If you are new to MDT/MDTX, please take a look at the manual as a first step. This should clarify many of the questions you might have if you are new to it. The following link will always point to the latest version: MDT/MDTX Build Guide/Manual

This page covers the latest, bleeding edge version of MicroDexed. While it is fully tested technically, it lacks documentation in the build guide, is missing (changed) parts in the BOM, uses some new parts that might be difficult to aquire and what is most important:

It is not supposed to be built entirely manually by yourself. This version is designed with the goal to get the user a running device with as less manual work/soldering as possible. However, you still get only a partly built PCB, there still is component sourcing and some soldering necessary.

When buying this version, be aware you are supposed to use the assembly services of PBCWAY (PCB+Assembly) so that the SMD components (which are more difficult to solder) and also some basic THT parts come pre assembled to you.

However, regarding SMD parts, it is still required to solder the PSRAM chip(s) to the Teeensy (Unless you are not also buying that pre assembled from Protosupplies: https://protosupplies.com/product/teensy-41-microdexed/)

While it is technically possible, please do not buy this as a PCB only unless you have very deep experience soldering tiny SMD parts and also know exactly what you have to gather and to do. This is completely unsupported by the developers and you are fully on your own when you select this option.

If you do not want to buy a partly pre assembled PCB, please go to the latest version that is thought and designed to be the "DIY" way (And very well tested by plenty of users worldwide):

https://www.pcbway.com/project/shareproject/MicroDexed_Capacitive_Touch_64970fee.html

Please be aware that this build is labeled "bleeding edge" for a reason. Difficulties are to be expected, especially when acquiring the additional necessary parts. It's quite possible that significant modifications will be necessary here.

The main improvements/changes in this version are:

• Faster user assembly/build due to more pre build components (reduces several hours of gathering components and soldering)
• RGB Encoders (customizable colors for general state and edit state)
• Second SD Card slot for copy/moving files/flat directories between both cards (work in progress but already working in general)
• Enhanced Audio Circuit for better Output Quality (less perceived digital noises/hiss)

The encoders used in this version are currently of type: PEL12T-4021F-S1024. However that might be changed to allow a broader choice of encoder knobs in the future. If you go for premade encoder caps, instead of self-printing, it is probably better to go with a longer shaft size.

Most recent news:

2025/06/25

• updated the PCB with slightly larger Resistor Arrays. This PCB is not ment to be manually soldered but i see some users are trying it anyway, so this should make it a bit easier.

2025/06/12

• FDM prints are finalized. They need to be printed in white and without any support
• SLA prints added, they also need to be printed in white.

2025/06/10

• printed and tested attached FDM knobs. These must be printed in white color and without support. They are OK but it will probably be much more professional looking as an SLA print. Working on that.

2025/06/08

• removed the self-printed knobs since there are improvements going on. should be updated in a few days

2025/06/02

• enclosure parts for SLS prints and sheet metal are adjusted to fit this version.
• encoder knobs currently are available as a FDM transparent self-print. Looking for commercial options.

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For the enclosure, we have 3 options:

• full enclosure, 3D SLA printed, front + back part
• PCB based front+back panel (optional "empty" plate at the bottom as a cover)
• metal (aluminium) enclosure. You can choose metal type and various surface finishes. Links are at the bottom of this page.

Real photo (sheet metal enclosure but with outdated knob):

Real photos (pcb-based enclosure, outdated knob):

DESCRIPTION:

DIY Groovebox / Synthesizer / Sequencer with 2x16 voices 6 OP FM, 16x voices MDAepiano, 2xVA, 2x16 MIDI Channels, 8 voices Chromatic Sampe Player/Pitched Drum Samples and 8x voices Braids Oscillator (shared with sampe player voices), based on a Teensy 4.1 in a tiny box.

Microdexed-touch required a Teensy 4.1, PCM5102 Audio Board, 320x240 ILI9341 SPI Display with Capacitive Touchscreen and a PSRAM Chip for custom samples. Since 08/2024 the previous used serial Flash Chip (on a prebuild module) can be concidered optional.

Enhancements to prior version:

Capacitive touch display

Easy Access: PROGRAM Button (mainly useful for development)

Soft Power on/off (aimed at users building their own power/battery solution)

Option for Headphone amplifier

Digital output S/PDIF TOSLINK gives the best, possible sound quality output

If you do not want to solder the Teensy pins by yourself, or the (optional) PSRAM chip, you now can order it from:

https://protosupplies.com/product/teensy-41-microdexed/ fully soldered and tested, specially for MDT. (with 8 or 16 MB PSRAM)

Join our Discord Chat:

https://discord.gg/XCYk5P8GzF

Detailed build instructions, BOM, full source code are at the project homepage/repository linked below.

Project Playlist:

https://www.youtube.com/watch?v=-JIxHMlZM0k&list=PLHTypoMU1QoGOXPli8bjR6MknPiQpubHl

User manual & build guide is available at:

https://codeberg.org/positionhigh/MicroDexed-touch/raw/branch/main/doc/MicroDexed-touch-manual.pdf

MicroDexed started as a Teensy based, 6-operator-FM-synthesizer. The first generation is still maintained at: https://codeberg.org/dcoredump/MicroDexed

Compared to the previous Version, there are a lot of new features/improvements:

"Large" Graphical Interface, view and edit multiple Parameters in one Screen

Use external MIDI gear over USB or Mini TRS Jacks (DIN MIDI with adaptor) from 2 x 16 MIDI Channels in the Sequencer

Map MIDI CC to external MIDI Devices to control Input/Parameters

Global plate reverb, 2 global delay effects (500ms, with added PSRAM chip 60 seconds or even more)

Loading, playing and editing multi-sampled instruments or layered instruments in a "live" mode or played by the sequencer. Auto detection sample zones but also can be edited manually. This is early work in progress and currently not stable when using pitch shifting and polyphony

2 instances of "Virtual Analog" Monosynths with one OSC, PWM, Multimode Filter and Noise. A lot of useful new sound possibilities.

8 voice polyphonic Oscillator, based on the code of Mutable Instruments - Braids. No wavetables but added individual envelopes and multimode filters for all voices

Much improved Sequencer with 8 Tracks, 16 Step Patterns, 16 Step Pattern Chains, up to 16384 Song Steps, Arpeggiator with 1/8 - 1/64 Steps, Arp Patterns including Euclidean settings, Pitched Drum- and Instrument Sample playback

LIVESEQUENCER 12 tracks with DAW like MIDI realtime recording / mute recording

The sequencer can also play chords of various types, stacked up to 7 notes, using only a single sequencer track

Global Mixer View with all Channels

Multiband Master Compressor with 4 bands

Sample Management from SD-CARD and SPI FLASH/PSRAM, samples can be loaded from SD-CARD to PSRAM during runtime.

Since 08/2024 PSRAM is the prefered method to work with custom samples and is fully stable.

Touch Mute Matrix for live / realtime performance

Tracker View (Editor) - work in progress

Track Print/Recording - work in progress

Remote control in web-based 1:1 UI with added features (filemanager,filetransfer, screenshots etc.) Work in progress - connected to PC via Teensy MicroUSB Connector

Feature request 08/2024 Survey:

https://qvgopz6on.supersurvey.com/

11/2025:

Live Sequencer Editor Pattern/Track Mode

Live Sequencer Editor Song Mode

Granular Synthesizer

NoiseMaker - create 808/909 drum sounds on device

Sample Editor with trim, fade out and save to sd card

Sample Editor with trim, fade out and save to sd card, mono and stereo samples

Sample Slicing

LiveSequencer Graphical Editor

LiveSequencer Editor Mode

Virtual Keyboard in DrumPad Mode

Virtual Keyboard much improved for drum sample input to sequencer

Direct Screen Captures:

Please check the project homepage/repository for more details, build instructions, diagrams and much more.

CASE/ENCLOSURE

The matching enclosure parts are located at the bottom of this page, you can get them printed in high quality by pcbway printing services or download them.

If you prefer a PCB-based, alternative enclosure - "Developer Edition" :

Developer Edition - short video tutorial:

Developer Edition - Alternative_PCB_based_Enclosure_Top (DISPLAY 3.2")

https://www.pcbway.com/project/shareproject/mdt_pcb_enclosure_front_3_2_DISPLAY_96ddfb78.html

Developer Edition - Alternative_PCB_based_Enclosure_Bottom

https://www.pcbway.com/project/shareproject/mdt_pcb_enclosure_bottom_plane_39654ff7.html

Metal (Aluminium) Case:

Metal Front Part

Metal Back Part

Selective Laser Melting (SLM) Process (Aluminium) Enclosure:

TOP

BOTTOM