An Envelope Filter is an electronic music effect where a filters resonant frequency is controlled by the dynamic changes of a musical instrument. Mostly used with electric guitars Envelope Filters are part of music history and continue to be a vital part of today’s music.

 



( Sweep generator thru a Mu-Tron III in BP mode )



Emulating the Mu-Tron III using the Electro-Harmonix Enigma

by Richard Lingenberg 9/5/09

Mike Beigel and I worked on the development of the EHX Enigma and built the first breadboard and first hardwire prototypes. Now that EHX has put it into production I recently purchased one to try it out and test how well the production model works. While testing it I thought that it may be possible with the right settings to emulate the function and sound of the Mu-Tron III.

For this emulation I used my vintage original Mu-Tron III for reference. Six parameters ( gain, start frequency, max frequency, peak, attack and decay ) were matched as closely as possible first with test equipment then later with a guitar and checked by ear. The Mu-Tron III settings I used for matching were: mode = LP, peak = 10, gain = 3.7, range = low, drive = up.

The EHX Enigma settings will be in clock terms with 7:00 being minimum, 12:00 mid point and 5:00 being maximum.

The settings for the EHX Enigma are:

Blend = 5:00 or max

Mode = LP

Attack = 8:00

Decay = 7:00 to 8:00

Start = 10:00

Stop = 3:00

Q = 2:00

Sensitivity = 12:00 to 1:30

Distortion = off

 



The decay is least like the Mu-Tron III as the Mu-Tron will decay faster. This problem can be helped by reducing the sensitivity more towards 12:00.

If you need to emulate the Mu-Tron III in high range the EHX Riddle should be used but will probably have completely different settings.

Try it and hear what happens !

Richard Lingenberg



Mu-Tron III Power Supply and other accessories available on Products page.



Envelope Filter Links:

Electro-Harmonix Bi-filter 

Electro-Harmonix Enigma 

Beigel Technology Corporation 

List of envelope filters by Discofreq 

 



Mu-Tron repairs and mods

 



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