If you've been a fan of music with guitars tuned lower than standard in the last 30 years, there's a chance you've heard of this hot new sound, usually associated with heavy riffs and power tools. In lay terms, the Catalinbread Carbide Distortion 1.96 x 4.33- Inch Pedal with Dry Volume and Wet Volume Controls is a pulverizing distortion with heady boosts to certain frequency bands- three of them, to be exact- and a ton of volume. Officially, obtaining this chainsaw sound, as it came to be known, consists of plugging into a Boss HM-2 Heavy Metal and maxing all four knobs. Carbide starts with this at its base, then tweaks the majority of the distortion circuit for maximum crunch and thud. Instead of giving you a paltry blend control, the Carbide splits your signal into two paths; one path heads to a powerful clean boost specially configured to down-tuned instruments, and the other heads into the gears of the distortion. Each path is given its volume knob before being mixed in parallel, letting you fine-tune the right amount of dirt. An Emphasis control tightens up the extreme low end while cutting treble, letting the boosted frequency bands jump out of the mix.

Dry Volume and Wet Volume

These two knobs control the volume levels of the dry, boosted path and the wet, chainsaw path. When either one is down, it disappears from the mix. These two circuits are in parallel, so you can mix both sides to your taste or rig. 

Emphasis

The stock HM-2 circuit gives you two color mixes, or EQ knobs: L (Low) and H (High). The L knob controls a frequency boost at 87Hz, but the H knob controls two different bands simultaneously, at 958Hz and 1279Hz. The Carbide keeps these three boosts intact, but the Emphasis control cuts frequencies around these bands, making them pop a little more. Like the H knob of the original, the Emphasis control adjusts two different filters simultaneously, one at 63Hz and a treble shelving filter. The Q of the low filter is just wide enough to butt up against the onboard bass boost. while knocking out pesky sub-bass.

Power Supply

The Carbide accepts a center-negative DC power supply from 9 to 15 volts, capable of supplying at least xxmA of current (over is fine). Plugging in anything other than this (center-positive, AC, higher voltage, etc.) will potentially brick the Carbide. Check your supply and make 100 percent sure it says all the right stuff. If you plug in the wrong supply, you'll immediately send your pedal to the shadow realm.