Kai's Tone Shader

A JSFX (Reaper) library that explores a non-skeuomorphic approach to guitar tone.

Instead of simulating physical circuits (capacitors, tubes, voltage), this project builds tone using pure mathematical functions and signal processing concepts. I call this "Tone Shading"—similar to how graphics shaders calculate color, I calculate sound.

Philosophy

Most amp sims try to replicate 50-year-old hardware, limiting you to the flaws and interfaces of the past.

Here, I deconstruct the guitar amp into its mathematical functions rather than simulating physical components:

1. Distortion is Waveshaping: I use kernels (tanh, sigmoid) and Chebyshev polynomials to shape harmonics, not tube simulations.
2. Tone Stack is EQ: I use precise digital Biquad filters, avoiding the messy interaction of passive analog circuits.
3. Cabinet is Convolution: I use procedural Impulse Responses and envelope followers to shape the frequency and dynamics.

Audio Demo

A comparison to verify that this approach produces a usable tone (it doesn't have to be "better" here).

Sample	Description	Playback
Riff 1 (A)	Modern High Gain	▶️ Listen (Source A)
Riff 1 (B)	Modern High Gain	▶️ Listen (Source B)

🔍 Click to reveal sources

• A: Logic Pro's Amp Designer, "Modern British Stack" (Circuit Emulation)
• B: Kai's Tone Shader (Functional "Shading")

Structure

The DSP is split into three modules:

1. Core (Preamp): Handles waveshaping and harmonic distortion.
2. Tone Stack (EQ): A flexible 3-Band EQ.
3. Output (Power Amp/Cab): Handles physically-inspired EQ and final time-domain smearing (procedural IR).

How to Use

1. Download this repository.
2. Open Reaper.
3. Create a new JSFX plugin and paste the code from the effects folder.