2 layers48.4 × 106.3 mm
2 layers45.4 × 89.7 mm
1U module for mixing left and right signals
- Size
- 45.4 × 89.7 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 37
- Nets
- 24
- Pads
- 93
- Tracks, vias
- 120, 5
- Pours
- 3
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 3 May 2026
- Updated
- 6 Jun 2026
Overview
Wetmix is an open-source printed circuit board by thismatters, from the thismatters/EurorackWetMix repository on GitHub. It is a 2-layer board of 45.4 × 89.7 mm with 37 parts on 24 nets, routed with 120 tracks and 5 vias.
It is built around the TL072 and BAT54S. Its parts include 10 resistors, 8 connectors, 3 capacitors, 2 diodes and 1 IC.
Main components
2README
README.mdWet Mix
Fade between two signals.
The basic principle behind this circuit is described by Electric Druid. It's a cool trick to allow use of a single-gang potentiometer to act like a double by exploiting mathematics.
The KiCAD project here uses the library/footprints found in my companion repo.
Width
9hp on an Intellijel 1U rack.
Inputs
Two signal jacks One sliding potentiometer
Outputs
One signal output
Vendors
There are part numbers in the BOM for many of the parts (not for basic passives though) at the following vendors:
- Mouser: Needs no introduction. Get your ICs from here (or digikey).
- Tayda Electronics: Good supplier for passive components; audio jacks, and potentiometers. Their audio jacks are slightly smaller than the thonkiconn from thonk.
- Love My Switches: Has really good knobs to go on those potentiometers!
- OSHPark: Fast and (relatively) cheap PCB manufacturer. Prototype run pending.
Changelog
V1 (TODO)
- Added (possibly passive) mult for each input.
- Changed to LED illuminated slider pot for visibility
Parts
37| Qty | Value | Footprint | References |
|---|---|---|---|
| 7 | 100K | Resistor_SMD:R_0805_2012Metric | R3, R4, R5, R6, R7, R8, R9 |
| 4 | Standoff | MountingHole:MountingHole_2.7mm_M2.5 | H5, H6, H7, H8 |
| 3 | mount1 | Eurorack:Mech-MountingHole | H2, H3, H4 |
| 2 | 10 | Resistor_SMD:R_0805_2012Metric | R1, R2 |
| 2 | 22u 50V | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C1, C2 |
| 2 | BAT54S | Package_TO_SOT_SMD:SOT-23 | D1, D2 |
| 2 | Conn_01x03_Pin | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J2, J4 |
| 2 | Conn_01x03_Socket | Connector_PinSocket_2.54mm:PinSocket_1x03_P2.54mm_Vertical | J3, J5 |
| 1 | 100n | Capacitor_SMD:C_0805_2012Metric | C3 |
| 1 | 1K | Resistor_SMD:R_0805_2012Metric | R10 |
| 1 | A | Eurorack:Mech-AudioJack-Hole-Input | H9 |
| 1 | B | Eurorack:Mech-AudioJack-Hole-Input | H10 |
| 1 | B100K | Potentiometer_THT:Potentiometer_Bourns_PTA2043_Single_Slide | RV1 |
| 1 | Conn_02x05_Odd_Even | Eurorack:PinHeader_2x05_P2.54mm_Vertical | J1 |
| 1 | IN_1 | Eurorack:AudioJack2_Tayda_A-2566 | J6 |
| 1 | IN_2 | Eurorack:AudioJack2_Tayda_A-2566 | J7 |
| 1 | OUT | Eurorack:AudioJack2_Tayda_A-2566 | J8 |
| 1 | OUT | Eurorack:Mech-AudioJack-Hole-Output | H11 |
| 1 | SLIDER | Eurorack:Mech-Slider-Hole-2043 | H12 |
| 1 | TL072 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U1 |
| 1 | mount0 | Eurorack:Mech-MountingHole | H1 |
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Questions
How big is the Wetmix PCB?
It measures 45.4 × 89.7 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Wetmix use?
37 parts, built around the TL072 and BAT54S. 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 Wetmix KiCad files?
From the thismatters/EurorackWetMix repository on GitHub, at the commit this page was made from: the board is wetmix.kicad_pcb and its schematic wetmix.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Wetmix design in my own project?
Its repository states no licence, so its author keeps all rights: ask thismatters before reusing the design.