According to the schematic the maximum output is 1.4 Volts peak to peak as a sine wave. These signals are then fed off to the filter boards, left and right where they are also getting transferred from analogue to digital before being sent to the microprocessor. Essentially they are the signals dictating the position of the imbalance from the reference input. At this level I think the 3 Volt spec is understandable and all the other units have those capacitors. I'm still intrigued as to what effect a different value of capacitance might have had on the output that someone had fitted with the 125uF @15 Volts capacitor. I presume there would be an effect on the lead or lag of the signal??