The MXR Dyna Comp is an effects unit, which is an electronic device that alters the sound of a musical instrument.
Made since the 1970s, the MXR Dyna Comp, which adds its own coloring to the tone, has become a frequently copied and widely used guitar effect, even a standard.
[1] The compression effect helps to smooth out differences in volume between notes,[2] such as in quick runs played by chicken picking.
[1] Its "thickening" effect is especially appreciated in Nashville, where many country music guitar players who use Fender Telecasters use it to thicken the otherwise thin sound of the single-coil guitar; besides, the compressor's lessening of the initial attack "gives the effect of a pedal steel player working his volume pedal".
[4] The MXR Dyna Comp is not considered tone-neutral; that is, it adds its specific coloring to the sound,[5] which is appreciated by many users.