UPDATE - When I originally wrote this piece in October of last year, I seem to have overlooked some of the more compact pedals - possibly because they were hard to get or out of stock at the time. Now as my pedal-chain has reached 39 slots, there is no way I could accommodate anything beyond a compact-size pedal - so I’ve appended those original choices to this features - namely the Analog.Man Block Letter Envelope Filter, the Mu-FX Micro-Tron III and VFE Mini Mu.
I have already covered off some of the simpler Envelope Filter pedals in my piece on Wah / Auto Wah pedals. All of those featured here are somewhat more feature-rich and add different flavours into the mix like fuzz, phasing and oscillation. I tend to me more aligned to the more compact pedals - so most of these are a little large for my needs, my Boss MD-500 has some superb filter options too and really supplies me with most of the envelope filter functions I need - I also have backup from my Dr Scientist BitQuest.
In terms of the medium-format ones listed and If I had space, the only one I would really seriously consider acquiring would be the superb Subdecay Prometheus DLX. There’s 3 proper big box pedals here - the Q-Tron+, Envelope Phaser EP2 and Protostar, while the Interstellar Orbiter, Evil Filter and Happiness Filter all have sizeable enclosures too. If you want the best mix of features and form factor, it would seem that you should likely go for the Wonderlove Deluxe, Wonder Filter or Prometheus DLX - I also actually have a soft spot for the Happiness Filter.
As stated, each has something different to offer, several of these have overdrive or gain textures and several have oscillators to - for more warble and vibrato. There should be something here for everyone.
For my own current needs though, my preferred choice would be the Micro-Tron III which is awaiting a second production batch, then the VFE Mini Mu - which is discontinued, and finally the Analog.Man Envelope Filter which is limited to a total of 100 units, and whose discontinuation is imminent too!
Pedals are listed alphabetically by brand:
This one is for all you funk fans - with lots of options to accentuate and mix up your groove: 7 dials - Sensitivity | Attack | Decay | Tone | Blend | Resonance | Boost, 4 on/off toggles - Range, Sweep, Band, Buffer, and a 2nd footswitch which toggles between envelope and expression pedal control. This pedal certainly crams features into its medium sized enclosure.
I have caught various demos and reviews of this pedal, including on a fairly recent That Pedal Show episode, and every time I hear it, it sounds fantastic. You know with Mike Piera that you are going to get amazing tone, and he updates and improves the original MXR pedal in every way - with a significantly re-designed circuit with some super extras. Instead of the original 2 controls dials, you get a 3rd Emphasis / sort of bias dial as such which ramps up the quack of the filter, then you get a two - way toggle which allows you to switch the filter sweep between up and down pass modes. This is a really cool filter pedal, available in strictly limited quantities and usually involves a waiting list - reasonably priced though for the extra features.
Evil Filter is a combination of Octave Fuzz and Envelope / Resonant filter. For the Fuzz you can select level and whether square or sine wave, you also have a footswitch to toggle the fuzz on/off. For Filter you have 4 dials - Frequency | Output | Waveform | Resonance - with High/Normal Resonance toggle. This delivers some really gnarly and sinister 70's funk fuzz tones - a touch specialist perhaps but really good.
If 'Knobs' features you, you know you're quirky cool and this Envelope Filter has a really impressive range of tones - with so many different ways to modulate the filtering. The pedal features 7 dials - Frequency | Resonance | Depth | Master | Rate | Shape | Speed, State toggle - High/Band/Low Pass, and Scramble toggle (Sample & Hold). The above Knobs video is the perfect introduction.
A dual resonant filter with individual Intensity | Resonance | Mix dials for A + B filters and master control dials for Rate | Direct | Frequency. This pedal gives you somewhat spacey phasey sounds with some lovely warble as you turn up the Rate dial. It's a cool pedal for sure, but quite larger really for what it delivers in my opinion.
One of the best-loved envelope filters, and as used by John Mayer on many occasion. Has a 4-mode dial - Low/Band/High Pass and Mix. then separate Response | Range | Peak | Gain | Boost dials and a Sweep Up/Down toggle. Gives you all the funk you need, and has been the industry standard big-box filter pedal for a while. It's not as specialist as some of these others, but covers off all the obvious areas well.
Another funk-focused pedals - well demoed for various bass modes above. It features a 5-mode Dial - Notch Filter | High Pass | Band Pass | Low Pass | No Filter, then Boost | Gain | Attack | Mix | Peak (Resonance) - and Low/High Range and Down/Up Drive toggles. The cool thing about this pedal is that you can select 'No Filter' mode and just use it as a boost - with our without gain.
This is currently my front-runner for filter pedal - I obviously really like the Subdecay Prometheus DLX too, but don't really have space for more than a compact format pedal, so a miniaturisation of the legendary Mu-tron III is the way to go. You get all the same features - Low Pass, High Pass, Band Pass, High and Low Range, and the really cool thing here is the separate footswitch to change direction on the filter sweep - Up/Down. This really is the pedal to get, the first batch was released in August of last year, but sold out in double-quick time. The occasional one appears on Reverb.com now and again at inflated price. I and many others are waiting for Mike Beigel to push the button on the second batch of manufacture.
I've already mentioned this hybrid pedal before - which combines the best of phasing and filtering in a single workstation. In truth it is rather more a phase shifter than a filter pedal, but that phasing can be controlled by Envelope, LFO or a blend of the two. You have a series of 5 dials and five toggles which allow you to sculpt the texture of the phasing, smooth it out, make it more staccato, invert, accentuate and ramp up the resonance. You also have a variety of pedal controls to impact filter trigger, sweep and speed. It's quite different to the other pedals featured here and gives you something pretty cool and unique.
Most of the pedals featured here are kind of large, this for me therefore is the best compromise therefore of form and function in the most compact - medium size enclosure. You have 4 smaller dials - Warp | Frequency | Depth | Resonance, two large 11 position mode dials - one for Wave Shape and one for Mode, then a 3-way toggle for Low/Band/High Pass. There is also a second footswitch for Tap-tempo and Sample/Hold. If I was in the market for any of these - this would be my go-to!
If for whatever reason I am unable to track down a Micro-Tron III then this would be my second choice - it has all the same functionality with and additional Mid-range Frequency setting too, yet vs the Micro-Tron has a toggle for the Up/Down sweep selection instead of a separate footswitch which would be my personal preference. This one sounds and works great, it is alas not currently available - having been discontinued, but versions do occasionally show up on Ebay and Reverb.com. It's yet another superb VFE pedal - as you can hear in the above Mike Herman's demo. I'm a touch sad really that so many great VFE pedals have been discontinued.
I've featured this pedal before in my '16 Weird and Wonderful Guitar Noise Pedals' piece - this is likely the most full-featured of the filter workstations with a whole plethora of tone-sculpting abilities by way of a 9 socket CV Patch Bay, 9 Dials - Attack | Threshold | Envelope Amount | Resonance | Frequency | LFO Rate | LFO Amount | Compression | Dry/Wet, built-in LFO, 4 filter modes - Notch Down | High Pass | Band Pass | Low Pass. Dennis Kayzer gives you another superb demo of the kind of sounds this pedal is capable of - probably my favourite of the big boxes on show here.
When I did my original analysis, the Subdecay Prometheus DLX was my favourite - with the Wonderlove DLX and Dwarfcraft Happiness Filter sort of runners-up. Now with my extensive 39 slot pedal-chain and limited floor-space it would be very tricky to accommodate any of those medium-sized enclosure types. Hence my preferred option here is the Mu-FX Micro-Tron III - with second footswitch to change direction of sweep - although VFE Mini Mu - runs in pretty close in all other respects. It's pretty typical for me that some of the key pedals I want are in pretty limited supply and not generally available - it means keeping your eyes pealed on the second-hand market - meaning Ebay and Reverb.com in particular. I really hope Mike Beigel commissions a second batch of Micro-Trons - that would instantly solve my situation here. I understand that Subdecay is bringing out more compact pedals too - like the recently launched Quasar Phase Modulator. Possibly we can hope for a compact-size competitor Prometheus too - to mix it up with the other 3 I have mentioned here.