KMA Audio Machines GUARDIAN OF THE WURM

Calling a pedal legendary or a cult classic is often stretching the truth, but when it comes to the Boss HM-2 MIJ it’s absolutely on the money. We’ve never tried to hide the fact that the WURM Distortion is our unabashed sonic love letter to this filthy box of doom and gloom, taking the essential ingredients of this classic, while in the process developing a way more flexible metal-distortion pedal.


While WURM absolutely nails that Swedish death-metal chainsaw sound, the pedal is not all about that and is adept for so many other genres. To give you an idea, famous players like David Gilmour, Prince, Johnny Marr, Belinda Butcher, Lee Ranaldo, Daron Malakian and others have all made their mark with this style of distortion.


With GUARDIAN of the WURM, we’ve evolved our take on this venerable circuit and added a bunch of really useful new features. Whether you’re playing guitar, baritone, bass or synths through this pedal, we’re sure you’ll appreciate the immense flexibility on offer here. So let’s dig in.


We of course kept the iconic active HM-2 dual band EQ section, but added two more bands, giving a much wider range of tones to tailor your evil and gritty distortion sound. Each band now has a dedicated centre-frequency control on the front of the pedal, allowing you to quickly and easily change and fine-tune your tone.


The EQ-STYLE mode, now also on the front of the pedal, helps you carve out even more tonal variation. Selecting HM-II mode will get you that classic ‘chainsaw’ high-mids character. However, in KMA mode the EQ is a little more tonally balanced, less peaky and a bit wider in response. Selecting BOTH fattens and doubles up the tone stacking, allowing you to rank the LOWS and the HIGH MIDS and rip that Swedish forest even more to shreds.


To adjust the extent of drive compression, you can choose between 3 different clipping styles. Silicon (Si) delivers the original compression, for rich harmonics and singing leads. Asymmetric (A-S) increases the headroom and gives you more grit by retaining complex harmonics, while the OFF position lifts the sound of the Diodes for a slight compression and way more clarity, which is perfect for baritone guitars or bass.


Plus, the Clean Blend feature helps to preserve your natural core tone. Simply twist the BLEND control o mix in the original unprocessed signal, allowing the initial pick attack of your tone to breathe. It is also especially useful when running the GUARDIAN of the WURM into an already distorted high-gain amp.


When talking about high-gain, we all know drive circuits like this at full tilt can be noisy malice monsters. To get a grip on the potential noise floor, we designed a sophisticated, yet easy to use Noise Gate. This is based on a high-performance Blackmer® VCA and provides lightning fast and precise performance. Simply set the Threshold to taste via the GATE control and enjoy the silence. Fast palm-mutes? No problem. Decaying notes? Dead simple to accomplish. For even more tweakability, we fitted an internal DIP switch to change the trigger-source from pre- or post-Distortion or even pre-Noise Gate.


Pre-Noise Gate? Well, that’s because we added a TRS FX-Loop that works between the Distortion and the Noise Gate sections, allowing you to insert whatever fun noise-making pedals you might wish between them. You can also use this feature to place the Noise Gate section in your amplifier’s FX-Loop. Those who like to experiment with sound designs might even use the Noise Gate in other ways, for instance by using an external trigger source. No problem, the EXT TRIG jack hooks up to your source of choice.


In extreme settings, the WURM can sometimes begin to feedback, which can’t even be suppressed by the Noise Gate. To tame that high-frequency content, flip the internal dip-switch to activate the input filter to help smoothen things out. Yup, we did think of everything.


But wait, there is more! As the cherry on top, we added relay-based soft switches and also two different activation modes to suit the needs of different players.


"Independent mode" is exactly what it says on the tin. Both sides of the pedal can be switched on and off independently via the TERROR or TAME switches respectively. However, in “Synced mode” the entire pedal is switched on and off via the TERROR switch. In this mode the Noise Gate can also be switched in and out of the circuit as desired. Changing between modes is really simple to do. Just hold down both switches while connecting the pedal to the power supply, and you’re good to go. Once set, GUARDIAN of the WURM will remember the setting, even when powered off.


So here it is. Crank it up and you will feel the rage of the ancient WURM, while the GUARDIAN will help you tame that beast when needed, making GUARDIAN of the WURM your perfect pairing for an evil and gritty tone that never gets out of control… unless YOU want it to! \m/


Powered by an optional standard 9V DC (max.) PSU (negative center, 2.1mm, >150mA current draw)


Every pedal is designed, assembled, silkscreened, tested and numbered by hand in our small workshop. We use external manufactured PCBs to guarantee our high quality standard and keep the price of our pedals reasonable. The use of an indestructible powdercoated die-cast enclosure ensures a maximum durability.


Controls
Gain
Sets the amount of distortion

Master
Sets the overall volume of the WURM Section

Gate
Sets the threshold of the Noise Gate

Blend
Blends in the input signal, often called "Clean Blend"

Clip-Style (Toggle-Switch)
SI (Silicon Diodes): The sound of the original HM-2 clipping
A-S (Asymmetrical): More grit and less compression
OFF (Lifted Diodes): Perfect mode for bass and baritones

EQ-Style (Toggle-Switch)
HM-II: activates original HM-2 High Mids EQ with fixed centre-frequency
KMA: activates KMA-designed High Mids EQ with adjustable centre-frequency
BOTH: activates both EQ-Styles

Low
Active Semi-Parametric EQ for low frequency boost (up)/ cut(down) with adjustable centre-frequency between 60-150 Hz via below potentiometer (midpoint: 90Hz)

L-Mid
Active Semi-Parametric EQ for low-mid frequency boost (up)/ cut(down) with adjustable centre-frequency between 300 Hz -1,05 kHz via below potentiometer (midpoint: 490 Hz)

H-Mid
Active Semi-Parametric EQ for high-mid frequency boost (up)/ cut(down)
EQ-Style "KMA": with adjustable centre-frequency between 850 Hz-3 kHz via below potentiometer
EQ-Style "HM-II": original HM-2 dual high-mid EQ with fixed centre-frequency

High
Active semi-parametric EQ for high frequency boost (up)/ cut(down) with adjustable centre-frequency between 1.4-5 kHz via below potentiometer (midpoint: 2 kHz)


Footswitches
Terror
Activates the High Gain Distortion and Noise Gate circuit or only the High Gain Distortion circuit depending on the Switching Mode

Tame
Activates the Noise Gate circuit

Switching Modes
• Independent: High Gain Distortion and Noise Gate can be switched on/off independently
• Synced: TERROR switches the entire pedal on and off, the Noise Gate can be switched on and off to taste while the distortion is active then.

(Changing between both modes by holding down both switches while connecting the pedal to the power supply)


Jacks
Input (Arrow Down)
Input for your incoming signal

Output (Arrow Up)
Outgoing Signal

External Trigger (EXT TRIG)
Input for an external trigger source to trigger the noisegate

TRS FX Loop (FX LOOP)
The FX Loop after High Gain Distortion and before Noise Gate, can be used to insert other pedals which have to be placed after the high gain distortion and before a Noise Gate or to insert the Noise Gate into an amplifier’s FX Loop

Internal Controls
Input-Filter
Activates a high-cut at the Distortion input to reduce the risk of oscillation when cranking the Gain/Master and all the EQs – set to taste


Trigger-Source
Sets the source for the Noise Gate's trigger as followed:

Pre-Gain: Instrument In
Post-Gain: Distortion Out/FX Loop In
Post-Loop: FX Loop Out/Noise Gate In

Gate-Response
Choose between a Soft or Hard Gate response

Distortion-Level
Sets the maximum volume level of the Distortion section, before getting mixed with the Clean signal. Quite helpful when using no clipping to adjust it to the clean blend.

Clean Volume Trim
Sets the maximum level of the Clean signal available. Perfect to set the right level when using active or high-output pick-ups. Hard clipping will appear at maxed out Blend settings.