Roland SH-101 Owner's Manual page 24

Functions for Sound Synthesizing
VCO
{Voltage Controlled Oscillator)
The VCO is the Voltage Controlled Oscil-
lator that controls the pitch, and creates
(@) RANGE selector knob
This is to change the pitch of the VCO in
exact one octave steps from 2' to 16' (2',
4', 8', 16'). 8' is the standard, and when
the knob is set to 8', the lowest C note
corresponds to the Middle C of the piano
keyboard. (Transpose : M}
@) PWM Mode selector switch
When this switch is set to MAN, the pulse
width can be controlled with the PWM
Slider @) . When it is set to LFO or ENV,
the intensity of the modulation is con-
trolled with the same slider @) . i.e. the
pulse width is controlled by the corre-
sponding signal from the LFO or the
Envelope Generator.
@) PWM e Pulse Width Modulation knob
@) MOD e Modulation Depth knob
When the Modulator signal is control-
ling the pitch of the VCO, this knob
adjusts the amount of the signa! (depth of
the modulation). How it affects the depth
of the modulation varies depending on the
waveforms of the MODULATOR.
24
three types of waveforms which are the
sound source of the synthesizer.
vco
PULSE WIDTH
PULL LELE
<Pulse Wave>
When the top and bottom portions of the
square wave are unequal, the result is what
is called a pulse wave. The harmonic con-
tent of the pulse wave will depend greatly
on the width of the pulses. It is possible to
modulate, or change the pulse width by
means of the LFO or the Envelope Gener-
ator.
<Waveforms>
There are 2 types of waveforms from the
VCO( Tis and 1 ) which are sent to the
SOURCE MIXER and mixed at any por-
tion you like.
<Other Sound Sources>
@ SUB Oscillator
This is the VCO's subordinate Oscillator
which generates the output signal one
octave or two lower than the VCO's. The
output waveform of this Oscillator is Pulse
Wave.
@ NOISE