Reverberator adjustements for proper functionality: Before we connect the power supply, extract IC2 and IC3 from its base and adjust the potentiometers to middle position. On one of IC2 or IC3 entries connect a frequency-meter and/or oscilloscope. On oscilloscope monitor will be visualized the rectangular pulses with point to point amplitude equal to power supply voltage and a space factor of 1:1. The frequency of this pulses is adjusted with P3 between 3 and 18kHz. Check that voltage value on IC2 pin 5 is 7.5V dc. Disconnect the power supply, reconnect IC2 and IC3 and reconnect the power supply. Connect the oscilloscope to IC1.3 pin 8 and adjust P1 and P2 to ground. Apply a 200Hz, 1.5Vrms sinusoidal signal at the reverberator input . Adjust SR1 untill you obtain the best sine wave on the oscilloscope. Apply a 200Hz, 1Vrms sinusoidal signal at reverberator input. On IC1.4 pin 14 connect a multimetero or oscilloscope and adjust SR3 untill the overdue signal amplitude reaches 2Vrms.