KMA Machines launches the Mandrake Octo-Shrieker, promising player-friendly octave-up fuzz magic from a compact, tweakable stompbox

KMA Machines has gone rummaging in the circuitry of its Moai Maea for inspiration and has reworked and improved its octave-up circuit for the Mandrake Octo-Shrieker, a guitar effects pedal that is like classic octave-ups of yore only more tweakable, more user-friendly – and more pedalboard-friendly too.

The Mandrake offers “subtle tone enhancement to full-on dual octave grind”, and presents players with ample control over the octave-up sound. KMA Machines says this new circuit is blessed with better tracking, making for a sound that’s more robust no matter how you choose to use it.

Flexibility was the goal, which is not necessarily a gimme in the world of octave-up fuzz effects. They can be temperamental, running away with themselves and letting the upper-frequency harmonics take over. 

This applies a quote/unquote “enhanced rectification circuit topology” to a discrete transistor-based fuzz, and pairs this with an active pre-gain second-order filter to keep your electric guitar’s signal pristine for the octaver. 

The second-order filter is controlled by a Filter knob, and the further you turn it clockwise the smoother it gets, with quasi-synth fuzz sounds at its extreme. 

Set it below noon, or leave it fully counterclockwise – you animal! – and you’ll get “unhinged, cutting and shrieking mayhem”, hence the name Mandrake, which as legend has it would shriek as it was plucked from the soil, destined for a potion or poison. 

Either way, Filter is your friend when switching over from single-coil guitars to humbuckers. Timbre is another key control for shaping the octave-up voice to complement your signal. Fully counterclockwise, KMA says it might sound a bit “crunchy and percussive” but as you turn it up the sound blooms.

Once more, the extremes of a control yield an extreme sound to work with – “a crushingly saturated doom-hammer, instantly ready to wreak havoc with each power chord you throw at it!” as KMA puts it.

Again, bringing things back to practicality and versatility, there is an all-important mini-dial for Mix to adjust the balance between the processed signal and the sound from your guitar, and there’s another mini-dial to control the level of the octave-up effect.

So yes, the Mandrake Octo-Shrieker, it’s an octave-up pedal for fuzzy retro sounds a la QOTSA, Jack White et al, and it can get wild, but it does subtle, too, and crucially it is easy to dial in your tone. 

The Mandrake takes 9V from a pedalboard power supply, drawing 30mA, it is true bypass, and it’s available now, priced £149. See KMA Machines for more details.