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History of The Musitronics Mu-Tron III and the Mu-Tron 3X (by Mike Beigel)

The Mu-Tron 3X (and Tru-Tron 3X in the U.S.) is the authorized re-issue and upgrade of the venerable Musitronics Mu-Tron III, authorized and endorsed by the Stockholders of the original Musitronics Corp (Incorporated in Rosemont, NJ, 1972).* Mike Beigel and Aaron Newman collaborated to design the product, and along with Derf Nolde and Danny Lamb formed the original founders and stockholders of the company.

Now, the true Original inventor and designer of the Musitronics Mu-Tron III has come back to his favorite MUSIC industry after years of high-tech invention and product design work in numerous other fields of industry (but still including 9 product designs for Electro-Harmonix in musical sound modifiers from 1996 to 2011)

While, sadly, the EXTERIOR of the original product has been copied from the original Musitronics Corp. artwork, the circuit inside it is definitely NOT "The Original", and caused a lot of confusion among younger musicians for the past few years. The form of the circuit in the copy had been long ago tried and REJECTED by the original designer as having inferior sound quality to the circuit that WAS designed into the Original Musitronics product. I can say this with confidence since I am the original designer and inventor of the two patents (system patent and design patent) that protected the original product from copying for 17 years after it was issued in 1975. The unauthorized copy appeared, it seems in 1993 or 1994 (one or two years after the expiration of the systems patent.

Claims have even been made that the original endorsers of the Musitronics Mu-Tron III “also” seem to endorse this illegitimate copy. Considering that a number of these “endorsers” had died before the copy was made, the statement rings very hollow.

In more recent years, more HONEST clones have been made of various original Musitronics product designs. None of them are authorized by Musitronics Corp, and none have been tested by myself.

Even more surprising, the name MUSITRONICS has been trademarked in the USA by a person who had fraudulently trademarked the Mu-Tron name and logo, and subsequently lost it to the person who made the unauthorized “look alike” copy of the Mu-Tron III.

When I decided to make my own product designs again, I could not use AD the original name and trademark of Musitronics, Mu-Tron, or the logo in the USA. Although I am confident that the stockholders of the original company have legal rights to its “intellectual property” including these trademarks and the goodwill created over many years, I decided to spend my time and funds on product design rather than start a potentially un-ending legal battle with the two “usurpers” of the name, product design exterior, and goodwill of the original company.

Fortunately, enough people remember who REALLY designed the original products for me to have started up limited production and hope for wider acceptance by the public, since “word of mouth” speaks louder than trademarks, false advertising, illegitimate trademarking and misstatements of truth about Inventorship, “originality” and endorsements by musicians living and deceased.

This short summary of a long and complex story will, I hope, settle many misconceptions and doubts about what happened over 40 years ago, and the progression to the present time.

I am very happy to re-introduce and where appropriate, truly improve these venerable products without losing the original design concepts and “mojo” that made them such collectible items for MUSICAL USE and not just investment.

Mike Beigel
October 20, 2013

Musitronics Corporation (New Jersey 1972) and its relation to Beigel Technology Corporation and its subsidiary Beigel Sound Lab, producer of the Mu-FX product line including the Tru Tron 3X
The original Musitronics Corp. Mu-Tron III envelope controlled filter (produced from 1972 to 1978 by Musitronics (New Jersey) and from 1978 to about 1980 by the “Mu-Tron Inc.” division of ARP Synthesizers (Boston MA). Beside the “Uni-tron 5 by Unicord” and the Mu Tron III by in Mexico, there are no other authorized or approved versions of the original Mu-Tron III by Musitronics Corp. Only the Mu-Tron 3X by Beigel Sound Lab division of Beigel Technology Corp. is an authorized and approved reissue-upgrade of the original Mu-Tron III. Michael Beigel, (an original founder of Musitronics Corporation) has been elected as the sole and authorized representative, without limitation, of the original Musitronics Corporation and its shareholders by authorization letters by the known surviving stockholders in 2007 and in 2012. A portion of the revenues from the sale of the products by BSL/BTC is sent to the known original stockholders of the corporation and/or their estates.


Mike about his NEW product (excerpt from Facebook):
"Then there is the NEW page which will introduce a new product and hopefully PRODUCT LINE based on the Musitronics Mu-Tron original products (and some prototypes which never got to the marketplace).

While remaining TRUE to the original "Mu-Tron mojo" (you should always be able to set them so you can NOT tell the difference between the new designs and the original vintage designs), we will also take advantage of the latest manufacturing techniques and components to bring you more compact and versatile products at reasonable prices, and NEVER deviate from Musitronics original principles of providing the BEST Performance, Form-follows-function exterior design, and fanatical quality control so you don't have to try 5 products (of the same design and logo) to get the one that "sounds best".
We are close to ready with first design, but will announce once we know delivery dates so you can pre-order with confidence that you WILL get your product and WHEN you will get it.

Mike is talking about some features of the NEW Mu-Tron3X (excerpt from Facebook):
"The unit, although smaller than its predecessor, the Musitronics Corp Mu-Tron III, is BIGGER in features and EQUAL OR BETTER (my opinion) IN SOUND AND VERSATILITY.

When the unit is set in "MU" mode, it works as exactly the same (and to my ears sounds exactly the same) as the Mu-Tron III vintage unit--I have tested it against 2 Mu-Tron III units AND some of the other envelope filter products I designed.
HOWEVER, the Q CONTROL dial goes to 11 and for a good reason!
I have added a significant amount MORE Q to the filter. So to get Mu-Tron III Q, you just need to turn the dial back a little from what you would usually use to get the same Q as on a Vintage Mu III.
The MU DIAL (top left control) controls the signal gain to BOTH THE FILTER AUDIO AND THE ENVELOPE GENERATOR, as in the Vintage M-III

The FILTER MODE switch now has 4 positons instead of 3. The 4th position, "MIX" is a carefully mixed blend of the original signal and the LOWPASS MODE from the filter. It's the best mix sound I could get from all the possibilities I tried.

There are also TWO OVERLOAD INDICATOR LEDs to help you dial in the sound you want.

The first ENVELOPE SATURATION, to the right and above the MU knob, shows when the envelope signal begins to go into saturation, and gets brighter and stays on longer the more the envelope is "pushed" further into saturation. So when it NEVER lights up, the envelope always follows the shape of the loudness of your instrument signal, and never overloads. When it goes on only on the loudest notes or chords you play, it overloads at the peak of the signal, and from there, the more it goes and stays on, you know that you have "topped out" the envelope (making the filter sweep through its full range) with every note you play. ALL THESE SETTINGS AND INDICATIONS HAVE MUSICAL USES, as I have discovered by playing different kinds of riffs into the MU-3X.
The ENV SAT LED is only responsive to your signal and the setting of the MU control. The red numbers on the dial tell you that you will be hitting env sat with almost everything you play.

The other overload indicator, AUDIO DIST(ORT) responds when the audio signal to the filter hits clipping. THIS IS A VERY DIFFERENT KIND OF THING because you will be able to hear the OP-AMP CLIPPING distortion and in the "middle ranges" of the MU control, it might or might not sound good to you... and the higher you set the MU control, the louder the audio signal gets, till it mignt be much louder than the BYPASSED signal from your instrument in TRU-BYPASS mode. But I have found that when the loudness is boosted so that it distorts almost ALL the time, it can (surprisingly!) make some very musical distortion tones when it goes through the filter , especially in SOME modes and settings.
But when you drive the audio to FULL DISTORT with the MU control, you also saturate the envelope (both lighty will go on) so every note is "slammed" to full sweep. This is not, in my opinion, optimum for many kinds of more subtle effects.


That's why the MU <-> PRE toggle switch between and below the MU and the PRE(AMP) controls is a NEW FEATURE of the MU-3X.

Time for "a break", and I will post the explanation for the other features and controls........ m mt"

US-model Tru-Tron3X besides original Mu-Tron III plus measurement devices

A.T. Music Electronix - owner: Dieter Baron - Fichtenstraße 49 - D-90763 Fürth (Bay), Germany - Tel.: +49-911-80190447 - Fax +49-911-80190449