Awesome

What is it?

Stompbox is a guitar amplification and effects library.

This repository is the core codebase. It can be run as a headless jack client using the stompbox-jack application.

StompboxUI is the front-end GUI repository for stompbox. It can be used as a remote application to connect and control stompbox-jack, or it can be built along with the core code into a VST3 plugin.

I run it as both a VST3 plugin in a DAW on my PC, and (mostly) headless on my Raspberry Pi pedalboard.

Here is a video of it running on my pedalboard:

This is the hardware I'm using:

• Raspberry Pi 4
• Hotone Jogg audio interface
• Hotone Ampero Control MIDI Controller
• Wio Terminal (used for a display using my SerialTFT app)

Features

• Headless operation with a separate UI app that can be run remotely or locally
• MIDI support for switching presets, toggling effects
• Neural Amp Modeler and RTNeural model support
• Cabinet impulse responses
• Tonestack/EQ
• Noise Gate
• Drive (clean boost, tube screamer)
• Time-based effects
  • Delay
  • Reverb (algorithmic and convolution)
  • Compressor
  • Chorus
  • Phaser
  • Flanger
  • Tremolo
  • Vibrato
  • Wah/Auto-Wah
• Tuner
• Audio file player

Building

If you just want to run Stompbox as a Windows VST plugin, head over to the StompboxUI repository and you can download binaries from the Releases section there.

To build it yourself, read on.

First clone the repository:

git clone --recurse-submodules -j4 https://github.com/mikeoliphant/stompbox

Building stompbox-jack in Linux

To build the stombox-jack client, you need to have the jack development libraries installed:

sudo apt-get install libjack-jackd2-dev

Then compile the plugin using:

cd stompbox/build
cmake .. -DCMAKE_BUILD_TYPE="Release"
make

Building stompbox-jack in Windows

You need to have jack for windows installed:

https://jackaudio.org/downloads/

Configure the stompbox build with cmake:

cd stompbox/build
cmake.exe -G "Visual Studio 17 2022" -A x64 ..

This will get you a Visual Studio solution with projects for the core library and stompbox-jack.

Running stompbox-jack

After building, the binary will be in build/stompbox-jack.

You must have jack installed and configured to run on your audio device. If jack is running (as the same user you run stompbox with), the running instance will be used, otherwise jack will be started using your default configuration.

stompbox-jack takes a single optional command-line argument - the name of the preset to start with.

Currently it will connect to the first available jack audio input, and the first two available jack audio outputs. It will also connect to any available jack midi inputs.

The following folders are epected to exist in the same folder as the stompbox-jack executable:

Presets - folder to store configuration presets

NAM - folder containing .nam amp models

Cabinets - folder containing .wav format cabinet impulse responses

Reverb - folder containing .wav format convolution reverb files

Music - folder containing .wav audio files for the built-in audio looper

MIDI Support

If you have MIDI enabled in jack, MIDI devices can be used to control stompbox behavior.

Via the remote user interface, you can configure ("..." -> "MIDI CC Map" in the UI) any MIDI CC to control whether an effect is enabled, or to control any effect parameter.

In addition, if you send a MIDI patch change event, stompbox will attempt to load a preset starting with the patch number (ie: MIDI patch change to 2 would load "02MyCoolPreset").

Some more complicated MIDI stomp-based UI is also available if you are running the serial display interface - it gives interactive access to patch changes, tuner, stomps, etc.

Display Options

There are a number of display options for interfacing with stompbox:

• StompboxUI - that repo has apps that can run as remote displays on Windows, Linux and Android. The Android interface also has a display mode designed for a phone or tablet mounted on a pedalboard.
• Serial display. Stompbox has built-in support for talking to a USB-connected microcontroller with display. I'm using a Wio Terminal , but any Arduino-compatible microcontroller with an SPI display should work. It requires installing my SerialTFT Arduino sketch on the microcontroller.

This is what the Windows/Linux remote looks like:

This is what it looks like running as an Android remote: