Note 1:43 in the video. Patternflow can be used as a controller via OSC.
"Patternflow is an open-source LED synthesizer — a 128×64 HUB75E matrix driven by an ESP32-S3, with four knobs wired straight into the pattern math. Turn a knob, and the pattern bends with your hand.
Everything is open source: STL files, Blender sources, PCB gerbers, and firmware. The full build runs around $100 depending on where you order parts.
— What's in the video —
0:00 This is Patternflow
0:08 How it works
0:26 Build your own (~$100)
1:04 Make patterns in your browser
1:42 OSC — a pocket-size VJ rig
2:03 Why it's open source
Patternflow began with Nam June Paik's Participation TV (1963), the first work where the audience could touch the image. I wanted to go one step further — so I built an instrument where you make the image yourself.
Polyphonic D50 sampler synthesizer with ESP32 in YAMAHA DX21 Hardwer :)
video upload by László Róbert Kasza
"Unfortunately, the motherboard of my dx21 synth is broken beyond repair. So she got new electronics. I have uploaded a code I wrote using Roland D50 sound samples.
So what everyone feared has come true. The Yamaha Roland DX-D50-21 :)
Abilities:
-4 d50samples
-TVA Envelope
Course, Fine, Keyfollow
-The sampling frequency is 48000Hz.
Signal on 16 bits or more
-The device is polyphonic up to 10 tones
2 LFO controlled 2 parametric EQ
-Upper Lower Choruse
-Reverb engine
-Roland D50sysex compatibility...
-hd44780 compatible LCD Display (Not implement more)
-https://data.dynareg.se/breadandbutte...
(If we are bored, we can listen to internet radio on it.)
"An update on the ESP32-S3 Polysynth build.
I've got the sound engine working really well, and it now has patch storage and retrieval, along with 2 wavetables - .wav files loaded off an SD card.
Next up is making it look pretty to match the sounds it can make!
In the video, all the sound is out of the back of the DAC, but as the synth is not multitimbral ( the ESP32 would melt ) I've multitracked a couple of tunes to demo the sort of sounds it can make.
Headphones on, and bonus points if you can identify the tracks!!"
"AcidBoxMynah is an alternative firmware that turns the Mynah into an acid groovebox. Based on the open source AcidBox project for ESP32. It provides an acid combo of tb303 + tb303 + tr808 like synths. Filter cutoff, reso, env mod, accent, wavefolder, overdrive within each 303, per-instrument tunings, hi-pass/lo-pass filter and bitcrusher in drums, send to reverb, delay and master compression
While the original project is headless, the AcidBoxMynah fork provides direct control with the Mynah hardware and adds a number of additional features detailed in the user Manual below. Like the original firmware, the AcidBoxMynah is open source and made available under the MIT license.
More info at https://groovesizer.com/"
Update: press release follows:
"Hot on the heels of Mynah's launch this past May, Groovesizer has released AcidBoxMynah - a free, open-source alternative firmware that transforms the ESP32-S3-based sampler into a dedicated acid groovebox.
Built on copych's open-source AcidBox project, AcidBoxMynah takes what was originally a headless engine and gives it a full physical UI on Mynah hardware - 24 tactile switches, an 8×2 NeoPixel grid, OLED display, and a single pot for hands-on parameter control. Under the hood, it's a combo of two TB-303-style synths plus a TR-808-style drum machine, with filter cutoff, resonance, envelope mod, accent, wavefolder and overdrive per synth voice, plus hi-pass/lo-pass filtering and bitcrushing on the drums, all routed through send effects and master compression.
The Mynah fork adds a 16-step sequencer with per-step note, accent and slide editing, 16-lane synth and 8-lane drum automation, scale quantization, swing, and manual Sequencer Mode in addition to the original's autonomous Jukebox Mode. Quality-of-life additions include runtime drum kit browsing, per-voice muting, and pot-lock to prevent accidental parameter jumps.
Like the original AcidBox, it's fully open source under MIT license.
Switching is effortless. Owners can flash AcidBoxMynah straight from the Mynah web app's firmware tab and swap back to standard Mynah firmware anytime - AcidBoxMynah keeps its own folder on the SD card, so nothing overwrites or conflicts with existing samples and patterns.
AcidBoxMynah is available now at groovesizer.com/acidbox-mynah."
"I built a simple 4 operator FM synthesizer using Elecrow's 10.1 ESP32-P4 smart screen ( https://tidd.ly/4yIlbuX ). Nothing groundbreaking, but I want to show you an UI idea I had, and if you're convinced, please start using it in your FM synths.
00:00 hi, what's this?
01:03 ESP32-P4 panel features
02.47 How to install ESP-IDF 5.4.4 in Visual Studio Code
04:29 A problem with common FM synthesizers
06:13 Reminder: FM principles
06:43 My UI idea
08:22 Sound demo
09:10 Conclusion
"This clip shows some of the range of sounds the synth produces. The Architecture is natively stereo, so put your headphones on!
I've added patch recall and storage via SD card, and got the arpeggiator running, so some of the sounds in the clip are just the arpeggiator, and I then adjust gate length / release / frequency etc.
Got a couple of little bugs to work on, but I'm pretty pleased with how it's progressed to date! Hope you enjoy the sounds :)"
"Carrying on from the initial clip, the Synth has now got its routing matrix on the CAN bus, so I can assign various modulation sources ( LFO1 / LFO2 / ADSR / Velocity / Mod wheel ) to any global destination ( Resonance / Frequency / Level / LFO2 / Unison Detune ) or any of the parameters for any of the oscillators - up to a maximum of 12 separate routes.
It's also Stereo now, so each oscillator has Pan control as a new addition.
All the audio in the clip straight out the back of the DAC on the ESP32 :)
Next step, I've added an SD card to the ESP32 so there will be patch storage, and also the ability to change wavetables, as it currently just uses a single Sinewave generated at startup.
"Today, we’re launching a new music hardware platform! Meet the AMYboard, a 10HP modular-sized synthesizer brimming with inputs and outputs for digital and analog audio, MIDI, and two CV channels. The AMYboard firmware runs Micropython, and can be controlled and programmed over the web, where you can share your own creations with others. You can also use AMYboard in Arduino to create music devices of your own design. It’s only US$29.90 - a very inexpensive way to get started making your own modular-capable synths. It can be powered over USB or a 10-pin modular power cable, and comes with a 10HP laser-cut faceplate. You can buy one today!
AMYboard is powered by AMY, the synthesis and effects toolkit that DAn Ellis and I have been working on for the past few years. AMY is a beautiful-sounding, efficient re-creation of classic analog synths – like the Juno-6 – and FM synths – like the DX-7. It can also act as a sampler, play WAV files, or let you make your own synthesizer setups in code from bare oscillators, effects, and filters. AMY is open-source and runs on all sorts of hardware. It already powers some neat synths like the Diapasonix, the Spark, and our own Tulip Creative Computer. AMYboard is our “reference hardware” for AMY - running the same ESP32-S3 as Tulip with 8MB of RAM, but with new features including both analog and S/PDIF (digital) audio input and output, enabling live effects, sampling, and filters. We’ve also added an SD card for sample storage, and an I2C host port for connecting your own displays and knobs!"
AMYboard launches with AMYboard online – a web based simulator and control surface for the AMYboard. You can experience AMYboard online before even buying an AMYboard. AMYboard online runs the same core engine as the AMYboard hardware (ported to WebAssembly) so you can set up and interact with the synthesizer over the web. When you’re ready, you plug in your AMYboard, download your patch, or control it in real time over the web, including the capability to edit and store code on your hardware that will boot up the next time you turn it on. AMYboard’s default firmware allows anyone to code their synth creations in MicroPython running on the hardware; the AMY synthesis engine itself runs in bare-metal C, but you can load your own “sketches” onto the board to build complex environments. For example, here’s a generative house track with a Derrick May custom “WOODPIANO” FM patch. Or here’s a TB303 + 808 acid setup. Or add a filter and reverb to a DX7 patch. AMYboard online also comes with AMYboard World, an online community for AMYboard users to share sketches with each other. We’re really excited to see your cool creations, please do share them!
"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."
"Rekke will be a hands-on experince, something new to make artists surpass the creative block through innovative sequencing tools and workflow.
This is an early prototype showcasing one of 8 channels, and 8 of 9 displays. Non-linear sequencing with Trigger repeat, note, division, length are shown"
Våld Labs Rekke at Synth Geekery #sequencer #diysynth #synth #electronicmusic
"Shout out to our aussie friends at Renzee podcast Synth Geekery for the kind coverage of our Rekke! #diysynth #techno #synth #sequencer #electronicmusic #synthesizer #arduino #3dprinting #esp32 #music"
"The MYNAH is a compact, DIY sampler that lets you record, chop, and perform your sounds anywhere.
Mynah is a compact, 6-voice polyphonic sampler you build yourself, powered by an ESP32 microcontroller and designed for musicians and sound explorers who want a truly tactile creative tool. Behind its approachable looks, Mynah hides a deep feature set including a 16-step sequencer, real-time and momentary effects like delay, reverb, filter, stutter, gate, and bit crusher. Mynah features dual audio inputs for recording from a microphone or line-in source. Samples are stored on SD card and loaded into RAM, giving you up to 16 samples per song and over two minutes of total sample capacity. Whether you’re programming beats, shaping textures, or performing live, Mynah puts serious sampling power in the palm of your hand.
Mynah‘s 16-bit, 32kHz ADPCM audio engine delivers the crunchy, characterful sound of classic samplers, while a companion web-based tool keeps your workflow modern and efficient. Manage your samples and songs, and export high-quality stems — all from your browser."
Synth engine:
Wavetable engine.
Sampler: WAV files on SD card 44100Hz, 16 Bit, Mono
16 sound polyphony.
A track can be sampler or synth
Multi OSC feature..
Sequencer:
16 step/pattern editor and random generators (pattern, sound parameters and notes)
16 memories (each 16 patterns of 16 tracks)
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"
"I quickly built this encoder based hardware editor for Tauntek upgraded poly 61 boards, it's fairly simple and uses an ESP32 Dev board and io port expanders."
"Finally got hold of an Akai AX-80 to test my replacement displays and after having to replace one ESP 32 because it refused to load a sketch I finally managed to wire up all 3 displays to the AX, I had to replace the AX power supply as my 220v to 110v converters all gave out. But it does mean the power is 100-260v now for any country. Still need to build the second board and buy some more ESP32 Dev boards."
"Here's the #seeed 'XIAO MIDI' #synthesizer, a $20 box based on the #SAM2695
synth-on-a-chip and the XIAO ESP32-C3 MCU. You can get it here:
https://www.seeedstudio.com/XIAO-MIDI...
Table of contents:
00:00 quick sound impression 00:12 hi 00:38
hardware overview 00:57 default firmware 01:50 creating a firmware
that actually supports MIDI (shoutout to @SimpleDIYElectroMusicProjects ) 03:12
build a 5 pin MIDI in plug 05:23 some sounds: piano 06:20 saw wave
pad 06:34 "crystal ep" 07:13 analog pad 07:27 'glass pad' 08:05
synth brass 08:23 drum kit 08:33 on NRPNs and SYSEX using
@intechstudio 's GRID controllers 09:13 NRPN explained (Filter cutoff
frequency control) 10:54 SYSEX explained (Reverb time control) 11:38
calculating the checksum 12:20 live tweaking demo 13:01 same, but
using multiple tracks 14:25 conclusion; some feedback to SEEED
Features 1: Zero-Barrier Creation, Perfect for Music Beginners
With three preset modes and plug-and-play functionality, you can dive straight into music creation—no complex setup required. Built-in speaker and four tactile buttons deliver an intuitive, self-contained experience that eliminates external dependencies. Start making music from the very first note, no prior expertise needed.
Features 2: All-in-One MIDI + Metronome – Smarter, Smoother Workflow
XIAO MIDI synthesizer comes with a pre-set Metronome Mode, where you can press the buttons to change your BPM and toggle the drum track to effortlessly sync rhythms and control your entire beats with one single device. No need for extra devices or apps.
Features 3: Pro-Grade Performance for Advanced Players
Open-source hardware/software architecture supports deep customization and advanced sound design. With 64-note polyphony and 128-note capacity, unlock limitless sonic possibilities—craft your own signature sound engine, whether you're a beginner or an audio hacker.
Features 4: Ultra-Portable & Fully Hackable
Pocket-sized design (71mm × 49mm × 28.5mm) lets you capture inspiration anytime, anywhere. The 3D printed enclosure is fully open-source for you to remix and customize—not just an instrument, but your personal music canvas.
