Glenn Poorman, June 2011
Updated from an article originally written in June, 2008.
My interest in synthesizers goes back to the early 70s. As a very young music
student, I was paired with a local high school student for lessons and I ended
up studying with her for several years. Her musical tastes and knowledge of
genres covered a lot of ground and she regularly opened my eyes to things well
outside my narrow field of vision including the world of synthesizers. We would
listen to the Beach Boys and talk about the use of the Theremin. We listened to
Henry Mancini and talked about the synthesizers he used in the TV themes for
"The Mystery Movie"
and for "Cade's County"
. We talked about the
work of Wendy Carlos and the instruments built by Bob Moog. We talked about the
ARP units that fueled some of Pete Townsend's work as well as Edgar Winter's
In 1979, I managed to briefly put my hands on a real synthesizer while attending
the Summer Arts Camp at Interlochen. The instrument was made by Univox. I was in
the high school jazz ensemble that summer and our instructor brought the
instrument along to loan to our piano player. For most of us this was a first
so we were understandably anxious to give it a try. Then in 1984, I came into
possession of the Roland Juno-60. By then I was recording my own music and the
121normal studio was in its second location. I had the Juno-60 for the better
part of three years and used it in several of the recordings from that era.
In spite of all the time I put into the Juno-60, I still never really understood
how it all worked. I just tweaked knobs and sliders until I got the sounds I
liked. I was able to save the sounds in memory so I wouldn't have to repeat my
hunt and peck
process every time I fired it up. After a while, I simply
became good at remembering what the various sliders did even if I didn't really
know why they did it (turn that doohickey over there so the note makes that
After taking a brief hiatus in the late 80s, analog synthesizers made a huge
comeback during the 90s. As we moved into the 21st century, computers took over
and the newest synthesizers came in the form of software. While the heart of
today's software synth works very much like its hardware ancestors, the almost
unmeasurable amount of additional control makes that hunt and peck
of creating sounds that served me so well on the Juno-60 virtually impossible
today. There are simply too many variables. For many hobbyists, this isn't
necessarily a problem as both modern hardware and software synths come with
enough presets to keep the average user busy for the life of the synth. If you
want to go off and create your own sounds though, a basic understanding of sound
synthesis has become an absolute must.
So what is a synthesizer? By its very definition, a synthesizer is something
that produces by synthesis or by combining parts to form a whole. An electronic
music synthesizer provides components to simulate the various aspects of sound
and then those components are combined to produce what we finally hear.
There are several methods of synthesis used in both hardware and software units
including subtractive synthesis
, additive synthesis
(also called FM synthesis
, and sample based synthesis
(just to name a few). Many of
today's units, especially the software units, will combine several methods of
synthesis allowing the user to choose the method they want to use. For our
purposes, we'll focus on subtractive synthesis
as this method was used by
the original units of the 60s and tends to be the most popular (and easiest to
Sound (simple version)
Of the many definitions of the word sound
in the American Heritage
Dictionary of the English Language, the first reads as follows:
vibrations transmitted through an elastic solid or a liquid or gas, with
frequencies in the approximate range of 20 to 20,000 hertz, capable of being
detected by human organs of hearing.
That's a fairly cold definition for something that can be so moving when it
comes in the form of music. It's also a very human-centric definition as we
know that other members of animal kingdom are capable of detecting sounds well
outside the range of 20 to 20,000 hertz and that many instruments generate
frequencies outside of that range as well. For our purposes though, the heart
of that definition works.
In musical terms, a sound is essentially made up of three components.
The pitch is the frequency of the sound or in musical terms, the note. It
is determined by the number of times a sound wave repeats itself within one
second of time. A single repetition of the sound wave is called a cycle
and the number of cycles that occur in a second is called the frequency.
The timbre of a sound is that quality that allows us to (for example)
distinguish the sound of a piano from the sound of a clarinet or a human
voice. Most sounds are actually made up of an array of pitches all at
different frequencies. The base frequency is called the fundamental
while the additional frequencies are called overtones or
harmonics. The fundamental combined with the overtones makes up the
harmonic series. The timbre of an acoustic instrument is going to be
determined as much by the shape, size, and material of that instrument as it
is by the origin of the tone itself. That is because those aspects of the
instrument's design will naturally suppress or filter certain frequencies in
the harmonic series giving that instrument its unique sound.
Loudness or volume is exactly that. The volume of the sound. Every sound has
some amount of volume both initially and over time. The sound also has a
beginning and an end as well as an initial attack and decay.
The Basic (Subtractive) Synthesizer
In simplest terms, subtractive synthesis
subtracts harmonic content from
a sound by passing that sound through an audio filter. The basic subtractive
synthesizer is generally broken up into three sections corresponding directly
with the three basic components of sound. Those three sections are the
(pitch), the filter
(timbre), and the amplifier
(loudness). On the original analog synthesizers, these components were all
voltage controlled and were frequently referred to as the VCO
(voltage controlled filter
(voltage controlled amplifier
). It's not uncommon to see the
old acronyms still in use today even on units that are no longer voltage
Let's take a look at what would be the world's simplest and most basic
subtractive synthesizer and then discuss the sections in greater detail.
Figure 1. The most basic synthesizer
The oscillator section corresponds to pitch and is the heart of the
synthesizer. This is where the waveform is generated. The frequency of the
oscillator determines the pitch. There are a variety of ways that the
frequency might be determined but the most common is through the press of
a key on a piano-style keyboard. Even the simplest of synthesizers will
offer their user a selection of waveforms to choose from. At a minimum,
the selection will likely include a square wave, triangle wave, and
sawtooth wave as well as a sine wave. These basic waveforms are shown in
Figure 2. Basic
These waveforms generate distinctly different tones as you can hear in the
samples below. Each sample plays the identical arpeggio using different
wave selections. The sine wave consists of only the fundamental and has a
very mellow tone to it. The triangle contains the odd harmonics but there
is a decrease in amplitude in the upper harmonics. The square wave contains
all of the odd harmonics and has a sound that resembles a clarinet. The
sawtooth contains all of the harmonics and sounds more brassy.
Many units also provide a pulse wave (sometimes referred to as a
rectangular wave) which is similar to the square wave except that
the upper and lower parts of the wave are not symmetrical. The width of
the upper part of the wave (referred to as pulse width) can be set
by the user and is usually measured as a percentage of the entire cycle
(where 50% is the equivalent of a square wave). These waves can resemble
the sound of a saxophone or oboe depending on where the pulse width is set.
The sample below plays the same arpeggio again using a pulse wave with the
pulse width set at around 20%.
Figure 3. Pulse Wave
Once the sound is generated, the next stop is the filter. As we discussed
in the section on sound, a sound generated by any source is going to be
made up of an array of frequencies that make up the harmonic series. On
acoustic instruments, filtering of those frequencies occurs naturally as
a result of the characteristics of the instrument itself. On the
synthesizer, the filtering is user controllable. A waveform generated by
an oscillator will originate with the full spectrum of frequencies
characteristic of that waveform. Using the filter, the sound can be
modified by removing and/or enhancing frequencies in the harmonic series.
The most common type of filter used in synthesizers is called a low
pass filter. The low pass filter allows lower frequencies to pass
through while removing higher frequencies that reside above a certain
cutoff frequency. This is where the subtraction in subtractive
synthesis occurs and this cutoff value is controlled by the user.
The following sample plays a single tone using a sawtooth wave. The tone
starts with all of the frequencies audible, slowly decreases the cutoff
value, and then slow increases it again.
Some synthesizers will also include a high pass filter which works
just the opposite of the low pass filter. In other words, the high pass
filter allows higher frequencies to pass while removing frequencies below
The following sample plays the single sawtooth tone again with all
frequencies audible. Then the cutoff value is slowly increased and then
slowly decreased again.
There are other types of filters you might see depending on the unit or
software. The band pass filter allows frequencies within a certain
range or band to pass through while rejecting frequencies outside of that
range. The comb filter removes frequencies across the spectrum
resulting in a frequency response consisting of a series of spikes
(resembling a comb).
In addition to removing frequencies, the filter also allows frequencies to
be enhanced by feeding a portion of the signal at the cutoff frequency
back through the filter again. This control is referred to as
resonance. Adjusting the resonance can generate some interesting
sounds and is responsible for some of the classic sounds that people
consider to be the most "synthy."
In the samples below, we play the single sawtooth tone again and play with
both the cutoff frequency and the resonance demonstrating how the two
interact with each other. In the first sample, we'll set the cutoff at a
middle of the road location and vary the resonance. In the second sample,
the resonance is turned up fairly high and the cutoff frequency is varied.
The amplifier section of the synthesizer controls the volume of the sound.
On an analog synthesizer, the oscillators never really stop oscillating.
They are generating their waveform all of the time but that sound is
patched into the amplifier where it is stopped with a zero volume (like a
river running into a dam). The sound is then essentially cut loose via a
key press and makes it to your ear at the volume set on the amplifier.
The volume is a simple adjustment as it is on any piece of audio gear.
When a sound is generated (not taking any additional components into
account), it is immediately heard at the volume the amplifier is set at
until such time that the sound is stopped and just as immediately goes
quiet. This is the basic tone you can hear in the sample below.
A Better (Subtractive) Synthesizer
The basic synthesizer from the previous section, while a useful teaching tool,
isn't much good for anything else. Only the most basic tones are possible and
the character of those tones is fairly cold. There has never been a single
commercially available synthesizer, however, that didn't come with some extra
bells and whistles to color up the tone and make it a bit more interesting.
To start with, even the most basic synthesizer comes with at least two
oscillators allowing you to generate more than one waveform at a time. The
additional waveforms are generated from the same key stroke as the primary
waveform so they sound in unison. The shape of the waveform can be
independently set on the additional oscillators. The frequency of the added
oscillator can also be set. On some units, only the added oscillators have a
frequency setting and that setting is relative to the frequency of the first
oscillator. On other units (and in the figure below), all oscillators have a
setting allowing the frequency to be set relative to the original key press.
Figure 4. Basic synth with two oscillators
The samples below illustrate the sound of two oscillators triggered by the
same note with varied waveform and frequency settings. In the first sample,
both oscillators play the same notes but each has a different waveform. This
simply adds some body to the overall tone. In the second sample, both
oscillators generate a sawtooth wave but the frequency of the second is set
such that it sounds a full octave above the first. In the third sample, each
oscillator generates a different waveform and the frequency of the second is
set such that it sounds a perfect fifth above the first.
In addition to the oscillators themselves, the oscillator section of any
synthesizer will also include a noise generator. This does exactly what you
would expect based on the name. That is, it generates noise (think of the
sound of a television or radio that is not getting a signal). Noise is
generally characterized as the presence of all possible frequencies at once.
Some units will offer a selection between white noise (where the
amplitude of the frequencies is even across the spectrum) or pink noise
(where the amplitude falls off across the spectrum).
Figure 5. Two oscillators and a noise generator
The samples below illustrate both white noise and pink noise by themselves as
well as the sound of noise generated along side a single sawtooth wave.
Upon first listen it might sound as if the noise generator doesn't really
bring much to the table. In the samples above, the use of the noise generator
sounds like ... well ... noise. But in context, it can be very useful. The
most common use is to create percussive sounds (like a snare drum). Noise is
also used to provide some special effects sounds as well. One of the samples
below illustrates a synth line where some percussive sounds created by the
noise generator are mixed with some tones. The other sample uses the noise
generator to create the sound of surf.
In addition to the three basic components of sound described way back in the
section on sound (pitch, timbre, loudness), a sound is also shaped by an
initial attack and subsequent decay in both volume and filtering of
frequencies. This attack and decay shape is referred to as an envelope
and the type of envelope used in sound synthesis is referred to as an ADSR
envelope (where ADSR stands for Attack, Decay,
Sustain, and Release).
Figure 6. Typical ADSR envelope
Your basic synthesizer will contain at least two envelope generators
used to control the initial attack and decay of a sound's volume and also the
initial attach and decay of the filter cutoff frequency. That means one will
be added to the amplifier section of the synth while a second will be added
to the filter section. These envelope generators along with the other
components we've already discussed make for a much more realistic looking
analog synthesizer as seen in figure 7.
Figure 7. A more realistic synthesizer
In the amplifier section, the envelope is used to control the attack and
decay of the volume and the parameters can be described as follows:
- Attack - how long it takes for the tone to go from zero
volume to full amplifier volume once the key is pressed.
- Decay - how long it takes, once the tone has reached full
volume, to decay down to sustain level.
- Sustain - the level the tone plays at after the decay time
has passed. This cannot be higher than the amplifier volume so you
could think of it as a percentage of the amplifier volume.
- Release - how long it takes for the tone to go from sustain
level down to zero once the key is released.
In order to further describe how these settings relate to the final
sound, let's look at some settings and listen to the effect. There are
couple of important things to point out before we do so however.
- To understand how the ADSR settings apply to what you're hearing,
it is important to know the duration of the notes. For each of the
samples below, we use the identical phrase made up of four quarter
notes with quarter rests in between.
- The values used for the ADSR settings will vary from manufacturer
to manufacturer. For our purposes, let's assume that the value
range for each parameter is 0 to 10.
Start with the basic tone from the amplifier section. This is the tone
that started and ended so abruptly. That tone is the result of setting
A (attack) = 0, D (decay) = 0, S (sustain) = 10 and R (release) = 0.
It's important to note here that since the S value is set to the
maximum, the setting of the D value has no effect (since we have nowhere
to decay to).
The next sample plays the identical phrase but increases the attack to 8.
This gives us a long fade in. Still using the maximum sustain value and
no release value, the note fades in and then cuts off abruptly.
In the next sample, the phrase is played again but here there is a low
attack value, a medium decay value and then a low sustain value. The
release value is still zero so the result is a note that swells to full
volume quickly, then just as quickly decays to a lower volume, and then
cuts off abruptly again.
In the last sample we set the envelope just as we did for the basic tone
(attack = 0, decay = 0, sustain=10) but we slightly increase the release
value. The result is that the tones appear to sound longer because there
is a decay after the note ends as opposed to an abrupt cutoff.
The envelope in the filter section works exactly as it did for the
amplifier section except that, in this case, it is the filter cutoff
that varies instead of the volume. The envelope parameters are the same
but their effect is a little different.
NOTE: In the parameter descriptions below, I will refer to the
minimum and maximum cuttoff frequency value. On the unit
I used to generate the samples, the minimum value is determined by the
cutoff frequency the filter is currently set to while the maximum
value is whatever the maximum for that cutoff can be (likely 20,000hz).
All filter envelopes essentially do the same thing but I've seen
variances in how they relate back to the original cutoff frequency
setting. In other words, you might have to experiment with your
particular synth to get the same results.
- Attack - how long it takes for the cutoff frequency to go
from the minimum to the maximum value.
- Decay - how long it takes, once the cutoff frequency has
reached its maximum, to decay down to the sustain value.
- Sustain - the cutoff frequency after the decay time has
- Release - how long it takes for the cutoff frequency to go
from sustain level down to the minimum once the key is released.
The samples below use the identical phrase used in the amplifier
envelope samples made up of four quarter notes with quarter rests in
between. In all but the last sample, the settings for the amplifier
envelope are A=0, D=0, S=10, R=0.
In the first sample the initial cutoff frequency on the low pass filter
is set to zero. We then put a low attack value on the envelope which
will cause the cutoff to increase from it's attack value to the maximum
fairly quickly. We follow that with a mid-range decay value and a zero
sustain value. This means that shortly after sounding, the cutoff will
decrease to zero. The release on both the amplifier and filter envelope
means the notes cut off abruptly. Note how the use of the envelope on
the filter gives the overall sound a low brass quality (like a trombone).
To exaggerate the filter envelope, the next sample plays the identical
phrase using the identical settings for both the filter and amplifier
envelopes. The difference here is that we turn up the resonance on the
filter to really bring out the effect.
The last sample is a little tricky to understand. In this sample,
instead of using a decay value to get that wah effect, we set the
envelope such that once the attack is finished, the note stays at the
full spectrum. We then add a slight release value so that the cutoff
will decrease after the note ends.
The tricky part here is that since the release on the filter only kicks
in after the note ends, you'll never hear the effect unless you also
increase the release value on the amplifier envelope. So for this sample,
we set the release on both the filter and amplifier envelopes to be the
Low Frequency Oscillator (LFO)
Another common addition seen on most synthesizers is the low frequency
oscillator (or LFO). The LFO is used for modulation effects and unlike the
oscillator used to generate a tone, the LFO generates a signal at a frequency
that is below 20Hz creating a pulsating rhythm rather than an audible tone.
On some units, the LFO might be its own specialized oscillator. On other units,
one oscillator might be designated to serve either purpose (tone generation
or LFO but never both at the same time). In either case, the LFO can be used
to modulate pitch and/or filter cutoff.
As with any oscillator, the waveform for an LFO can be set by the user and
just like with a tone, the different waveforms product different results. The
samples above both used a nice smooth sine wave. Note the difference in the
next sample that uses a sawtooth wave to modulate the pitch.
Another common use of the LFO is to modulate the pulse width. If you recall
from the initial discussion of oscillators, a pulse wave (or rectangular wave)
is similar to a square wave except that the upper and lower parts of the wave
are not symmetrical and this pulse width can be set by the user. On
most synthesizers, if your tone generating oscillator is set to generate a
pulse wave, your LFO can be used to modulate the pulse width. This will be
commonly referred to as pulse width modulation or PWM. The
sample below illustrates a single oscillator generating a pulse wave and an
LFO being used to modulate the pulse width.
More Bells and Whistles
What we've looked at so far could be considered the bare essentials. These are
the components that a synthesizer would be useless without. Most (if not all)
units will provide some other bells and whistles though to make the unit more
interesting and more musical. The added components vary and there's no way to
cover all of them but we can touch on some of the more common additions.
The dictionary defines portamento as a continuous gliding movement from
one tone to another. This setting is often referred to as glide
depending on the manufacturer. Using portamento, you can play an interval
and hear a noticeable glide from one tone to the next. Synths with
portamento will provide a speed setting so that you can adjust the speed
of the glide.
The samples below demonstrate portamento of various speeds. The first two
samples use the same phrase at the same tempo. The third sample slows the
phrase down a bit so you can hear the glide.
An arpeggiator function will repeat notes that you hold down on the
keyboard in sequence. For example, if you hold down a simple C major triad
(C-E-G) with the arpeggiator function turned on, you will hear the notes
repeat sequentially (like an arpeggio) as long as you hold the keys down.
The speed and manner in which the notes repeat are generally user settings.
Those settings will include speed, number of octaves and the pattern (up,
down, random, etc).
The samples below demonstrate the arpeggiator function on a simple C major
chord (C-E-G-C) varying the arpeggiator settings. The last sample adds a
little portamento for some extra flair.
The step sequencer is similar to the arpeggiator but it can do much more.
In simplest terms, the step sequencer allows the user to alter synth
parameters over a series of steps at a given rate. The basic settings on
the step sequencer are the number of steps and the speed. The steps are
broken up evenly and repeat at the given speed. The most obvious use of
the step sequencer is to set it up to sequence pitch. Given a note
(determined by pressing a key), you can setup the sequencer at each step
to vary the pitch relative to the original note thus automatically playing
a phrase. You could think of it like an arpeggiator except that, instead
of using multiple keys to determine the notes, the notes are defined ahead
of time relative to just a single key.
That's just the beginning though. With a step sequencer, you're not
confined to only varying pitch. You can patch the sequencer into many of
the synth's parameters and even patch it into more than one parameter at a
time. For example, you could just patch the sequencer into the filter
cutoff. So now when you press a key, the note simply repeats but with each
repetition comes a change in the filter cutoff which you can program at
each step. Or you could patch the sequencer into both the pitch and the
the filter cutoff varying both.
The samples below demonstrate some step sequencer uses.
If you want a good example of that sequenced filter usage, the next time
you have on a classic rock station and they play Emerson, Lake and Palmer's
"Karn Evil 9: 1st Impression - Part 2", listen for that filter
sequenced beginning just before Greg Lake starts in with "Welcome back
my friends to the show that never ends ..."
One limiting aspect of the early synthesizers was their lack of polyphony
or the ability to play more than one note at the same time. This was
largely a matter of cost as polyphony required additional oscillators and
a host of added circuitry to make it work. Some early attempts at
polyphony involved a marriage of synthesizer circuitry and electric organ
circuitry. The most notable of these attempts were the ARP Omni and the
PolyMoog. Yamaha was one of the first companies to offer real polyphonic
synthesizers such as the CS-80 but these units were heavy and costly. The
first polyphonic unit to get wide usage was the Prophet 5 made by
Sequential Circuits. By the early 80s, polyphonic units became the norm.
Later as more units started going digital, voice limitations became
Listen to some polyphony samples below.
Note about that last sample: In the overlapping notes sample, we
set the release value on the amp envelope somewhat high and play a single
note passage. You might be thinking that you could do this with a
monophonic synth and you would be correct. The difference, however, is
that that once you played the next note on a monophonic synth, the release
on the previous note would be immediately interrupted. In the sample above,
the release continues to ring while the next note sounds because the unit
As the circuitry inside of the various synth modules began to go digital,
manufacturers starting introducing effects into their units. The extent of
the effects generally depends on the unit but at a minimum, today's synth
units (either hardware or software) will provide the time based effects
such as chorus, delay, flanger and reverb.
The samples below show how effects can be used to spruce up some simple
In this last sample, we'll use a patch from the Arturia Moog Modular
simulation to combine a couple of features and have some fun. This is a
step sequencer patch varying both the pitch and the filter with a long
digital delay applied for a really cool sequence. The sample is the result
of simply holding down middle C for a couple of measures.
How Some Classic Units Worked
Synthesizers have been commercially available since the 60s. Ever since the very
first units hit the scene, the trick as a manufacturer has always been to
provide the customer with all of the control that makes these units so powerful
but present that control in such a way that can be easily learned and understood.
For the most part I believe they succeeded. But to really get the most out of
any synth unit (either then or now) you still need to know the basics. Let's
take a quick overview at some of the classic synths that have existed over the
years and how they map back to the components discussed here.
The Moog Modular system was the first from pioneer Bob Moog. These systems
hit the market in the early to mid 60s, were made to order, and were very
expensive. At first glance, most people thought these units were a bit insane
and wondered how anyone could possibly figure out how to use them. Some of
the larger systems filled entire walls with patch cords hanging in every
direction. Once you got beyond the initial visual though, the Moog Modular
systems were actually brilliant in their simplicity.
Figure 8. Moog Modular System
These systems used the components we already discussed and really nothing more.
How many of these components came in your system was up to you as a customer
and how much you were willing to spend. The voltage controlled oscillators, the
filters, the amplifiers, the envelope generators and everything else were all
built as separates. When you decided how many of each you wanted, Moog built
your system into some nice cabinetry and your custom synth was born. By
itself, the system was nothing more than a bunch of discrete components in a
larger box and made no sounds. To create your sounds, you had to decide what
components to use in what order and then create your path using a series of
So for example, say you wanted the basic sawtooth wave with no envelope or no
filtering applied. You could set the waveform selection on one of your
oscillator components to sawtooth and then run a patch cord from the output of
that oscillator to the input of one of your amplifiers. Turn the volume up on
that amplifier and you're done.
Now if you want to add some filtering and an envelope on the amp, run a patch
cord instead from the oscillator to a filter, another cord from that filter
into an envelope generator, and then another cord from that envelope generator
into an amplifier. Set your cutoff and resonance on the filter, your ADSR
settings on the envelope generator, the volume on the amp and you are done
once again. After that you can patch an LFO into the oscillator or filter if
Of course these are just a couple of very simple examples. You can have any
number of oscillators, filters, amps, etc with patch cords running in every
direction. On top of all that, Moog also made an amazing step sequencer for
the Modular system.
While the system came into existence in the early to mid 60s, the Moog
Synthesizer was put on the map when Wendy Carlos recorded Switched on
Bach, a brilliant example of what these systems could do and a recording
that still holds up today.
In 1970, Moog introduced the MiniMoog. The MiniMoog was a small unit designed
to be more affordable and approachable by the average musician. With this
unit, Moog made some decisions to what most players would want or need in a
compact unit wiring just a handful of components all together into a single
Figure 9. The MiniMoog
The MiniMoog had three voltage controlled oscillators and one noise generator.
The third oscillator could be used to generate a tone or as a low frequency
oscillator. The noise generator created a mix of white and pink noise. The
unit contained one filter and one amplifier each with its own ADSR envelope
generator. All in all a very similar unit to what was diagrammed here back in
the section on envelope generators.
The ARP 2600 was introduced in 1971 by ARP Instruments Inc. This was the first
unit designed to be a hybrid of a wired and modular system. Out of the box,
the unit generated sound and there was a fair amount you could do just using
the knobs and sliders. Similar to the Moog Modular system though, a series of
patch cords could be used to really open the unit up.
Figure 10. The ARP 2600
The most notable parts of this system were the overall wonderful sound of the
ARP oscillators and also the step sequencer. The unit packed much of the power
of a larger modular system but was considerably more compact. During the 70s
the ARP 2600 proved to be one of the more popular synthesizer units being
used by the likes of Pete Townsend, Brian Eno, David Bowie and Herbie Hancock.
Perhaps the most notable use of this unit was by Edgar Winter who absolutely
ripped lead lines, accompaniments and sequences in the song
In 1982 Roland introduced the Juno-60 which is probably still their most
popular synthesizer to this day. This era was really the dawning of the age
of polyphony. Sequential Circuits had already released the Prophet 5 which
was really the first unit that put polyphony into a package that was
reasonable to manage and was also one of the first units to introduce patches.
The Juno-60 followed up with similar functionality and a lower price tag.
Figure 11. The Roland Juno-60
The Juno-60 swapped out the familiar voltage controlled oscillator (VCO) for
a digitally controlled oscillator (DCO). These oscillators overcame tuning
issues that could occur with the earlier VCO components by controlling the
frequency with a microprocessor. The oscillator itself was still fully analog.
The unit was 6-voice polyphonic with one DCO per voice which also contained a
sub-oscillator capable of generating a tone one octave below the fundamental.
The overall sound of the Juno-60 was superb. During the 80s, the Juno-60 was
one of the mainstays of pop music and was used by numerous popular artists.
Personally I had an almost obscene amount of fun with the Juno-60 and still
regret letting it go.
Roland GAIA SH-01
Introduced in 2010, the Roland GAIA SH-01 is hardly a classic. It is a small
inexpensive unit that has barely been on the market for a year. It warrants a
little discussion for a couple of reasons though.
Figure 12. The Roland GAIA SH-01
First, the SH-01 is one in a line of many of today's fake analog
synthesizers. These low priced units look and are controlled like a real
analog synth in every way but they are digital units modelling the analog
world. This is ok really. Many of them sound really good and the price is
The other thing I particularly like about the SH-01 is that it is possibly the
best unit today to use as a synth teaching tool. If you read an article such
as this one and then study the control panel on the SH-01, you will recognize
just about everything you see immediately. The sections are logically laid out
and extremely easy to tweak. For the money, I don't believe you'll find a unit
that is more fun to play with.
Today, software synthesizers are everywhere. These are synthesizers that come
in the form of software for your computer. These programs can be used as stand
alone synthesizers allowing you to generate the tones via a MIDI keyboard
controller (or any other kind of MIDI controller). The same programs can also
be used as plug-ins for your favorite DAW software allowing MIDI tracks to be
recorded and then assigned to the synthesizer plug-in for playback. They are a
revolution and keeping track of them all is virtually impossible. Many of these
synths are, at their heart, subtractive synthesizers simulated via software.
Many are a combination of different kinds of synthesizers including but not
limitied to subtractive synths.
Classic emulations are very much in style right now. That is, software
synthesizers that emulate vintage units. In most (if not all) cases of
classic synth emulation, firing up the software brings up a display that
looks just like the original hardware unit. One example of this is the
MiniMoog emulation by Arturia shown below.
Figure 13. Arturia Minimoog Display
Using a program such as Arturia's Minimoog, you control your synth and
setup your sounds by using the knobs and switches exactly as you would on
the original unit. Arturia even makes a Moog Modular and ARP 2600 emulation
(shown below) that requires the use of virtual patch chords to edit sounds.
These virtual patch chords behave just like the real patch chords from the
original hardware units. If you're looking to learn something about how
these vintage units worked, you really can do so by studying the Arturia
emulations. There are very well done.
Figure 14. Arturia ARP 2600 Display
Unlike the original units though, the niceties afforded via software are
generally added into these packages such as polyphony and a host of digital
effects. Using the Minimoog as an example yet again, the software wakes up
as a monophonic unit so as to emulate the original exactly. Polyphony is
easily turned on though and the number of voices is a configurable
parameter. You can also add digital chorus and delay to the tone which was
never available on a real MiniMoog unit.
Beyond the Classics
The real fun comes when you break out of the past and embrace the future.
Software provides the ability to do things never done on the old hardware
units and many manufacturers have embraced this and provided packages capable
of generating sounds never heard before. Just about every DAW package comes
with a host of stock synthesizer plug-ins. Third party manufacturers have
poured serious development time into creating programs that could very well
become legendary like some of the hardware units of the 60s, 70s and 80s.
Figure 15. NI Absynth 4 Display
My personal favorite software synthesizer is Absynth made by Native
Instruments. Absynth comes pre-stocked with hundreds of sounds but, of
course, allows the user to modify any sound or create new sounds from scratch.
Combining many different kinds of synthesis, digging into the inner workings
of Absynth can appear daunting. But if you start with a brand new sound and
activate the patch window, you'll see some things you should recognize by now.
Namely, an oscillator patched into a filter patched into an amplifier and an
Of course, from there you can go wild adding oscillators, creating custom
waveforms, generating an infinite number of envelopes controlling any of the
hundreds of parameters. But if you break it all down, the basic premise is
still very much like everything we've discussed here. Of course, the end
results can be wild as demonstrated in the following sample generated from a
factory Absynth patch and a single middle C on my USB keyboard.
What kind of waveforms, filtering, and envelopes do you suppose it took to
make that sound?
I loved synths when I first learned of them and have really never stopped. They
allow you to continuously go beyond traditional sounds in music and create new
ones. With the proliferation of software synths, more people than ever have
access. For the most part, you can have a lot of fun picking apart the presets
and experimenting in the dark. A good grasp of how synths work, however, will go
a long way toward making your musical visions become reality. Armed with a
little knowledge, you can not only create the sounds you want to create but you
can also look at how some of those presets were created and say "aha ...
THAT's how they did that"
. As with most things in life, a little knowledge
can go a long way.
Most of all though ... it's fun! Lots and lots of fun!