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Mu-Tron III

envelope filter

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionMar 7, 2026
Entity authorityQ17104353 ↗
Source-derived summary

The Mu-Tron III is an envelope filter made by Musitronics Corporation. "The world's first envelope-controlled filter" was first made in 1972 by Mike Beigel and quickly became an essential effect for many funk musicians. It was produced again, in a modified version, in 2014.

Mu-tron III

Extracting elements from one of the prototypes of a synthesizer he was developing for Guild Guitar Company, Mike Beigel based the Mu-Tron III, at the instigation of Guild engineer Aaron Newman, on a prototype called the Timbre Generator. The Mu-tron III could be used for any number of electric instruments. Beigel said he chose the envelope-controlled filter over other synthesizer elements, such as ring modulation, because it sounded more musical; it was a more general effect that would lend itself to a variety of applications, and it was easy to use.

The Mu-tron III was an instant success and was used by jazz/fusion guitarist Larry Coryell, Funkadelic bass player Bootsy Collins (for his "Space Bass"), guitarist Jerry Garcia, Yes bassist Chris Squire, and Stevie Wonder, who used it on his Clavinet for the song "Higher Ground".

Beigel was successfully granted a patent for the circuitry of the Mu-tron III. Musitronics licensed the Mu-tron III circuitry to a few different companies in the seventies – the Univox Funky Filter and Monacor Effectmatic are notable examples.

The original Mu-tron III ran on two 9V batteries used as a Bi Polar power supply; this gave it a wider dynamic range and more headroom compared to effects that ran on 9 volt. There was an optional power supply (the PS-1), and with later versions had built-in AC power supplies.

Editorial summary

This brief starts where responsible research should: with the source description of “Mu-Tron III” as envelope filter. Everything that follows is an evidence route, not borrowed authority.

Editorial reviewA practical starting point whose main value is the path it opens into stronger specialist and primary sources. The current lead gives the account dated anchors—1972, 2014—that can be checked directly. The selected authority fields contribute no independent date. The account is most persuasive where Mu-Tron, envelope and filter can be independently traced.
Editorial analysis

Why this record matters

The subject matters to the general reference register because the source frames it as envelope filter. Its deeper value depends on whether names, dates, institutions and citations support that framing.

Evidence profile

Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Mar 7, 2026. The linked authority identifier is Q17104353. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1972 and 2014.

Critical limits

The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

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Source & attribution

This entry incorporates text from “Mu-Tron III” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.