WL-4033 - "RUSTY HUM"


Rusty Hum is an electret condenser microphone module for explorations in room tone and feedback in the vein of the late Alvin Lucier, Masonna, and others. The small microphone is exposed to the outside world (albeit behind a mesh screen for protection) and introduces external sounds directly into the modular format. It features vactrol control of the microphone's level for CV-controlled room feedback or tremolo effects on the incoming audio.


  • 6HP wide
  • Skiff-friendly
  • 35ma~ at +12v, 35ma~ at -12
  • 1kOhm input / 100kOhm output impedence
  • Vactrol control with CV in



    Microphone output level control.

  • CV

    Vactrol CV control of LEVEL - knob acts as an offset when CV is injected.

  • OUT

    Main output.


  • During testing, we found that having a mixer with a 3- band EQ (low, mid, high) allowed us to shape / tame the feedback effectively.

  • Filters with a resonance / Q control can be used to invoke feedback more easily, and sweeping the filter's cutoff smoothly accentuates feedback overtones.

  • More textural sounds can be achived by tapping, scraping, rubbing, or using an angle grinder on the module's panel.


Please do not hesitate to reach out to us with questions, comments, repair requests, returns, parables, assembly opcodes, and general support. You can reach us via:

EMAIL – mailto:wildfirelaboratories@gmail.com

INSTAGRAM – https://instagram.com/wildfire_laboratories

WEBSITE – https://wildfirelaboratories.com d


All Wildfire Laboratories devices have a 5-month warranty from time of purchase. This covers manufacturing + assembly issues. Incorrect power connections (power supplies with wrong polarity, too much power, etc), wear and tear from normal use, and issues due to modifications are not covered by said Warranty (although you should absolutely email us with any mods you do).

We will repair, replace, or refund depending on the circumstances. Shipping will be paid by the buyer.