Abstract: An output stage with automatic level control for power line signalling, including a controlled amplifier (F.sub.1) and a feedback circuit for sensing the output voltage (V.sub.0 +V.sub.0) of the output stage and for supplying a control signal (v.sub.4) to a control input of the controlled amplifier (F.sub.1). The feedback circuit includes a comparator (K) for comparing an alternating voltage (v.sub.1) which is responsive to the alternating voltage component (v.sub.0) at the output stage and which is furthermore superposed on a first direct voltage (V.sub.1) with a second direct voltage (V.sub.2). As control signal to the controlled amplifier (F.sub.1) there is utilized the voltage (v.sub.4) across the capacitor (C.sub.4), the voltage of which increases or decreases in response to the comparison result of the comparator (K).