Greetings fellow tone tweakers! This
month we’re going to examine overdrive,
distortion, and fuzz, and perhaps help
clarify the distinctions between these
common terms. It seems most guitarists
use these descriptions almost interchangeably,
thinking of the difference in terms of
degree – i.e. dirt, more dirt, and most dirt.
Some players also use these definitions to
describe certain sonic qualities or characteristics
that set one pedal apart from others.
While there is some validity to both of
these ideas, they don’t tell the whole story.
Part of the problem is the vagueness of
the words themselves. First of all, the
word overdrive, as used by guitarists, is
both a noun and a verb. When we consider
the verb form, to overdrive, we’re
looking at a very broad range of possibilities.
I can overdrive my amp in any number
of ways. For example, I can choose
from a wide assortment of pedals that
can increase the signal level going to the
front end of my amp, including an overdrive
(of course), buffered boost, treble or
full-range boost, distortion, fuzz, or even a
compressor; I can try using hotter preamp
tubes, I can run the speaker out of one
amp to the input of another amp (not recommended),
I can use the wrong power
tubes (again, not recommended), or I can
just plain crank it up – all of which will
result in some sort of overdrive.
We have a similar situation with distortion
– distortion can occur in a number of
ways that may or may not be desirable,
like blown speakers. Add to this the various
adjectives guitarists use to describe their
dirt, such as crunch or grit, and it’s easy to
see how players can get confused. So, setting
aside these definitions, let’s look at our
dirt strictly in terms of pedals.
Examining the actual circuits of these various
dirt boxes, we can see specific differences
that serve to classify each as either
fuzz, distortion, or overdrive. We’ll start
with fuzz since – from a pedal builder’s
point of view – that’s the most distinct.
A fuzz pedal can be defined as a simple
circuit using transistors to create a “clipping”
effect. A true fuzz circuit will always
be discrete, meaning it does not use
integrated circuits (or IC chips). A notable
exception is the last version of the original
Big Muff ð, which was revised to use opamps
instead of transistors (the “IC Big
Muff”). This may be part of the reason
the Big Muff is alternately referred to as a
fuzz and a distortion pedal.
The first commercially produced fuzz,
debuting in 1962, was the Maestro FZ-1
Fuzz-Tone. This is the pedal Keith Richards
used for the signature riff in “Satisfaction”
by the Rolling Stones. Many other classic
fuzz designs were originally created in the
mid-to-late 60’s, including the Fuzz Face
and Tone Bender. The type and quality of
transistors, which can be germanium or
silicon, is integral to the sound of the fuzz
pedal. In some circuits, such as the Fuzz
Face, the transistors need to be handselected
and matched for gain in order to
get the best sound. This is why it is difficult
to find great sounding Fuzz Face type
pedals made in high-volume, production
The difference between overdrive and
distortion is not as easy to define with
regards to circuit design. In most cases,
both will use a combination of ICs and
“clipping diodes” to create their effect.
Most overdrive pedals use clipping diodes
in the feedback loop to gently clip the
sound for a smooth, mild degree of distortion.
This is often referred to as “soft clipping.”
The archetypal overdrive pedal in
this category is the Ibanez Tube Screamer.
Distortion, on the other hand, will run the
clipping diodes to ground to create a “hard
clipping” effect. The MXR Distortion + was
one of the first distortion pedals of this
type. Overdrive and distortion pedals can
use germanium diodes, silicon diodes, or
even LEDs to achieve their clipping effect.
These are not hard and fast rules, however,
and there can be a good bit of overlap
between overdrive and distortion. There are
even some pedals that dish the dirt using
an actual preamp tube.
To conclude our quick and dirty course
on dirt, we’ll leave you with this short
list of famous dirt pedals in their respective
Fuzz Face, Tone Bender, Big Muff,
Mosrite Fuzzrite, Jordan Bosstone, Univox
Super Fuzz, Foxx Tone Machine, Fender
Blender, Roland Bee Baa
Tube Screamer, Boss OD-1,
Boss SD-1, Tube Driver
MXR Distortion +, DOD 250,
Pro Co Rat, Boss DS-1
Well, that’s enough dirt for one day
– I’m hitting the shower! Next month
we’ll tell you about “Eight Great Pedals
You Must Try Before You Die.” Until then,
keep on stompin’!
Tom Hughes (a.k.a. Analog Tom) is the
owner and proprietor of For Musicians Only (formusiciansonly.com
author of Analog Man’s Guide To Vintage Effects. For Musicians Only is
also the home of the FMO Gear Shop.
Analog Man (analogman.com) is one of the largest boutique
effects manufacturers and retailers in the business, established by
“Analog” Mike Piera in 1993. Mike can be reached at AnalogMike@aol.com