White noise through a modulated bandpass filter is the practical modular hat synthesis patch

The standard eurorack hi-hat voice starts with white noise as the source (rather than multiple oscillators) and runs it through a bandpass filter whose cutoff is swept by a fast decaying envelope. A second envelope shapes the VCA amplitude; an accent input lengthens the VCA envelope for louder, longer hits. Filter resonance and center frequency set the tonal character — around 2 kHz with high resonance is a common starting point. This approach is inspired by the 808’s topology but replaces its six oscillators with noise, making it feasible in a minimal system. Tweaks beyond the basic patch: add reverb or distortion as further processing.

Examples

Patch: white-noise source → bandpass VCF (cutoff ~2 kHz, high resonance) → VCA. Dual envelopes from a dual-EG module (e.g., Pons Asinorum): env 1 modulates VCF cutoff; env 2 modulates VCA. Sequencer gate triggers both envelopes; accent CV lengthens env 2 for emphasis.

Assessment

Given a patchbay with a noise source, a VCF, a VCA, and a dual-envelope module, describe the patch order and which envelope modulates which destination. Then adjust filter cutoff and resonance to contrast a closed-hat versus open-hat sound.