Analog music synthesizers
— the kind with all the
knobs and patch cords —
were extremely popular 10
to 15 years ago. In those
days, the name Moog
(pronounced like vogue)
was a household name.
Digital music synthesizers
eventually overshadowed
the popularity of the
analog ones and a steady
stream of ever-improving
computer-driven
instruments continues to
line the shelves of music
stores.
Today, however,
whether due to
nostalgia or the same
thing that drives old
clothes back into style,
analog synthesizers are
seeing a resurgence of
popularity.
■ FIGURE 1. Sound Lab Mini-Synth
Block Diagram.
BUILD THE SOUND
LAB MINI-SYNTH
SOUND
SYNTHESIZER
This article will show you how
to build a very cool analog
sound synthesizer. You will learn
about analog sound generation,
have a great project building
experience, and have hours of
sound synthesizing fun. I would
say that the difficulty of this
project is somewhere between an
intermediate and advanced level.
It involves making a printed circuit
board, fabricating a front panel
and case, and a good bit of wiring
and soldering. I think you will find
it well worth the effort. I am
making PC boards available for
sale from my website, if you would
rather not etch one yourself. I
invite you to visit my website at
www.musicfromouterspace.com
and hear the Sound Lab Mini-Synth for yourself.
Introduction
Refer to Figure 1. The Sound
Lab Mini-Synth is a battery-powered analog sound synthesizer
complete with two voltage controlled oscillators (VCOs), a white
noise source (Noise), a mixer
(MIX), one voltage controlled state
variable filter (VCF), one voltage
controlled amplifier (VCA), an
attack release envelope generator
(AR), and one low frequency
oscillator (LFO). Together, these
modules provide sound sources,
sound modifiers, and modulators
— the tools to create a wide range
of electronic sounds. Let’s take a
look at each module in detail.
Attack Release
Envelope Generator
The Attack Release Envelope
Generator (AR) is one of the Sound
Lab’s modulators (see Figure 2). It
produces a voltage which rises and
falls at a rate set by the attack and
decay pot settings, respectively.
The higher the knob setting,
the longer the rise (attack) or
fall (decay) time of the voltage
produced by this module.
Sounds generally have a
characteristic envelope or overall
shape. The envelope of the sound
of a bell, for instance, has a fast
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March 2006