4PDT Order Switcher

Not Verified, all this can change

ℹ️ Note: This board hasn't been built yet, but its order switching and LED wiring were verified as part of another build.

Table of Contents

1. Introduction
2. Schematic
3. PCB
4. Pads
5. BOM
6. Notes

Introduction

The 4PDT Order Switcher swaps the order of two effects with one toggle. In one position the signal runs IN > S1 > S2 > OUT, in the other IN > S2 > S1 > OUT. The fourth pole switches a bicolor LED so you can see which order is selected.

You can also use a 3PDT toggle in the first three columns of the switch footprint (pads 1-9) if you don't want the LED; leave D1 and R1 off. The 3PDT's bushing sits about 2.4 mm to the side of where a 4PDT's would, so drill the enclosure for the switch you use.

Schematic

PCB

Front	Back

The back is shown as viewed from the back of the board. The board is 30 x 20 mm.

Gerbers: GERBER-4PDT-Order-Switcher-r2026-10-16.zip

Pads

Pad	Connects to
IN	From the input (or the previous pedal stage)
S1 / R1	Send to and return from effect 1
S2 / R2	Send to and return from effect 2
OUT	To the output
+ / -	9 V for the LED

BOM

Resistors

Component Name	Value	Note
R1	4k7	LED current limiting resistor, choose to taste (2k2 for brighter)

Diodes

Component Name	Value	Note
D1	3 mm bicolor LED	Common cathode (3 legs, cathode in the middle)

Switches and connectors

Component Name	Value	Note
U1	4PDT	On / on mini toggle (or a 3PDT, see the introduction)
J1 - POWER	2 pin header	+9 V and ground, for the LED only
J2 - ORDER	6 pin header	IN, S1, R1, S2, R2, OUT

Notes

1. The "1 > 2" and "2 > 1" labels next to the switch name the rows of lugs. The LEVER key on the front shows which way to throw the lever for each order: lever down gives S1 > S2, lever up gives S2 > S1. Toggles connect the row on the opposite side from the lever, so check one row with a meter if your switch is different.
2. Which LED color goes with which order depends on the LED; turn it around to swap the colors.
3. The LED only needs +9 V and ground; the audio path is entirely passive.

Licensing

This layout is licensed with a Creative Commons BY-NC-SA 4.0 license (Attribution, Non-commercial, Share-alike).

Versions

• 2026.10.16 - First release. The board itself hasn't been built yet; the switch wiring was verified as part of another build.

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Files for this board live in the main repository: Utility-Boards/4PDT-Order-Switcher/