Freakish Filter Madness for Your Pedalboard

Synth-style filter modulation may not be for everybody, but if you enjoy funky filter sweeps or simply want to explore new avenues to enhance your guitar effects, then you're going to love the Electro-Harmonix Blurst modulated filter pedal. The Blurst follows the tried-and-true modulated filter formula used by countless synthesizers: you start with a variable resonant filter — usually a lowpass filter like the one featured in this pedal — and then modulate the filter cutoff point with an LFO (low-frequency oscillator). The results can be exceptionally stunning, especially when you combine the Blurst with other effects.

Why modulation makes this filter pedal so cool

The "modulated" part of this filter has to do with how you control the filter cutoff point. On its own, the Blurst uses its internal LFO to sweep the lowpass filter's cutoff point between a frequency range you can specify via the Range knob. You can set the speed of the sweep via the Rate knob, and the Shape mini toggle lets you choose from back and forth, upward, or downward filter motion. A tap tempo footswitch allows you to sync the LFO to the beat, ensuring that it pulses in time with your music, and letting the LFO run freely creates a fun asynchronous sweeping effect that's not entirely dissimilar to a phaser.

Transform the effect with an expression pedal

Got an expression pedal handy? If not, you may want to pick one of those up as well, because an expression pedal can add dimensions of additional effects to the Blurst. There are three settings for the Blurst's expression mode: Range, Rate, and Filter. By setting the range on the fly, you can extend the phaser-style sweeping effect. For instance, you may want to crank it up for rhythm parts but pull it back to tighten up your leads. Controlling the rate lets you pull off rotary-cabinet-style ramp-up effects or sheer chaos, depending on how hard you tilt your expression pedal. Love the wah-wah-like quality of your Blurst? Just turn down the range and use your expression pedal to sweep the filter manually.

Wonderful effect enhancer for your pedalboard

There are tons of great ways to use the range of effects you can get out of the Blurst in your guitar rig. On its own, it can add spice to a clean tone, but it's also a great companion for other effects. Toss it on a dirty channel or inline with your favorite distortion box, and you'll get sweeping accents that don't blur your tone the way a phaser, flanger, or chorus does. But you can also combine it with another modulation effect to get intricate counter-point sweeps. Finally, if you totally crank the rate, you'll achieve something akin to frequency modulation (FM) synthesis, totally transforming your guitar tone.