The Spark Booster is a stompbox-style boost, overdrive and EQ pedal from TC Electronic. It features level and gain controls, a fat/clean/mid tone selector and a 2-band EQ.
The pedal's level control offers 26 dB of clean boost and is designed to simply add volume to your guitar sound without distorting or altering the tonal character. It can be used as a volume boost to your clean guitar, or at higher settings, to create overdriven sounds by pushing your amp harder. The gain boost control on the other hand, adds slight overdrive and compression. This can be useful in situations that call for the sound of an overdriven amp, but require that your volume be kept low, such as when playing a restaurant or coffee house gig.
The Spark Booster's 2-band EQ controls consist of bass and treble knobs, which allow both cut and boost. Bass frequencies can be boosted for more punch, or rolled off a bit for a tighter sound that may otherwise sound boomy when playing through larger cabinets. Add more treble to your tone to brighten up darker sounding amps, or to compensate for signal lost in long cables. Treble can be reduced for softer, jazzier tones.
The pedal can be run in 3 separate modes that can be chosen using the fat/clean/mid tone selector. The "clean" setting boosts your guitar signal equally across the frequency spectrum, while the "fat" setting adds more low-end punch to your sound, also allowing for more precise control of your tonal shape when using the EQ and Gain knobs. The "mid" setting provides a bump in the midrange that will give your guitar tone more "cut-through" in the mix.