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

(SLA PRINTED ENCLOSURE, DISPLAY SIZE LEFT: 2.8", MIDDLE: 2,8" and RIGHT: 3.2")

(PCB BASED FRONT/BACK PANEL, DISPLAY SIZE LEFT 2.8" and RIGHT 3.2")

You can build MDT with a 2.8" or a 3.2" Display and in 3 different styles.

The MDT PCB is always identical, no matter what enclosure or display size you choose.

Always check the Manual/Build Guide for latest information

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.

For all three options, be careful to select the correct front part, maching the display size and the enclosure type.

The BACK plate / enclosure is identical regaring the screen size but you still have to match it to the enclosure type (SLA printed or PCB-based)

The aluminium case parts are only available for the newer, 3.2" display.

THIS PAGE COVERS THE MOST RECENT DIY MDT PCB

If you want to see the lastest, bleeding edge version, partly preassembled and enhanced, check out:

https://www.pcbway.com/project/shareproject/[MDTX]_MicroDexed_Extended_Edition_2810710b.html

Most recent news:

06/2025: updated the PCB to incorporate as many enhancements from MDTX (SMD Version) as possible but of course without the RGB Encoders and second SD Card Slot.

Image 2 and 3 show what you will receive when you are ordering this (DIY) version as partly assembled.

10/2024: A full user manual & build guide is available. Get the latest version at :

MDT MANUAL AND BUILD GUIDE

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 pre build 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

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

Standard MIDI File (SMF) player (work in progress)

Sidechain compression (work in progress)

Work in progress - Sample Slicing:

Demo Reel/Usage/Feature Videos:

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.

This unified case will fit for the most current and also for the previous pcb-version.

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

(2.8" DISPLAY)

(2.8" DISPLAY)

(2.8" DISPLAY)

(2.8" DISPLAY)

(3.2" DISPLAY)

Developer Edition - short video tutorial:

Developer Edition - Alternative_PCB_based_Enclosure_Top (DISPLAY 2.8")

https://www.pcbway.com/project/shareproject/W424985ASE20_pcb_enclosure_front_plane_c17b035e.html

or

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

The Bottom Part is identical for both display sizes, 2.8" and 3.2":

Developer Edition - Alternative_PCB_based_Enclosure_Bottom

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

If you want the bottom side fully covered, you can get an OPTIONAL plate for that here:

mdt_pcb_enclosure_optional_back_cover

Metal (Aluminium) Case:

Metal Front Part

Metal Back Part

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

TOP

BOTTOM