You can use this circuit with any walkman or CD player since it is designed to take a standard 500mv RMS signal. A 15 watt amplifier made using discrete components. Sergio designed this circuit for his Electronics Level II course. This amplifier uses a dual 20 Volt power supply and delivers 15 watts RMS into an 8 ohm load.
Q1 operates in common emitter, the input signal being passed to the bias chain consisting of Q8, Q9, D6, D13 and D14. Q8 and Q9 provide a constant current through the bias chain to minimize distortion, the output stage formed by a discrete darlington pair