Build a 60-dB Range Compressor For Audio

A 60-dB Range Compressor circuit shown in the schematic diagram below can produce consistent output of 1.4V P-P over entire 60dB range that is very useful for audio level/volume stabilization.  As the main components, this circuit uses a 741 opamp and JFET. With input range of 20mV to 2oV, this circuit has delay time of 0.4s (decay time)  and response time of 1.2ms (attack time). The JFET is used as  voltage-controlled resistor in peak-detecting control loop of 741 opamp. Here is the schematic diagram of the circuit.

 A 60-dB Range Compressor schematic diagram