Mu-FX Tru-Tron 3X

Just like the original Musitronics Mu-Tron III™ envelope filter pedal… Only Better!
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.

The Tru-Tron 3X is bar none the best envelope filter pedal for guitar. Actually, the Tru-Tron 3X is the best envelope filter for bass, keyboards, sax or any instrument that can be plugged in!



  • MU controls the envelope and filter audio drive
  • MU/PRE switch determines the PREamp and ENVelope drive modes of the device
    • MU position works exactly like the original Mu-Tron III
    • PRE position enables the MU to control only the envelope drive and enables the PRE to control only the filter audio drive
  • PRE controls the preamp drive
    • UP position produces familiar “auto-wah” sound – like a heel-to-toe sweep on a wah pedal
    • DOWN position produces a “down swoop” sound – like a toe-to
  • PEAK (or Q) controls the filter audio response from very weak to very strong. The original Mu-Tron III’s peak maximum was at about 8 on the dial, the Tru-Tron 3X peak is much stronger, from about 9 to 11 on the dial. If trying to match the setting of the original Mu-Tron III, set the Tru-Tron 3X proportionately lower
  • MODE
    • LP (lowpass filter) passes all the signals below the peak and attenuates signals above the peak
    • BP (bandpass filter) passes signals only near the peak and attenuates signals below and above the peak
    • HP (highpass filter) passes all signals above the peak and attenuates signals below the peak
    • MIX is an optimized mixture of the dry (unfiltered) signal and the filtered signal
    • LOW sets the filter sweep to a low range for most rhythm guitar, bass and lower fret uses
    • HI sets the filter sweep to a high range for accenting string harmonics or for up-the-neck and solo work


  • 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
  • Owner’s Manual
  • Mu-FX Sticker


Duties and Taxes: Import duties and taxes are not included in the product price or shipping and handling cost and it will be collected upon delivery from the carriers for certain packages. These charges are recipient’s responsibility as we are only charging the transportation fee for the packages. You may check with your country’s customs office to determine what these additional costs will be.

Reviews & Demos:

Premier Guitar’s Charles Saufley Tru-Tron 3X Review

Premier Guitar’s John Bohlinger Demo

John Pahmer’s Tru-Tron 3X through a Clavinet Demo

Gearmanndude’s House of Tone Review