The ThorpyFX Pulse Doppler is a fully analog phaser pedal that also covers vibrato and tremolo territory, built in the UK and designed with circuit engineer Dan Coggins of Lovetone fame. It is a reworked and refreshed version of the Lovetone Doppelganger, the much sought-after phaser/vibrato pedal from the 1990s, and it was the first ThorpyFX design released after Coggins became a full-time member of the team12. ThorpyFX describes it as designed from the ground up to provide versatile and original phaser sounds from an analog effect1.
Where a basic phaser gives you one sweep character, the Pulse Doppler splits the signal into two frequency bands, referred to as notches, and offers five selectable modes through its two toggle switches, including Bi-Directional (figure of 8) and Dual Phasing23. Delicious Audio called it a rather peculiar modulation pedal that can deliver anything from phaser to vibrato to tremolo3.
A Lovetone Doppelganger phaser reworked
The Pulse Doppler's circuit traces back to the Lovetone Doppelganger, a four-stage optical phaser first released in 1995937. Gearnews described the project as two circuit wizards taking the original '90s Lovetone Doppelganger to create a MKII version2, and Guitar World's Trevor Curwen notes that Coggins was behind Lovetone's much sought-after Doppelganger phaser/vibrato from the 1990s, which surely donated some of its character to the new pedal7.
The Pulse Doppler is a more compact proposition than the Doppelganger that inspired it4, and it was redesigned from the ground up rather than simply reissued. MusicRadar's review characterizes it as a reworked and refreshed version, with the idea that it would be a sort of do-it-all phaser pedal4. Gearnews went further in its verdict, suggesting it could take the original 1995 design further, at a fraction of the cost the originals now sell for used2.
A related page covers the earlier Pulse Doppler Phase Shifter announcement.
The controls
The Pulse Doppler has five knobs, two toggle switches and two footswitches13.
| Control | What it does |
|---|---|
| Depth | Sets modulation depth; needs careful management, as the modulation vanishes below one o'clock and gets motorboaty beyond three8 |
| Rate | Sets the speed of the sweep |
| Blend | Mixes the effect with the dry signal |
| Enhance | Shapes the intensity; cranking it can bring pew-pew synth effects8 |
| Manual | Sets the default notch for the filter frequencies and controls the range of the LFO sweep3 |
The Manual knob is worth a note for players new to this design: it adjusts the frequency range of the swirl in a way that dramatically alters its tonal character, with the useful zone between 11 and 12 o'clock8.
The two toggle switches select between five modes2:
- Pulse toggle: Normal or Invert2
- Dual toggle: selects the phasing configuration, including Dual Phasing and Bi-Directional (figure of 8)2
- Normal position: simple phaser3
The Invert position matters in practice. Guitar.com's reviewer found a throbby volume bump toward the low end of the sweep that can be tamed by flipping to Invert mode8.
Power and connections
The Pulse Doppler runs on 9-volt operation with a standard DC input, drawing 50mA1. MusicRadar lists it as a 9V DC adaptor, not supplied4.
There is no battery option. The pedal is powered by a 9-volt mains supply only8, and ThorpyFX stopped fitting battery compartments in its pedals years ago, with founder Adrian Thorpe calling them a waste8.
For connections, it has a standard input with dry and wet outputs4. ThorpyFX points stereo pedal enthusiasts to those dry and wet outputs for stereo use1, and Delicious Audio confirms the wet and dry outputs support stereo configurations3.
The build follows ThorpyFX's usual approach: a laser cut anodised aluminum enclosure wrapped in a burgundy red powder coat base1, with 1 per cent metal film resistors, WIMA and Panasonic capacitors (where possible) and robust through-hole plated PCBs4. MusicRadar calls the build typically robust ThorpyFX construction4. Dimensions are 100 (w) x 129 (d) x 54mm (h)4. Optional ThorpyFX Barefoot Button extras are available1.
History and versions
The Pulse Doppler was announced as a new analog modulation pedal, with Gearnews, Guitar World and MusicRadar all covering the launch256. Guitar World reported it available now for $3767, and MusicRadar gave the UK price as £264.996. ThorpyFx describes it as a fully analog phaser designed from the ground up, a MKII version of the Doppleganger, and the first design released since Dan Coggins became a full time member of the team1. MusicRadar describes it as a reworked and refreshed version of the Lovetone Doppelganger, with the idea that it would be a do-it-all phaser pedal4.
The current product page lists the Pulse Doppler Phaser V2 at £264.991, and Guitar World's 2026 review gives the price as $376 / £2647.
What reviewers said
MusicRadar's review found the Pulse Doppler to be a hugely versatile stompbox capable of classic phase shifting sounds, vibrato/tremolo and more, with a wide array of controls making for a wide array of sounds and a typically robust ThorpyFX build. Its listed reason to avoid: no presets to save favorite sounds4.
"A more compact proposition than the Lovetone Doppelganger that inspired it, the Pulse Doppler is a hugely versatile stompbox"
Guitar.com's reviewer highlighted both the range and the quirks: the Enhance knob's pew-pew synth effects at high settings, the Manual knob's useful zone between 11 and 12 o'clock, and the Depth control's need for careful management8.
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Questions
Does the ThorpyFX Pulse Doppler take a battery?
No. The Pulse Doppler runs on a 9V DC mains adaptor only, which is not supplied with the pedal. ThorpyFX stopped fitting battery compartments in its pedals some years ago, and this one follows that policy, so you will need a power supply or pedalboard power block to use it.
Is the Pulse Doppler true bypass?
No. MusicRadar's review lists the Pulse Doppler as having buffered bypass rather than true bypass. That means a buffer stage stays in the signal path when the effect is off, which can help drive long cable runs, though players who prefer a fully hard-wired bypass path should take note.
Can the Pulse Doppler be used in stereo?
Yes. The pedal has separate dry and wet outputs, and ThorpyFX points to both for stereo use. Running the dry and wet outputs to two amps gives a stereo spread of the phase shifting, which is one of the features the original Lovetone Doppelganger was known for.
What does the Invert mode do on the Pulse Doppler?
The Pulse toggle has Normal and Invert positions. Guitar.com's reviewer found the pedal can have a throbby volume bump toward the low end of the sweep, and that flipping to Invert mode tames it. Invert effectively flips the phase relationship of the modulation, giving a different feel to the sweep.
Does the Pulse Doppler save presets?
No. MusicRadar's review notes there are no presets to save favorite sounds, which it lists as a reason some players might avoid the pedal. Every sound is dialed in with the knobs and toggles, so switching between very different settings mid-gig means bending down to adjust them.
Sources (9)
- PULSE DOPPLER, ThorpyFx
- ThorpyFX Pulse Doppler Phase Shifter, gearnews.com, 2021-05-27
- ThorpyFX Pulse Doppler Phaser/Tremolo, Delicious Audio, 2023-04-25
- ThorpyFX Pulse Doppler review, MusicRadar, 2021-10-01
- ThorpyFX debuts feature-packed, fully analog phaser pedal, the Pulse Doppler, Guitar World, 2021-05-28
- ThorpyFX unveils the Pulse Doppler, MusicRadar, 2021-05-28
- ThorpyFX Pulse Doppler review, Guitar World, 2021-08-09
- ThorpyFX Pulse Doppler review: The Lovetone Doppelganger reimagined, Guitar.com, 2021-06-02
- Quadratron Twin Phaser / Lovetone Doppelganger, Aion FX, 2021-07-02
