FXpansion DCAM Synth Squad Operation Manual - Manual (Page 28)

8
Oscillator FM in Cypher
Harmonic tuning
Cypher’s pitch control unit/snapping options (see section 1:3) allow you to specify each osc’s frequency as either of the
following:
• an absolute frequency multiplier of the master pitch, expressed in semitones.
• a perfect pitch-ratio of the master pitch, expressed in harmonics (using the
Just and Harmonic modes).
Using the Harmonic mode, you can easily set up harmonic pitch relationships between oscs.
FM depth
Before Osc3 has any effect on Osc2, it is necessary to set the depth of modulation with Osc2’s FM from control. As the
control is increased, more sidebands are introduced – additional tonal partials appear in the frequency spectrum.
Demonstrating osc FM in Cypher
Here’s a practical example to demonstrate FM, starting with an initialized Cypher state:
1. Set the Osc tuning controls to Harmonic mode by
right-clicking on an Osc Scale control and selecting
Harmonic from the context menu.
. With the master Pitch set to 0 semitones, set the Osc3 Scale con-
trol to 3. Leave the Osc2 Scale control unchanged (1).
. Set the Gain controls of Osc1 and Osc3 to 0, and fully turn up
Osc2’s Gain.
4. Set the Wave parameter of both Osc2 and Osc3 to a Triangle shape
(move the control fully to the left).
5. Gradually increase the FM from control on Osc2 from 0 to 1 while
playing a key.
The pitch ratio of 1:3 (carrier:modulator) is a harmonic ratio – the resulting sounds are musical rather than dissonant.
Inharmonic ratios can be useful, however, just like detuned pitching of multiple analogue oscillators. Try setting the Osc3
Scale to 3.09. The result still has an overall harmonic tone, but with an interesting dissonance. More extreme inharmonic
scaling of the modulator can create bell-type sounds, one of the staples of FM-based synthesizers.
You may have noticed that as you sweep the
FM from control, the change in timbre is reminiscent of a filter sweep.
When using FM, it is possible to achieve a very broad range of tonal characteristics using the oscillators alone. More
conventional subtractive synthesizers are heavily reliant on the filter stage for most of their tonal variety.