Moraydular Eurorack Busboard pcb (12 headers)

£6.99 (exc VAT)

Github

A compact (50x200mm) 12-way power distribution PCB for Eurorack modular synthesizers.

Can be built as a simple passive bus board with shrouded or unshrouded headers, using flat connectors / mounting tabs or .156″ connectors for power input. Optional power indicator LEDs (highly recommended!) and onboard minimal +5V regulation from +12V rail may be added.

Populating the PCB should be relatively straightforward. Some notes:

  • The LED polarity follows standard convention: the short leg / cathode / notched side of LED goes where there’s a notch in the silkscreen.
  • The pads for connectors have quite wide thermal reliefs, so soldering them may require some extra heat and patience. In particular, the -12V (bottom row) pins in ribbon connectors will take some warming up for the solder to flow properly.
  • When using mounting tabs, you may want to solder them on both sides for extra sturdiness because it usually takes some force to detach the cables.
  • If not building the +5V adapter, leave out parts as indicated in BOM below

When using onboard +5V in multiple bus board system, either build the regulator circuit for all boards and leave out +5V link cables or populate the regulator circuit for just one board and distribute +5V to all boards. Never link +5V rails of two boards together if they both already have their own +5V feeds.

Bill of Materials

For plain passive board:

  • 12x 16-pin (2×8) 0.1″ shrouded box header (eg. Reichelt WSL 16G) OR unshrouded pin strip
  • 6x PCB-mount Faston / Abiko style mounting tabs (eg. Reichelt FS-P 6,35)
    • Alternative: 1x 4-pin 0.156″ PCB mount connector (MTA156, Molex KK .156)
    • Or you can just solder the wires from PSU directly to the PCB
  • 3x 3mm LEDs
  • 3x Current limiting resistors according to LEDs you’ve chosen (2x 1K, 1x 220R as indicated on PCB silkscreen should be fine at least for normal red or green leds)

For +5V onboard regulation add the following:

  • 1x 7805 voltage regulator
    • Use a heatsink according to your planned current draw
    • Pin-compatible DC-DCs such as OKI-78SR-5/1.5-W36-C should work and provide more current with better efficiency and no heatsink required, but currently untested
  • 2x standard rectifier diodes, any of 1N4001…1N4007 will do
  • 1x 10uF electrolytic capacitor, 16V or higher voltage rating
  • 1x 100nF ceramic capacitor

In stock

Additional information

Weight 40 g
Dimensions 200 × 50 × 2 mm

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