TYPE-2 Autonomous Polyphonic Synthesizer

Version: v1.0.0
Author: Alexandre Esnard

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.

Hardware BOM

• ESP32-S3 Microcontroller (16MB Flash, PSRAM strictly required)
• PCM5102A I2S DAC Module
• SSD1306 128x64 OLED Display
• KY-040 Rotary Encoder
• 1x Tactile Navigation Button
• 2x MPR121 I2C Capacitive Touch Sensors
• Copper tape (for creating capacitive touch keys)

Core Features

• Hybrid DSP Engine: Fast polynomial saturation and dual-rate architecture.
• Signal Chain: Factorized 24dB/Oct Moog Ladder Filter, Tube Overdrive, and Studio Digital Delay.
• User Interface: Cylindrical rotary menu interface and responsive topological grid visualization.

Setup & Installation

1. IDE Setup: Install the Arduino IDE or PlatformIO with ESP32 board support.
2. Compiler Settings: To ensure the DSP engine and display tasks run properly, configure your IDE with the following exact parameters:
   • USB CDC On Boot: Enabled
   • CPU Frequency: 240MHz (WiFi)
   • Flash Mode: QIO 80MHz
   • Flash Size: 16MB (128Mb)
   • Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS)
   • PSRAM: OPI PSRAM
   • Upload Speed: 115200
3. Libraries: Install Adafruit GFX, Adafruit SSD1306, and Adafruit MPR121.
4. Wiring: Refer to the provided wiring diagram schematic to route the I2S, I2C, and GPIO connections correctly.

Roadmap

• Core 7-voice polyphonic DSP engine implementation
• Tube overdrive, analog slop, and delay effects
• Real-time topological grid UI and hierarchical menu
• Advanced firmware optimization
• Manage the creation of presets from a dedicated menu
• External MIDI communication (USB/Serial)
• ESP32 Bluetooth communication integration
• Battery management and portable power components integration
• Custom PCB design
• Enclosure design and manufacturing

License & Copyright

This project is an open-source initiative developed for the benefit of the maker and synthesizer community.

• Community Use: You are entirely free to study, modify, and build upon this code for your personal projects.
• Commercial Restriction: The commercial resale of this project, its code, or any hardware derivatives based directly upon this architecture is strictly prohibited.
• Patent Restriction: No patents, trademarks, or restrictive intellectual property rights may be filed on this work or its derivatives.

Links & Contact

• GitHub Repository
• YouTube Channel
• LinkedIn Profile
• Reddit Development Log
• alexandre.esnard006@gmail.com