The board is discontinued. Big thanks to all who supported this project!

Build your own here: https://github.com/toto99303/Prusa-MK2-Ext.-Driver-Board

So, what is this? This is an external stepper driver board for X and Y stepper motors of the original Prusa MK2/MK2S/MK2.5/MK2.5S printers. It allows usage of TMC2100/TMC2208/TMC2209 drivers (Silent Step Stick and similar, (TMC2209 are recommended), so your printer will become a lot quieter and much smoother due to the 256 step interpolation (same as on the MK3). This is the latest upgraded version 2.4 of the board.

Basics:

The Mini-Rambo v1.3a board does not have much spare pins, and since the MK2.5 upgrade from prusa the free pins are extremely limited. So I’ve decided that the new revision 2.4 of the board will need to have all 8 data wires soldered to the back of the Mini-Rambo. This way you do it once, and you have it all – works with the official firmware and all current and future upgrades from Prusa.

This kit is recommended for DIY enthusiasts who are not afraid to mod their machines.

Please read below the two important things you need to know before deciding if you want this mod!!
1. By soldering on the back of your Mini-Rambo you’re practically voiding your Prusa warranty!
2. I take no responsibility if you mess this modification up and/or damage your printer. You need to have basic soldering skills. Do at your own risk, or get someone more experienced to do it for you!

Features:

Silent! – I’ve tested it with TMC2100/TMC2208/TMC2209 drivers and the printer is very quiet in StealthChop/StealthChop2 mode. Now the part cooling fan is noisier than the X-Y movements. (TMC2209 are recommended)
Almost easy installation – You’ll have to solder 8 wires to the back of the Mini-Rambo on large and easy to solder copper pads.
Works with the official firmware – No need anymore to flash custom firmware, works fine with the official one.
Printable box – convinient printable box for the mod compatible with the original design. (https://www.thingiverse.com/thing:2777899)
New in v2.4!! Config jumpers – Solderable jumpers for selecting the different modes on TMC2100/TMC2208/TMC2209 (Stealthmode(2) or Spreadcycle). (Note: IMPORTANT !) (no more soldering on the actual drivers as was on v2.3)
Easy revert – you can easily switch back to stock by just disconnecting the motor cables and plugging them back in the Mini-Rambo
12/24V power input – You can power the board with 24V if you like, but stock 12V work just fine, too.
Fan connector – There’s a fan connector on the board for an easy connection to the external cooling fan.
Works with MMU1.0 and MK2.5(S) (MMU2.0) upgrades – You do the mod once and it’s upgrade-proof. Any current or future upgrade from Prusa will work just as fine.
(Optional) Silent Z motors – you will need to purchase two external driver board kits. First one is for X and Y motors, the second is used for the two Z motors.

What’s included in the kit:

1 x MK2(S)/MK2.5(S) Ext. driver board v2.4
1 x Data cable
1 x Power cable

What’s NOT INCLUDED:

No stepper drivers are included in the kit !!! You’ll have to buy them separately! Make sure you buy ones with bigger heatsink!
The recommended drivers are TMC2209 directly from Watterott: https://shop.watterott.com/SilentStepStick-TMC2209-V2-soldered
If you want TMC2100 get these: Ebay (EU), Ebay (US, not tested yet)
The additional Noctua fan you see on the pictures is not included. I strongly suggest you put one as the TMCs are getting very hot. Get the 12V version. Noctua fan
The voltmeter you see on the pictures is not included, but you can buy one here: Ebay
I highly recommend using heavier heatsinks like these: Aliexpress