Instructions
13
The word “synthesize“ may be translated to “put things together”. Obviously a
synthesizer provides a system to produce any kind of sound, e.g. the sound of
a musical instrument or even the sound of a thunderstorm.
A synthesizer transforms electrical energy into all kinds of tune signals. These
tunes may be transformed by several special eects. A single chip will provide
all these functions. In the end the signals may leave the synthesizer chip and
enter the loudspeaker to be heard by the human ear.
A synthesizer provides a number of signal generators. Several tone genera-
tors will be used to produce pure frequencies at a predened pitch, which will
generate a clean acoustic wave at a loudspeaker. Synthesizers also provide a
noise generator, which is used for producing hissing, whistling and percussion
sounds. Of course the system will need a mixer to add several signals and a
number of lters to eliminate or to enforce signal spectrums. Some synthesi-
zers will contain a slow oscillator function, generating a slowly increasing and
decreasing signal, used to modulate the volume or pitch of a tone generator.
Modulating the frequency of a tone generator by a slow oscillator signal will
result in a slowly increasing and decreasing frequency, which we will interprete
as a siren signal. At a faster speed and at a lower level the tone generator will
produce a vibrating tone and the eect is called “vibrato”. These functions will
all be provided in a single chip!
In a synthesizer all functions may be altered or programmed, e.g. the pitch,
the sustain period, pitch or volume alterations and lter parameters.
Using only four parameters you may imitate almost any instrument: Attack,
Decay, Sustain and Release.
8. What is a synthesizer