

The Proton by 3Leaf Audio is an envelope filter pedal designed as a modern homage to the classic Mutron III envelope filter. It features a wide frequency response that complements various instruments. The version 3 of the Proton has increased input sensitivity to work better with low-output instruments and adds a tone knob for variable control over the filter cutoff frequency.
Key Technical Specifications:
- Power Requirement: 9V DC, 25mA minimum
- Power Connector: 2.1mm center-negative (Boss-style) plug
- Warranty: Guaranteed against defects for one year
- Bypass: Relay-based silent true bypass that automatically switches to
bypass mode if power is lost
Key Features and Controls:
- Gain: Adjusts the response of the filter to playing dynamics
- Peak: Controls the "wetness" of the filter sound
- Decay: Sets the time it takes for the filter to sweep
- Tone: Provides variable control over the filter cutoff frequency
- Sweep: Determines the direction of the filter's sweep
- Wide frequency response suitable for all instruments
The Proton by 3Leaf Audio is known for its ability to generate funky tones in the style of the Mu-Tron III, making it a versatile and expressive tool for musicians and audio enthusiasts.
Watch the latest video demos and reviews for the Proton from YouTube. Stompbx updates this every six months to reflect the most popular reviewers and guitar pedal demos for each pedal.
Below are live Reverb listings for the 3Leaf Audio Proton from Reverb. Stompbx automatically aggregates current offers to give you a quick look at available models, conditions, and prices. Perfect for comparing options and making an informed purchase.
Excellent
$325
Very Good
$344
Very Good
$528.95
Very Good
$524.77
Browse through eBay listings for the Proton compiled in real-time. From vintage finds to brand-new units, see a variety of purchasing options. This automated collection helps you explore deals and find the right pedal at the right price.
Used
$963.61
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