Terra Firma


The power-amp distortion.

It’s about to get doomy.

Our heaviest distortion to date, the Terra Firma packs a huge punch of pure, unadulterated power-amp distortion. Voiced specifically for down-tuned guitars, it’s perfect for capturing those big, beefy (and slightly fuzzy) stoner and doom rock tones. It also has a monstrous amount of volume on tap that’ll really get those speakers shaking.

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We set out with the goal of creating something for those playing those slower/heavier types of music, as well as something that would give you that huge sound with both smaller rigs, as well as the usual backline of multiple 4x12s, and we’ve nailed it if we do say so ourselves.

The Terra Firma is based around the LM386 power amp chip which offers the perfect blend of character and raw output volume to add a bunch of additional supporting circuitry to.

In addition to the regular level and gain controls, the Terra Firma offers many other controls that allow you to tweak the tone to your setup. Tone is a dual high/low pass filter, which works interactively with the Scoop control which shifts the mid focus, offering everything from punchy desert rock tones through to tighter, almost metal like tones. The Input control adjusts the gain going into the second stage of the circuit, which allows you to push the distortion into noisy, fuzzy high gain madness.

The Terra Firma also features our signature diode rotary switch, which lets you choose between eight clipping types for added versatility:

  • Germanium: Smooth, sweet, and classically ‘amp-like’. 
  • Silicon: Louder, brighter, and a little bit brittle. 
  • LED: Louder again, with less saturation and more punch. 
  • Asymmetrical germanium: A more aggressive version of germanium. 
  • Asymmetrical silicon: A more aggressive version of silicon. 
  • Asymmetrical LED: A more aggressive version of LED. 
  • Transistor/MOSFET: Similar to silicon, but sweeter and crunchier. 
  • No diodes: Loads of output and much less gain.

On this pedal the diode rotary will be more/less obvious depending on where the pedal’s internal master volume trimpot is set, as stock we set it a bit lower so you can really get a feel for the differences.

For those wanting to switch between low and high gain settings, the Terra Firma’s Blast footswitch turns the gain all the way up, and activates a second volume control for seamless transitions between low and high-gain sounds.

There are seven controls that you’ll use to tame the American Geek:

  • Gain: Gain control
  • Tone: High/low pass filtering 
  • Scoop: Mid-range focus
  • Input:Second-stage input gain adjustment
  • Level: Output volume
  • Blast: Output volume (in Blast mode)
  • 1-8: Clipping diode selector

It also has two footswitches: 

  • Engage: Turn it on and off 
  • Blast: Activate Blast mode 

The Terra Firma features both momentary and latching switching, which means you can hold down one of the footswitches to temporarily engage an effect and then release it to return to normality.

Not to mention: 

  • Top-mounted in/out jacks
  • Power requirements: 9V DC (center-negative) supply
  • Current draw: 125 mA


  • (W)67 mm x (L)122 mm x (H)60 mm