zerua nahasi

polyphonic granular synthesizer module for eurorack

zerua nahasi

zerua nahasi is a 4-voice polyphonic granular synthesizer for the eurorack modular format, with a wide range of granulation possibilities. It allows loading independent samples into each voice (slot), either by recording them or by loading them from a sd card, and controlling each slot's parameters individually or as a group, which provides a wide variety of sound manipulation possibilities. Live mode is also available: in this mode, the synth acts as a real-time granular delay.

The main granulation parameters are the grain volume, position, size, density, pitch/speed, envelope shape, and the polyvalent xxx knob. Each of these parameters can be cv-controlled and randomized individually per slot: with extreme parameter positions and heavy modulation, the granulation sound source becomes completely unrecognizable, and the sound exploration possibilities are huge. Furthermore, the synth features a convolution reverb engine, with a dry/wet control to affect each slot individually.

  • 4 stereo voices (slots) - each slot can hold over 20 seconds of audio.
  • smallest grain length is 5 ms - longest is multiple seconds.
  • grain density can be as low as 1 grain per second, and as high as 20 simultaneous grains. per voice!
  • different grain types use different processing algorithms, and the pitch/speed and xxx knobs have a different behavior depending on the grain type in use on each voice.
  • the knobs can control the parameters of a single slot or many of them, depending on how many are selected. This gives a lot of control flexibility.
  • pressing the rand button while moving a knob, a per-grain stochastic offset can be applied to the corresponding parameter - grain volume, position, length, density, pitch/speed, shape and xxx can be randomized.
  • these knobs can be cv-controlled too - some of them even have a per-slot cv input.
  • the sync mode button allows the grain scheduling of the 4 voices to be synchronized in different ways.
  • when live mode is activated, the selected voices start performing real-time granulation on the input stereo audio signal - granulation can be done on the most recent audio (with minimum latency), or on over 30-seconds-old audio.
  • the convolution reverb explained in the barcelona reverbera section is integrated in zerua nahasi too. There are 2 global controls, size and color, and the dry/wet control defines how much reverb is applied to each slot.