3 ‐ PSU Assembly - chrisjameschamp/DIY-Active-Pedal-Design GitHub Wiki

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Choosing the Correct Power Supply

There are two compatible power supplies for this project. These instructions are written around the LRS-600-36, but the process is very similar for the LRS-350-36. The enclosure design and mounting points support both models.

MEANWELL LRS-600-36 MEANWELL LRS-350-36
600W 350W
If you're building a full 3-pedal setup, you'll need to use the LRS-600-36. It's tested and recommended. For builds with 1–2 pedals, the LRS-350-36 may be sufficient. Use at your discretion.

Assembly

Mounting the PSU into the Enclosure

PSU Placement

  1. Place the power supply into the enclosure.
  2. Align the mounting holes in the PSU with the countersunk holes in the case.

Screws

⚠️ Important: Screws for the bottom of the PSU must not exceed 10mm in length — longer screws may damage the internal PCB.

Underside

Wiring the IEC Power Connector

Use 16-gauge wire and spade connectors to connect the IEC inlet to the PSU.

Wire color convention:

  • Black → Live (L)
  • White → Neutral (N)
  • Green → Ground (⏚)

IEC Wiring

  1. Strip the other ends of the wires (~10mm / ½") and twist the strands.
  2. Feed all three wires through the rightmost hole on the rear of the enclosure.
  3. Attach each to its corresponding terminal on the PSU. If using the suggested colors:
    • Black → L
    • White → N
    • Green → ⏚ (ground symbol)

The extra slack can sit to the left of the terminals inside the housing.

PCIe Cable Prep & Installation

Use three 6-Pin PCIe Extension Cables. Each will be cut and wired into the PSU.

  1. Cut the cable about 75% down the female side, keeping the male end for wiring.
  2. Save the female ends — you’ll use them later.

Cable Prep

If your cables are braided:

  • Use a lighter to carefully melt the end of the braid.
  • Pull the melted portion off with pliers.
  1. Strip each wire (~10mm / ½").
  2. Twist the three top wires together (clip side = positive), and three bottom wires together (opposite = negative).

Cable Strip

Wire to PSU as follows:

  • Positive bundle (top/clip side) → V+
  • Negative bundle (bottom) → V-

💡 Tip: Tuck each wire under the left edge of the screw clamp so the tightening action pulls the wire into the terminal instead of pushing it out.

Terminal Wiring

Once wired, insert the plastic PCIe connector into the rectangular cutout in the PSU housing. It should press fit securely in place.

Repeat for the remaining PCIe cables.

Cable Inserted

Installing the IO Cover

The rear panel (IO cover) secures the IEC and PCIe connectors in place.

  1. Insert six M3x0.5mm Heat Set Inserts into the printed holes around the rear IO and top side of the PSU housing.

Heat Set Prep

Tips for inserting:

  • Use a soldering iron or heat-set insert tip.
  • Allow the insert to sink in naturally with light pressure.
  • If plastic mushrooms up around the insert, trim it flush with an X-Acto or razor blade.
  • For nylon prints: Hold the insert in place with tweezers as it cools — they can try to pull out otherwise.
  1. Align and install the IO cover onto the enclosure.
  • The IEC and PCIe connectors are "sandwiched" in place by the inside cutouts of the IO cover.
  • It should be obvious when seated correctly.

IO Fit

  1. Install six M3 Flat Head Screws:
  • Use 18mm screws on the PCIe connector side (2x)
  • Use 14mm screws for the other 4 positions

Final Assembly

✅ Congratulations — you've successfully completed the power supply assembly!