Boss SD-1 Mods
Boss SD-1 Mods - Free:
Boss SD-1 Blanket Modification:
Here is a simple mod. Locate C6. Either clip it off or de-solder it. If you de-solder it, you can put it back if you don't like how it sounds. Doing this will "open up" the pedal and make it sound smoother. If you like how it sounds, you can put C6 on a DPST switch and switch between normal SD-1 and the clipped C6 SD-1.
Boss SD-1 Bass Modification:
The input capacitor [C3] is only .047uF and can let only a certain amount of bass into the circuit; for more bass up it to a .1uF capacitor. - Submitted by N. Williams