Make Electronics

Experiment 30: Fuzz

260 Chapter 5

BAckground

Stomp-box origins

The Ventures recorded the first single to use a fuzz box,

titled “The 2,000 Pound Bee,” in 1962. Truly one of the most

awful instrumentals ever made, it used distortion merely

as a gimmick and must have discouraged other musicians

from taking the concept seriously.

Ray Davies of the Kinks was the first to embody distortion

as an integral part of his music. Davies did it initially by plug-

ging the output from one amp into the input of another,

supposedly during the recording of his hit “You Really Got

Me.” This overloaded the input and created clipping—the

basic fuzz concept. From there it was a short step to Keith

Richards using a Gibson Maestro Fuzz-Tone when the Roll-

ing Stones recorded “(I Can’t Get No) Satisfaction” in 1965.

Today, you can find thousands of advocates promoting

as many different mythologies about “ideal” distortion. In

Figure 5-56, I’ve included a schematic from Flavio Dellepi-

ane, a circuit designer in Italy who gives away his work (with

a little help from Google AdSense) at http://www.redcircuits.

com. Dellepiane is self-taught, having gained much of his

knowledge from electronics magazines such as the British

Wireless World. In his fuzz circuit, he uses a very high-gain

amplifier consisting of three field-effect transistors (FETs),

which closely imitate the rounded square-wave typical of an

overdriven tube amp.

Dellepiane offers dozens more schematics on his site, devel-

oped and tested with a dual-trace oscilloscope, low-distortion

sinewave oscillator (so that he can give audio devices a “clean”

input), distortion meter, and precision audio volt meter.

This last item, and the oscillator, were built from his own

designs, and he gives away their schematics, too. Thus his

site provides one-stop shopping for home-audio electronics

hobbyists in search of a self-administered education.

Before fuzz, there was tremolo. A lot of people confuse this

with vibrato, so let’s clarify that distinction right now:

• Vibrato applied to a note makes the frequency waver
  up and down, as if a guitarist is bending the strings.


• Tremolo applied to a note makes its volume fluctuate,
  as if someone is turning the volume control of a guitar
  up and down very quickly.

9V

DC

Input

Jack

Output

Jack

0.1uF

2K2

100K

22uF

100pF

10K

log

3K3

5K trimmer

22uF

0.1uF

1M

2N3819

2N3819

2N3819

Figure 5-56. This circuit designed by Flavio Dellepiane uses three transistors to simulate the kind of distortion that used to be cre-

ated by overloading the input of a tube amplifier.