Based on a classic wah pedal design (Hint: You’re old enough to know better) the Wah Baby is fitted for Eurorack and includes CV control over the effect, with input for CV from an external source, or use the built-in LFO. Pair this with the Wocka for some classic psychedelia. Whoa, man…

Note: The schematic below represents the full vision for this module. The version in the image to the left was pared down for lack of a SP3T switch. The module in the image doesn’t include the sine and square outputs from the LFO. The triangle output connects directly to pin 3 of SW2.

Schematic

Schematics are provided as-is. Never trust that any schematic on the internet is foolproof. Test your build in isolation before introducing it to the rest of your modules.

BOM

• Resistors
  • 300R (1) R7
  • 2.2k (1) R8
  • 10k (5) R1, R4, R12, R14, R19
  • 22k (2) R11, R20
  • 27k (2) R2, R15
  • 68k (1) R3
  • 82k (1) R17
  • 100k (5) R5, R6, R9, R16, R18
  • 470k (2) R10, R13
• Capacitors
  • 0.001uf (3) C1, C6, C8
  • 0.01uf (2) C2, C4
  • 0.1uf (2) C5, C7
  • 4.7uf (1) C3
• Potentiometers
  • 100k (1) Wah frequency RV2
  • 1M (1) LFO frequency RV1
• Transistors
  • MPSA18 (1) Q1
  • MPSA42 (1) Q2
• Inductor
  • 500mH (1) L1 (Recommend a Dunlop Fasel inductor)
• ICs
  • TL074 (1) U1
• Audio jacks (2) J1, J3
• Switched audio jacks (1) J2
• SPST switch (1) SW2
• SP3T switch (1) SW1

Demo

Coming at some point in the future.