WL-4033 - "RUSTY HUM"


If any issues arise please click here to contact us via email first. We'll walk you through any problems you may be having (with the module).


for v2.0 boards

Part Value Qty. Link Other Notes
IC1 TL074P 1 here For versions earlier than 2.0, this will be a pre-soldered SMD part.
IC2 78L05Z 1 here
D1/D2 1N4004 2 here
R3, R4, R5, R6, R9 1k 5 all resistors**
R7, R8, R10 100k 3
R1 470R 1
R2 2.2k 1
C1 to C4, C8, C10 100nF 6 here
C5 22pF 1 here
C6 4.7uF 1 here
M2 Electret Microphone 1 here
GAIN 50kB Trimpot 1 here
VR1 10kB Pot 2 here
n/a Pin Headers 1 here 2 strips of 5
LDR1 / LDR2 Vactrol 2 5528 LDR / 5mm red LED / 6-7mm Heatshrink Vactrol guide here
Knob n/a 1 here Or any knob w/ brass screw and insert, get creative!

** this link is to a quick-order page for ALL resistor values.


  • Before powering on for the first time, check for shorts between the GND, +12, and -12 test points.

  • Values for all components are listed on the board itself.

  • The microphone itself will rest on the resistors a bit, this is normal!

  • The components marked OUT and CV are 3.5mm audio jacks - they're marked as such for easy troubleshooting.