Abstract: An amplifier comprising at least one emitter-coupled transistor pair with a signal source connected in the emitter line. Amplifier non-linearities mainly caused by the second harmonic are compensated by supplying the base of at least one of the transistors with a compensation signal of suitable phase that is derived from either the input or the output signal of the amplifier. This results in a multiplication process which produces a second harmonic in the collector current of the two transistors which, with the correct phase of the compensation signal at the input, exactly compensates the second harmonic caused by the amplifier non-linearity. If the transistor pair is used for gain or volume control, the direct voltage between the bases of the two transistors, and the compensation signal, will both be varied.

Abstract: The circuit arrangement in accordance with the invention comprises an RC-element, to which the same direct voltage is applied as the amplifier. When the direct voltage is switched on or off the capacitor is either charged or discharged, the resulting oppositely directed voltages being applied to the anti-parallel base-emitter junctions of two transistors, whose collectors are interconnected. The collector voltage of these transistors serves to control a semiconductor switch included in the audio frequency branch.