15 Watt Amplifier
Circuit : Sergio García de Alba Garcin from Guadalajara,
Mexico
Email: turboman80@hotmail.com
Description:
A 15 watt amplifier made using discrete
components. Sergio designed this circuit for his Electronics Level II
course.
Notes:
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
(Q2,Q4) and (Q7,Q11). The last two transistors are power Transitors,
specifically the 2N3055 and MJ2955. The 7.02K resistor, R16 was made using a
series combination of a 4.7K, 680 Ohms, and two 820 Ohms. The 1.1K resistor, R3
was made using a 100 Ohms and a 1K resistor. You can use this circuit with any
walkman or CD player since it is designed to take a standard 500mv RMS
signal.
Sergio García de Alba Garcin
Guadalajara, Mexico
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