ES E oscillator parameters in Logic Pro for iPad
The ES E oscillator generates a waveform, which is then sent to other portions of the synthesizer engine for processing or manipulation.
ES E oscillator parameters include an LFO (low frequency oscillator), which generates a cyclic waveform that is used to modulate the ES E waveform.
The behavior and effect of the LFO depend on whether a sawtooth or pulse wave is selected.
If Wave is set to sawtooth, the LFO modulates the frequency of the waveform, resulting in a vibrato or siren effect—depending on the LFO speed and intensity.
If Wave is set to a pulse wave, the LFO modulates the waveform pulse width—pulse width modulation (PWM).
Oscillator parameters
Wave knob and field: Select the waveform of the oscillator, which is responsible for the basic color of the tone. The leftmost setting of the Wave parameter causes the oscillators to output sawtooth signals. Across the remaining range, the oscillators output pulse waves, with the average pulse width determined by the Wave parameter position.
Tune knob and field: Tune the instrument sound in cents. A cent is 1/100th of a semitone.
Octave buttons: Tap to switch the pitch in octaves—transpose it up or down. The lowest setting is 16 feet, and the highest is 4 feet. The use of the term feet to determine octaves comes from the measurements of organ pipe lengths. The longer and wider the pipe, the deeper the tone.
LFO parameters
Vib / PWM knob and field: Define the intensity of LFO modulation.
LFO Speed knob and field: Set the frequency of LFO modulation.
Note: When the pulse width becomes very narrow, the signal sounds as if it is being interrupted—“breaking up.” Given this potential artifact, set the PWM intensity with care. Set the Wave parameter to the 12 o’clock position (50% rectangular) for pulse width to attain the maximum modulation range.
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