120W Power Amplifier + Power Supply

This is 120W power amplifier schematic using TO-3 package complementary transistors, NPN and PNP polarity. The well-known power transistor pair of 2N3055 and MJ2955 used in this circuit.  +/- 50V symmetrical (split/dual polarity) power supply with minimum 3A electric current should be used for maximum performance.

20W Power Tube Amplifier with EL34

The following diagram is the circuit diagram of 20W power amplifier which build based tube component EL34. EL34 is very famous tube and great for power tube amplifier. The circuit above is complete circuit contains tube amplifier circuit diagram and power supply circuit diagram. To make the stereo channel amplifier, build the similar amplifier circuit… Read More »

20W Hi-Fi Power Amplifier with TDA2040

This is a 20W Hi-Fi power amplifier circuit build based on single power amplifier IC TDA2040. The single TDA2040 has able to deliver 20W power output. The bridge amplifier which consist of double TDA2040 can deliver 30W power output (8 ohm loudspeaker). About power amplifier IC TDA2040: The TDA2040 is a monolithic integrated circuit in… Read More »

Variable / Adjustable DC Power Supply 1.2V – 25V using LM338K

This is variable DC power supply circuit, or we can call it adjustable DC power supply which give us a 1.2V-25V output voltage. The power supply schematic above is taken from the datasheet of regulator LM338K manufactured National Semiconductor. The circuit uses IC LM338K as the voltage regulator, so we will get the stable and… 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 »

0-24VDC Digital PIC Power Supply

This is 0-24VDC digital PIC power supply circuit. This variable power supply controlled with PIC microcontroller. There is LCD display in this circuit which will show the actual value of power supply output. This power supply use push on switch to adjust the output voltage and current value. Schematic Diagram: Component List: C1 = 2000uF… Read More »

25W Hi-Fi Audio Amplifier based LM1875

Here the circuit diagram of 25 watt Hi-Fi (high fidelity) audio amplifier that build based on single power amplifier IC LM1875 that should be run using heatsink attached on its. Components List: R1 _____________ 1K R2 _____________ 1M R3 _____________ 22K R4 _____________ 10K R5 _____________ 180K R6 _____________ 1R IC1 ____________ LM1875 C1 _____________… Read More »

25W HiFi Audio Amplifier with MOSFET

This is high fidelity, high quality 25W HiFi audio amplifier circuit delivers great audio performance. You don’t need pre amplifier circuit for this design since it can be directly connected to the input devices such as computers, phones, radios, TVs, etc. Component list: R1,R4 = 47K 1/4W Resistors R2 = 4K7 1/4W Resistors R3 =… Read More »