For controlling the level of electrical signals a circuit arrangement is formed with two series connected amplifiers. A first amplifier containing a first variable resistor, operates at maximum amplification when a low input signal level is received. A second amplifier comprises a series connection of a second variable resistor and a current-controlled voltage source with two complementary outputs. The outputs of the voltage source are connected to a comparator and a controller with two separate outputs. One of the controller outputs transmits a control signal while the other output simultaneously transmits a blocking signal. A first output of the controller is connected with the first variable resistor, while a second output of the controller is connected to the second variable resistor.