2 layers223.5 × 160 mm
2 layers27.9 × 66 mm
Modular Synths for Everyone
- Size
- 27.9 × 66 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 8
- Nets
- 14
- Pads
- 38
- Tracks, vias
- 44, 8
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 4 Oct 2024
- Updated
- 25 Oct 2026
Overview
4 att is an open-source printed circuit board by bread-modular, from the bread-modular/bread-modular repository on GitHub, published under the MIT licence. It is a 2-layer board of 27.9 × 66 mm with 8 parts on 14 nets, routed with 44 tracks and 8 vias.
It belongs with the audio and music boards of this library.
README
README.mdBread Modular
An open-source hardware modular synthesizer format designed to be minimalistic and cost-effective: USB-powered, breadboard-friendly, with analog/digital modules and MIDI alongside CV & Gate.
Find your starting point
- Build or explore: modules, specification, common parts.
- Set up KiCad libraries: workspace/library setup. Projects
use the shared
opt/fp-lib-table; initialization copies local submodules rather than cloning them. - Check/export/source parts: KiCad toolkit.
Canonical tools, JLCPCB utilities and skills live under
opt/kicad-tools/.
KiCad quick start
python3 -B opt/kicad-tools/kicad_tools.py --help
python3 -B opt/kicad-tools/kicad_tools.py doctor
python3 -B opt/kicad-tools/kicad_tools.py export --helpPython + installed KiCad CLI; no extra packages for core tools. Private checks,
Gerber/BOM/CPL export, native netlist helpers and read-only sourcing have
distinct requirements and safety boundaries.
Exports are not electrical/release/order approval; keep frozen module scripts
and production designs untouched. Historical opt/kicad-jlcpcb and
.agents/skills/{kicad-workflow,jlcpcb-assembly} resolve through
relative compatibility symlinks.
Agents: start with the KiCad workflow skill or assembly skill, then actual CLI help.
Project references
Module catalog · Modular MIDI · PCB assembly
- Standalone exporter / native part-number setup
- Sourcing, audits and passive planning
- 32bit-5v sourcing / release HOLD
- 16bit-5v sourcing HOLD evidence
Project image and full feature overview
- Modular design: Just like Eurorack.
- USB-powered: It can be portable.
- Minimal design: Cost-effective.
- Modular MIDI support: Communicate between modules; CV & Gate still supported.
- Analog and digital signal paths: It’s your choice.
- Diverse built-in modules: A wide range of pre-designed modules.
- Configurable digital modules: Voice and CV using AtTiny 1616 or ESP32.
- Fully open source: Schematics, PCB designs and code.
- Ease of customization: Create modules tailored to your needs.
- No case required: Use directly on a breadboard or a simple base module.
Parts
8| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 100K | Potentiometer_THT:Potentiometer_Alpha_RD901F-40-00D_Single_Vertical | 1, 2, 3, 4 |
| 2 | Conn_01x04_Socket | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | INPUTS, OUTPUTS |
| 2 | Conn_01x05_Pin | Connector_PinHeader_2.54mm:PinHeader_1x05_P2.54mm_Vertical | 5V1, GND1 |
Questions
How big is the 4 att PCB?
It measures 27.9 × 66 mm and has 2 copper layers, 1.6 mm thick.
What parts does the 4 att use?
8 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 4 att KiCad files?
From the bread-modular/bread-modular repository on GitHub, at the commit this page was made from: the board is modules/_deprecated/4_att/4_att.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the 4 att design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
More from bread-modular/bread-modular
12- 4 layers91.4 × 68.6 mm
- 2 layers30.5 × 68.6 mm
- 2 layers30.5 × 68.6 mm
- 4 layers30.5 × 68.6 mm
- 2 layers30.5 × 68.6 mm
- 4 layers30.5 × 68.6 mm
- 4 layers30.5 × 68.6 mm
- 2 layers30.5 × 68.6 mm
- 2 layers30.5 × 68.6 mm
- 2 layers84.3 × 74 mm
- 2 layers30.5 × 68.6 mm
Similar boards
- 2 layers20.5 × 24.8 mm
- 2 layers14.4 × 10.5 mm
OSO SWAB B1-00 Sensor Watch Accelerometer
joeycastillo/Sensor-Watch
A board replacement for the classic Casio F-91W wristwatch
8 parts2.1k - 2 layers7.9 × 39.1 mm
Brain board STM32F407 SD wing it
rusefi/rusefi
rusefi - GPL internal combustion engine control unit
8 parts1.2k - 2 layers59.9 × 25.7 mm
Buffer
hoglet67/RGBtoHDMI
Bare-metal Raspberry Pi project that provides pixel-perfect sampling of Retro Computer RGB/YUV video and conversion to HDMI
8 parts1kGPL-3.0 - 2 layers52 × 12.6 mm
USB
shanteacontrols/OpenDeck
A platform for building interactive control and sensing devices using MIDI and OSC built with Zephyr RTOS.
8 parts960Apache-2.0 - 2 layers87.5 × 48.5 mm
7 input macropad
hackclub/OnBoard
💡 Join 1,000 teenagers and make your first PCB with a $100 grant!
8 parts915 - 2 layers36.2 × 63.1 mm
PicoMemcard pico
dangiu/PicoMemcard
Emulating PSX Memory Card (or controller) using a Raspberry Pi Pico
8 parts694GPL-3.0 - 2 layers36 × 10 mm
PCB4-PWR BTN Rev.A
OLIMEX/DIY-LAPTOP
Do It Yourself Open Source Hardware and Software Modular Hacker's Friendly Laptop
8 parts578Apache-2.0