3Leaf Audio Proton - Envelope Filter



3Leaf Audio

The Mutron III envelope filter was a staple of 1970′s funk and soul music that shaped the sounds of Bootsy Collins, Stevie Wonder and Jerry Garcia among others. But as good as the Mutron sounded, it was not without its problems. It was huge and required a special power supply, and it had a sensitivity control that changed your volume when you kicked it on. Then there’s the price – originals routinely fetch $500 or more on eBay!

The new Proton envelope filter contains the essence of what made the old Mutron sound so good, without all of the drawbacks of the original. It’s small, it runs on a standard 9-18v DC power supply (no battery), and it won’t change your volume when you kick it on. But most importantly, it sounds FUNKY. With its simple control layout, you can easily dial in the slurpy, wet filter sounds of the original. Set the sensitivity with the GAIN control and the resonance with the PEAK control, and you’re good to go! It also features high and low range positions, lowpass and bandpass modes, and a sweep reverse. It has a wide sensitivity range that will drive active or passive instruments, and the filter range is such that it will sound great on guitar, bass, and whatever else you can throw at it.

3Leaf Audio about the new version

  • Slick new custom steel enclosure.
  • Relay true bypass system for bulletproof switching.
  • Decay knob for fine control over the filter sweep.
  • No electrolytic capacitors for increased reliability.

3Leaf Audio (v3 press release, October 12, 2015)

3Leaf Audio Introduces Next Generation Proton and Wonderlove Envelope Filters

Seattle, WA (October 12, 2015) - 3Leaf Audio is excited to introduce the next generation Proton and Wonderlove envelope filters into its line of boutique effects pedals. The Proton and the Wonderlove are the gold standard for envelope-controlled filters, and the new versions take the sound made famous by Stevie Wonder and push it to new heights.

Proton Envelope Filter – a modern homage to the classic Mutron III.


  • Tone knob for fine control over filter cutoff frequency.
  • Increased sensitivity range for better compatibility with low-output instruments.
  • Phase-correct output for easy use in blend pedal signal chains.
  • Price: $229 USD

The Proton and Wonderlove have a wide frequency bandwidth that works with any instrument. They include features that are standard across the 3Leaf Audio product line, including custom folded steel enclosures and relay true bypass system that automatically switches to bypass in the case of power failure. All 3Leaf Audio products are built in Seattle by musicians.


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2015-11-12V310/10  ......

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