2 layers19 × 17.2 mm
Breadboard scalers gates
doctea/eurorack-breadboard-tools
Some quick and dirty boards for interfacing eurorack with 3.3v-based microcontroller boards (Arduino, Raspberry Pico/Pico2 (RP2040/RP2350), Teensy 4.x).
22 parts1
2 layers15.1 × 22 mm
Breadboard scalers bipolar
doctea/eurorack-breadboard-tools1Some quick and dirty boards for interfacing eurorack with 3.3v-based microcontroller boards (Arduino, Raspberry Pico/Pico2 (RP2040/RP2350), Teensy 4.x).
- Size
- 15.1 × 22 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 24
- Nets
- 20
- Pads
- 68
- Tracks, vias
- 169, 9
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 25 Jan 2026
- Updated
- 25 Jan 2026
Overview
Breadboard scalers bipolar is an open-source printed circuit board by doctea, from the doctea/eurorack-breadboard-tools repository on GitHub. It is a 2-layer board of 15.1 × 22 mm with 24 parts on 20 nets, routed with 169 tracks and 9 vias.
It is built around the MCP6004-E/P. Its parts include 16 resistors, 4 capacitors, 2 connectors and 1 IC.
Main components
1README
README.mdEurorack-MCU breadboard tools
Some quick and dirty boards for interfacing eurorack with 3.3v-based microcontroller boards (Arduino, Raspberry Pico/Pico2 (RP2040/RP2350), Teensy 4.x).
KiCad files and gerber files provided so you can modify them, incorporate the schematics in your own projects, and get them manufactured easily. I might also have spares from my own production runs that I could sell, get in touch.
Ready
breadboard-scalers-bipolar
Take 4 x bipolar (-5v to +5v) CV signals and scale them to inverted 0v to 3.3v range, to avoid frying ADC pins on your MCU.
Tested briefly, seems to work OK!
- TODO: increase precision?
breadboard-scalers-gates
Take 4 x eurorack gate signals and bring them down to 3.3v, to be used by GPIO on MCU boards.
- TODO: add indicator LEDs to these
- TODO: make input and output side voltages separable so we can use these as gate outputs too
Unready/todo/future
- breadboard-scalers-gates for outputs: Take 4 x 3.3v GPIO signals and output 5v Eurorack gates.
- breadboard-scalers-unipolar: Take 4 x 0v to +10v signals and scale them to 0v to 3.3v range.
If you use these, let me know!
Parts
24| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 100k | Resistor_SMD:R_0402_1005Metric | R1, R2, R3, R4, R5, R6, R7, R8 |
| 8 | 33k | Resistor_SMD:R_0402_1005Metric | R9, R10, R11, R12, R13, R14, R15, R16 |
| 4 | 1n | Capacitor_SMD:C_0402_1005Metric | C1, C2, C3, C4 |
| 1 | Conn_01x04_Pin | Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical | J2 |
| 1 | Conn_01x08_Pin | Connector_PinHeader_2.54mm:PinHeader_1x08_P2.54mm_Vertical | J1 |
| 1 | MCP6004 | Package_SO:TSSOP-14_4.4x5mm_P0.65mm | U1 |
| 1 | SolderJumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Bridged2Bar_RoundedPad1.0x1.5mm | JP1 |
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Questions
How big is the Breadboard scalers bipolar PCB?
It measures 15.1 × 22 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Breadboard scalers bipolar use?
24 parts, built around the MCP6004-E/P. 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 Breadboard scalers bipolar KiCad files?
From the doctea/eurorack-breadboard-tools repository on GitHub, at the commit this page was made from: the board is breadboard-scalers-bipolar/breadboard-scalers-bipolar.kicad_pcb and its schematic breadboard-scalers-bipolar/breadboard-scalers-bipolar.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Breadboard scalers bipolar design in my own project?
Its repository states no licence, so its author keeps all rights: ask doctea before reusing the design.