Neutrino Envelope Filter


Our Funky, Tripped-Out Neutrino Envelope Filter and Auto Wah!

This dynamic wah sound is an effect based on your pick attack or strength. The harder you pick, the harder it “wahs”!

Out of stock

Product Description

The brand new Keeley Neutrino Envelope Filter and Auto-Wah! This funky, tripped-out circuit is something I’ve wanted to do for over a decade. Reviews have been stellar.  Each opto-coupler is tuned to perfection; every Keeley Neutrino is like finding a magical vintage unit with that perfect tone. NOW IN STOCK AND SHIPPING WITHIN A FEW DAYS!

The Keeley Neutrino gives you all the classic, funk, auto-wah sounds and that Jerry-In-A-Box sound. We have used the classic opto-coupler design for a rich and warm depth to the effect.  Envelope filter sound is an effect triggered by your pick attack or strength. The harder you pick, the harder it “wahs”! Sounds bubble up from a deep rounded warmth to a shinning brilliance. Solo notes are individually expressive based on how hard you play. Create incredible vowel sounds… Can you say “Let’s get it on”?!? Chord-work “stabs” sound right out of the disco dictionary, play that funky music white boy!

The Neutrino Envelope Filter has a simple set of controls so you explore a wealth of tones with ease.

There is a Gain control to set the input level to an appropriate strength so that you can trigger the effect with any type of pickups or instrument level.  This control is critical.  Pick an open string on your guitar and adjust this control until you hear the wah sound rise and fall.  Set just right it sounds like a wah pedal rocking back and forth as you play a note.

The peak control is how “sharp” or “warm” the effect is.  You can think of this a way to make your wah sounds really mellow or really “quaky”!

The Filter Selector lets you choose between 3 types of filters to carve out different tones and timbers.

The Range Switch adjusts what frequencies are being stressed HI or LO. Easily find your voicing.

A side-mounted Direction Switch allows you to control which direction the wah sound goes.  Wah up, wah down!

The Neutrino Envelope Filter is designed to work with bass guitar and keyboards as well. Simply adjust the Gain to get it to trigger the way you want. Then, adjust the Peak control to set how much it “wahs”.

Use a Keeley Compressor after your Neutrino to create a wall of lushly filtered tones that really stand out.  Then, even with the more delicate sounds of the BandPass or HighPass settings you will be able to improvise with stunning clarity.


Paul Priest – of Chicago’s OLD SHOE. Recently signed, he took time out to create a first true demo video!

Neutrino on Down sweep.

This is a great demo of the Neutrino in High Pass mode.

From Craig Marshall of Cubensis
Greetings gentlemen! Happy to report I received the shipment on Friday just in time to use both pedals at our gig that very night. The Katana was a no-brainer…no set-up involved and great for lead tones all night. I didn’t have much time to preview the Neutrino, but happily it came out of the box with a perfect setting for my guitar…very smooth effect as far as the dynamics are concerned. So far, very happy and impressed with the devices, and will continue to tweak and explore the Neutrino for what treasures it may hold. I’ll report findings, of course.
Thanks again!

From Zach H. Austin, TX
Robert, you all have outdone yourselves! I can’t stop playing this pedal! Side by side with the Mu-Tron III, back and forth with Eyes of the World, Fire,Estimated Prophet. Jerry would shed a tear of delight at the shear beauty of the Neutrino’s tone. No one has succeeded at such a recreation, and I’ve tried them all. You had the settings on the Neutrino spot-on for my Mu-Tron III to boot. I might even ask for another of the original batch. Very, very happy.

Craig Marshall – Cubensis
Sean Lennon – GOASTT Band
Paul Priest – Old Shoe
Robbie Seahag Mangano
John Fogerty

All Keeley pedals include a one year parts and labor warranty!

For all repairs you must complete the Repair Ticket Form below before you return a pedal for repair. We only repair pedals that have been made or modded by us, or pedals that are going to receive our mod while they are getting repaired.

There may be repair fees for pedals that will be receiving mods or pedals that have malfunctioned from user error like plugging in wrong power supply, running over it with a truck, etc… Thank you for your cooperation!

Go to our Warranty Page to fill out a Repair Ticket Form.

Product Manuals


Fuzz Head
Keeley Compressor
Nova Wah
Seafoam Chorus
Time Machine Boost


Width (Not Counting Jacks) – 2.35″
Height (Not Counting Jacks) – 4.41″

Input / Output Jack Location – Side
DC Jack Location – Top

Order in Chain –

Just remember that any change in signal level before the Neutrino will make it respond differently. I like to run it pretty early in the chain. I like to run a compressor after it to keep the peaks in check. A compressor makes it sound smoother.
Power Supply: 9 volt negative tip, isolated supply. 30mA

Keeley Neutrino Envelope Filter Instructions

Keeley Neutrino Envelope Filter Instructions

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