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Tru-Tron 3X Envelope Controlled Filter Limited Collector's Edition (hand-signed by Mu-Tron III inventor Mike Beigel)


The Tru-Tron 3X™ is the modern all-analog refinement of the classic Mu-Tron III™ envelope controlled filter. Mike Beigel*, inventor/designer of the Mu-Tron III™ and co-founder of Musitronics Corp., has retained all the mojo that made the 1972 unit so popular with Stevie Wonder, Jerry Garcia, Bootsy Collins, Larry Coryell, Frank Zappa, Carlos Santana, Joe Zawinul, George Duke and many more. The Tru-Tron 3X™ is the closest you’ll find to the original Mu-Tron, because at its heart—it is.


  • 1/4" Input and Output Jacks
  • True Bypass/Convertible to Active
  • Signal to Noise Ratio: 85dB or better
  • Input Impedance: 390K Ohms
  • Nominal Input Level: -10dBu
  • Output Impedance: 150 Ohms
  • Nominal Output Level: -10dBu
  • Maximum Output Level: +16dBu
  • Case: 2mm aluminum
  • Weight: 16.3oz/462g (unit only)
  • Dimensions: 7” x 4 15/16” x 2 1/4”
  • Includes 12VAC 200MA adapter
  • 1 year limited warranty
  • Made in USA to ISO 9001 standard

Included in the box:

  • Tru-Tron 3X
  • 12VAC power supply
  • Manual

"The MU is Back!" Tru-Tron 3X T-Shirt

Mu-FX by Beigel Sound Lab is now offering t-shirts with the Tru-Tron 3X logo graphic screened on the back. 


  • Adult Men 
  • Crew neck
  • 100% Cotton Pre-Shrunk
  • printed in USA

$ 19.99 USD and FREE shipping