Friday, March 12, 2021

Simple 3 Transistors Power Amplifier push a 600W RMS Subwoofer + PCB

Fig. 1 - Simple 3 Transistors Power Amplifier PCB

This is a simple amplifier that uses only 3 transistors, and has the ability to push a 600W RMS Subwoofer speaker with great mastery.

The circuit is quite simple, and easy to assemble, we took this circuit from our Brazilian partner FVM Learning, and this is their direct link

This mini amplifier was tested in two stages, one with 24V, with a non-symmetrical power supply, and in 30V also with non-symmetrical power, the result you can watch in the original video at the end of this post.

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The Amplifier Circuit

The amplifier circuit is very simple to be arranged in figure 2 just below, it is divided into two stages: 

  • The first stage is the pre-amplification and at the same time used as a drive to boost the output stage. It is formed by a transistor medium power the BD139, which supports a voltage of up to 80V and a current of 1.5A with 12.5 W of power, according to the Datasheet of the same.

  • The second is the power stage, which is formed by the complementary transistors NPN - 2SC5200 and the PNP - 2SA1943 transistor, with 100W of power and high fidelity, whose collector current supported is 15 Amps.
Fig. 2 - Simple 3 transistors Power Amplifier schematic diagram


Place the power transistors in a heat sink, especially if you are going to apply a voltage greater than 20V and use the amplifier continuously, they will heat up.

Component List

  • T1 ---------- NPN 2SC5200 Power complementary transistor
  • T2 ---------- PNP Complementary Power Transistor 2SA1943
  • T3 ---------- NPN BD139 transistor

  • D1, D2 ----- Diode 1N4007

  • C1 ---------- Electrolytic capacitor 2.200uF - 63V
  • C2 ---------- Electrolytic capacitor 4.7uF - 25V

  • R1, R2 ----- Resistor 0.22 ohms - 5W - (red, red, silver)
  • R3 ---------- Resistor 1k ohms - (brown, black, red)
  • R4 ---------- Resistor 100k ohms - (brown, black, yellow)

  • P1 ---------- 10K ohm potentiometer

  • Others ----- Wires, Welds and Etc.

Watch the original video of the FVML channel of the tests, and the assembly step by step, and be surprised !!!!

We are offering to download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.

Direct link to download

Click in the link below to download the Files: PCB Layout, PDF, GERBER
Click Here!!!

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

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My Best Regards!!!


  1. hey!!!! All files are missing!!! Please re send me the files!!! [email protected]

    1. Hello @MARTIN LUCERO
      The link has now been repaired.
      It may already be downloading the files.

  2. Can this really push 600w? Usually for 2 power transistors it's about 100w..


      This amplifier doesn't have 600W output, it's impossible to do that with two transistors.
      The title says it pushes a 600W Subwoofer.
      In our tests, the maximum we got was 90W.
      It's a great entry-level amp to build.