Rock music and distortion have pretty
much always gone hand in hand. But
what is it we mean by “distortion,” and how
does it differ from “overdrive” and “fuzz”? A
quick perusal of the intergoogle easily turns
up hundreds of pedals laying claim to one
or another of those appellations. One site
offers 50 pedals with the word “distortion”
in the name, and Boss alone makes five different
distortion pedals. The names of other
pedals give no clue as to whether they are
overdrive, boost, distortion, or fuzz. (Way
Huge Fat Sandwich, anyone?) More definition
complications ensue when we add amp
distortion and booster pedals to the mix.
So how, exactly, do we determine whether
a pedal provides a boost, overdrive, distortion,
or fuzz effect—particularly when a
given model may perform more than one
function? To start unraveling this mess, we
need to get technical for a minute.
Catch a Wave
You might have heard the term “sound
waves.” It refers to the fact that sound
travels in waves similar in some ways to
the ones we see in the ocean: If you put a
clean audio signal through an oscilloscope,
you will see a line with smoothly rounded
peaks and valleys. When an amplifier
reaches a level at which it can no longer
increase the output signal without altering
the input signal, that is called
distortion (it’s
also known as
clipping). On the ’scope, this
distortion shows up as flattened peaks and
valleys rather than the previously rounded
peaks and valleys. This is true of instrument
amplifiers as well as pedals, which use tiny
amplifiers in their circuitry. Distorting a
signal adds harmonic content or overtones
that did not exist in the original. These
overtones are actually present in everything
from bird songs to flutes and cellos—yes,
Virginia, there was distortion before rock ’n’
roll—and they add much of the character
we love in so many guitar tones.
The amount that the waveform is
squashed by this distortion goes a long way
toward defining the difference between
overdrive, distortion, and fuzz. A clean
boost pedal’s job is to increase the output
of your guitar signal only enough to give
you extra volume or drive your amp to
distort, without adding any grit of its own.
An overdrive pedal adds some distortion to
the signal but not a lot, while a distortion
effect crushes the wave pretty heavily—and
fuzz even more so.
In addition to adding extra harmonics to
the signal, the squashing effect of distortion
also compresses it, thus reducing the attack
and dynamic range while adding sustain
similar to what you’d get from an MXR
Dyna Comp or another compressor pedal.
Now that we understand a bit about the
technical differences of boost, overdrive,
distortion, and fuzz, let’s take a look at how
this plays out in the world of sound and tone.
Stacking the Deck
We’ve all heard the “plug-me-straight-in”
philosophy from those who claim nothing
beats the sound of a great guitar plugged into
a great tube amp, without any pedals between
them. Given the right instrument, the right
stack or combo, the right player, and the
right circumstances, it is hard to refute that
theory: The tone produced by power tubes
being pushed past their limit is hard to beat.
And though preamp distortion—the
distortion that comes from the EQ circuit
rather than from driving the amp’s power
section beyond what it can output without
distorting—has come a long way since
the days of the silverface Master Volume-equipped
Fender Twin, the sound sought
by most adherents to the “plug-me-straight-in”
philosophy is most definitely that of
power tubes working hard. In the case of
the earliest tube amps, the sound is attained
by working them much harder than the
designers originally intended. Crank up a
Fender Deluxe, Vox AC30, Marshall plexi,
or a boutique clone of a vintage amp, and
the resulting distorted tone is a thing of
beauty that’s highly responsive to pick
attack and guitar-volume control. There
is just one problem: These amps only
achieve this sound within a limited range of
volume. In other words, the amp has to be
loud to get that sound.
If you only play in your basement or studio,
with no complaining neighbors or family—problem solved. You can use an amp at
its optimal volume to your heart’s content.
When you play out in clubs, theaters, or
even arenas, however, you will often find
the sweet-spot volume to be either too loud,
or in the case of smaller combos, not loud
enough. If it’s too loud, you’ll probably
be asked to turn down until all that lovely
distortion turns into a clean “plink.” If it’s
too soft, you might find yourself turning up
until your gorgeous, open, singing sound is
converted into a raspy, overly compressed
mosquito buzz.
However, if you’re committed to this
type of grit, there
are solutions:
- Power attenuators like the Rivera
RockCrusher (street $499,
rivera.com, reviewed June 2011)
and THD Hot Plate (street $328,
thdelectronics.com) can be placed
between your amp’s speaker output
and speakers to lower the volume
without having to turn down the amp.
You will lose the part of the tone that
is caused by the speaker breaking up,
but it should get you pretty close to
that “plug-me-straight-in” sound.
- Some players put a Plexiglas sheet
in front of their speakers to reduce
the stage volume. While this makes
soundmen, bandmates, and the first
couple of rows happy, it will seriously
alter what you hear onstage.
- Some higher-powered amps (such as a
Fender Twin Reverb) will still work properly
if you pull half of their power tubes
(two of the four, in the case of the Twin)
to drive them harder and get cranked
tones at lower volumes. Check with the
manufacturer before you try this.
- Bring several amps of differing wattage
to your gig. At soundcheck, determine
which one enables you to get the tones
you want without excessive volume.