The controls are as follows:
Boost: Controls the overall volume of the unit.
Gain: Controls the overall gain of the unit.
Tone: Controls what section of the Overall EQ is being boosted. At full clockwise, only the higher end of the EQ spectrum is being boosted, effectively acting as the more traditional treble booster. As you turn counter-clockwise, the band of boosted is widened, providing a full range Boost. This is extremely useful for smoothing out booming guitars or a balancing out differences in tones if using multiple guitars or gain pedals.
This pedal is best used in a couple applications. One use is to tighten up your tone in front of a gain pedal. This allows you to get very tight distortion tones. Another use is in front of a amp to add some overdrive or break up into a somewhat clean amp. Although these would be the more common uses, it can also be used after a gain pedal as a Solo boost.
Like all PLX FX pedals, this pedal is a true bypass, so there is no coloration to your sound when it’s turned off. It utilizes a standard 9v 2.1mm power adapter and NO battery snap.