EVOC 20 TrackOscillator oscillator in Logic Pro for iPad
The tracking oscillator follows the pitch of incoming monophonic audio signals and mirrors these pitches with a synthesized sound. The FM tone generator of EVOC 20 TrackOscillator consists of two oscillators. The frequency of Oscillator 1, the carrier, is modulated by multiwaveform Oscillator 2, the modulator, which deforms the sine wave of Oscillator 1. This results in a waveform with rich harmonic content.
In classic FM synthesis, sine waves are used as both modulator and carrier waveforms. The EVOC 20 TrackOscillator modulator oscillator provides a number of additional digital waveforms, which extend its sonic capabilities significantly. These waveforms contain additional harmonics that add a new level of richness to the resulting FM sounds.
Important: Many parameters discussed in this section are available only if the Synthesis in pop-up menu is set to Oscillator.

Tracking Oscillator 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.
Side Chain: 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 plug-in menu bar.
Oscillator: Set the tracking oscillator as the synthesis source. The oscillator mirrors, or tracks, the pitch of the analysis input signal. Choosing Oscillator 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.
Track Mode pop-up menu: Choose the pitch tracking mode.
Old: Pitch tracking mode based on a Fast Fourier Transform calculation.
Cepstrum: Pitch tracking mode based on analysis of harmonic spacing, enabling grouped harmonics and/or sidebands to be identified.
AKF: Pitch tracking mode based on analysis of harmonic content, enabling the fundamental frequency to be identified.
Max Frequency knob and field: Set the upper frequency of the pitch tracking oscillator.
Fixed Note knob and field: Set a fixed note frequency or set to the 0 position to enable tracking mode.
Glide knob and field: Set the amount of time pitch correction takes, allowing sliding transitions to quantized pitches. See EVOC 20 TrackOscillator pitch controls.
Oscillator Wave knob and field: Choose an oscillator waveform from 100 Digiwaves for oscillator 2, the modulator.
Digiwaves are very short samples of the attack transients of various sounds and instruments.
Osc. Pitch knob and field: Set the pitch offset of the oscillator in semitones.
Tune field: Drag to adjust the tuning in hertz.
Osc. Ratio knob and 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%.
FM Intensity knob and field: Determine the intensity of modulation. Higher values result in a more complex waveform with more overtones.
At a value of 0, the FM tone generator is disabled and a sawtooth wave is generated.
At values above 0, the FM tone generator is activated. Higher values result in a more complex and brighter sound.
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