This open-source ESP32 touch synth just got a massive upgrade, and it's only €35 to make

Credit: Alxdreee Published Aug 26, 2026, 8:42 PM EDT Simon is a Computer Science BSc graduate who has been writing about technology since 2014, and using Windows machines since 3.1. After working for an indie game studio and acting as the family's go-to technician for all computer issues, he found his passion for writing and decided to use his skill set to write about all things tech. Since beginning his writing career, he has written for many different publications such as WorldStart, Listverse, and MakeTechEasier. However, after finding his home at MakeUseOf in February 2019, he would eventually move on to its sister site, XDA, to bring the latest and greatest in Windows, Linux, and DIY electronics. Sign in to your XDA account Summary This ESP32 touch polyphonic synth returns as a bigger, better v2 you can build for ~€35. The new build fixes nasty audio issues by reassigning cores and redesigning touch copper lanes. Open-source TYPE-2 is accessible with near-zero build difficulty, with MIDI (USB/Serial) and Bluetooth features planned. The cool thing about checking out ESP32 projects is that they will sometimes evolve. We'll sometimes see a project reappear after a year or two with a brand new look and design, and sometimes people will get a new version out within a month of releasing their first iteration. For example, earlier this month, we saw someone turning their ESP32 into a touch-activated polyphonic synthesizer. Now, before the month ended, they've returned with a new version that's bigger and better than ever. Best of all, you can make your own with around €35 worth of hardware. This ESP32 touch synth is back with a new look and more features It didn't take long for a second version to come out Over on the ESP32 subreddit, user Alxdreee showed off what they've been working on: a cool ESP32-powered touch synth. It turns out that the first version had some nasty audio issues, so they worked hard to solve those problems by changing which cores perform which job, and tweaking how the copper lanes pick up signals from your finger. Everything is open-source, so if you'd like to learn more about it, feel free to head over to the TYPE-2 Autonomous Polyphonic Synthesizer GitHub repo. Here's how Alxdreee describes the project on the GitHub page: The TYPE-2 is a microcontroller-based hybrid polyphonic synthesizer. Engineered entirely around a highly optimized DSP core, it leverages fast polynomial saturation, a dual-rate processing architecture, and analog-modeled filters to deliver a heavy, studio-quality audio signal flow. Designed with accessibility in mind, it is highly affordable (around €35 in total components) and features a near-zero difficulty build process requiring minimal wiring. Despite the project coming leaps and bounds since we last checked on it, Alxdreee has a roadmap that's only about a third done at the time of writing. Future updates include adding external MIDI communication via USB and Serial, as well as integrating ESP32 Bluetooth communication. Be sure to keep your eyes on this project if you love what it does.