PedalBro

Filter · 3Leaf Audio

3Leaf Audio Proton

The Proton is an envelope filter inspired by the Mu-Tron III design, featuring a decay control for shaping how quickly the filter effect fades and an extended tonal range compared to its inspiration.

  • 9-18V DC · center −
  • Mono
New
No price yet
Used (asking)
from $300

The rundown

Highlights

  • Envelope filter with Mu-Tron III heritage
  • Decay control for adjusting filter sweep timing
  • Accepts 9V or 18V DC power
  • True bypass with relay switching
  • Compact stompbox format

Best for

Bassists and guitarists seeking dynamic filter effects with extended tonal flexibility.

Quick facts

Power
9-18V DC
Polarity
Center negative
Dimensions
63.5 × 115.8 mm
Controls
Gain, Peak, Decay, Sweep, Tone
Stereo
No
MIDI
No
Year
2010
Status
In production

Where to buy 3Leaf Audio Proton

Used listings asking $300–$369.50, median $319 (3 listings, small sample). Asking prices, not sold prices.

Current offers
SellerConditionPriceLink
ReverbUsed$300View
ReverbUsed$319View
ReverbUsed$420View

Prices last checked 20 hours ago. Links to sellers are affiliate links.

Frequently asked questions

What power supply does the Proton use?

The Proton runs on 9-18V DC, center-negative power.

Does the Proton have true bypass?

Yes, the Proton features true bypass with relay switching.

What controls does the Proton have?

The Proton has Gain, Peak, Decay, Sweep, and Tone controls.

Similar pedals

Same type, similar features.

Specs from pedalfilter. Summary written by PedalBro from those specs and public descriptions.

Page last updated September 29, 2026.