Proa

12 V AUDIO AMPLIFIER WITH TRANSISTOR ELECTRONIC DIAGRAM

In use, R9 should be carefully adjusted to provide minimal audible signal cross-over distortion consistent with minimal measured quiescent current consumption; a good compromise is to set the quiescent current at about 10-15 mA.To measure this current, wire a DC current meter temporarily in series with the collector of Q3.

List Component

• P1_____________10K Log.Potentiometer
• R1,R2__________33K 1/4W Resistors
• R3_____________33R 1/4W Resistor
• R4_____________15K 1/4W Resistor
• R5,R6___________1K 1/4W Resistors
• R7____________680R 1/4W Resistor
• R8____________120R 1/2W Resistor
• R9____________100R 1/2W Trimmer Cermet
• C1,C2__________10µF 63V Electrolytic Capacitors
• C3____________100µF 25V Electrolytic Capacitor
• C4,C7_________470µF 25V Electrolytic Capacitors
• C5_____________47pF 63V Ceramic Capacitor
• C6____________220nF 63V Polyester Capacitor
• C8___________1000µF 25V Electrolytic Capacitor
• D1___________1N4148 75V 150mA Diode
• Q1____________BC560C 45V 100mA PNP Low noise High gain Transistor
• Q2____________BC337 45V 800mA NPN Transistor
• Q3____________TIP31A 60V 4A NPN Transistor
• Q4 ___________TIP32A 60V 4A PNP Transistor
• SW1___________SPST switch