Waldorf Blofeld Keyboard - Manual (Page 89)

Sound Synthesis Basics
89 Blofeld User´s Manual
Sound Synthesis Basics
Oscillators Introduction
The oscillator is the first building block of a synthesizer. It
delivers the signal that is transformed by all other
components of the synthesizer. In the early days of
electronic synthesis, Robert A. Moog found out that most
real acoustic instrument waveforms could be reproduced
by using abstracted electronic versions of these
waveforms. He wasn’t the first who came to that
conclusion, but he was the first in recreating them
electronically and building them into a machine that
could be used commercially. What he implemented into
his synthesizer were the still well-known waveforms
sawtooth, square and triangle. For sure, this is only a
minimal selection of the endless variety of waveforms, but
the Waldorf Blofeld gives you exactly these waveforms at
hand, plus other classic waveforms like pulse (which is
the father of the square waveform) and the sine wave (also
part of every other waveform).
Now, you probably know how these waveforms look and
sound, but the following chapter gives you a small
introduction into the deeper structure of these waveforms.
Let’s start with the most basic one.
The Sine Wave
The Sine Wave is the purest tone that can be generated. It
consists only of one harmonic, the fundamental, and has
no overtones. The following picture shows the sine wave
and its frequency representation:
The Sine Wave
There is no acoustic music instrument that generates a
pure sine wave; the only instrument that comes close to it
is the pitch fork. Therefore, the sine wave sounds a little
artificial to the ear. However, the sine wave can be an
interesting oscillator waveform to emphasize a certain
harmonic while other oscillators are playing more
complex waveforms, or as FM source for frequency
modulation.
The sine wave is the most basic building block of each
waveform. Any waveform can be broken down to several
or many sine waves that are arranged with different
frequencies and magnitudes. These sine waves are called
1 4 8 12 16
Frequency
Magnitude
Time
Amplitude
Harmonics