The Mod Rex Polyrhythmic Generator houses four independent modulation engines—Mod, Trem, Pan, and Filter—that contain a host of effects and tweakable parameters. The Mod engine offers vibrato, flanger, chorus, and phaser, and includes a Depth and Feedback knob. The Trem modulates the amplitude of your signal. When the unit's stereo outs are used, Pan allows a wide separation of the left and right channels (but while in mono mode, it acts as another tremolo section). Finally, the Filter section gives the choice of low-, high-, and band-pass filters.