KOMPANDERKRETS

In a circuit for the automatic dynamic compression or expansion of a signal between its input and its output, the circuit presenting a useful signal path connected between its input and its output and connecting a first variable gain member which is electronically controllable for varying the transmission factor between the circuit input and output, the circuit also presenting a branch path connected at one point to the useful signal path and containing a second variable gain member which is electronically controllable for varying the transmission factor exhibited by the branch path, and a control voltage generator for generating a control voltage applied to control the variable gain members for effecting a counterregulation of the transmission factor of the branch path, relative to the transmission factor variation imparted to the useful signal path, there is further provided a combining circuit which receives the output signal from the second variable gain member and a signal proportional to a signal at a point in the useful signal path and which applies to the control voltage generator a control signal dependent on the difference between the signals received by the combining circuit.