The MM4 offers you 16 of the most popular and sought after modulation effects from the sweet warble of modeled tube bias tremolo, through 2 types of rotary speaker, to the rarest stereo choruses from the '80s. With fully programmable effect parameters and extra control available with the optional EX1 expression pedal, if making things shimmer and shake is your thing, the MM4 may become your favorite tool.
MM4 Modulation Modeler page at Line6 's website...