Oscillators / Waveforms
Oscillators
The oscillator is really the heartbeat of the synthesizer. It generates an electronic wave (which
creates the vibrations). This waveform is produced at a controllable musical pitch, initially
determined by the note played on a keyboard or other MIDI controller. The initial distinctive
tone or timbre of the waveform is actually determined by the wave’s shape.
Many years ago, pioneers of musical synthesis discovered that just a few distinctive waves
contained most of the useful harmonics for musical synthesis. The names of these waves
reflect their actual shape when viewed on an instrument known as an oscilloscope. They are:
WAVEFORM
WAVESHAPE
HARMONIC STRUCTURE
F
Sine wave
The sine wave contains no harmonics, just the fundamental frequency and is the purest sound
available.
F
3
Triangle wave
5
The triangle wave is another pure sound but it does contain a few odd-numbered harmonics.
Square wave
F
3
5
7
9
11
The square wave is a very bright but hollow sounding waveform, not unlike the tone of a
clarinet. It consists of a wide range of odd numbered harmonics.
On many synths (the V-Station included), it is possible to vary the width of the square wave:
The so-called ‘pulse’ waves at either extreme have a very different harmonic content to the
square wave and sound ‘thinner’ and more ‘nasal’. However, because the pulse width is totally
variable, the harmonic content of each variation in between the extremes also differs. If the
pulse width is controlled by something like an LFO, a very vibrant and animated sound can be
created - this is called Pulse Width Modulation.
F 1 2 3 4 5 6 7 8 9 10
Sawtooth wave
11
The sawtooth wave is probably the brightest sounding waveform of all and contains a wide
range of odd and even numbered harmonics in equal proportion. It is good for a wide range of
sounds including strings, brass and more.
11
Synthesis Tutorial
