Creating Movement With Pulse-Width Modulation - Dave Smith Instruments Sequential PROPHET X User Manual

Creating Movement with Pulse-Width Modulation

Another essential technique is to use an LFO to modulate the pulse-
width of the oscillator waveforms. This adds a great deal of movement
and thickness and has long been used to create string pads.
First, set up a simple square-wave sound.
To create a basic string sound:
1. Recall the Basic Program. (See previous examples if necessary.)
2. In the Mixer, turn up Oscillator 2 to 127. (Osc 1 is already at 127.)
3. In the
oscillators
4. Set
slop
5. Display the Mixer parameters (turn either of the oscillator level knobs)
then press Soft Button 2 to select
2
osc pan
6. Set filter
7. Set filter envelope
to 50. Set filter
8. Set amplifier envelope
release
To add pulse-width modulation:
1. In the
lfo
2. With the LFO 2 parameters shown in the main display, press Soft
Button 3 to select the
Soft Knob 1.
3. Set LFO 2
tion (osc1 shape modulation).
4. Set the LFO 2
modulation.
5. Now set separate pulse-width modulation for oscillator 2 for a more
random, organic feel: In the
the triangle wave.
Prophet X User's Guide
section, set both oscillators to
1&2 to 15 to add a little analog-type oscillator drift.
to 40R for a nice stereo spread.
to 117 and filter
cutoff
attack
env amount
attack
to 50.
section, select
lfo
lfo dest
to 70 to set the speed of the pulse-width modula-
frequency
to 65 to control the intensity of the pulse-width
amount
and set
panning
resonance
to 11, to 60,
decay
to 0.
to 87, to 60,
decay
2 and set its shape to the triangle wave.
menu tab, then select
section, select
lfo
Modulation Techniques
.
pulse
1 to -40L and
osc pan
to 20.
to 22, and
sustain
to 127, and
sustain
1
osc shape
3 and set its shape to
lfo
release
with
95