The Land Devices HP-2 Percolator is a compact distortion pedal that Land Devices built as a modern reproduction of the Interfax Harmonic Percolator HP-1, an extremely rare fuzz and overdrive from the mid-1970s12. In the maker's own words, "The HP-2 walks the line between harmonic richness and total sonic destruction"3. Delicious Audio describes its range as running "from mild overdrive to face melting fuzz," with a rich, fat and warm even-order distortion character4.
The circuit pairs silicon and germanium transistors, which Pedal of the Day credited with giving "rich layers of sound that add presence and power to any rig or setup"5. That germanium and silicon combination is the signature of the original HP-1, which used a PNP germanium transistor paired with an NPN silicon so it could run in a standard negative-ground configuration2.
The controls
The HP-2 keeps the control layout of the original Interfax: two knobs and a switch. Land Devices describes what each does743:
| Control | What it does |
|---|---|
| H (Harmonics) | Adjusts the input gain, from clean boost to broken speaker3 |
| B (Balance) | Sets the output level, "letting you tame or unleash the chaos"3 |
| Rocker switch | Left for '70s-inspired saturation, right for face-melting aggression3 |
Guitar Pedal X lists the same control set as H (Harmonics), B (Balance), and a clipping rocker switch labeled "70's / Absolute Destruction"7. The H knob mirrors the original HP-1's Harmonics slider, which controlled input gain7.
One behavior worth knowing before you plug in: turn either knob fully counterclockwise and, in Land Devices' words, "your signal disappears into the void"3. Neither control works like a conventional volume at minimum, so finding usable settings means working with both knobs together.
The rocker switch is the pedal's biggest tonal decision. Delicious Audio describes the two positions as the original circuit on the left and "doom" on the right, with the right position giving a louder but less compressed tone than the stock character4.
Where it came from: the Interfax Harmonic Percolator HP-1
The HP-2 is a tribute to one of the most obscure pedals of the 1970s. The Interfax Harmonic Percolator HP-1 is described by Aion FX as "an extremely rare and highly sought-after fuzz/overdrive from the mid-1970s," and the original units had their transistors and some components gooped or obscured, which kept the circuit's details hidden23. Several circuit changes were made throughout the run, and two versions are known: "stock" and "Albini"2.
The original circuit featured 2N404 germanium and 2N3565 silicon transistors7, and Guitar.com notes the germanium/silicon combo of the original HP-1 as the defining feature later pedals copied78. JHS Pedals' history of the format reports that "Land Devices put the HP-2 together as a modern reproduction"1.
What reviewers said
Guitar.com named the HP-2 the best Harmonic Percolator type in its 2026 fuzz pedals buying guide9. Pedal of the Day's 2018 review highlighted the silicon and germanium transistor pairing and the input control's range, from the left knob adjusting signal input on up through the full gain range5.
"can go from mild overdrive to face melting fuzz. Left knob for harmonics and right knob for balance. Switch left for original circuit and switch right for doom"
Availability and finish options
The HP-2 Percolator is listed as sold out on the Land Devices product page as of October 20263. A variant, the HP-2 Percolator in Scream, offers the same pedal in a green finish with identical dimensions and specifications, and it is also sold out10. Its regular price is listed as £211.00 GBP by Land Devices3. Land Devices describes the pedal's character in their own words: "The HP-2 walks the line between harmonic richness and total sonic destruction."3
Videos
ProGuitarShopDemos
Reverb
60 Cycle Hum
Questions
What does the rocker switch do on the Land Devices HP-2 Percolator?
The rocker switch selects between two clipping characters. Left gives 70s-inspired saturation, the character of the original Interfax circuit, while right goes for what Land Devices calls face-melting aggression: a louder, less compressed, doom-oriented tone. Delicious Audio describes the right position simply as the doom setting.
What power supply does the HP-2 Percolator need?
It takes 9V DC from a center negative supply through a 2.1mm DC connector, and draws 33mA. That is standard pedalboard power, so any typical 9V center negative output will run it. There is no battery option mentioned in the maker's specifications.
What is the original Interfax Harmonic Percolator HP-1?
The Interfax Harmonic Percolator HP-1 is an extremely rare fuzz and overdrive from the mid-1970s. It used a PNP germanium transistor paired with an NPN silicon transistor, and the transistors and some components were gooped or obscured in the original units. Several circuit changes were made during its run, with two known versions called stock and Albini.
How big is the Land Devices HP-2 Percolator?
The enclosure measures 117mm x 95mm x 52mm, roughly a standard compact pedal footprint. It connects with 1/4 inch mono jacks for input and output.
Is the Land Devices HP-2 Percolator still available?
As of late October 2026 the HP-2 Percolator is listed as sold out on the Land Devices product page, including the green Scream finish variant. Its list price was $229 USD as reported by Guitar.com in February 2026 and by Guitar Pedal X in 2024.
Sources (10)
- WHAT IS A LAND DEVICE?, JHS Pedals
- Particle Vintage Fuzz / Interfax Harmonic Percolator, Aion FX, 2021-02-19
- HP-2 - Percolator - Land Devices, Land Devices
- Land Devices HP-2 Harmonic Percolator, Delicious Audio, 2023-07-31
- Land Devices HP-2 Distortion, Pedal of the Day, 2018-12-21
- Superlunar SR-01 review, Guitar.com, 2026-02-09
- Guitar Pedal X, Guitar Pedal X, 2024-05-13
- Zander Circuitry Cafetiere review: A brilliantly tweakable take on the InterFax Harmonic Percolator, Guitar.com, 2022-06-14
- The best fuzz pedals for all styles and budgets, Guitar.com, 2026-01-14
- HP-2 - Percolator in Scream - Land Devices, Land Devices
