35W Power Audio Amplifier based LM391

Here the 35W power audio amplifier circuit based on LM391. Inductor L1 is constituted by 20 coils of wire, with thickness 0.9mm, round resistor R16. The transistors Q3-4 are the final amplification section, it should be placed on heatsink. If are used the Q3-4 in packing TIPxxxx they can be placed straight above in PCB.… Read More »

Car Audio System Anti Theft Security

This is the circuit diagram of car audio system anti theft security which can be effectively used to protect and secure your expensive car audio system from stealing. This simple circuit designed based on popular CMOS NAND chip CD4093,. When the circuit is switched on via switch S1, the indicator LED1 will glow and the… Read More »

Stereo Tube Amplifier 4 Watts

This is the circuit diagram of stereo tube amplifier using 6SQ7-GT and 6V6-GT. The tube amplifier circuit is uses the total of 5 power vacuum tube. The diagram is based on the output section design of typical late 1940’s old AM Trutone radio with 6 tubes. The output will be 4 Watts per channel (2x4W… Read More »

20W Bridge Amplifier using TDA7240A

This is a simple 20W bridge amplifier based on TDA7240A. This circuit is designed for car audio system, but you may use this circuit for your small home audio application… 🙂 . Schematic Diagram: This circuit operated with 18VDC asymmetrical power supply (positive (+) and ground only). Mount the power IC on a heatsink to… Read More »

TDA7381 4 x 25W Quad Audio Amplifier

The following is 4 x 25W quad audio amplifier circuit (amplifier with four inputs and four outputs) based TDA7381. This amplifier is designed for car audio system, but you can also use this circuit for other purposes. This circuit has a design very simple and very easy to build. Schematic diagram: If properly layouted and… Read More »

TDA7383: 4 x 35W Quad Bridge Amplifier

Here is the circuit diagram of 4 x 35W quad bridge amplifier. This is a power amplifier that has four input channels and four output channels or commonly called the quad amplifier. Power amplifier is designed specifically for car audio system applications. With a fairly large output power per channel, low distortion and low output… Read More »

50W Power Amplifier with STK-1050

This is the circuit diagram of  50W power amplifier based on audio power amplifier IC STK-1050. Symmetrical power supply used to operate this circuit with maximum voltage rated at 53V and recommended supply is 36V. This is a single channel (mono) amplifier circuit, for stereo audio system, you should build two similar circuit. Power supply with… Read More »

2 x 5.8W Stereo Power Amplifier with KA2211

This is a stereo power amplifier based on Samsung IC KA2211. With single chip, this circuit will deliver stereo output channel up to 5.8W on each output channel. The circuit can be supplied with general purpose power supply. KA2211 is a dual audio power amplifier for consumer application. It is designed for high power, low… Read More »