The PastFx Jet Phaser is a faithful reproduction of the 1970s Roland AP-7 Jet Phaser, a pedal that was unique for its time in putting a fuzz and a phase circuit in one box1. The original could achieve thick swirling phase and faux Leslie rotary speaker effects, and PastFX's version recreates that combination using 8 hand matched JFET transistors1.
Where the original Roland forced the fuzz and phaser to work together, the PastFx version adds a "Phase Off" setting that lets the fuzz run on its own, something the original does not allow1. For a player shopping in the fuzz and phaser families, that makes it two pedals in one enclosure rather than one locked sound.
Fuzz and phaser in one pedal
The Roland AP-7 was unique for its time, incorporating a fuzz and phase circuit within one pedal2. Roland packaged the phaser and fuzz together in the AP-7, and the original combined the 8-stage phaser from Roland's AP-2 with a menacing fuzz/distortion31. On the PastFx reproduction, the Jet Level control acts as the fuzz volume, and the Jet fuzz is foot switchable on its own footswitch, separate from the true bypass Normal / effect footswitch1.
The controls on the pedal:
| Control | What it does |
|---|---|
| Jet Level | Fuzz volume1 |
| Resonance knob | Feedback control1 |
| Slow knob | Adjusts phase speed when the Slow toggle switch is selected1 |
| Phase Depth toggle | Low / Deep phase, or phase off1 |
| Fast / Slow switch | Activated with a toggle switch1 |
| Jet Footswitch | Foot switchable Jet fuzz1 |
| Normal / Effect footswitch | True bypass on/off1 |
The Resonance knob works as a feedback control, shaping how pronounced the phase peaks are, while the Slow knob sets the phase speed whenever the Slow toggle is engaged1. The Phase Depth toggle is an independent switch, giving Low phase, Deep phase, or phase off1.
Internal trimpots and switch
Inside the enclosure, PastFx has added a few adjustments the original Roland did not expose. A black push button at the base of the enclosure, the Flip Switch Mod, swaps the function of the Jet Footswitch between turning the Jet on or off and controlling the Fast & Slow switch1. A micro slide switch adjusts the depth intensity of the Low Depth toggle switch position1.
There are also two internal trimpots, and they are not equal:
- The round trimpot adjusts the phasing frequency range higher or lower. PastFx recommends leaving it as stock1.
- The rectangular precision multi-turn trimpot must not be adjusted, or the pedal may stop phasing1.
If you open the pedal, leave the rectangular trimpot on the right alone. Adjusting it can stop the pedal from phasing entirely1.
A reproduction of the Roland AP-7 Jet Phaser
The Roland AP-7 Jet Phaser dates from the 1970s, and its "jet" stage is the circuit best known from the Roland AF-60 Bee Gee, which Aion FX describes as the standalone version of the "jet mode" of the AP-74. In the AP-7 adaptation, the tone control is simplified into a two-position switch with only "full bass" and "full treble" settings4.
On the original, the fuzz could not be operated independent of the phaser; fine tuning was limited to a few preset voices, the resonance control, and the jet level, which regulated gain intensity3. The PastFx reproduction removes that limitation with its Phase Off setting1.
The same limitation survives in other reproductions of the circuit. Reviewing the Warm Audio Jet Phaser for Premier Guitar, John Bohlinger noted that the fuzz and phase are integrated there, save for two fuzz-less phaser voices, and listed as a con that you "Can't use otherwise excellent fuzz without phaser"5. A player comparing reproductions of the AP-7 will find the PastFx version the only one of the two that separates them.
Power and setup
The pedal requires a 9V DC supply with a 2.1mm jack and negative tip, the industry standard, and draws approximately 15 mA1. PastFx recommends a regulated, isolated linear or transformer based supply, and says high quality pro audio switch-mode supplies are also acceptable1.
The 2.1mm negative tip requirement means the pedal runs on a standard 9V DC center negative power supply, the same connector most pedalboards already use1.
Videos
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Questions
What is the PastFx Jet Phaser based on?
It is a faithful reproduction of the 1970s Roland AP-7 Jet Phaser, a pedal that combined a fuzz and a phase circuit in one unit. PastFx builds it with 8 hand matched JFET transistors in a 1590BB style enclosure, and adds a few features the original did not have.
Can I use the fuzz without the phaser?
Yes. The PastFx version has a unique Phase Off setting that lets the fuzz run independently of the phase circuit, which the original Roland AP-7 did not allow. Phase Depth has its own toggle switch for Low, Deep, or phase off.
Is the PastFx Jet Phaser true bypass?
Yes. The pedal uses a true bypass Normal / effect footswitch, so with the effect off your signal passes through without the circuit. A second footswitch handles the Jet fuzz, and its function can be swapped with the internal Flip Switch Mod button.
What power supply does the PastFx Jet Phaser need?
It runs on a 9V DC supply with a 2.1mm jack and negative tip, drawing approximately 15 mA. PastFx recommends a regulated, isolated linear or transformer based supply, though high quality pro audio switch-mode supplies are also acceptable.
Should I adjust the internal trimpots?
The round trimpot adjusts the phasing frequency range higher or lower, but PastFx recommends leaving it as stock. The rectangular precision multi-turn trimpot must not be adjusted, or the pedal may stop phasing. The micro slide switch sets the depth intensity of the Low Depth toggle position.
Sources (5)
- PastFx_Jet_Phaser_Manual_2021.pdf, PastFx, 2021
- JFet Fuzz Phaser, PastFx, 1970
- Wicked Phase Meets Wickeder Fuzz, Premier Guitar, 2021-05-17
- Antipode Vintage Fuzz / Roland Jet Phaser Fuzz, Aion FX, 2019-11-28
- Warm Audio Jet Phaser Review, Premier Guitar, 2020-12-10
