Buffered Mult

Buffered Mult Faceplate

This directory contains the mechanical specifications and KiCad panel files for the Buffered Mult control board faceplate.

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Technical Specifications

Panel Outer Dimensions

• Format: 3U Eurorack (6 HP width)
• Height: 128.50 mm (±0.20 mm tolerance)
• Width: 30.00 mm (incorporates standard -0.48 mm clearance against nominal 30.48 mm to prevent rail binding)
• Thickness: 1.60 mm (standard PCB FR4) or 2.00 mm aluminum

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Mechanical Clearance & Drill Specifications

1. Mounting Screw Slots

To allow minor horizontal alignment adjustments when mounting modules:

• Screw Size: M3 (3.0 mm)
• Slot Shape: Horizontal oval slot
• Slot Dimensions: 6.00 mm (width) × 3.20 mm (height)
• Hole Center Spacing (Vertical): 122.50 mm (3.00 mm margin from top and bottom panel edges)
• Hole Center Spacing (Horizontal): 7.50 mm from left and right edges (22.50 mm offset center-to-center)

2. Component Hole Diameters & Tolerances

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Component Layout & Grid

The panel accommodates 3 identical channel groups (Channel 1, Channel 2, Channel 3) vertically aligned.

Per-Channel Grid Layout

Faceplate Component Placements

Faceplate to Control Panel offset = (128.5 - 110)/2 = 9.25mm

Distance between channel groups, 29mm vertical separation.

Measurements from top left of control board.

Channel 1

• D1: Negative LED Indicator (-)
  • x: 5.77mm
  • y: 7mm
• D2: Positive LED Indicator (+)
  • x: 11.27mm
  • y: 7mm
• J2: Channel 1 Input Jack
  • x: 8.48mm
  • y: 15mm
• J5: Channel 1 Output Jack 1
  • x: 21.52mm
  • y: 15mm
• J6: Channel 1 Output Jack 2
  • x: 8.48mm
  • y: 25mm
• J7: Channel 1 Output Jack 3
  • x: 21.52mm
  • y: 25mm

Channel 2

• D3: Negative LED Indicator (-)
  • x: 5.77mm
  • y: 36mm
• D4: Positive LED Indicator (+)
  • x: 11.27mm
  • y: 36mm
• J3: Channel 2 Input Jack
  • x: 8.48mm
  • y: 44mm
• J8: Channel 2 Output Jack 1
  • x: 21.52mm
  • y: 44mm
• J9: Channel 2 Output Jack 2
  • x: 8.48mm
  • y: 54mm
• J10: Channel 2 Output Jack 3
  • x: 21.52mm
  • y: 54mm

Channel 3

• D5: Negative LED Indicator (-)
  • x: 5.77mm
  • y: 65mm
• D6: Positive LED Indicator (+)
  • x: 11.27mm
  • y: 65mm
• J4: Channel 3 Input Jack
  • x: 8.48mm
  • y: 73mm
• J11: Channel 3 Output Jack 1
  • x: 21.52mm
  • y: 73mm
• J12: Channel 3 Output Jack 2
  • x: 8.48mm
  • y: 83mm
• J13: Channel 3 Output Jack 3
  • x: 21.52mm
  • y: 83mm

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KiCad Faceplate Design & Fabrication Guidelines

When designing the KiCad PCB faceplate (faceplate.kicad_pcb):

1. Board Outline (Edge.Cuts): Draw a exact 30.00 mm × 128.50 mm rectangle on Edge.Cuts with 0.5 mm fillet radii at the 4 outer corners.
2. Copper & Mask Clearance:
   • Keep copper traces and copper fills at least 0.50 mm away from all board edges.
   • Add exposed unmasked copper rings connected to GND around mounting slots on front/back for ESD chassis grounding.
3. Silkscreen Graphics:
   • Use high-contrast silkscreen text (F.Silkscreen / B.Silkscreen).
   • Clearly label Channels (CH 1, CH 2, CH 3), Inputs (IN), Outputs (1, 2, 3), and LED polarities (+, -).
4. Recommended PCB Fabrication Specs:
   • Material: FR4, 1.6 mm thickness
   • Solder Mask: Black (Matte Black or Glossy Black)
   • Silkscreen: White
   • Surface Finish: HASL Lead-Free or ENIG (Electroless Nickel Immersion Gold)

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Reference Standards

• Exploding Shed Eurorack Dimensions Guide
• Doepfer Eurorack Mechanical Specifications