Texture synthesizer

Clouds is a granular audio processor - with a couple of twists.

Unlike granular sample players, Clouds is focused on the realtime granularization of incoming audio signals, and the acquisition of textures from them.

Classic controls such as grain position, size, and pitch are provided. Clouds can superimpose up to 16 grains simultaneously and thus create thick textures. Control over texture density, independently of grain size, is thus provided. An external trigger input allows grains to be seeded in sync with LFOs or rhythmic generators.

To provide a richer variety of timbres, Clouds allows the shape of the grain's envelope to be morphed - from sharp rectangular edges to a smooth bell curve. In addition, a diffusion network can further dissolves the edges of grains into blurry textures.

"Grain mesh" modes automatically adjust grain density, size, and the offset between successive grains in order to generate a continuous stream of audio that can be pitch-shifted / time-stretched in the manner of old-school samplers (or time-domain pitch/time processors).

Finally, to cover various applications of granular synthesis without the need for additional modules, Clouds' comes with four voltage-controlled "blend modes" for mixing and re-routing its output signal: VC dry/wet balance, VC channel crossfade, VC feedback, and VC reverberation.

Clouds' delay memory ranges from 1s to 8s depending on audio quality settings.

Features

• Recording buffer duration: 1s (32kHz, 16-bit, stereo) to 8s (16kHz, 8-bit µ-law, mono). 4 quality settings.
• Grain size: 16ms to 1s.
• Maximum number of concurrent grains: 40 to 60 depending on recording buffer resolution.
• Grain generation time-base: periodical, randomized, or externally clocked.
• Grain envelopes: continuously variable between boxcar, triangle, Hann.
• Playback modes: granular, microlooper/buffer-lock, time-domain pitch-shifter/time-stretcher (WSOLA), spectral.
• 4-AP diffuser to post-process the granularized signal.
• Post processing (blending) settings: dry/wet, random panning amount, feedback amount, reverb amount.
• 4 memory locations for "frozen" recording buffers.

Controls

• Freeze push-button.
• Blend mode (or audio quality) selection button.
• Load/save button.
• Grain position, size and pitch knobs.
• Input gain knob, -18dB to 6dB.
• Grain density and texture knobs.
• Multi-function "Blending mode" knob.

Inputs and outputs

• Buffer freeze gate input.
• Grain generation trigger input.
• Grain position CV.
• Grain size CV.
• Pitch-shifting/transposition 1V/Oct CV.
• Dry/wet CV (or feedback, balance, reverb amount - depending on blend mode).
• Grain density CV.
• Grain texture/timbre CV.
• 2-channel audio input (line-level, with pre-amplifier/attenuator).
• 2-channel audio output (modular level).

Technical characteristics

• Input impedances: 100k.
• CV range: +/- 5V. CVs outside of this range are simply clipped.
• Internal processing: 32kHz, 32-bit floating point. RAM Recording buffer uses 16-bit (high quality) or 8-bit µ-law (low quality) resolution.
• Open-source hardware and firmware.
• Easy firmware updates through an audio interface.
• Cortex-M4 ARM processor.
• 18-HP.
• Current consumption: +12V: 120mA ; -12V: 10mA.

www.mutable-instruments.net/modules/clouds