Dynamic compressor – passive components, no power supply

This dynamic compressor with passive components reduces high signal to a lower, more constant signal. If you look at this compressor schematic , you’ll notice it has no power supply, the required power is obtain thru the output signal.
If you respect the schematic values this audio compressor will output a constant 70mV when the input voltage is between 100mV and 10V !

Passive compresor circuit diagram