Teensy-4.1 Adapter Board

For using a Teensy-4.1 on the TMA board an adapter board is available. For more information take a look at the build manual.

Revision 1.8

TeensyMIDIAudio (also known as TMA) is a flexible kit to build a synthesizer or effects unit based on a Teensy-3.x microcontroller. For example, you can load MicroDexed or MicroMDAEPiano onto your Teensy using the Arduino IDE and then select a MIDI instrument.  It has onboard MIDI-IN/OUT sockets (and a MIDI-THRU on pin-headers). Also it supports the Teensy-audio-shield (Revision C) and has RCA connectors for audio input/output. For the power connection a USB-B socket is used and if connected with an adapter cable this socket can also be used for programming then Teensy. Another USB-A socket can be used for USB-host connections towards the Teensy-3.6.

For more information please look at the build manual.

Changes between Revision 1.7 and 1.8:

  • Internal MIDI THRU connector

  • Placement of some components

  • Dedicated encoder pin rows


Download / Repositories


Revision 1.7

This is my first creation of a complex board and my first time using KICAD. I created this PCB for having a flexible microcontroller-synth-platform. The first software implementation for this is a port of a famous “Yamaha 6-OP FM synth“ emulation based on the open source synth Dexed. This is called MicroDexed.

First I used a stripe board as a prototype and stackable connectors for the Teensy-3.6 and the Teensy-Audio-Board. After trying I found out that a simple LCD display and two encoders would be helpful to change banks and sounds. So I decided to create a better platform for this and created a modular PCB.

The same PCB should make available a cheap and simple (or more complex) synth or audio effect – (or both) on top of the same hardware. So you have the option to simply use the PT8211 (with only audio outputs) and the onboard USB-MIDI (USB-host) as base for a synth or a full armed version with DIN-MIDI, encoders, LCD display and Audio input and output.

You can build MIDI playable synths, effects or just sound generators – it’s your part to decide what to do. For this the Teensy is a really good platform to start. You can use the Arduino-IDE and several very good libraries especially for the audio stacks. Also there are many third party libraries for nearly every hardware you want to add – or you can decide to write your own library. 

The size of the board is designed for using it inside a Rittal CMC-TC case. I have some of them which can be recycled as cases for this project.

Downloads / Repository