User Tools

Site Tools


EuroRack - Midi IO - Board

PCB Size is 100x40mm

FIXME - The Connection from J1 to J2 is wrong - its 1:1 but it has to be crossed.

Hardware Requirements

  • Soldering Iron - with a Dip that can Handle Thruhole-Parts and 1206 SMDs, solder Paste…
  • The other Parts from the BOM
  • a Midibox Core32

Building and BOM

All necessery Information is printet on the PCB, but also check the Shematic

AB1 - AB61649-1012938192001BLF 2×20 Pin Header2×3 Pin Header 2.54 * 2.54 Pitchto set Midi A-B Standard
Jumper12571-8815451 JUMPERJumperto set Midi A-B Standard
C1 – C44187-CL31B104KBCNNND 100nF unolarized1206 inch - 3216 metricUnpolarized! > 10V
C5 – C62963-TMK316AB7106KLHT10uF unpolarized1206 inch - 3216 metricUnpolarized! > 10V
D1 – D44241-1N4148W_R1_00001 1N4148WSOD123-DIODEdoesnt draw much current
J1 – J22571-12150790 TE Connnectivity2x5P Micromatch FemaleTo solder in the PCB
J1 – J24571-1-2178712-0TE Connnectivity2x5P Micromatch MaleCrimp Connector for Flat-Cables
J3 – J86490-SJ1-3535NG CUI 3.5mm Audio Jack3.5mm Jackthose you know from PC-Mobos
LED1 – LED22696-SSL-LX30FT4ID LED ROTLED_3mmthere are 8 LEDs you use only 4…
LED3 – LED42696-SSL-LX30FT4GD LED GRÜNLED_3mm… front or back soldered
R1 - R1414RC1206FR-07220RL2201206 inch - 3216 metric5 10% doesnt matter
R15 – R184CR1206-JW-472ELF 4K71206 inch - 3216 metric5 10% doesnt matter
R19 - R20 2AC1206FR-071KL 1K1206 inch - 3216 metric5 10% doesnt matter
U1 - U22630-6N138-000E6N138DIP-8Optocoupler
U1 - U22437-1108730441001101IC Socket 2x 4 PinDIP-8Socket for Optocoupler
Cable1617-09180407001Flata quantity forEver

copy following Lines in the box - and make a new project

then decide how often you want to order all off, the BOM Quantity is for 1Module
On one PCB you have 2 ident MidiIO-Modules, on JLCPCB you order typicaly 5 PCB, so your quantity may be 10x
BUT dont buy multiple Flatbandcables… these are hundrets of meter!

1 times: 45€ 25€ parts and 20€ shipping…shipping excl fat
if you go over 50€ shipping is free.
lets take a look if we order it
5 times: 95€ incl free shipping excl fat
10times:176€ incl free shipping excl fat

4x (or 20x) Leiterplatten Montageblock aka Standoffs 100x summed 30€
You will also need M3 Screws - 2 off them…
Also here it is clever to order 100 pieces for a cheaper price - you will need this on all my projects…


GERBER-Files Rev B for Production
I already received and testet Rev A, i hade some small Bugs which i got fixed with some wires…
So i got it fully working… the Bugfixes are includet in Rev.B
—never the less i did not testet Rev.B… since i have enough Rev.A for my whole Modular-Rack @ home
so feel free to test - and report!

FIXME - dont use this - because of J1-J2 connection is wrong (this matter if you chain 2 Midi-IO-Modules


I made a DXFFile which you can print, and drill it DIY or
you can send to: in germany 17,08€ a panel (5x-10%, 10x-20%, 20x-30%, 30x-40%, 100x-50%)
I tested one with them - and yes they looking good - and they fit!:

another good guy: The Beast - UK

Recommend Material
2mm x 128.5 x 17.78 Aluminium, anodised

A cheaper way is: order a 1,6mm thick Aluminium PCB as Frontpanel:
this are the gerbers:
I have testet it, and this 1.6mm Aluminium from JLCPCB is too thin, i endet up by sandwith 2 off them togehter - so its strong enough, since the Labels are reversed when use the PCB reversed - i now removed them in this gerber file!

To Do

Use a other Midi-OUT-Activity Shematic! - its not working for high speed midi! - while Note-ON off is ok, Midiclock can make trouble (the Charge-Discharge Circuit in this Design is not sufficent for this!)

Community users working on it

  • Phatline = PCB & Shematic, Documentation…

Just let a Private message on the forum to user already involved.

euro-midi-io.txt · Last modified: 2022/02/11 15:23 by phatline