2 layers181 × 113 mm
Quad VCA Mixer
MitchReyno/Electronics-Projects
A collection of various electronics projects I've worked on over the years
132 partsGPL-3.0
2 layers132.6 × 127.9 mm
VCF State Variable
MitchReyno/Electronics-ProjectsA collection of various electronics projects I've worked on over the years
- Size
- 132.6 × 127.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 41
- Nets
- 46
- Pads
- 103
- Tracks, vias
- 88, 0
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 27 Feb 2026
- Updated
- 25 Jun 2026
Overview
VCF State Variable is an open-source printed circuit board by MitchReyno, from the MitchReyno/Electronics-Projects repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 132.6 × 127.9 mm with 41 parts on 46 nets, routed with 88 tracks and 0 vias.
It is built around the TL072. Its parts include 24 resistors, 9 connectors, 4 capacitors, 2 transistors and 1 IC.
Main components
1README
Eurorack/Eurorack_PSU/README.mdEurorack PSU
A mains-powered linear power supply for a Eurorack modular synthesizer case.
What it does
Converts 240 VAC mains to the four standard Eurorack DC rails:
| Rail | Regulator |
|---|---|
| +12 V | LM7812 |
| −12 V | LM7912 |
| +5 V | LM7805 |
| −5 V | LM7905 |
Key components
| Component | Role |
|---|---|
| Mains transformer (240 VAC, 20:1) | Mains isolation and step-down |
| GBU6A | Full-bridge rectifier |
| LM7812 / LM7912 | ±12 V linear regulators |
| LM7805 / LM7905 | ±5 V linear regulators |
| 10 000 µF bulk caps | Reservoir filtering |
| 1N4007 diodes | Rectifier protection |
Files
KiCad 8 project files are in the root directory (.kicad_sch, .kicad_pcb, .kicad_pro).
Revision: 1 (2026-02-28)
Parts
41| Qty | Value | Footprint | References |
|---|---|---|---|
| 5 | 100K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R6, R9, R10, R43, R49 |
| 4 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R11, R25, R31, R34 |
| 4 | 2K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R13, R14, R36, R39 |
| 3 | 100nF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm | C4, C5, C8 |
| 2 | 100K | Potentiometer_THT:Potentiometer_Single_Horizontal | R4, R47 |
| 2 | 10K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R3, R8 |
| 2 | 2N3904 | Package_TO_SOT_THT:TO-92_Inline_Wide | Q1, Q2 |
| 2 | 33K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R5 |
| 2 | 49.9K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R48, R52 |
| 1 | 100K | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | R58 |
| 1 | 100R | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | R2 |
| 1 | 100pF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm | C1 |
| 1 | 1N4148 | Diode_THT:D_DO-34_SOD68_P7.62mm_Horizontal | D1 |
| 1 | 475R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R7 |
| 1 | BP | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J9 |
| 1 | CV1 | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J1 |
| 1 | CV2 | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J2 |
| 1 | HP | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J8 |
| 1 | IN1 | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J4 |
| 1 | IN2 | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J5 |
| 1 | IN3 | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J6 |
| 1 | LP | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J10 |
| 1 | TL072 | Package_DIP:DIP-8_W7.62mm | U1 |
| 1 | XRES | Connector_Audio:Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J7 |
More from MitchReyno/Electronics-Projects
5- 2 layers100.8 × 84.8 mm
LFO VC
MitchReyno/Electronics-Projects
A collection of various electronics projects I've worked on over the years
105 partsGPL-3.0 - 2 layers
Clocky
MitchReyno/Electronics-Projects
A collection of various electronics projects I've worked on over the years
48 partsGPL-3.0 - 2 layers95 × 58 mm
Eurorack PSU
MitchReyno/Electronics-Projects
A collection of various electronics projects I've worked on over the years
27 partsGPL-3.0 - 2 layers59.5 × 77 mm
Nixie PSU MK1
MitchReyno/Electronics-Projects
A collection of various electronics projects I've worked on over the years
26 partsGPL-3.0
Similar boards
- 2 layers148 × 84.5 mm
Panel daisy
ohmtech-rdi/eurorack-blocks
Software to Hardware Prototyping for Eurorack using C++, Max/Gen~ or Faust
259 parts410 - 2 layers39.6 × 99.1 mm
ESP32-Eurorack Audio
ctag-fh-kiel/ctag-tbd
CTAG TBD >>to be determined<< an extendible open source Eurorack sound module
128 parts260 - 4 layers121.9 × 109.2 mm
Plinkyblack hwmidi jacks
plinkysynth/plinky_public
a public release of the plinky sw and hw
300 parts227 - 2 layers58 × 110 mm
- 2 layers37 × 113.9 mm
- 2 layers111.3 × 106.4 mm
Super Sixteen v1
matthewcieplak/super-sixteen
Code and schematics for the Super Sixteen Eurorack sequencer
141 parts171 - 2 layers27.9 × 101.6 mm
MFOS Eight Stage Phase Shifter - Main
mzuelch/CATs-Eurosynth
Analog Synth Eurorack Modules
105 parts166MIT - 2 layers85.1 × 62.2 mm
Mic extension board
StoneRose35/cortexguitarfx
guitar effects processor implemented on various arm cortex platforms
75 parts146
Questions
How big is the VCF State Variable PCB?
It measures 132.6 × 127.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the VCF State Variable use?
41 parts, built around the TL072. 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 VCF State Variable KiCad files?
From the MitchReyno/Electronics-Projects repository on GitHub, at the commit this page was made from: the board is Eurorack/VCF_State_Variable/VCF_State_Variable.kicad_pcb and its schematic Eurorack/Bong0/Bong0_Cat.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the VCF State Variable design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).