V1 TRIANGLE BIG MUFF PI - This variant is from around 1970-71. Similar to the example shown above, but minor component value changes were made across the circuit. The R2 input resistor was reduced slightly to increase the signal. Clipping stage input resistors at R19 and R12 were enlarged to 12k for slightly less crunch and drive. Feedback resistors at R9/15/17 were dropped to 390k for less gain, but the collector resistors at R13 and R11 were also reduced slightly to increase the gain in the clipping stages. R5 and R8 were reduced to 22k for a more scooped mid range. The result was a smooth distortion, slightly less gain when the sustain knob was maxed, but still with a mean, deeply scooped mid range.

Note that the Silicon diodes are listed here as 1N914 but the actual diode types used are unknown. They had various markings such as SYL GD938, or SYL GY925 926, or GY819. Based on measurements, and the diodes used in later Big Muff versions, these measure about 0.5 - 0.6V, so some modern equivalents that work similarly are 1N914 or 1N4148. THIS PROJECT TAKEN BY http://www.bigmuffpage.com. I just draw pcb.