DH_Granulator

The DH_Granulator SynthEdit module was developed to be a single-stream quasi-synchronous granulator. It buffers input audio and releases it in discrete grains of a specified duration, at a specified rate. Random variation can be applied to the grain length and grain rate, and they can be modulated by an external source.

Random variation can be applied to the pitch shift, and in can be modulated by an external source. Extra buffering is required if the pitch shift is to be modulated at audio rates so that it will increase within each grain. See Gliss Allowance below.

Grains may be shaped using a variety of envelope functions, which are listed under the Envelope Type pin description below.

The phase of the grain generator can be adjusted so that streams from multiple instances can be offset and mixed.

Inputs: Input - Audio to be processed

Pitch - Pitch shift, 1 volt/octave, 5 volts = no change.

Grain Size (ms) - Duration of each grain, in milliseconds.

Grain Rate (ms) - Interval between the start of one grain and the start of the next grain in the stream, in milliseconds. Should be set at least as long as the Grain Size.

Pitch Var - Amount of random variation to apply to Pitch Shift.

Grain Size Var - Amount of random variation to apply to Grain Size.

Grain Rate Var - Amount of random variation to apply to Grain Rate.

Phase Shift - Shifts the phase of the oscillator that drives grain production. Range: 0 (for 0°) to 10 (for 180°).

Off/On - Turns module completely off.

Envelope Type - Selects the function used to shape the grain's amplitude envelope:

None (rectangular)

Sine

Gaussian

quasi-Gaussian

Rectified Sine

Triangle

Trapezoid

Gliss Allowance (Variable-pitch Grain mode only) - Higher settings cause the unit to start further back in the buffer to retrieve samples, to allow for an increase in pitch shift over the grain's duration. Use this if you will be increasing the amount of pitch shift over the course of individual grains. The settings correspond roughly to the number of octaves of change that can be accommodated, but use the lowest setting that avoids audio glitches, to avoid adding unnecessary latency. Also, when you increase the Gliss Allowance, check the Latency output, and make sure that you have set the Max Buffer size large enough to hold that many milliseconds of audio.

Outputs: Latency (ms) - Amount of time between sample recording and output. This varies dynamically depending on grain size, the amount of pitch shift, and (in Variable Grain Pitch mode) the Gliss allowance.

Output - Audio out.

Parameters: (right-click Properties) Max Buffer (ms) - Size of the buffer into which audio is continuously recorded, measured as the number of milliseconds of audio it can store.

Grain Pitch - Selects between Fixed- and Variable-Pitch grains. A Variable-Pitch grain can contain internal pitch shift, while a Fixed-Pitch grain maintains its initial pitch shift amount throughout the length of the grain.