The Build

The preenfm3 comes on 2 pre-solder SMD PCBs. Presoldered but you still have to add different components.

If you plan to put your preenfm3 in a Van Daal Electronics metal enclosure, DO NOT follow this guide.
The height between the PCBs is not compatible.
Their metal case comes with all the headers, spacers and screws you need.

On the main PCB you need to add different headers, jumbers and solder the audio, midi, usb and dcIn sockets.

On the control board you'll have to solder encoders, and switches

Then every thing must be put into a box.

More information about the components can be found in the BOM here.

PART 1

Update : I finaly think it's better to have 5 F/F 12mm spacers and replace the 5 nuts by 5 screws 6mm.
So the list is different from what you see on the picture.
The following list can be M2.5 or M3

For the First 3D printed Case :

• Hex spacers M/F 20mm * 5
• Hex spacers F/F 20mm * 4
• Hex spacers F/F 12mm (10mm + nut on the picture) * 5.
• Screws 6mm * 9

The second 3D printed Case has an angled top surface so the spacers are a bit different :

• Hex spacers M/F 15mm * 2
• Hex spacers M/F 20mm * 2
• Hex spacers F/F 20mm *
• Hex spacers F/F 12mm (10mm + nut on the picture) * 5.
• Screws 6mm * 8

Only one of the above is required.
Then all the following :

Long leg / stackable headers (They sometimes are provided with the PCB)

• 10+ pins for the TFT (can be between 10 and 16)
• 4 pins for the TFT (6 pins works if you remove manually 2 pins)
• 8 pins for the control board
• 5 pins for the control board ((6 pins works if you remove manually 1 pins)

Other headers and jumpers

• 2 pins male header for the USB ground connection
• 2 pins male header for the USB 5v connection
• 2 pins male header for the DCIn 9v connection
• 3 pins male header for the boot0
• 4 Jumpers

TFT

• 2.8" ili9341 TFT It should look like this.
  Look the "2.8 TFT SPI 240x320 v1.1" (or v1.2) on the PCB and double check the dimension.
  Some TFT bought on aliexpress have a reported non working SD card reader (bad wiring) and bad dimension. I never had any problem from the ones i bought from amazon (search ILI9341 2.8)
  Only 9 pins are used on the bottom header of the TFT (No touch).
  The Touch is not used by the preenfm3. TFT with touch are a bit thicker and a bit less contrast.
  But the touch layer makes a good protection.

Here is how to use those spacers :

Why do we have to use long legs / stackable header ?

The main PCB to Control board distance is too long for regular header (a bit too long).

The TFT is much nicer when close to the enclosure surface, so the main PCB to TFT distance is too long for regular header.

All long legs have to be soldered after everything is assembled to adjust the space between the start of the plastic and the main PCB. For the TFT, the 4 * 20mm hex spacer help knowing which distance is needed. (insert something (~1mm) under the TFT if you need additional protection between your TFT and the final enclosure)

Make sure you solder with one header at least the 9 pins that have a reference on the preenfm3 PCB. So you need a 10+ pins long leg header. Other pins are not used but can be solder without any problem.

For the control board, the need is more subtile. But the long legs help to get a nice soldering.

PART 2

Here is the BOM of the control surface.

• Encoders PEC12R-4220F-N0024 * 6 (PEC12R-4220F-N0012 also work)
• Switch TL1100F160Q * 13 (12 for he control surface + 1 optional one for the reset button on the back)
• Any knobs that fits the encoders
• e-switch serie 5j *12 (choose your color)

No particular instruction to solder this components. Just put them on the correct side of the control board.

In the center of the control board, there is a blue led that is not wired by default. You have to solder the "led" bridge. Then the led will blink in sync with the sync beat or with any external midi clock.

Picture of the finished control board :

PART 3

External connections :

• Din 5 PCB mount midi jack * 2 (height<20mm see BOM or use a wire cuter)
• Neutrik NRJ4HH * 6 (audio jack)
• Usb Type B PCB sock (like this)
• DcIn socket (like this)
• A regular size SD card (Not on the picture)

So the finished assembled PCBs look like :

And in the 3D printed case :