The Frus Muff is built to recreate the Big Muff sound used by John Frusciante across different eras. The “NYC” side emulates the first American reissue Big Muff Pi (V9 / EC3003), while the “Russian” side gives the flavor of the original Black Russian Big Muff (V8). The three classical controls respond according to the selected mode. It is fully analog and true bypass.