The Heptode Virtuoso is a phaser pedal from France's Heptode company, a recreation of the Maestro PS-1A phase shifter first sold in 19711. Where the original Maestro was a bulky tabletop unit, the Virtuoso delivers its vintage tones in a modern, pedalboard-friendly enclosure1. It was announced in May 2013 as a new addition to the Heptode line of guitar effects, distributed by European Musical Imports23.
It is a six-stage phaser, deeper than the four-stage designs used in the Uni-Vibe and the MXR Phase 901. Like the original, it works well with guitar or keyboards3, and its output is mono only1.
A Maestro PS-1A in a pedalboard-sized box
The Maestro PS-1A was the first effect to be named a phase shifter, though it was not a pedal: it was a tabletop device, a larger box meant to be mounted on a mic stand, with three paddle rocker knobs56. Premier Guitar described it as "a bulky external unit with the large plastic switches of the era's home organs"1. You can hear the original on a lot of classic recordings from the very early seventies5, and keyboardist John Paul Jones of Led Zeppelin used one in the 1970s2.
Heptode's take cuts that design down to a manageable footprint7. Guitar World describes the Virtuoso as a pedal that "replicates the Maestro's vintage tones for players who want a modern pedalboard-friendly update"8. At 6" x 2" x 2" it is not a small pedal, but it is a stompbox rather than a tabletop unit, and its presets are selected with standard footswitches instead of the Maestro's plastic paddles1.
Three presets: slow, medium and fast
The Virtuoso keeps the original's operating concept: three non-editable presets offering slow, medium and fast speeds, and those are the only choices1. There is no speed knob, but MusicRadar's reviewer, Trevor Curwen, did not miss one, finding that "the three speeds cover plenty of musical possibilities"7.
One behavior carries over from the Maestro: when you switch from one speed to another, the effect ramps up or down rather than jumping instantly3. Curwen called this a great onstage asset, allowing changes on the fly7.
| Control | What it does |
|---|---|
| Footswitch 1 | Selects the slow preset1 |
| Footswitch 2 | Selects the medium preset1 |
| Footswitch 3 | Selects the fast preset1 |
Power and practical points
The Virtuoso runs on a 9V battery or a standard power supply1. One quirk worth knowing: despite the large enclosure, you must unscrew the cover to swap batteries1, so a power supply is the practical choice for regular use.
Output is mono only, matching the original Maestro1. Players who need a stereo phaser should look elsewhere.
What reviewers said
Premier Guitar's 2021 review was blunt in its praise:
"A superb clone of a superb phaser. Easy to use. No bad sounds."
MusicRadar's Trevor Curwen highlighted the ramping speed changes as an onstage asset and found the three fixed speeds covered plenty of musical ground7. Vintage Guitar noted that, like the original, it works well with guitar or keyboards3.
Videos
gearmanndude
Guitar Player Magazine
MrSanSystem
Questions
What is the Heptode Virtuoso based on?
It is a recreation of the Maestro PS-1A phase shifter, the effect first sold in 1971. Premier Guitar called it a superb clone of a superb phaser, and Heptode's version packs the original's circuit into a pedalboard-friendly enclosure with standard footswitches instead of the Maestro's large plastic switches.
Can the Heptode Virtuoso run on a battery?
Yes. It runs on a 9V battery or a standard power supply. Swapping the battery requires unscrewing the cover, even though the enclosure is fairly large at 6 by 2 by 2 inches, so most players will prefer powering it from a supply.
Does the Heptode Virtuoso have stereo outputs?
No. Like the original Maestro PS-1A it was modeled on, the Virtuoso's output is mono only. Players building a stereo rig will need to look at other phasers.
Can you edit the presets on the Heptode Virtuoso?
No. It has three non-editable presets, slow, medium and fast, accessible via standard footswitches. There is no speed knob, but MusicRadar's reviewer found the three speeds cover plenty of musical possibilities.
How many stages does the Heptode Virtuoso have?
It is a six-stage phaser. Premier Guitar noted that the Uni-Vibe and the MXR Phase 90 employ four stages, so the Virtuoso follows the Maestro PS-1A's deeper six-stage design.
Sources (8)
- Heptode Virtuoso Phase Shifter Review, Premier Guitar, 2013-09-10
- Pedal News Heptode Virtuoso Phase Shifter, Delicious Audio, 2013-05-06
- Heptode Line Expands with Virtuoso Phase Shifter, Vintage Guitar magazine, 2013-05-03
- Beetronics Larva review, Guitar.com, 2025-08-11
- 4 WAYS TO USE A PHASER PEDAL, JHS Pedals
- Best Phaser Pedals In 2024, Delicious Audio, 2024-09-16
- Heptode Virtuoso Phase Shifter review, MusicRadar, 2017-01-21
- How the Maestro PS-1 Phase Shifter changed popular music, Guitar World, 2026-07-03
