This circuit is a pure Class-A headphone amplifier featuring an NPN/PNP transistor pair emitter follower output stage. This push-pull Class-A design makes it possible to gain an improved output driving capability. It gives an output power of about 400 mW(rms) into 32 Ohm speakers. The single voltage gain stage allows the easy implementation of a parallel-feedback circuit that is giving perfect frequency stability.
The circuit is powered directly from the mains. It has a power on LED indicator.
BD136 PNP transistor, BD135 NPN transistor and 7805 voltage regulator requires heatsinking.
If you want to use this amplifier in stereo mode, you must double all the component except P1, IC1, R14, D1, D2, D3, C8, T1, SW1, SW2, J2 and PL1.
The tilt control allows three modes of operation. This operation modes are explained in the original circuit page.
Read More: redcircuits.com/Page136.htm