“We didn’t want to just make a one trick pony octave up device”: Jimi Hendrix, Tony Iommi and Josh Homme all championed the octave pedal – now KMA Machines’ Mandrake Octo-Shrieker looks to take the effect to new heights

KMA Machines Mandrake Octo-Shrieker
(Image credit: KMA Machines)

Berlin-based effects specialist KMA Machines has unveiled the Mandrake Octo-Shrieker – a new octave pedal that looks to take the effect beloved by the biggest names in guitar to new heights.

Indeed, in the brand’s own words, the Mandrake looks to rectify a key issue found in the octaves that were all used by the likes of Jimi Hendrix, Tony Iommi, Josh Homme, Billy Corgan, Jack White and more.

That issue is specifically concerned with apparent untamed and “nasty” clashing overtones that can arise from octave effects. In KMA’s own words, “We didn’t want to just make a one trick pony octave up device.”

To eliminate the identified problem, the Octo-Shrieker offers a refined and improved take on the brand’s Shriek circuit, which is lifted from KMA’s Moai Maea Octaver.

With an “edgy and fuzzy character”, the new-and-improved circuit adds a lowpass filter, a Timbre parameter and individual Mix controls to offer a more versatile – and robust – octave up experience.

In practice, the analog octave pedal offers a transistor-based fuzz with enhanced rectification circuit, ultra-fast tracking and a tonal character akin to “the best vintage octave-up pedals”.

As for the controls, the Filter knob tames the upper harmonics and supposedly improves tracking. Turning this all the way left releases “unhinged” octave action, while dialing it clockwise is said to tap into a “synth-like texture”. It’s also apparently a tool that helps the Mandrake adapt to different pickups.

Timbre, meanwhile, dictates the level of fuzz in the upper octave, from “crunchy and percussive tone” to “crushingly saturated doom-hammer” tones.

Two final smaller knobs can also be found on the front panel: Dry and Oct+. Both are self-explanatory – Dry sets the amount of clean signal in the mix, while Oct+ sets the level of upper octave.

The Mandrake Octo-Shrieker is available now for $170.

Visit KMA Machines to find out more.

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Matt Owen

Matt is a Staff Writer, writing for Guitar World, Guitarist and Total Guitar. He has a Masters in the guitar, a degree in history, and has spent the last 16 years playing everything from blues and jazz to indie and pop. When he’s not combining his passion for writing and music during his day job, Matt records for a number of UK-based bands and songwriters as a session musician.