Abstract: A Class B push-pull amplifier designed for use at low supply voltages (e.g. 1 to 2 volts) wherein complementary push-pull output transistors T.sub.3, T.sub.4 are biased by a biasing chain consisting of resistor R.sub.1, transistor T.sub.1, resistor R.sub.2, transistor T.sub.2, resistor R.sub.3, with the signal to the bases of T.sub.3, T.sub.4 being supplied from opposite ends of R.sub.2. The value of R.sub.2 is twice that of R.sub.1 and R.sub.3. The circuit is preferably used in a bridge configuration with a second similar amplifier set at unity gain driven from the first amplifier. It may be used to power the loudspeaker of a miniature radio receiver.