EHX took their famous Big Muff Pi and shrunk it to a pedal board friendly size. Electro-Harmonix promises that the Nano Big Muff Pi sounds exactly like the original Big Muff Pi so there are no down sides to this down-sizing. Load both to the TonePedia player and see how similar they are. Sound wise what is there to say?! The Big Muff is a rich fuzz / distortion pedal that delivers violin-like sustain. It is one of those pedals that shaped the face of Rock and Roll. Glad to see it evolves.