ER-301/Velvet Noise

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  • Generating random triggers at a target rate.
  • As smoother sounding alternative to white noise.
  • Throwing sand at a hard surface.


Velvet noise is a random train of positive and negative pulses that are each only one sample in length. Digitally speaking, it is a random sequence of the following three values: -1, 0, and 1. The rate (and hence the density) of the velvet noise can be controlled by changing the probability that a zero value will be generated.

FYI: I first encountered velvet noise when studying reverbation algorithms. You can read about the role of velvet noise in creating reverbs here.



Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Gain/Bias yes gain (-10,000 to 10,000)

bias (10 octaves above and below 27.5Hz)

frequency in Hertz

The rate parameter controls how often (on average) this unit outputs a trigger. Each trigger has a 50/50 chance to be positive or negative. For example, setting the rate to 1Hz means that this unit will a trigger on average once a second.