Motivation

Modern saturation plugins increasingly treat warmth as a signal path rather than a single transfer curve. Commercial tools such as Ableton Roar, FabFilter Saturn, Soundtoys Decapitator, Goodhertz Tupe, transformer models, and tape models all show the same broad pattern: shape the spectrum before the nonlinear element, control the dynamics around it, and suppress aliasing enough that the added harmonics read as density instead of digital glare.

Hearth takes that lesson but narrows the product goal. It is not meant to be an all-purpose sound-destruction palette. The first release is a live-safe Max for Live device whose default operating region favors body, nostalgia, and low-risk musical coloration. The core question is how much harmonic interest can be added while keeping brightness, roughness, transient damage, and stereo drift under control.

In audio DSP, saturation means a nonlinear process that bends waveform peaks and creates harmonics. That can make a sound feel louder, thicker, or more present, but it can also create harsh high-frequency energy, aliasing, DC offset, and stereo image shifts. Hearth is built around the idea that pleasant saturation is as much about restraint and compensation as it is about distortion.

• Target use cases: vocals, clean guitar, bright synths, drum buses, and full-mix glue.
• Primary constraint: density without roughness.
• Implementation target: one Max for Live audio effect with most DSP in a Gen core.