Browse over 10,000 Electronics Projects

Portable Headphone Amplifier by BC337,BC327

Portable Headphone Amplifier by BC337,BC327

An interesting upgrade for this circuit was suggested by Mike Baum, NY USA. This involves the use of a Lithium Ion Prismatic Rechargeable 340948 Battery, featuring a nominal voltage of 3.7V and a current rating of 1200mAH.

R1_____________10K 1/4W Resistor
R2____________100K 1/4W Resistor
R3_____________68K 1/4W Resistor (see notes)
R4______________1K5 1/4W Resistor
R5______________3K3 1/4W Resistor
R6____________330R 1/4W Resistor
R7______________4K7 1/4W Resistor
R8______________2R2 1/4W Resistor


C1______________1µF 63V Polyester Capacitor
C2____________100µF 25V Electrolytic Capacitor
C3____________470µF 25V Electrolytic Capacitor

Q1____________BC239C 25V 100mA NPN High-gain Low-noise Transistor
Q2____________BC337 45V 800mA NPN Transistor
Q3____________BC327 45V 800mA PNP Transistor

J1____________Stereo 3mm. Jack socket

SW1___________SPST Switch

B1____________3V Battery (two 1.5V AA or C cells in series, but see Notes)

Visit Here for more.