This amplifier has an excellent audio quality, and use four output power transistors, it reaches a sound power of 300W RMS under load of 4 ohms, powered with a symmetric power supply. You can check the schematic diagram in Figure 2 below.

Power Supply

The power supply consists of a symmetrical transformer 45V - 0 - 45V center tape, 6 Amperes current supply, can be used. After rectified, we will have approximately 63Vcc at the output of the symmetrical power supply .

Components list

Q1, Q2, Q3, Q5 ......... C1815 NPN Transistor

Q4 .............................. A1015 PNP Transistor 

Q7 .............................. TIP 42C PNP Transistor

Q10, Q11 ................... 2SA1494 PNP Power Transistor

Q6 .............................. TIP41C NPN Transistor

D1 to D7 .................... 1N4148 diode, or equivalent diode 1N4001 

C1, C4 ......................... 2.2uF - 25V Electrolytic Capacitor   

C2 ............................... 220pF Polyester / Ceramic Capacitor 

C8 ............................... 100nF Polyester / Ceramic Capacitor 

R2, R10 ....................... 47k ohms resistor (yellow, violet, orange, gold)

R3, R5 ......................... 2.2k ohms resistor (red, red, red, gold)

R4 ................................ 270 ohms resistor (red, violet, black, gold)

R6, R7 ......................... 51K ohms - 1/2W resistor (green, brown, orange, gold)

R11 .............................. 470 ohms resistor (yellow, violet, brown, gold)

R12 .............................. 390 ohms resistor (orange, white, brown, gold)

R13, R14 ..................... 100 ohms - 2W resistor (brown, brown, black, gold)

R17, R18 ...................... 6R8 ohms - 1W resistor (blue, gray, gold, gold)

R15, R16, R19, R20 .... 100 ohms - 1W resistor (brown, brown, black, gold)

R21, R22, R23, R24 .... 0.33 ohms - 5W resistor (orange, orange, gold, gold)

R25 .............................. 22 ohms resistor (red, red, black gold)

R26 .............................. 10 ohms - 1W resistor - (brown, black, black. gold)

P1, P2 ........................... 2 Pin - PCB Terminal Blocks - EK500V-XXP 20A - or equivalent

P3 ................................. 3 Pin - PCB Terminal Blocks - EK500V-XXP 20A - or equivalent

L1 ........................ 5uH - Air Core Coil 10 Turns 18AWG, 3/8" Core

Others ........................... Loudspeaker, Wires, Solders Etc.