Guild Foxey Lady Replica known as the GFL. The original stompbox from the 70’s was manufactured by Electro Harmonix and is in fact a Big Muff Pi distortion! The values on the units traced have some part value differences from any of the Big Muff versions, so we thought it was worthy of posting in case you love that sound and have to have one! Note that the PCB is the same PCB used in the BMP project and does have the label “BMP” on it. The Wiring Diagram and PCB layout below are “borrowed” from the BMP project.

Description from General Guitar Gadgets.