The Red Witch Pax Harmonia is an optical univibe pedal from Red Witch Pedals, built as a limited run of 99 units, each with its own version of the circuit and its own artwork. It is 100% analog, hand wired with through-hole components, and carries a list price of 599 USD. The pedal is sold out1.
What it does
The Pax Harmonia was an attempt, in Red Witch's words, to "Create an optical univibe that delivered every single one of the classic univibe sounds"1. At its heart is the classic optical arrangement: a hand-wired circuit built around "a beautiful incandescent bulb that pulses perfectly to an internal audience of 4 light dependent resistors" controlling the phase shift1.
The headline departure from the original design is the chorus/vibrato control. A traditional univibe uses a two-position switch to choose between chorus and vibrato modes. The Pax Harmonia replaces that switch with a dial, so the two can be blended: "instead of a switch to toggle between chorus and vibrato modes, the Pax Harmonia has them on a dial, so that you can ble[nd them]" as MusicRadar put it in its coverage of the pedal2.
Controls
| Control | What it does |
|---|---|
| Vibrato/Chorus dial | Replaces the original two-option switch, enabling a blend of vibrato and chorus mode1 |
| Speed | Pulses faster and slower than the original univibe1 |
| Depth | Dials in everything from the most subtle pulses to the most swirling sounds, with impact at any speed1 |
An internal slide switch selects between two modes: "classic" and "interstellar". Red Witch says interstellar mode offers a different flavor of tone, phase shift, reaction and "immersion"1.
The classic/interstellar switch is internal, so changing modes means taking off the back plate rather than reaching for a knob mid-song.
Expression pedal
The Pax Harmonia accepts an off-the-shelf expression pedal, which controls the velocity of the modulation. Red Witch recommends the Moog EP31. For players who like to sweep univibe speed by foot, this turns the Speed control into a performance control rather than a set-and-forget knob.
Design and construction
The pedal was designed by Red Witch's Ben Fulton2, with the LFO (low frequency oscillator) section designed in collaboration with Paul Crowther, whom Red Witch calls the original "Godfather" of boutique effects and the creator of the Crowther Hotcake1. The circuit builds on Fumio Mieda's original univibe design from the 1960s, expanded on rather than copied1.
The enclosure is described by Red Witch as a "bespoke, nickel plated pressed steel amphitheatre"1, and the artwork is drawn from old Victorian books of "creatures of the deep" line illustrations, transformed for each pedal and never used again on another1.
The 99 one-of-one pedals
Each of the 99 Pax Harmonia pedals has its own unit version of the circuit, and Red Witch is explicit about the consequence: "No two Pax Harmonia sound the same. The specific sound your pedal makes is yours and yours alone."1 MusicRadar's headline went further, suggesting Red Witch "might just have created the ultimate uni-vibe in the process"1.
For players comparing it with other Red Witch modulation pedals, the Pax Harmonia sits apart from the maker's chorus line, which includes the Red Witch Binary Star, Red Witch Empress and Red Witch Medusa Chorus Tremolo. Those are chorus designs; the Pax Harmonia is a univibe, closer in spirit to the phaser family than to a straight chorus pedal1.
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Questions
How many Red Witch Pax Harmonia pedals were made?
Red Witch made 99 Pax Harmonia pedals. Every one of the 99 has its own unit version of the circuit, and each carries its own unique artwork, so no two pedals sound or look the same. The maker describes the run as a collection of one-of-one pedal designs, and the pedal is now sold out.
Is the Pax Harmonia analog?
Yes. Red Witch describes the Pax Harmonia as 100% analog, fitted with premium Neutrik sockets. The phase-shifting is done optically, with an incandescent bulb pulsing against four internal light dependent resistors, and the circuit is hand wired with through-hole components.
Is the Pax Harmonia true bypass?
Yes. The Pax Harmonia uses an ultra long-life true-bypass footswitch, according to both Red Witch's product page and MusicRadar's coverage of the pedal.
Can you use an expression pedal with the Pax Harmonia?
Yes. You can plug in an off-the-shelf expression pedal and use it to control the velocity of the modulation. Red Witch recommends the Moog EP3 for the job.
What are the classic and interstellar modes?
An internal slide switch lets you run the Pax Harmonia in classic mode or in interstellar mode. Red Witch says interstellar offers a different flavour of tone, phase shift, reaction and immersion, while classic mode covers the traditional univibe territory.
Who designed the Pax Harmonia?
The Pax Harmonia was designed by Red Witch's Ben Fulton. The LFO (low frequency oscillator) section was designed with Paul Crowther, whom Red Witch calls the original godfather of boutique effects and the creator of the Crowther Hotcake.
