2 layers38.1 × 65.4 mm

Clock back pcb

A collection of free & open source DIY synthesizer module designs for Eurorack

Size: 38.1 × 65.4 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 9
Nets: 35
Pads: 72
Tracks, vias: 133, 0
Pours: 1
Routed: Yes
KiCad: KiCad 7 (file 20221018)
Created: 17 Dec 2019
Updated: 3 Nov 2026

Overview

Clock back pcb is an open-source printed circuit board by QuinnFreedman, from the QuinnFreedman/modular repository on GitHub. It is a 2-layer board of 38.1 × 65.4 mm with 9 parts on 35 nets, routed with 133 tracks and 0 vias.

Its parts include 5 connectors and 2 capacitors. It belongs with the audio and music and lEDs and displays boards and the AVR (ATmega, ATtiny) boards of this library.

README

README.md

This project is an attempt to make Eurorack modular synthesis affordable and accessible to everyone.

This repository contains open source software and hardware schematics for Eurorack modules which are designed to be assembled easily and cheaply without any technical knowledge. Every module should be able to be assembled for around $20 in about an hour of work, even with limited experience.

To get started, check out some of the links below. Or get in touch! Send me a message at freemodular@gmail.com. Follow my reddit, Etsy shop, or GitHub.

Happy travels on your modular journey!

Go to the website to see more

Modules

{% include_relative docs/modules.md %}

Parts

Qty	Value	Footprint	References
2	Conn_01x04_Pin	Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical	J9, J10
1	100nF	Capacitor_THT:C_Disc_D4.7mm_W2.5mm_P5.00mm	C1
1	10uF	Capacitor_THT:CP_Radial_D4.0mm_P2.00mm	C2
1	Arduino_Nano_v3.x	Module:Arduino_Nano	A1
1	Conn_01x03_Socket	Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical	J13
1	Conn_01x11_Pin	Connector_PinHeader_2.54mm:PinHeader_1x11_P2.54mm_Vertical	J11
1	Eurorack_2x8_Power	Connector_IDC:IDC-Header_2x08_P2.54mm_Vertical	J12
1	logo_small	FreeModualr:logo_small	G1

Questions

How big is the Clock back pcb PCB?

It measures 38.1 × 65.4 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Clock back pcb use?

9 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Clock back pcb KiCad files?

From the QuinnFreedman/modular repository on GitHub, at the commit this page was made from: the board is modules/Clock/PCBs/clock_back_pcb/clock_back_pcb.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.

Can I use the Clock back pcb design in my own project?

Its repository states no licence, so its author keeps all rights: ask QuinnFreedman before reusing the design.

Category and platform

Audio and music LEDs and displays AVR (ATmega, ATtiny)

Topics

eurorack music modular

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/quinnfreedman-modular-clock-back-pcb" title="Clock back pcb in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/quinnfreedman-modular-clock-back-pcb.jpg" alt="Clock back pcb" width="1200" height="900">

A picture that opens the board, for a README

[![Clock back pcb](https://pcbkit.io/embed/boards/quinnfreedman-modular-clock-back-pcb.jpg?size=s)](https://pcbkit.io/boards/quinnfreedman-modular-clock-back-pcb)

Source

Repository: QuinnFreedman/modular
Board file: modules/Clock/PCBs/clock_back_pcb/clock_back_pcb.kicad_pcb
Commit: c78d208
Homepage: freemodular.org
Licence: Not stated

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