The Electro-Harmonix Micro Q-Tron Envelope Follower Effects Pedal is everything you love about the Mini Q-Tron, in an even smaller, rounded-corner die-cast case! The Micro Q-Tron is a unique type of sound modifier, in which the user's playing style controls the effect. The volume of the input signal (also called the envelope) controls the cutoff frequency of a swept filter. As the volume increases or decreases, so does the pitch of the filter. The Micro Q-Trons effect is controlled by the user's playing dynamics a stronger attack will yield a more dramatic effect, while softer playing will produce more subtle effects. Use the full range of control settings in combination with different playing techniques to obtain a number of different and unique effects combinations.