Simple home audio power amplifier circuit schematic

Here is a new audio power amplifier schematic built around TIP darlington pair transistors. You can use this circuit for home audio power amplifiers and car audio amplifiers. The TIP142 and TIP147 darlington pair transistors forms a push pull high power amplifier configuration while the two BC558 PNP transistor provides a mini audio pre amplifier circuit. The audio signal is applied to the pre amp through a capacitor, then it is coupled to the push pull power amp via TIP141 transistor. The values and ratings of different components of power amplifier design are also given in this article. Implementation cost of this mini audio amplifier circuit is too cheap, near $5. The circuit can deliver 150 W RMS to a 8 Ω (150 Watt power amplifier).
Also Read:

Circuit diagram audio amplifier

Simple+home+audio+high+power+amplifier+circuit+schematic Simple home audio power amplifier circuit schematic
Click on the circuit for enlarged view 

Components required

  1. Transistors (TIP141; TIP142; TIP147; BC558 x 2)
  2. Resistors 7 watt(0.33Ω x 2)
  3. Resistors 1 watt (3.3kΩ x 2)
  4. Resistors ¼ watt (22kΩ x 2; 220Ω; 1.5kΩ; 33Ω; 27kΩ)
  5. Capacitors 50V (100µF; 10 µF x 2)
  6. Speaker (8Ω, 150Watt)

Working of 150 watt amplifier

  • Our new audio power amplifier project is based on TIP 142 and TIP 147 (complementary darlington pair power transistors which can handle 5 A current and 100V).
  • The two PNP (BC 558) transistors forms a pre amplifier section to the preceding high power push pull amplifier built around TIP141, TIP 142 and TIP 147 darlington pair transistors.
  • We are using 2 PNP transistors to form a preamplifier section, it is nothing but a differential amplifier to improve overall performance of the amplifier. The application of a differential amplifier in the input phase reduces noise.
  • Input signal is applied to the differential amplifier section via 10µF DC decoupling capacitor. Capacitor removes the DC voltage from the input audio signal.
  • 10kΩ potentio meter is used for volume controlling.
  • Feedback voltage is applied through the 22K resistor.
  • A complementary class AB push pull power amplifier stage is built around the TIP darlington pair transistors to drive the 8Ω 150 watt speaker (The circuit can deliver 150 W RMS to a 8 Ω).
  • The diodes (1N4007) biases the complementary pair and guarantee class AB amplifier configuration.
  • Transistor TIP141 drives the push-pull pair (TIP142 & TIP147) and its base is directly connected to the collector of pre amplifier stage.
  • +/-40V, 5A dual power supply is necessary to provide supply for this simplest amplifier circuit. Use 30V-0-30V step down transformer and construct a dual lab power supply for this project.

Pinouts of TIP141, TIP142, TIP147 and BC558

Other popular amplifier circuits

16 thoughts on “Simple home audio power amplifier circuit schematic

  1. The 150W output power of this amplifier is impressive. What are the distortion and other specs of this amplifier? Can the input signal be fed from another preamp? If so, can we do away with the volume pot control? Has anyone used this in a HiFi setup and what are the comments and impressions? Sorry for so many questions. Thank you.

    • Hey Robert,
      You can use preamp with this circuit without the volume pot control. Since we’re using transistors only there’s probability of distortion.

  2. I build this and it sounds good. but when i increasing volume, 33R become very hot and get burned. please help.

  3. I built tis amp works best on low voltages up to 30 beyond which tip 142 gets red hot and short circuited. Any solution. Also it is tip41 or tip141 please clarify.

  4. With some nominal change, the circuit is now working absolutely ok at 45 volt dc. A nice and cheap circuit.recommended to be built by all interested.

      • The only changes you have to make is to replace 22k resistor with 33k resistor if you want to increase the voltage up to 85volts.This also increase the amplifier wattage from 150w to 250w

  5. In series with 3 diodes, instead of fixed 20 ohm resistor, I used a preset 100 ohm and adjusted it for 50 ma current. Circuit is working ok and fine.rest as it is.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>