User Guide

6.98 VCS 153
Typical Use
The VCO is used for generating the starting signal of an analog synthesizer. Figure 92 shows a
standard patch using this module.
Figure 92: Typical VCO Use.
6.98 VCS
The VCS module is very similar to the VCO module except that
it only generates sine waves. This module has 2 modulation inputs
and 1 output.
The first input controls the pitch of the output signal. The signal
of this input is multiplied by a value determined by the adjustment
of the mod1 gain knob. The second input signal is used to perform
frequency modulation (FM modulation).
Tuning the Output Pitch
The coarse, fine and range are used to tune the output frequency (or
pitch) to the desired level. The variations in output pitch caused by
changes in the modulation signals are relative to this level. When the two knobs are in their center
position (green LEDs on for the coarse knob), the range knob is in the left position and there is
no modulation signal, the playing frequency has a value of 261.6 Hz, which corresponds to the
C3 key on a piano (middle C). The range knob transposes the pitch by multiplying the frequency
appearing in the frequency counter by the number appearing in the range counter. This enables to
generate the different harmonics of the fundamental frequency appearing in the frequency counter.
The reading on the counter gives the frequency of the output signal, in Hertz, when there is no
modulation signal.