The Sirius-Vocoder
Vocoder-Basics:
How does the Vocoder work?
The Vocoder of the Sirius:
Basically the Vocoder transmutes one audio-signal into another. This somewhat boring definition
does not really describe the fascinating and almost inexhaustable sounds you can create with a
Vocoder: change your voice into a polyphonic church choir or a robot version of ALF. Create impres-
sive synthesizer sounds controlled by your voice. Your drums will learn to speak and the sound of a
symphony orchestra appears as a rhythmic base for a Dancefloor-track.
The Vocoder will boost your creativity infinitely.
Modern professional producers use the Vocoder to create some of the hippest sounds of today- its or-
igin however lies way back. In the 70's, Vocoders were relatively complicated machines which cost a
five figure sum. In 1979 the "Elektor" electronics magazine (Dec. 79) predicted that "in a few years,
keyboards would be fitted with a "Vocoder"-switch". Well, this prediction did not come true. But now
the era of the home keyboard is far behind us, and the Vocoder in the Sirius hails the dawning of a
new age.
It is not necessary to go into too much detail: just imagine the Vocoder as a box with two inputs and
a stereo output. One input is the "Analyse", the other the "Carrier".
You can now for instance connect a microphone to the Analyse-Input and connect the Carrier-Input
to the audio-output of a synthesizer. If you now speak into the microphone and press a key on the
synthesizer simultaneously, it will sound as if the synthesizer is talking. The pitch is not referring to
the voice but to the note you are currently playing on the synthesizer. So if you are playing a melody,
the synthesizer will "sing". If you play four notes simultaneously you will hear a four voices choir. The
basic principle of it is the following: The Analyse-signal as well as the Carrier are being cut up into
several "frequency-slices", the 'Bands' of the Vocoder. Now the "frequency-slices" of the Analyse signal
are analysed and simultaneously transmitted to the respective "frequency-slices" of the Carrier. All this
in real-time. You can now try to imagine the result if you don´t use a voice but a complete drum-
groove as an Analyse-signal. But you might as well just listen to the Demo-Song Nr. 2 of the Sirius
("VOC Grov").
The Sirius has a Vocoder with 11 frequency Bandwidths and an integrated filter bank. These are not
Vocoder "effects" but make up a full-blown Vocoder with numerous configuration possibilities. In
many areas the functions of the SIRIUS-Vocoder go way beyond those of other systems:
The Vocoder
78
Vocoder
Analyse-Input
Carrier-Input
Stereo-Output
In order to call up
the DEMO Songs,
press both DEMO-
keys simulta-
neously and select
Number-Key 2.
F
