TC Electronic built the Crescendo Auto Swell to give guitarists the possibility to create rolling and mighty volume swells. The effect can be compared with a noise gate, but only in the reverse way. The sound starts with a low amount of volume and swells up to the full volume, just like a crescendo effect known from a violin being bowed. Now imagine what kind of magical tones you can create with this pedal on your guitar. The 2-knob-concept (Sensitivity and Attack) makes the handling mega simple and it's fun to use.