18W Audio Amplifier

This is an audio amplifier which gives 18w. so you can enjoy with this..I have tested this so you will be able to get maximum results






Amplifier parts:

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



Notes:

* Can be directly connected to CD players, tuners and tape recorders. * Do not exceed 23 + 23V supply. * Q3 and Q4 must be mounted on heatsink. * D1 must be in thermal contact with Q1. * Quiescent current (best measured with an Avo-meter in series with Q3 Emitter) is not critical. * Adjust R3 to read a current between 20 to 30 mA with no input signal. * To facilitate quiescent current setting add R8 (optional). * A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of J1, P1, C2, C3 & C4. Connect C6 to the output ground. * Then connect separately the input and output grounds to the power supply ground.


Technical data:

Output power: 18 Watt RMS into 8 Ohm (1KHz sine wave) Sensitivity: 150mV input for 18W output Frequency response: 30Hz to 20KHz -1dB Total harmonic distortion @ 1KHz: 0.1W 0.02% 1W 0.01% 5W 0.01% 10W 0.03% Total harmonic distortion @10KHz: 0.1W 0.04% 1W 0.05% 5W 0.06% 10W 0.15% Unconditionally stable on capacitive loads