Otto Passive Mono DIY Kit

Product status: Retired

Thank you for purchasing this KIT!

See here for manual and more information about the pre-built version of the Otto Passive Mono.

See here for inspiration about what you can do with the Otto Passive Mono module when you have built it.

KIT Parts

  • 1 black front panel
  • 1 blue PCB
  • 8 mono jacks
  • 8 nuts
  • 2 screws
  • 1 plastic isolation film
  • 1 male pinstrip 32-pin
  • 1 female header 16-pin
  • 1 wire
  • 1 sticker sheet
  • Plastic zip bag

Building instructions

NOTE! For each step, look at the pictures before you start!

1. Front panel

Carefully remove the protecting tape from the front panel.

2. Plastic isolation film

Here you will need a needle or other sharp tool to make the small holes in the film.

Make holes for the jack-legs in the plastic isolation film. Use the blue back-PCB as a template. Place the film on top of the PCB and press the needle through the film for each of the jack-leg-holes.

Each jack has 3 legs, so in total you will make 3×8=24 holes with the needle.

Don’t make the holes too small because it will then be difficult to mount the jacks later.

3. Solder the 32-pin male pin-strip

  • Mount the pin-strip in the top 32 holes and leave the 6 bottom holes empty.
  • The pins should point out on the back-side.
  • Solder on the top-side, where the jack-icons are.
  • Make sure to not solder any shorts between any pins. Some multimeters have a “beep-function” for measuring/testing this.

4. Mount isolation film and jacks

  • Make sure that each hole in the plastic film is wide enough for a jack-leg. Use a jack and test this for all holes in the film.
  • Place the plastic isolation film on top of the PCB. Orientate it correctly. Look at the group of 4 holes to get it right.
  • Mount all 8 jacks on top of the plastic film. Press the jack-legs through the film and then through the PCB. If this is tricky, you need to widen the holes in the plastic film. Don’t use force or violence here because the jack legs are fragile.
  • Note that the bottom 3 jacks are rotated 180 degrees.

5. Mount the front-panel ant nuts

  • Mount the front-panel to get all jacks aligned correctly.
  • Mount the 8 nuts and tighten them gentle by hand.

6. Solder the jacks

  • Press the blue PCB towards the jacks so that a little part of the jack-legs are coming through on the backside for soldering.
  • Try to align the back-PCB in the same angle as the front, so that the pin-strip points 90 degrees backwards
  • It will and should be a gap between the jacks and the blue PCB. This is because of the pin-strip soldering. And that is also why the plastic isolation film is needed.
  • Try to get this gap exactly the same for each of the 8 jacks.
  • Now you can solder the 8 jacks. In total 8×3=24 solder points.
  • Make sure to not make any shorts!

7. Tighten the nuts

Now you have finalized the module and can tighten the nuts with a pliers or other suitable tool.

8. Next step?


450 SEK

Technical specifications


Width: 2 HP
Depth: 21 mm

Current consumption

+12V: No current consumption. Completely passive.

Additional files, images and videos