mellasse sent me a schematic for an old Guytatone fuzz, Guyatone DS2 Sustainer. Looking at the schematic I noticed it was really similar to another Guyatone offering, HD Harmonic Distortion. The main difference is the tonestack, HD2 is scooped and SD2 is more mid focused. So this layout have a switch for both SD2 and HD2 modes. Some additional mods had to be made for more versitalty. The fixed tonestack with two 47k resistors is replaced with a 100k.potentiometer that pans bettwen a low pass and high pass filter…just like in a big muff.
