Oscillator channel node
Generates sounds in two ways.
The Oscillator chop generates sounds in two ways. It synthesizes tones using a choice of common waveforms, or it repeats a prepared incoming audio clip of any duration.
When it is synthesizing tones from the basic waveforms, it steps through the waveform at a rate that depends on the Pitch Control input. By default, a Pitch Control of 0 gives a middle A at 440 Hz; A 1 gives 880 Hz; A -1 gives 220 Hz. Steps of 1 in Pitch Control are 1 octave apart. Steps of 1/12 (.08333) are 1 semitone apart.
Up to three input chops can be used.
Pitch Control
The first input affects the pitch. (It is “logarithmic”.) Output channels are generated for each Pitch Control channel.
Reset Pulse
The second (optional) input contains pulses that restart the oscillator from the beginning of the wave or the Playback Source. 0 in the input means “play the oscillator”. 1 means “stop the oscillator and cue it at the start of the waveform or Playback Source”.
Playback Source
The third (optional) input is a replacement of the waveform Type. It is a sound clip to play at a rate modified by the Pitch Control, and can contain any number of channels. These channels are generated for each Pitch Control channel. The Waveform Type and the Base Frequency parameters are disabled.
If you plug any sound clip into the Oscillator chop’s Playback Source, and Pitch Control is a constant value of 0 of any duration, it will just repeat the Playback Source. If you feed a Wave chop as its Pitch Control, it will raise and lower the speed/pitch of the input.
The Oscillator chop can serve as a general motion time-warper. If you put motion channels into the third input, you can control the time warp by feeding different Pitch Control curves. 0 pitch is normal speed, 1 is double speed.
Unlike the Waveform chop, this is an iterating chop, that is, it steps through the waveform while the pitch changes. To see this effect, feed a Wave chop into the Oscillator.
Parameters
Waveform
Type | The shape of the waveform to repeat. Sine, Gaussian, Triangle, Ramp, Square, Pulse |
Base Frequency | Cycles per second when Pitch Control is 0. |
Units per Octave | Amount that the Pitch Control needs to increase by to raise the pitch by one octave. The default of 1 means that a Pitch Control of 1 raises the pitch by one octave. |
Offset | Values output from the CHOP can have an added to them. |
Amplitude | Values output from the CHOP can be scaled. |
Bias | Shape control for Triangle, Gaussian and Square waves. For triangle waves, it moves the peak. For square waves, it alters the width. |
Phase | A value of .5 is a phase shift of 180 degrees, or one half cycle. |
Smooth Pitch Changes | Samples the pitch curve for every sample between frames vs. using a single per-frame value. |
Channel
Sample Rate | The sample rate of the CHOP. |