Quick Hit: String Theory EFX KE/64 Overdrive Review

Raw and super rich—the KE/64 packs a punch that never overpowers.



Top-quality build. Concise, rich, and crazy punchy.

A little pricey for a 2-knob overdrive.


String Theory EFX KE/64 Overdrive


Ease of Use:



I’ve been in a streamlining, minimalist kind of mode lately, so I guess I was ripe for the String Theory EFX KE/64. Still, even when I checked this potential, transitory bias at the door, this raw, feral, and somehow very sophisticated overdrive still knocked me silly.

As suits a temporarily minimalist fellow, the KE/64 has only a master volume, a gain control, and about 20 internal components fastidiously arranged on a perf’ board. Three CEN 2N5457 JFET transistors do the lion’s share of drive work. But KE/64 is a more-than-the-sum-of-its-parts proposition. It’s artfully and carefully built.

KE/64 is a more-than-the-sum-of-its-parts proposition. It’s artfully and carefully built.

Builder Michael Fumarolo says the spark behind the KE/64 was the sound of Dave Davies’ busting-at-the-seams Elpico AC-55 amp on “You Really Got Me”. To my ears it doesn’t sound specifically like that. But man does it have that Kinky ferocity. Individual note definition is superb. The harmonic balance is excellent. It also manages to sound simultaneously wide-spectrum and concise, making it a mix engineer’s dream. That quality makes chords incredibly punchy and complex, and lends leads a searing, Jimmy Page-circa-’69 feel. But it also means you can drive delay-stacked-on-modulation-on-top-of-reverb shoegaze miasma without losing the plot—even if you’ve lost your minimalist urge.

Test gear:Fender Telecaster Deluxe with Curtis Novak Widerange humbuckers, Fender Jazzmaster, ’68 Fender Bassman

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