8.0

Included VST Instruments
Prologue
233
Ratio (1–16)
This parameter is only active if the Freq Mod button is activated. It adjusts the
amount of frequency modulation applied to oscillator 3. It is normally referred
to as FM index.
Sync button (On/Off)
If Sync is activated, Osc 3 is slaved to Osc 1. This means that every time Osc
1 completes its cycle, Osc 3 is forced to start its cycle from the beginning.
This produces a characteristic sound, suitable for lead playing. Osc 1
determines the pitch, and varying the pitch of Osc 3 produces changes in
timbre. For classic sync sounds, try modulating the pitch of Osc 3 with an
envelope or an LFO. The Osc 3 pitch should also be set higher than the pitch
of Osc
1.
Tracking button (On/Off)
If Tracking is activated, the oscillator pitch tracks the notes played on the
keyboard. If Tracking is deactivated, the oscillator pitch remains constant,
regardless of the note that is played.
Freq Mod button (On/Off)
Activates/Deactivates frequency modulation.
Wave Mod button (On/Off)
Activates/Deactivates wave modulation.
Waveform pop-up menu
Sets the basic waveform for the oscillator.
About Frequency Modulation
Frequency modulation or FM means that the frequency of one oscillator, called the
carrier, is modulated by the frequency of another oscillator, called the modulator.
• In Prologue, Osc 1 is the modulator, and Osc 2 and 3 are carriers.
However, Osc 2 can be both carrier and modulator as if frequency modulation
is applied to Osc 2 it is modulated by Osc 3. If Osc 2 also uses frequency
modulation, Osc 3 is modulated by both Osc 1 and Osc 2.
• The pure sound of frequency modulation is output through the modulator
oscillators.
This means that you should turn off the Osc 1 output when using frequency
modulation.
• The Freq Mod button activates/deactivates frequency modulation.
• The Ratio parameter determines the amount of frequency modulation.