This is a reproduction of the ultra-rare Electro-Harmonix Pulsar tremolo pedal from the late 70s.
Some changes have been made to the factory schematic, namely:
1) The opamp has been replaced with a readily-available dual opamp with standard pinout.
2) The 33uF capacitor and bypass switch have been removed in anticipation of true bypass wiring
3) Two parallel resistors have been replaced with a single resistor of equivalent value.
This layout is verified and known to work.