Amplifier stage with low thermal distortion

Amplifier stage for audio signals, comprising at least one module presenting a first transistor, of first semiconductor type, the base of which constitutes an input terminal for an input signal and a means to maintain an appreciably constant current in the collector-emitter path of the first transistor, and including a feedback circuit (T.sub.3, T.sub.5) that provides a main current path between the active terminal (S'.sub.1) of the stage and the emitter to the first transistor (T.sub.1, T.sub.10);

• characterized in that said means consists of a first current source (I.sub.3), connected to the collector of the first transistor (T.sub.1) and in that the feedback circuit is connected so that the value of said main current is a function of the difference between the voltage (V.sub.3) of a reference-voltage source and the potential (VCT.sub.2) of the collector of the first transistor (T.sub.1);
• the feedback circuit gain is selected such that the potential at the collector of the first transistor (T.sub.1, T.sub.10) is appreciably constant and the voltage (V.sub.3) of the reference-voltage source is independent of the supply voltage and is selected in order that the first transistor (T.sub.1) function with an appreciably constant collector-base voltage.