The Slammi Plus Polyphonic Pitch Shifter/Harmony Pedal from Electro-Harmonix transposes your pitch in two different directions over a +/-3 octave range (transpose up, down, or both) simultaneously. The 11-position Shift switch selects the maximum transposition starting with D (Detune) which is a shift of 17 cents that creates a chorus or doubling effect.

The Dual setting outputs two pitch-shifted signals. The first follows the Shift knob as if in UP mode. The second transposed signal depends on whether the Slammi Plus is set to Pitch or X-Fade. In Pitch mode, the secondary shifted signal bends at the same rate as the primary signal. When in X-Fade mode, the secondary signal is set by the Pitch Mix knob and does not bend. The interval choices are in half-step increments up to +/-1 octave. The volume of the secondary signal decreases by sweeping the pedal from heel to toe.