Overdrive
There's no hard line that separates overdrive from distortion from fuzz. They all kind of hang out in this nebulous world of spillover from a auditory standpoint. If looking at the manner in which the signal is manipulated to get the "clipped signal", it might be easier to arrive at a place where the distinction between the terms makes a difference.
Overdrive, as we understand the definition, is a clipped instrument signal, typically with only one half (the bottom half) of the waveform of the music signal being clipped. This tends to result in only even-order harmonics being generated. Also characterized by a "soft" type of clipping applied to sine wave with the hard edges of the "square" of the clipped signal end up being rounded off as opposed to hard-angled (when viewed in an oscilloscope).
Overdrive tends to be the most subtle of the three (overdrive, fuzz, and distortion), ranging from barely imperceptible (for example, when an Orange Squeezer compressor is applied to an electric guitar signal) to very pronounced (a Fender Tweed 5E3 with all the knobs turned to "10").
LET US BE CLEAR: Overdrive, for all intents and purposes, IS THE RESULT OF A FAILURE, whether intentional or accidental, of the electronics or of the physical components of the signal chain.
Contrast Guide
We do not expect this definition to be authoritative, however, it is a set of definitions that we have put together in order to be able to separate out how we understand the different forms of signal clipping to occur. What we hear isn't necessarily what you hear, but we can put definitions around what happens physically to the signals. This is how we understand the different forms of signal clipping as pertains to an audio signal and heavy music. Quote and link to these definitions at your own peril.
- Overdrive
- Minor waveform squaring-and-rounding from over-amplification, Effects usually only applied to one half of a sound's sine wave. Usually only through one or two gain stages.
- Distortion
- Major waveform squaring-and-rounding from over-amplification. Effects usually applied to both halves of a sound's sine wave. Usually cascaded through multiple gain stages.
- Fuzz
- Major waveform squaring without rounding due to diode clipping of waveform. Effect applied to both halves of a sound's sine wave. Usually only occurs through a single gain stage.
Overdrive Pedals
- Maxon OD-9
- Ibanez TS-9
- Boss BD-2 Blues Driver
- Boss SD-1 Super Overdrive
Amps known for Overdrive
- Fender 5E3 Tweed "Deluxe"
- Fender 5F1 Tweed "Champ"
- Fender 5F6A Tweed "Bassman"
- Marshall JTM-45
- Marshall JTM-45/100
Sources