18W Amplifier Schematic Circuit

18W Amplifier Schematic Circuit Part List

P1_____________22K Log. Potentiometer (Dual-gang for stereo)

R1______________1K 1/4W Resistor
R2______________4K7 1/4W Resistor
R3____________100R 1/4W Resistor
R4______________4K7 1/4W Resistor
R5_____________82K 1/4W Resistor
R6_____________10R 1/2W Resistor
R7_______________R22 4W Resistor (wirewound)
R8______________1K 1/2W Trimmer Cermet (optional)

C1____________470nF 63V Polyester Capacitor
C2,C5_________100µF 3V Tantalum bead Capacitors
C3,C4_________470µF 25V Electrolytic Capacitors
C6____________100nF 63V Polyester Capacitor

D1___________1N4148 75V 150mA Diode

IC1________TLE2141C Low noise, high voltage, high slew-rate Op-amp
Q1____________BC182 50V 100mA NPN Transistor
Q2____________BC212 50V 100mA PNP Transistor
Q3___________TIP42A 60V 6A PNP Transistor
Q4___________TIP41A 60V 6A NPN Transistor

J1______________RCA audio input socket

Power supply parts:

R9______________2K2 1/4W Resistor

C7,C8________4700µF 25V Electrolytic Capacitors

D2_____________100V 4A Diode bridge
D3_____________5mm. Red LED

T1_____________220V Primary, 15 + 15V Secondary, 50VA Mains transformer

PL1____________Male Mains plug

SW1____________SPST Mains switch

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HA 13118 bassed 18W audio amplifier circuit and explanation

This audio amplifier circuit diagram is a class AB audio power amplifier based on the Hitachi HA13118 audio integrated circuit . The Hitachi HA13118 audio amplifier circuit provide a high power output from a low voltage supply using the bridge tied load method, and a high gain of 55dB. This audio amplifier is ideal for audio applications where the input signal has a very low level .

The Hitachi HA13118 audio amplifier circuit can provide a maximum 18W power in a 4 ohms load using 18 volts DC power Supply but also can be obtained various output power : > 5W RMS on 8 ohm load using 18V DC supply , > 6W RMS on 4 ohm load using 12V DC supply .

Other specifications for this amplifier are :

S/N ratio : > 70 dB , THD <0.2% @ 1w , freq. response : ~ 30 hz to 30 khz, input level : <25 mv , input impedance ~ 30 k ohm .

For the Hitachi HA13118 audio amplifier circuit you will need a power supply that will provide a DC voltage between 8 and 18Vand at least 1 to 2 Amps.

If you want to obtain the maximum output power you will need a power supply that will provide 18 volts DC at more than 2 A , and if you will use a 4 ohms speaker .

The construction of this power supply is very simple and is require few external components .

Be careful when soldering the IC not to use excessive heat. If it’s possible use some heat sink compound between the heat sink & the IC .

If you need volume control or to attenuate the input signal you can connect a logarithmic potentiometer at the input pin .

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