Categories: Audio

Small Audio Booster

Here the simple, low cost and easy audio booster circuit. It uses a transistor of 2N3392 ad the main amplifier.

Component List:

R1 = 47K
R2 = 470K
R3 = 10K
R4 = 560R
R5 = 270R
C1 = 0.1uF/25v
C2 = 3.3uF/25v
C3 = 470uF/25V
P1 = 100K
Q1 = 2N3392
D1 = 5mm. Red Led
B1 = 9v Battery
J1 = RCA Audio Input Socket
J2 = RCA Audio Output Socket
S1 = On-Off Switch

This small audio booster circuit has a maximum gain of around 22 dB (voltage gain). The frequency response of the amplifier is decided primarily by the value of just a few components, primarily C1 and R1. The values within the schematic design present a response of ?3.0 dB from about 120 Hz to higher than 20,000 Hz. In fact, the frequency response is ruler flat from about 170 Hz to more than 20,000 Hz; it is the low end that deviates from a flat frequency response.

The low end’s roll-off is mainly a function of capacitor C1 (considering that RI’s resistive amount is fixed). If C1’s value is changed to 0.1 pF, the low end’s comer frequency-the frequency at which the low-end roll-off starts-is decreased to about 70 Hz. Should you need an even deeper low-end roll-off, modify C1 to a 1.0 pF capacitor; if it is an electrolytic type, make certain that it is installed into the circuit together with the appropriate polarity, with the positive terminal linked to Q1’s base terminal.

Take note that you must connect this small audio booster circuit before the power amplifier circuit.

circuit schematic

Share
Published by
circuit schematic

Recent Posts

Switched ON Bike Lamp

Do you have a bicycle..? why don't try to build this circuit..?. Powered using battery…

55 years ago

3A Switching Power Supply Regulator

This is the circuit diagram of 3A switching power supply regulator: Simple and cheap, the…

55 years ago

Remote Control Tester

Here is the remote control tester circuit. This circuit is really a simple and easy…

55 years ago

Current Output Multiplier for 78xx Regulator

This is the circuit diagram of current output multiplier designed for regulator IC LM78xx. By…

55 years ago

4 Transistor FM Tracking Transmitter

The following diagram is the FM tracking transmitter based on 4 transistors. No additional notes…

55 years ago

White Line Follower

This is the circuit diagram of white line follower toy. The actuator of the toy…

55 years ago