The Best Envelope Filter Pedals

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Written By Tanya

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The majority of effects pedals are universal effects that can be used on many tracks by any engineer or instrumentalist.

The envelope filter pedal (or auto-wah pedal) is designed primarily for electric guitars, basses, and pianos and can be used for funk music.

It doesn’t mean you won’t see it used creatively by talented thinkers. The envelope filter effect is what people associate with funk.

The Mu-tron III was the first envelope-controlled filter that musicians could use in 1972, during the height of funk and has been closely associated with it since.

There have been many names for it, including Q-wah and T-wah. However, the word “envelope filter” has become the most popular. Many still refer to it by the auto-wah effect because of its similarity to the sound that you can manually achieve with a pedal.

We do it automatically. Let’s talk about how these pedals work, what features to look for, and then let’s introduce you to our top picks for modern analog and digital options, as well as the strengths and weaknesses of each.

What is the Envelope Filter Effect and how does it work?

The envelope effect, also known as auto-wah and not to be confused with the wah pedal, is a self-adjusting peak filter. It accentuates certain frequencies and reduces or blocks out others.

The strength of the effect is determined by the amplitude of signal entering the pedal. This allows guitarists to alter the sound according to how hard they pick the strings. It is used frequently by electric piano players, bass guitarists, and synthesizer users.

The auto-wah’s cut-off frequencies are determined by the detection of the incoming signal, which is a direct measurement the volume of the signal. The envelope following filter is then modified to adjust the cutoff frequencies. These frequencies are typically defined by a bandpass reaction, but some filters allow for a lower-pass filter.

What are the Top Envelope Filter Pedals?

The knob that controls the effect’s sensitivity will be included in all auto-wah pedals. You will adjust your input gain to match the pedal’s levels. To get more or less effect, you can adjust this gain.

Many will include a control for cutoff frequencies in either bandpass or low pass filter forms. A depth control allows you to adjust the intensity and sweep of the overall filter effect.


If you want to create your own sound, you will want to be able to control other aspects of the envelope filters. These include the ability to select from a variety of pre-designed filters, the option of whether the filter sweeps up/down the frequency spectrum and a resonance control.

You can choose which frequencies to emphasize when the resonance is activated (wherever the bandpass filter is). Envelope filters shape your waveform with the same parameters as a compressor, however everything varies based on amplitude including the frequency range of the band-pass filter.

How to use an envelope filter pedal

Two aspects are necessary to use these guitar pedals efficiently: placing it in the correct spot in the signal pathway, and understanding how to handle all knob-based parameters.


Nature is known for its orderly sounds. This allows effects to be stacked on top of each other. We want to imitate that process as guitarists, so we use this setup.

  • Pitch Shifters, Filters, and Dynamics
  • Boost & Distortion
  • Modulation
  • Time

Envelope filters can be used as filters. It’s in their name! It only needs two effects before it, compression and equalization. You will shape your waveform first and then clean it up. Then you will need to apply the envelope filtering.

This is because if you first use a delay or reverb, you will filter out those that are just time-based replicas of sounds in your environment. It doesn’t happen in the natural world, so you don’t want it in your signal chain. Unless you’re doing some experimentation.


There will be many knobs that can be relabelled in different ways but the core set of buttons is always there. You can control the volume (or expression) of the envelope with many pre-built filters. The Level knob controls the volume, while the Filter knob controls the type of filter.

These options usually only include low-pass and high-pass. You can adjust the center frequency of the band-pass with a resonance knob.

You might also find a Q knob that allows you to adjust the band-pass for the frequency around which you select with the resonance knob. You’ll also see a Range button, which acts as the Q knob and controls the cut-off frequencies for the high-pass or low-pass filters.

The Best Envelope Filter Pedals

Note: Every image and text link takes you to, where you can read additional reviews, view technical details, view additional product sizes and options, and make your order.

Now we know what envelope filter pedals are, how to use them, and which features to be aware of. Now it’s time for us to explore the market and find the best options for our budget and needs.

These will not be ordered in any particular way, except for our top pick. However, you can scroll up to the top to see our other “best-in-class” picks. You may like one of these more than the others, so take them all into consideration.


Let’s begin with the Electro Harmonix Micro QTron, a smaller version of the most popular choice on this list. You can create an intense or subtle effect depending on the volume of your pick attack.

You can also create your sweep using three modes: low pass, bandpass, and high-pass EQ. This pedal is not only great for guitar but also for keyboards and other electric instruments.

The Q knob can adjust the frequency peak width. Your general set-and forget sweet spots are from noon to 2 o’clock. You’ll get the best auto-wah possible no matter what you do with the Drive knob. However, this knob can be adjusted to achieve different results. You can start at 12 o’clock and work your way up with the knob with a high output guitar.

This Mu-tron III inspired option is the perfect choice if you want to recreate the sound of Prince and Jerry Garcia. It is stronger than you would expect. It will always be there for you. It’s available in a larger version below if you need a more feature-packed version.

CHECK PRICE AT AMAZON Our Top Pick in a Smaller and Cheaper Version

  • Favorite LedgerNote


It is rare that there is an obvious choice in any category. There is usually a contender, or at the very least a runner up in any category. But the ElectroHarmonix QRon XO envelope holder is the clear leader.

You can only scratch the surface of what the Micro Q-Tron cousin can do. Want even more? Want more? The Q-Tron Plus version includes the effects loop. This one suits most players and doesn’t cost too much.

The Micro has everything you need, plus a Boost switch to enable the Gain knob. This allows you to increase the input volume of the pedal rather than the output of the guitar (in the case of other effects in the pedal path). You have full control over the Q’s width with the Peak knob.

You can choose from the three above options (low pass band pass high pass), band pass or band pass. The Mode switch also offers a Mix option which is a combination of a band envelope and a mix of your dry instrument signal. You can adjust the full-fledged effect to suit your needs, instead of reducing it. You can use the Range knob to enhance the vowel-like sound in the fundamental frequencies, or the highest overtones.

The Overload LED allows you to push the internal preamp and emulate the Mu-Tron III sound to achieve that Jerry Garcia sound. You can also create your own style and make your mark in the guitar world.


Take the best and make it better


This filter is our first list of envelope filters with a lot more features. The Pigtronix Envelope Phaser has become a leader in this new niche. You’re basically stacking an analog uni-vibe rotary phaser on top of a world-class envelope filtre.

Both can be used in combination or as an isolated unit. The envelope and LFO can be used to control the phaser in staccato mode, as well as with an LFO. Side-chaining another audio trigger is possible. Let’s not forget about the auto-wah. That’s why we are here. The rest is just icing on top.

This pedal’s envelope section, like the ones above, is modeled after Mu-Tron III’s quack sound. This pedal is unlike others that allow you to define your filter. You can control the direction of sweep either upwards or downwards through the frequency spectrum.

The digital intelligent envelope response allows you to not set a sensitivity nor worry about the volume of your input. They also allow you to keep full control over expression.

Based on six years of customer feedback about the EP1, the EP2 model was a success. It can be set up to play Hendrix-style wah or even outer space craziness. It can be triggered by any audio input, such as a drum beat or other musical sounds.

It has so many things going for it that I can’t even write it all. Just look at each knob or switch to see what I mean. It’s enough to power Mars Volta. If you are a fan of funk, this is something to consider. This is not a once-and-forever purchase.

CHECK PRICE ON AMAZON A Tinkerer’s Featured Pedal…


Some people don’t need extra features. They just want an easy-to-use, top-of the line autowah. That’s what the Spatial Delivery offers. This pedal is focused on the core product and does not include any gimmicks. It can stand up to serious scrutiny.

Pay attention to the switch between the knobs. This is your Mode selector, which includes Up Sweep and Down Sweep. You get the classic auto-wah, with up and down modes. The Sample & Hold control the filter with random voltages, instead of your picking amplitude. This keeps it in place, while you adjust the speed using the Range knob.

You can adjust the control of the knobs by allowing it to crossfade from low pass to band basse to low pass. The Range knob allows you to control the sensitivity as well as the reaction time in all modes. This is a combination of an intensity knob and a Q-width button. It’s built in a way that keeps it musical and doesn’t allow you to sabotage your own music.

The Resonance control acts as an oscillation knob. This allows you to keep your wah very clear and not add tons of body or ring. You can bypass it with all the other features you’d expect. It shines when it is paired with harmonizer and octave pedals, and other common options.

Flexi-switching allows you to fire it up temporarily too, adding what I call “ear candy”, to certain parts of your performance. Simply hold the switch down until you are done, then release. Otherwise, you can tap the switch to turn it on. This handmade option is worth a serious look. It is for many the best.


An easy, handcrafted, and interesting auto-wah…


I am usually the type of guy who wants exactly what I want. This is an envelope filter. The Dwarfcraft devices Happiness Multi-Filter does that and more. Auto-wah enthusiasts have a whole new world with the low frequency oscillator, or LFO.

There’s no genre you can’t find here, from dubstep to classic rock. It sounds natural every time. They are able to guarantee quality, but it is the versatility that has earned this pedal its place on the list.

This mother can be used for bass, guitar, drums or even electric violin. The envelope controls include Rez (controls oscillation resolution), Freq (mode switching like low pass), and Depth (intensity of the Q height).

You also get control for Speed, Shape, Rate and Speed since the phaser is similar to the Pigtronix option. The Scramble switch transforms it into a Sample & Keep mode, which can include external CV modulation.

The State switch acts as an EQ/Tone knob on your guitar. There are three filter options: a low pass (band pass), high pass (high pass), and a band pass (band pass). This pedal lets you take your auto-wah and remove the lid. It allows you to keep the classic sound, or dial in the most outlandish tremolo sounds. You can create almost any sound you want, even with secondary audio sources, by pairing it with reverb pedals and delays.

This is the ultimate choice for sound designers, envelope filter enthusiasts and anyone else who doesn’t like being confined in one place.



This is a full-featured option, just like the one above. However, the WMD Effects Protostar takes things to the next level. You get five modes of autowah and an LFO, as well as a compressor. They don’t compromise on quality like many companies.

Notice the 15 inputs & outputs. It’s amazing how much customization you can do with this program. Once you get used to it, you will find that you can dial in an envelope follower sound and then build upon that sound to create sounds you have never heard before.

We can’t even begin to list all of it here, oh my goodness! You can see the knobs to understand why. On top you will find your auto-wah strip, along with a phaser / tremolo strip and then a compression block. You can select your modes from the middle, which includes the usual options and an inverted bandpass. You can also get the CV sidechain.

You’re already familiar with the Super FatMan envelope filters, but this one has even more options. This is without a doubt the most versatile autowah ever invented. If you are passionate about creating your own sounds, please take some time to think about it.


The Most Complex and Featured Option Available…


We’ll be going back to basics. That’s where I like to live. The Maxon 9 Series Auto-Filter is a regular pedal that acts just like one. This simple option perfectly tackles the envelope filter effect. Although it doesn’t have the most striking visual appeal, it is still very effective. This bad boy is loud and clear.

The core desirables are included, along with a top-tier auto-wah and a few sweep filters to keep it interesting. To preserve the vintage sound of the shimmering envelope filters, they decided to keep things old-fashioned and use optocoupler circuitry. Like the others, it is also based on the Mu-tron III pedal. This is why many pros keep it, much like the Megadeth guitarist.

Let me tell you what the switches do. There are three filters modes to choose from: low pass, bandpass, and high-pass EQ. A sensitivity slider controls the threshold and a peak slider adjusts the intensity. You can choose to use an up or down sweep. The Range switch enhances the fundamental frequencies and overtones of the auto-wah.

This is the perfect no-frills, get it done right option. If you have a particular type of pedal board, it can also be a standard-sized pedal. This one deserves serious consideration. This is not a great looking bike, but it is a worthy contender. Maxon isn’t stopping Maxon from using Boss pedals as the best.

CHECK PRICE AT AMAZON The Core Functions with No Frills

These are the best envelope filter pedals available

The envelope filter industry has never been more popular. Companies are keeping the classic, plain auto-wah alive by creating new models or based on vintage options that you no longer have.

There are companies that will be the next generation of this sub-industry. It’s never been more exciting to buy one. That’s why we have included a mix of all three styles in our top envelope filter pedals.

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