping off the top of the waveform — but guitarists subdivide them by their sonic character 1,2.
Overdrive — the smoothest of the family. It mimics the way a valve amp breaks up: soft clipping gives a rounded, "warm" tone, and it's dynamic — play softly and it stays clean, dig in and it distorts. It transitions smoothly from clean to clipped 1,2.
Distortion — harsher and more "rough-edged". It hard-clips the waveform more abruptly, has less playing dynamics, and the extra odd-order harmonics help you cut through a heavy mix and make pinch harmonics jump out 2.
Fuzz — the most extreme. The clipping is so hard the signal is turned into a near square wave, giving a very synthetic, "rough around the edges" tone with lower mids and no dynamics at all — it responds the same whether you pick gently or hard 1,2. Fuzz was also the first transistorised floor pedal (the Maestro Fuzz-Tone, 1962) 6.
Quick ear reference from 
singemonkey 1:
- Overdrive: Stevie Ray Vaughan
- Distortion: Metallica
- Fuzz: the Satisfaction riff and most live Hendrix
Two practical notes: a valve amp (or an overdrive placed after a distortion) will smooth and round off any of these pedals' harsher edges 2. And fuzzes come in a few core families — Big Muffs, Fuzz Faces, Tonebenders, SuperFuzzes, Maestros and modern designs 7 — so check the Ultimate Fuzz Thread on the forum for examples before buying 1,7.
From these forum threads
- What is the difference between Distortion, and Fuzz? (2011)
- Distortion versus Overdrive (2009)
- Fuzz 101? (2020)
- The ultimate fuzz thread (2010)
