Signal Architecture

The Hearth signal path starts with DC filtering and input conditioning, then splits into an analysis bus and a compensated emphasis path. The nonlinear core is built from three lanes: an anti-aliased tube lane, a quasi-hysteretic flux-memory lane, and a transient-gated bloom lane. The lanes are recombined, passed through complementary de-emphasis, corrected for stereo safety, and finally trimmed through a soft safety stage.

This architecture is intentionally white-box. Each lane has a narrow purpose, and the adaptation layer modifies only a small number of musically meaningful parameters. The device stays easier to reason about than a broad multiband distortion environment while still being richer than a static waveshaper.

The three-lane split is a design choice about responsibility. The tube lane supplies the main curve, the flux lane supplies path-dependent density, and the bloom lane reacts mostly to attacks. Separating those behaviors lets the device reduce one risk, such as bright upper harmonics, without removing every kind of warmth at once.