pi-Stomp is an open source high definition multi-effects stompbox platform for guitar, bass and keyboards. The base install contains over 350 plugins - effects, modeled amps & cabinets, loopers and sound generators (synths).
It sports 24-bit, 48 to 96kHz stereo audio and a Raspberry Pi 64-bit quad core processor running at 1.4 GHz
Numerous virtual pedalboards containing up to dozen (or so) plugins, can be constructed via MOD, a super powerful yet easy to use drag-n-drop web user interface. Each pedalboard can be saved with multiple “presets”, each being a snapshot of all the parameters for a given sound.
Once your pedalboards are saved, only the pi Stomp is needed on-stage, at home or in the studio.
An LCD shows an overview of the current pedalboard. Navigation is done via rotary encoder and allows quick changes of the pedalboard, preset, plugin bypass, deep plugin editing and global settings.
The original pi-Stomp was the first DIY HD Multi-FX platform available in kit form. Over 40 pi-Stomp pedals have been built in 11 different countries!
A common request was the ability to further customize the hardware. The idea behind pi-Stomp Core is to provide the core functionality but allow the builder to decide the types of controls & how many, whether to include DIN MIDI, etc. Even the audio card and LCD can be exchanged for other models.
pi-Stomp Core is thus, smaller, cheaper, easier to build and incorporate into your dream audio processing project. This is possible by providing interface headers for all of the peripheral functions. The same default pi-Stomp software is used, leveraging the original pi-Stomp history and userbase.
pi-Stomp Core also adds a nifty color TFT LCD display and some usability features allowed by the increased resolution.
This wiki is admittedly quite text dense. Visual learners might get more from watching this 11 minute overview
358 Total plugins
All of these plugins are included: https://github.com/brummer10/GxPlugins.lv2
Most of the plugins listed here are included: https://pedalboards.moddevices.com/plugins
It's mainly the newer ones, or the plugins MODDevices charges for which are not
See a variety of actual pedalboards and listen to Recorded Samples
pi-Stomp Core Hardware Specs:
Here we have pi-Stomp Core configured to offer all the functionality as the original pi-Stomp including:
Here's a later build into a 1590J enclosure with 2 assignable analog tweak knobs and undermount LCD
Why pi-Stomp? Can I do XYZ and other Frequently Asked Questions: pi-Stomp Core FAQ
Because some build choices are dependent on the enclosure you plan to use, we recommend that you read this before building: Enclosure Consideration Guide
Go here for the build guide: pi-Stomp Core Build Instructions
Once you have your core system built, you'll likely still want to add switches, controls (knobs, expression pedal, etc.), MIDI in/out, etc.
This guide presents some options: Customization Guide
Go here for the Software Installation/Update Guide
If you run into any hardware or software problems, first, consult the troubleshooting guide
pi-Stomp is intended to be a platform. MOD is the current recommended software for audio processing and configuration, but other Linux audio software, especially if it uses Jack for audio routing, might “just work”.
Here we'll explore some possibilities: Other Software running on pi-Stomp hardware
You may not have noticed that the input and output jacks are “stereo” TRS jacks. This allows 3 general types of connection:
The rendered color for a plugin is determined by its assigned Category (as seen in the MOD webui). The category colors can be changed in pi-stomp/pistomp/lcdcolor.py. Defaults are:
Unless overridden by a *color* property in the default_config.yml file, any assigned (aka “midi learned”) footswitches or analog controls will be also be colored using the plugin category. For example, a footswitch assigned to the enable of an distortion plugin will show Lime green when enabled, gray when disabled. A potentiometer assigned to the distortion gain will display with a Lime green knob icon, a reverb control will display blue.
The System Menu includes a number of utilities for managing the system. Access the menu by scrolling to the wrench tool and click. Scroll to the desired action and click to execute.
Pedalboards are created and edited using a web browser via the MOD web UI. You connect to the pi Stomp over Wi-Fi. Just point a browser on your computer to
You can check the wifi mode and IP address from the System menu:
hotspot_active indicates whether pi-Stomp is available via hotspot or via router
The IP address to point your browser to is also displayed. For hotspot mode, this will likely be “220.127.116.11”. For router mode, it'll be the address space assigned by your router (eg. “192.168.1.150”)
The wifi mode can be toggled between hotspot and router modes by selecting Enable Hotspot or Disable Hotspot then clicking. It may take a few seconds to complete the connection.
Hotspot mode is generally preferred because it makes it more portable. Software download/updates require an internet connection and thus won't work in hotspot mode.
You should see something like the following showing your currently active pedalboard:
For detailed usage, see the MOD User Guide: https://wiki.moddevices.com/wiki/MOD_Web_GUI_User_Guide
Saving your pedalboards writes them to the pi Stomp SD Micro drive. No computer is required from that point while accessing your pedalboard(s) from the pi Stomp. Once you save a pedalboard via the MOD UI, you can sync the hardware: Long-press the encoder until the System Menu shows. Then select “Reload pedalboards”.
Please note that while you are editing pedalboards, it's best to use the MOD web UI for switching pedalboards, not the knob on the pi-Stomp. If you use the knob, it's likely that the web UI will not track correctly and any saves could end up overwriting a previous pedalboard. This is a known issue with the MOD web UI when controlled via REST. Hopefully, it can be resolved in a future update.
Although you can just pull the plug, there's a very small chance that the file system could become corrupt. It's best to shut down services cleanly before powering off a Raspberry Pi. That's typically done by a connected keyboard/monitor or connected computer, but we don't have that option. Instead, the best practice is to use the System shutdown action under the System Menu.
The “pi Stomp” splash screen text will appear red when shutting down and green when booting to indicate what it's doing.
If having a switch would simplify power on/off, these in-line switches work well. They're sometimes available as an add-on via the treefallsound.com parts store. If you find a similar model, make sure it has 5.5mm x 2.5mm connectors, not 2.1mm.
Tree Fall Sound exists to bring multi-effects projects to DIY musicians. So far, we're a company of one. My name is Randall Reichenbach.
My “day jobs” have been in Electrical and Software Engineering, but my main passion has always been music. I’ve been building effects pedals and other musical gadgets since the 1980’s (read “experienced”, not “old”). I’ve always been obsessed with tone, usability and clever features. I love my (mostly analog) pedalboard, but like many musicians, I’ve long desired the ability to store awesome presets, recall them in real time, and control the effects in unique ways. As a programmer/tinkerer, I've also always wanted to be able to code (not just tweak) my own effects.
How cool would it be to create a do-everything open expandable platform, easily modifyable by anyone not too afraid of Linux, Python, etc. ? That's the idea that got me rolling on this project. Raspberry Pi and high def sound cards along with some open source software like LV2 (plugin format) and MOD/MODEP, have finally made such an endeavor possible.
I created this project because I know there are others like me that would be waaay more excited playing with a piece of gear they built and can modify by getting under the hood of the hardware and software. I spend well over 20 hours on it every week and will continue to as long as there is new functionality and features to explore. I’m hoping others will join me in this endeavor and take this platform (or their own) to places I’ve not even considered.
Some of my music can be heard at: https://soundcloud.com/user-368371534
An extensive interview and more pi-Stomp background on Blokas Reads
I love the Earth. I hope you do too. Electronics are inherently not good for our planet. My hope is that by building something yourself that can be upgraded, you'll be able to make use of it longer than you would have a commercial product, and that you might be able to reuse or recycle many of the components when its life is truly over.
The only non-RoHS compliant components in the current design are:
When you are done with your pi-Stomp, please consider using the Raspberry Pi, LCD, etc. for other projects or donating them to your local Makerspace.
If you eventually dispose of your pi-Stomp components, please do so according to your local guidelines. Removing the non-RoHS parts shown above to deal with them appropriately is encouraged. Thanks!
The Internet is a huge polluter of the environment.
treefallsound.com is hosted by GreenGeeks
The carbon footprint is reduced (not offset) by matching every amp they pull from the grid with 3 times that in the form of renewable energy via Bonneville Environmental Foundation. They also plant one tree for every hosting account they provision.