Push-Pull Stereo Headphone Amplifier

What is introduced here is a stereo amplifier that can drive low-impedance headphones. It uses only one stage of preamplification and an NPN-PNP complementary push-pull amplifier circuit to drive the headphones.

The pre-stage is composed of transistors T1 and T6, which are used for left and right stereo input. The left channel signal is amplified by T1 and sent to push-pull stages T2 and T3, which then drive the left headphone. Similarly, the right channel signal is amplified by T6 and sent to push-pull stages T4 and T5, which then drive the right headphone.

The circuit has an output power of 100mw~200mw when using 6v-12v power supply voltage. Due to the extremely low power consumption, the circuit can be powered by a 9V-PP3 battery.