Surge XT's Nimbus effect ports Mutable Instruments Clouds granular texture processing into a plugin effect

The Nimbus effect in Surge XT imports the granular texture engine from Émilie Gillet’s Clouds Eurorack module. It takes the incoming audio signal and creates a cloud of micro-grains that can be frozen, time-stretched, pitch-shifted, and spatially scattered. The controls adapt their labels and ranges based on the active mode (matching the Clouds hardware modes). This gives Surge XT a full granular processing effect alongside its synthesis engine, enabling granular freezing and morphing of patches without additional plugins. Being identical in algorithm to the hardware module, users familiar with Clouds can directly apply their knowledge of grain position, size, density, texture, and blend parameters.

Examples

Play a sustained pad through Nimbus with Freeze on: the audio is captured into a granular cloud that can be pitch-shifted and textured while the original note changes beneath it.

Assessment

What is the practical difference between using Nimbus on a Surge XT output signal vs. using it as a send effect on an external audio source? Name two parameters (from the Clouds manual) that control the granular density and diffusion.