Spiral Electric FX’s White Spiral Boost is a JFET-based tone-lifter

Featuring a discreet Girth control that governs the level of low-end.

Spiral Electric FX White Spiral Boost

Spiral Electric FX has unveiled the White Spiral Boost, a JFET-based unit that can serve as both an always-on booster or the last device in your signal chain. Leaving the pedal on should get you more ringing harmonies with a touch of grit, while using it as an end-boost can help enliven an amp’s dirty channel.

The booster can be sculpted by three main controls: Output, Grit and Girth. The last of these, which featured on the brand’s Yellow Spiral Drive, isn’t your average tone control. According to Spiral Electric FX, Girth is a “rotary cap network” that can be used to increase or restrict your boost’s low-end.

Girth can be modified via a two-way toggle: Alpha and Omega. Selecting Alpha ‘places’ Girth before the Grit control, which is described as a low-gain clipping section. In this mode, you can use Girth to manage the amount of bass sent to Grit, changing the latter’s character and compression profile in the process.

Omega, on the other hand, routes Girth after Grit, letting you decide the amount of low-end that passes through the circuit. Sound-wise, this mode of Girth is described as “open, glassy, and hi-fi-sounding” by the brand.

Grit is responsible for shaping JFET character to produce distortion while also facilitating silicon clipping. Spiral Electric FX describes the combination of these two clipping types as “slightly asymmetrical”, a property that contributes to the pedal’s natural-sounding, low-gain grit that’s suited to already-driven amp channels.

Available late August at $199. More info at spiralelectricfx.com.


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