ESP32-S3 PolySynth - Work in progress

video upload by Bad Dog Designs

"This is a fully functioning Polysynth using an ESP32-S3 to model the audio in real time, from an initial single Sine wavetable calculated on power up. The control panels for the oscillators and common controls all use CAN bus to communicate parameter changes to the audio engine - rather than wiring up a lot of IO, it just sends a message like 'Change oscillator 3 to Sawtooth'

Basic spec so far:

6 oscillators in 3 pairs that have Sine / Triangle / Saw / Pulse / Noise and Chaos waveforms. There are then independent wave folding modifiers and Sample and hold modifiers. Each oscillator pair can also be hard sync'd to it's partner for mono use, or FM modulated.

Common controls have ADRS envelope control, High / Low / Band pass filter with Envelope and tracking control. Ring modulator and Play mode selector for Unison / Duo / Poly. 2 re-triggerable LFO's with delay.

Currently working on the routing section that will allow pretty well anything to modulate anything else stored as separate routes - up to 12 routes can be applied at once. Then patch storage and recall, and hopefully some nice analogue FX at the end.

In the clip, all the audio is straight out the back of the DAC with no processing or FX."

TRESSE by Våld Labs — 39 Engine Polyphonic Desktop Synthesizer | Demo 3

video upload by Våld Labs

"3-voice polyphonic synth powered by ESP32-S3. 24 modified Mutable Instruments Plaits engines + 14 original engines and a FreaqFM-inspired engine. DIN, USB-C & Bluetooth MIDI. Built-in FX. 1000+ presets.

🔗 More info soon

🔊 ALL 39 ENGINES (current count)

— MODIFIED PLAITS ENGINES (0–23) —

00 EastCoast · Detuned virtual analog, variable waveforms
01 PhaseDist · Triangle through waveshaper/wavefolder
02 DX7 I · 2-op FM bank 1, variable feedback
03 DX7 II · FM bank 2, metallic/percussive
04 DX7 III · FM bank 3, brassy/complex
05 Terrain · Dual formants, VOSIM/Pulsar/CZ-style
06 StrChor · String machine/organ chord generator
07 Chiptune · 8-bit chord engine

CLICK FOR MORE »

Våld Labs Tresse: a multiengine synthesizer based on Plaits, for desktop.

video upload by Våld Labs

This one was sent my way via Meska who had the following to say: "It's 'basicaly' a standalone MI Plait with 3voice and extended oscilator models."

Video description follows:

"Tresse — 3-voice polyphonic desktop synth, 38 engines

Hey all,

Been working on this for a while and it's finally at a point where I want to share it.

*Tresse* is a standalone polyphonic synthesizer built around Mutable Instruments' Plaits DSP code, running on an ESP32-S3 with a custom PCB. Three voices of polyphony, 38 synthesis engines, USB, DIN/TRS and Bluetooth MIDI, and perhaps Ableton Link and our upcoming stack (VMB) Våld Modular Bus, expected to ship this summer, and which will a new wireless comms protocol with negligible latency, auto discovery and machine mesh capabilities (to be released soon).
Also enough knobs and encoders to actually play the thing without menu-diving, and a battery for when you're bored outside of your studio.

*The core idea:* take the full Plaits engine library — all 24 algorithms — and make it polyphonic in a self-contained hardware instrument. Then keep going and add 14 more custom engines on top.
There are hundreds of options similar to this in modular systems and i thought why not bring all these god-level creative tools to bedroom, desktop producers who don't have the money or the space (or will) to mingle in the modular space, and bring them one contained box with all they need.

What's inside

*ESP32-S3* doing all the DSP across both cores (voices 0+1 on Core 1, voice 2 on Core 0, parallel render)
**PCM5102A DAC**, 24-bit output, 32kHz sample rate
*4 pots + 4 rotary encoders* through CD74HC4067 mux and MCP23017 I2C expander
*OLED display* (128×64) for patch info, engine select, preset browsing
*USB MIDI + BLE MIDI* — works with everything, no adapter needed for wireless
Custom PCB, all through-hole friendly

38 engines

The first 24 are straight from Plaits — East Coast, Phase Distortion, all three DX7 variants, Terrain, String/Chords, Chiptune, Wavetable, Speech, Swarm, Particle, the Rings modes, the three drum engines, etc.

Then 14 custom engines built from scratch:

*Karplus-Strong* — proper physical string modeling with excitation morphing (noise → impulse → tonal)
*ByteBeat* — 8 classic formulas with pitch-tracked rate, gets wild
*CZ Phase Distortion* — Casio CZ-style, three distortion shapes
*Supersaw* — up to 7 detuned saws with PWM, the obvious one but it needed to exist
*Formant* — vowel synthesis with 3 bandpass resonators, gender shift control
*2-Op FM* — clean FM with 13 ratios and operator feedback
*Wavefolder* — sine/tri/saw/square source into a proper folder with bias
*Noise Drums* — SVF-based with pitch envelope, covers kicks through metallic hits
*Modal Resonator* — 8 tuned bandpass partials, morphs from harmonic → bell → bar inharmonicity, with a bowed excitation mode
*Sympathetic Strings* — 3 coupled Karplus delay lines with controllable coupling and interval ratios
*Comb Resonator* — 4 parallel comb filters with spread control
*Drawbars* — organ-style additive with 8 Hammond-ratio partials
*Complex Oscillator* — FM into wavefolder, Buchla-adjacent territory
*Grain Noise* — granular noise with smoothing, good for textures and pads

Controls

Three parameter layers accessible via toggle buttons:

*Normal* — Timbre, Morph, Harmonics, Color on pots; Attack, Decay, FM, LFO Depth on encoders
*MOD* — Fold, Detune, Ring Mod, Chorus on pots; LFO destination/shape/speed/sync on encoders
*SHIFT* — Filter Cutoff/Reso/Env/Type on pots; Portamento, Octave, Vibrato depth/speed on encoders

Hold both buttons → engine select overlay. Double-tap MOD → system menu (randomizer, MIDI config, play mode). Double-tap SHIFT → preset browser across three banks (own patches, generated, branches).

Play modes: Poly, Mono, and chord modes (Major, Minor, 7th, Sus4, Power, Octave).

The randomizer is one of my favorite things — it generates random patches with procedural names (stuff like "Velvet Moth" or "Iron Shard"), you scroll through them with the encoder, and save the ones you like to a generated preset bank. 512 slots each for generated and branch presets, 128 for your own.

What it sounds like

Honestly covers a lot of ground. The Plaits engines already span everything from classic analog to FM to physical modeling to noise, and the custom engines fill in some gaps I wanted — proper supersaw, real Karplus-Strong, the modal/sympathetic stuff for metallic and evolving tones, and the ByteBeat engine for when you want to go full chaos. The global FX chain (filter, wavefolder, ring mod, chorus) ties everything together.

The project should be available from April 2026, in kit or assembled units! Price to be discolsed once i have the final FINAL prototype, but shouldn't hurt the wallet.

This is a *Våld Labs* project from Lisbon Portugal. Much more to come.

Would love to hear what people think, and happy to answer questions about the build or the DSP. Be aware that this is a pretty advenced prototype, but still a prototype"

https://valdlabs.com

Note they also have the Consequencer pictured left but no additional info aside from the following on it yet.

"A portable, desktop-first sequencer with modular DNA — built for the art of shaping chaos."

CubuSynth also has a Consequencer announced back in 2024, but they appear to be unrelated.

Introducing Pipo Interfaces

A Sneak Peak into Pipo modules video upload by Pipo Interfaces

"Video produced by Tom Bouchet

Music: "Transition" by Alex-Productions (CC BY 3.0)"

Press release follows:


Pipo Interfaces brings a new versatile toolkit for creative sensing and audiovisual interactions in real-time.

Developed by creative technologist Rupert Renevier, Pipo is a range of electronics modules that connect sensors to computers, and are meant to simplify creative interactivity between people, real-world objects, and digital creation.

Whether you're performing, designing experimental MIDI instruments, or interested in making installations, Pipo builds the foundations of an accessible and adaptable open source toolkit.

When digital experiences become sensible and tangible, they allow for greater engagement and connection. The idea of using sensors for audiovisual applications and arts is far from being new, but still requires building custom solutions on Arduino or Raspberry Pi, which tends to be complex, time-consuming, and therefore not easily accessible to most.

Pipo wants to unlock the creative potential of real-time sensing, and lower the technical barrier to it, by proposing tools that connect the physical world to the digital in a straightforward fashion.

The Pipo recipe is simple: small affordable modules, wireless capabilities, and an intuitive yet powerful user interface. All Pipo modules can be used alone or in combination, fixed, worn on the body, embedded in objects, etc... All Pipo modules have mounting holes to augment all kind of projects and casing will be made available.

The first 3 modules of the family are Pipo Motion, Pipo Range and Pipo Analog.

Pipo Motion is dedicated to sensing movement: orientation, acceleration and magnetic field, thanks to an advanced 9 axis IMU (Inertial Measurement Unit). It allows for relative and absolute orientation.

Pipo Range is an accurate distance sensing unit which can be used to detect hands, obstacles, objects, or people (up to 3m). It can be used the same way as a theremin, or as a people proximity sensor for eg.

Finally, Pipo Analog, a versatile Input/Output device. On one side it has 8 capacitive touch inputs to create original touch buttons (for eg: with wires, metallic tape, vegetables, conductive paint, etc...)

On the other side it has multiple analog voltage inputs/outputs (up to 8). With these you can acquire and use any external buttons, specialized analog sensors modules, knobs or control servo motors, drivers, etc...

Beyond these three first sensing modules, Pipo Interfaces carries a vision for a whole creative ecosystem for many more input and also output modules. It has a strong anchor towards open source development and wants to create a strong user community connection.

Pipo modules can all send standard MIDI and/or OSC data wirelessly for maximum compatibility.

The connectivity is made through WiFi, Bluetooth Low Energy, or USB and every module has an onboard battery charger, so that whatever idea you have, you can test it quickly and have it communicate to your audiovisual software in a matter of seconds (no matter your operating system).

All the settings can be tuned in the field through a web interface hosted on every module.
No need for an app or software, just open any web browser on your mobile. This interface allows you to set various settings like sensing parameters, ranges, and to adapt the incoming and outgoing data streams to your needs, quickly and easily.

You can for example eg fine tune the midi output, choose a note scale, channel, etc...

On a technical level, the project is developed with PlatformIO and the Arduino framework to make it easy for people to hack, modify, upgrade their pipos, or build their own custom Pipos. The software is open source, and the project runs on the Esp32-s3, one of the most versatile and powerful IoT chips around.

Pipo will launch as a pre-order campaign to fund the first production run. If you like Pipo, you can support it by entering your email address on the campaign page, it means a lot ! By doing so, you will also be notified of the launch date, so that you can be among the first people to get yours.

The launch date is pending on gathering a critical mass of people who want to see the project going live, so subscribing helps the project move forward.

All this happens on CrowdSupply, a platform dedicated to launching open source projects:

https://www.crowdsupply.com/pipo-interfaces/pipo