KMA Machines Wurm 2

The KMA Machines Wurm 2 is a high-gain distortion pedal with an active 4-band EQ, built around the sound of the legendary Boss HM-2 Heavy Metal. Released in March 2022, it is a revised, slimmed-down version of KMA's original Wurm, keeping the HM-2's active dual-band EQ section and adding two more bands for a much wider tonal range¹². Where the Boss original was replaced by the MT-2 Metal Zone, the HM-2's filthy "doom and gloom" distortion sound found a second life through pedals like this one²³⁴.

KMA Machines, a Berlin-based German manufacturer, describes the Wurm 2 as a "sonic love letter" to the original HM-2 MIJ pedal's distortion sound, taken much further³. Its thick walls of gain and sustain suit death metal, but RockBoard's PedalPedia notes it also works for many other styles, from shoegaze to prog rock⁵.

An HM-2 style distortion with an active 4-band EQ

The Wurm 2 takes the Boss HM-2 style circuit and pushes it hard. Gearnews described it as taking "the legendary Boss HM-2 style circuit to the brink of insanity"². The core of the pedal is its EQ: KMA kept what it calls the iconic active HM-2 dual-band EQ section and added two more bands, giving four active bands total: Highs, Hi-Mids, Low-Mids and Lows¹⁷.

The EQ controls offer a +/-8dB range, with the High-Mids band variable from 950 Hz to 3.2 kHz³. Internal frequency trimmers are provided for the Lows, Low-Mids, High-Mids and Highs bands, letting you fine-tune where each band sits⁷³.

The Terror knob, despite its name, is basically just the amount of distortion; cranking it up produces extreme gain³. An internal dip-switch activates an input filter that helps tame the high frequencies when everything else is exhausted²³.

Three EQ styles: HM-II, KMA and Both

A three-way toggle switch on the front panel selects between three EQ styles, focused on the High-Mids band³. Guitar World noted this switch is external on the Wurm 2, where it was internal on the original Wurhm⁸.

• HM-II: Selects the HM-2 style H-Mids EQ with a fixed internal center frequency, the band labeled "HIGH" on the original HM-2. KMA says this mode gets the classic "chainsaw" High-Mids character¹³.
• KMA: Selects a KMA-designed H-Mids EQ with an adjustable center frequency, effectively a parametric EQ. KMA describes this mode as more tonally balanced, less peaky and a bit wider in response¹³.
• BOTH: Combines both EQ styles, fattening and doubling up the tone stacking so you can ramp up the Lows and the High-Mids at once¹³. Gearnews characterized this mixture as one that will "tear the Swedish forest to pieces"².

Power and connections

The Wurm 2 runs on 9V DC with a center-negative 2.1mm barrel connector and draws 50mA¹³⁵. There is no battery option; it needs a standard pedalboard power supply output.

The pedal's top-mounted jacks and smaller enclosure make it, in Gearnews' words, "a lot easier to squeeze onto a cramped pedalboard rig" compared with the 2020 original².

Wurm vs Wurm 2

The Wurm 2 is an update of KMA's original Wurm, the company's high-gain flagship distortion³. By the launch of the Wurhm in November 2020, 1000 Wurm units had been made⁹. The Wurm 2 differs from the 2020 original in three main ways:

• A smaller, more pedalboard-friendly enclosure²³
• Top-mounted jacks²
• An external three-way EQ style switch, where the original used an internal switch⁸

Reviews and demos

Guitar Pedal X included the Wurm MK2 in its 2025 roundup of compact high-gain and heavy metal pedals, calling it "yet another fantastic take on the HM-2" and praising its three core voicing modes and semi-parametric EQ⁷:

RockBoard's PedalPedia entry for the pedal notes that when it comes to the Boss HM-2 MIJ sound, it is "absolutely on the money"⁵. The same page lists a demo video by Rabea Massaad in English⁵.

The pedal wears the black and orange color scheme reminiscent of its inspiration, the Boss HM-2¹.

Videos

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