10.6

142Logic Pro Effects
Logic Pro EVOC 20 TrackOscillator Synthesis in controls
The Synthesis in section controls various aspects of the tracking signal for the synthesizer.
The tracking signal is used to trigger the internal synthesizer.
Synthesis in parameters
• Synthesis In pop-up menu: Choose the tracking signal source.
• Track: Use the input audio signal of the channel strip that EVOC 20 TrackOscillator
is inserted into as the synthesis signal, which drives the internal synthesizer.
• SideCh (SideChain): Use a side chain as the synthesis control signal. You choose
the side chain source channel from the Side Chain pop-up menu in the upper-right
corner of the EVOC 20 TrackOscillator window.
• Osc. (Oscillator): Set the tracking oscillator as the synthesis source. The oscillator
mirrors, or tracks, the pitch of the analysis input signal. Choosing Osc activates the
other parameters in the synthesis section. If Osc is not chosen, the FM Ratio, FM Int,
and other parameters in this section have no effect.
Note: If you choose Side Chain and no Side Chain channel is assigned, EVOC 20
TrackOscillator reverts to Track mode.
• Bands field: Set the number of frequency bands analyzed and then used by the
synthesis engine.
Logic Pro EVOC 20 TrackOscillator oscillator controls
The tracking oscillator follows the pitch of incoming monophonic audio signals and
mirrors these pitches with a synthesized sound. The FM tone generator for the tracking
oscillator consists of two oscillators, each of which generates a sine wave. The frequency
of Oscillator 1, the carrier, is modulated by Oscillator 2, the modulator, which deforms the
sine wave of Oscillator 1. This results in a waveform with rich harmonic content.
Important: The parameters discussed in this section are available only if the Synthesis In
menu is set to Osc. See Logic Pro
EVOC 20 TrackOscillator Synthesis in controls.
Tracking oscillator parameters
• FM Ratio field: Set the ratio between Oscillators 1 and 2, which defines the basic
character of the sound. Even-numbered values or their multiples produce harmonic
sounds, whereas odd-numbered values or their multiples produce inharmonic,
metallic sounds.
• An FM Ratio of 1.000 produces results resembling a sawtooth waveform.
• An FM Ratio of 2.000 produces results resembling a square wave with a pulse width
of 50%.
• An FM Ratio of 3.000 produces results resembling a square wave with a pulse width
of 33%.