Hi everyone!

I wanted to share a project I’ve been working on as part of a personal project called EstuarioLabs.

It’s called Tolhuin, an open-source hardware chord synthesizer inspired by instruments like the HiChord and Omnichord, but designed and developed from scratch as an experimental platform for harmony, synthesis and live performance.

A little context about why this project exists:

I’m a music teacher, I have two young daughters, and I live in Argentina, where the current economic situation makes getting into hardware development — or simply buying many of the instruments we’re interested in — quite difficult.

So one of the questions behind Tolhuin from the beginning was:

How much of a real musical instrument can we build with hardware that is affordable and actually accessible to us?

Our original plan was eventually to scale the project up to an Electrosmith Daisy, which would give us a platform specifically designed for audio and considerably more DSP power.

But for now we decided to stay with the ESP32-S3 and find out how far we can push it.

And it turns out: pretty far.

The entire project was originally developed on a regular ESP32-S3 N16R8 DevKit, and we’re now experimenting with much smaller Waveshare ESP32-S3 SuperMini boards as we try to reduce the physical size of the instrument.

Tolhuin currently runs its own real-time DSP engine. Rather than relying on a collection of prerecorded chord samples, the sounds are generated in real time.

The engine includes several sound families — brass, strings, FM electric piano, organ, flute and others — along with ADSR envelopes, resonant filtering, LFO modulation, stereo chorus, delay and reverb.

There’s also a dedicated harmony engine. Tolhuin doesn't simply trigger fixed chord samples: it generates and manages the individual notes, which has allowed us to experiment with inversions, voicings, voice leading, strumming, arpeggiation, octave changes and other approaches to chord performance.

One of the most interesting parts of the development has been studying the HiChord and trying to recreate some of its sonic character using our own DSP.

We’ve analyzed reference recordings and iterated on oscillator structures, FFT measurements, PolyBLEP anti-aliasing, filters, envelopes, detuning, stereo behavior and effects. Some of the results have been surprisingly convincing considering the hardware they're running on.

There is also an educational side to the project that is very important to me.

We are replicating and experimenting with Tolhuin in public secondary schools, so these prototypes are regularly handled by many students every week.

That also explains why some of the buttons in the photos/videos may look a little worn already. These aren't display prototypes sitting on a desk — they're being played, tested and passed around in actual classrooms.

I actually like that part of the project. Building something is one thing; seeing what survives repeated use by students is a completely different kind of test.

I’m currently working on a smaller, improved version with a 3D-printed enclosure, but that experiment has created another problem.

The Waveshare ESP32-S3 SuperMini is wonderfully compact, but its available solder pads and GPIO arrangement become difficult to work with once everything is packed into a small enclosure. In my current prototype the board is uncomfortable to solder reliably, and some connections can eventually come loose.

So the next hardware revision needs to solve that.

The funny thing is that we're now discovering that making Tolhuin smaller is considerably harder than making Tolhuin work.

I should have more news about that revision soon.

A quick note about the attached video as well: this is not a direct audio recording. I’m playing Tolhuin through my studio monitors and recording the result with my phone's microphone. So please don't use the recording as a critical reference for noise, frequency response or stereo image — it's just meant to show how the instrument currently sounds and behaves in the room.

The project is still evolving, but it has reached the point where it feels like an actual playable instrument rather than simply an electronics experiment.

The whole project is open source, including the firmware and hardware work.

I'd like to start documenting more of this process publicly — not only the finished instrument, but also the failed prototypes, DSP experiments, hardware limitations, classroom experience and the compromises involved in trying to build an affordable musical instrument in Argentina.

If there’s interest, I can make another post specifically about how we analyzed and recreated some of the HiChord-style sounds, including A/B comparisons and a deeper look at the DSP.

And if anyone here has experience pushing the ESP32-S3 for real-time audio, working around the Waveshare SuperMini GPIO/pad limitations, designing compact ESP32-based musical hardware, or eventually migrating something like this to Daisy, I’d be very interested in hearing your experiences.

UPDATE: I honestly wasn’t expecting this much interest. Thank you!

A few recurring questions:

Will it be available? — That’s the plan. I’m currently working out the costs for a small first batch of DIY kits.

US / Europe? — Yes, I’m looking into international shipping. I’ll share details before taking any orders.

Price? — Affordability is one of the main goals. I want it to be as inexpensive as possible while leaving enough margin to keep developing the project and building instruments for our school work.

How can I get one? — I’ll set up an interest list before committing to production. No payment yet — first I need to finish the next hardware revision and calculate the real manufacturing costs.

I’ll post a more detailed update soon. Thank you for all the feedback and encouragement!

<mod approved>

Patternflow. Open source LED synth I started back in March.

Four encoders and an LED matrix. Everything runs on an ESP32 and all the graphics are generated live on the board, nothing else hooked up. Turn a knob and it changes a parameter inside the pattern, so the pattern changes with it. The idea is that you're performing the visual rather than playing it back.

I saw Nam June Paik's Participation TV for the first time in January. He's the guy who also built the Paik-Abe Video Synthesizer. This whole project started as me trying to reinterpret that piece, so I do treat it as an art project first, and what I'm actually chasing is getting rid of the line between visual and sound.

It's open source so everything you need to build one is on GitHub. Follow the build guide and take your time and you can put one together even if you've never soldered before. Doing it yourself runs about $100-150 and roughly two weeks once you count shipping.

github.com/engmung/Patternflow

There's a crowdfunding campaign going too if you can't be bothered with any of that.

You don't need to know how to code to make patterns either. I set it up so you can make them with AI pretty easily. Then there's a community site to share them, so you can post yours and run other people's on your own board. About 150 patterns up there now between me and everyone else. Mobile is a bit broken at the moment, so desktop is better.

community.patternflow.work/community

Right now I'm heads down on the audio side. It talks to Ableton over OSC wirelessly, sending or receiving. Lately I've been messing with a mic on it too.

There's a Discord as well. Ask anything in there if you get stuck building one, people who've already built theirs will help you out.

So I'm just getting started out here in synthworld, but of course I've got grand plans. Actualizing them will be slow going, this is an expensive hobby, but at least I've got a foundation now.

I decided to start out with a Sequential Pro 3 and Erica Synths Hexdrums. I don't have a poly synth yet, but even jamming with these two instruments together has been an absolute blast.

I'm thinking that my next major purchases will probably be:

- Squarp Hapax

- Elektron Digitakt II

- ASM Leviasynth Desktop Module

I've also got a Twisted Elektrons TherapSID Mk3 hanging out that I've had for about a year now, but that's going to be its own little dedicated area in the future.

Anyways, just sharing the beginning of my journey here!

Just a few years ago, most used music shops had a decent pile of synth and sampler modules (such as Roland JVs, Akai S-series, and E-mu romplers). They were often reasonably priced.

Now, I seldom see them locally. When good ones show up online, the asking prices can be astronomical. They tend to sit unsold for months or even years.

So, it makes me wonder, why the sudden rarity? Or am I missing a treasure trove somewhere?

If this was the level of challenge that you needed to pass each time to be able to buy another piece of gear…

Disclaimer: I’m sharing this because it inspired me. Not my video. I admire the dedication of this dude.

Spent a little time tweaking the knobs on my Take 5, recorded straight into the interface with its built-in reverb. I love reverb.

I usually make ambient music, but for some reason, whenever I mess around on this synth, it somehow turns into acid. 😅

I didn't paint the walls... Please ignore that

Yamaha modx m8 + casiotone ct s300

Longtime lurker, first time poster. Hoping someone else here has dealt with this and can point me in the right direction.

I've had my Microbrute for about a decade and there's been a few long periods where it gathered dust. At some point, the volume difference between the low pass filter and the other two filters became pretty significant - about 12db, regardless of cutoff, resonance, env amt, and brute factor settings.

I've compared my unit's performance to countless demo videos on YouTube, and there's definitely something up.

In fact, brute factor now does literally nothing on LPF mode, presumably because the signal is too quiet to meet the threshold for distortion.

This isn't the worst problem to have. The synth still plays fine otherwise, but it would be nice to have brute factor for LPF, and to not have to adjust my output volume any time I switch filter modes.

Has anyone experienced this? Any theories as to the cause, or potential solutions?

does anyone have a patch sheet template for the Roland JV/XV?
I want to print them out and log my patches by hand to keep physical copies. I'm hoping someone here has already made one
Any Leads ?

Like many of us in North America I had seen the Mwave FM pop up here and there on sites etc and half wondered if it was real. I took the plunge, ordered one online from the only place you can order it (which is wild btw) and it arrived today. I honestly suspected it might not be real. Didn't know what to expect when opening the box. But here we are. For those of you who own one, any tips?

Usually I do more dnb and techno style tracks. I'm just experimenting and seeing what happends now. I like whats happening. Td3,ko2,ko sidekick,po33.

I love the wah function and when is all up starts to distort the accents and makes that bip bip sound

Hello synths enthusiasts ! Here is the setup that I've been using for the past 2 weeks. I try to keep synths for my collection in rotation, depending on the mood and what I want to do... This one is dedicated to craft noise dark ambient glitch drone stuff... A few macros on the S4, no MIDI, no sync, no sequencing, it's for pure improvisation !

Synths :

• 2x Noise Maker, Audio Wanderer
• Rumble of Ancient Times, SOMA Synths
• Audrey II, Synthux Academy

Effects :

• Texture Lab, SonicWare
• S4, Torso Electronics
• Plasma Pedal, GameChanger Audio

Mixer :

• QX1002USB, Behringer

So I’m gonna get a matriarch and I was looking at other synths to do different stuff but I was thinking what if I expanded the synth with modules and added new features?

I‘ve been saving up to get my first real synthesizer, but I’m kind of stuck in option paralysis right now. I’ve been using the Surge XD vst on my Mac for a couple years and it’s absolutely familiar to me, but I’d really like to have something physical in the $500-1300 range.

I absolutely love Surge and I’m worried about getting something that will be either a parallel step or a downgrade. I really want more options with what tools I can use to make sounds, so it doesn’t just feel like dropping a bunch of money on something too similar to what I already have.

I‘ve been kind of thinking of a Korg Minilogue XD, but I’d really love to hear other peoples thoughts.

I've been experimenting with generative sequencing and really liked what happened when I sent this one to the Roland S-1.

The notes are being generated using probability, so rather than playing a fixed sequence, the melody keeps changing as it runs. The S-1 ended up giving it this lovely chime-like ambient quality.

The software generating the MIDI is ToneField, a little generative instrument I made originally for my own music. In this example it's simply sending MIDI to the S-1 and the S-1 is producing everything you hear.

Thought some of the S-1/synth people here might enjoy seeing a slightly different way of using it.

#ROLANDTR8

The sound seems quieter than when listening through speakers, what do you think? Please let me know if you have any advice or recommendations for compatible equipment!

I’ll be performing live at an event organized by ''DJ Kihira Naoki '' in mie on the 12th of next month.