TECH 21 BOOST DISTORTION Interesting unit here, a dual pedal offering a Boost circuit and a Distortion circuit, each can be used independently or together. If you’re keeping score the Boost circuit comes after the Distortion, so you could use it to knock up your dirty signal for solos, for example. You’ve got up to 21db of clean boost on tap, so that’s more than enough be heard. As for the Distortion side, well, if you remember that 80’s crunch, the tone here will be familiar. The Sag control is worth noting, replicating the compression of tube amp saturation as it is dialed up. And the Tone knob isn’t just bass to treble, more of a low pass filter that pulls highs without muddying up the sound.