The Pigtronix Envelope Phaser II, usually called the EP2, is a phaser pedal from Pigtronix that folds three modulation sources into one box: a touch sensitive envelope follower, an LFO for classic phase sweeping, and a resonant filter. Premier Guitar's reviewer called it "a funk machine, but it goes far deeper than a typical envelope filter"1. Vintage Guitar described it as having "a potentially daunting array of control knobs and switches," but found it delivered "nice phase tones without touching a single control" when run between a Gibson Les Paul and a Fender Princeton2.
The pedal sits in a compact aluminum chassis3 and carries a street price of $249 as listed in 20112. Circuit design is credited to Howard Davis, with sound design by David Koltai4.
The controls
Across the top of the pedal are knobs for Sensitivity, Depth, Center and Speed, plus Resonance1. Underneath the knobs sit five switches, which Pedal of the Day said "provide a vast array of tonal landscapes"4.
| Control | What it does |
|---|---|
| Sensitivity | Sets how responsive the envelope follower is to your playing12 |
| Speed | Sets the speed of the LFO; Pedal of the Day said it "does just what it says"4 |
| Depth | Sets modulation depth; in Blend mode it becomes a blend control between the envelope follower and LFO15 |
| Center | Sets the center point of the sweep1 |
| Resonance | Controls how much feedback is in the circuit, affecting the accentuation of harmonics and the vocal quality5 |
| Blend switch | Activates Blend mode, combining the envelope follower and LFO, so the initial attack of the envelope gives way to the LFO sound5 |
| Invert switch | Changes the polarity of the phase shifting, plus or minus. Positive acts as a bass enhancer; negative gives more of a bass cut with a more mid based sound5 |
| EF Sweep switch | Chooses whether the envelope sweeps up or down1 |
The envelope can also be set to travel up or down via switch3, and the Invert switch appears on the pedal as a plus or minus phase control4.
Trigger and sweep jacks
Alongside standard input and output, the EP2 has three jacks that open it up to outside control: an external filter trigger (EF Trigger), a Sweep Pedal input and a Speed Pedal input1.
- EF Trigger: Vintage Guitar noted the EP2 "can be triggered by an envelope follower, LFO, or anything you can plug into the EF trigger jack," giving examples as varied as a click track, a drummer or a drum machine2.
- Sweep Pedal: An expression pedal here controls the sweep of the envelope for a foot controlled phase-wah effect. Using it kills the pedal's own Sweep control25.
- Speed Pedal: An expression pedal here controls the speed of the LFO, which No Treble's Kevin Johnson described as giving "more stage-friendly access to changing the LFO speed." Using it kills the pedal's Speed control5.
Expression pedal inputs for both Sweep and Speed were part of the pedal's design from its announcement3. For more on controlling pedals this way, see expression pedals.
From the EP1 to the EP2 and the Bass Envelope Phaser
The EP2 is not Pigtronix's first envelope phaser. Premier Guitar's review states plainly that "The EP2 is the result of six years of customer feedback from the original EP1"1. No Treble dated the EP1's release to six years before its 2010 review of the EP25, and Guitar World has called the Envelope Phaser "the first Pigtronix pedal"6.
The EP1 was itself an envelope phaser pedal, described by its maker's product page as featuring "an incredibly fat and vocal, touch sensitive envelope phaser as well as a deep and chewy, univibe style rotary phaser mode," with footswitchable phase inversion and expression pedal speed control for rotary speaker effects71.
The line later reached bass players. Pigtronix introduced the Bass Envelope Phaser at Winter NAMM 2013, alongside the Philosopher Bass Compressor and Bass FAT Drive8. Premier Guitar's review notes it "is smaller than Pigtronix's older cousin, the Envelope Phaser, and is now tuned specifically for bass," using a 2-notch comb filter9. Bass Gear Magazine traced the family tree further back, reporting that the first version was unveiled at the 2004 NAMM Show as the Envelope Phase Shifter, since modified into a considerably smaller bass version with an optical isolator circuit10.
The Bass Envelope Phaser carries its own control set: an up/down mini-toggle switch that controls the direction of the sweep911, a mini-toggle to select up sweep or down sweep for the envelope effect10, and a High Speed Staccato Envelope feature12. Circuit design is again credited to Howard Davis12.
What reviewers said
Reviews of the EP2 were positive across the board, with praise aimed at both its sound and its usability15.
"I very much enjoyed the EP2 and while I couldn't cover every feature on the pedal due to space (it would fill a book to... it's clear that this is a winner."
Kevin Johnson's review at No Treble praised the pedal's layout and documentation:
"you can get so many great sounds without all the confusion"
He called the EP2 "full of funky, fascinating, and gorgeous sounds that spark creativity," found the owner's manual "extremely helpful without being verbose and includes a guided walkthrough," and summed it up as "a sonically and aesthetically pleasing pedal"5. His one criticism, per the dated review record, was the small size of the switches5.
Vintage Guitar's reviewer got pleasing results with the pedal set flat, and Pedal of the Day's Mike B. described its range as "everything from Mu-Tron-y funk sounds to thick, fat auto wah to HUGE auditory brain-melting out-of-this-world phasing"24.
For the bass version, Premier Guitar's reviewer found it "delivers a classic, funky sound with a uniquely customizable solo voice and no loss of bottom end"9, and Bass Gear Magazine's Lonnie NaVeau wrote that "The Bass Envelope Phaser should be a part of every bass player's pedal board"10.
Pigtronix carried the envelope-plus-modulation idea into later pedals as well, including the Tremvelope tremolo with envelope control and the Resotron pitch-following analog filter.
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Questions
What is the difference between the Pigtronix EP1 and EP2?
The EP2 is a rework of the original EP1 built on six years of customer feedback. The EP1 was an envelope phaser with a univibe style rotary phaser mode and footswitchable phase inversion. The EP2 keeps the envelope and LFO idea but adds a wider control set, including Sensitivity, Depth, Center, Speed and Resonance knobs, five switches under the knobs, and Sweep Pedal, Speed Pedal and EF Trigger inputs.
Can I use an expression pedal with the Pigtronix Envelope Phaser?
Yes. The EP2 has two expression pedal inputs. An expression pedal in the Sweep Pedal jack controls the sweep of the envelope for a foot controlled phase-wah effect, and one in the Speed Pedal jack controls the speed of the LFO. Using the Sweep Pedal input overrides the pedal's Sweep control, and using the Speed Pedal input overrides the Speed control.
Can the Envelope Phaser sound like a Univibe?
Yes. Vintage Guitar's review of the Envelope Phaser II notes that flicking a couple of its switches dials up its envelope filter, wah, and Univibe sounds. The original EP1 also carried a univibe style rotary phaser mode alongside its envelope phaser.
Is there a bass version of the Pigtronix Envelope Phaser?
Yes. The Pigtronix Bass Envelope Phaser is a smaller, bass-tuned version of the Envelope Phaser, introduced at Winter NAMM 2013 alongside the Philosopher Bass Compressor and Bass FAT Drive. It uses a 2-notch comb filter, an up/down toggle for sweep direction, and a High Speed Staccato Envelope feature.
Who designed the Pigtronix EP2 circuit?
Circuit design for the EP2 is credited to Howard Davis, with sound design by David Koltai. Howard Davis is also credited with the circuit design of the Pigtronix Bass Envelope Phaser.
Sources (12)
- Pigtronix Phi Echolution & EP2 Phaser Pedal Review, Premier Guitar, 2010-07-15
- The Pigtronix Envelope Phaser 2, Vintage Guitar magazine, 2013-10-29
- Gear Watch: Pigtronix EP2 Envelope Phaser, No Treble, 2010-06-14
- Pigtronix EP2 Envelope Phaser, Pedal of the Day, 2014-03-03
- Gear Review: Pigtronix EP2 Envelope Phaser, No Treble, 2010-08-31
- Pigtronix Moon Pool Tremvelope Phaser review, Guitar World, 2022-01-14
- PIGTRONIX EP-, Analog Man (analogman.com), 2015
- Pigtronix Debuts Bass Pedal Line, Premier Guitar, 2013-01-15
- Pigtronix Bass Envelope Phaser Review, Premier Guitar, 2013-08-28
- Quick Look, Bass Gear Magazine, 2019-05-13
- Pigtronix Bass Envelope Phaser, Bass Musician Magazine, 2014-10-01
- Pigtronix Bass Envelope Phaser, Pedal of the Day, 2015-11-09
