TDA7377 Subwoofer circuit

The below circuit is a simple 60W RMS TDA7377 subwoofer circuit system. This is an easy to build project, it does not need much effort and expenses. The components are easy to obtain from even scraps so that you don’t need to suffer in building this project!

This circuit has two transistors amplifiers at input stage. The amplifier section which is based on C2383 NPN bipolar junction transistor (BJT) is for low pass filter and amplification. The other transistor amplifier which is base on the C2655 NPN BJT is for the treble frequencies amplification. Meanwhile, you can use any NPN bipolar junction transistor (BJT) for the two. The output of each of the transistors amplifiers’ is fed to the inputs of the TDA7377 amplifier circuit.

In this TDA7377 subwoofer circuit, the output1 and output2 which is the treble output is at 30W RMS (15W RMS each). For the subwoofer, the output is bridged at pin14 and pin15 of the IC. Hence, the subwoofer output driver is at 30W RMS. The total output of this subwoofer circuit is at 60W peak.

TDA7377 Subwoofer Circuit Components

Below is the list of the main components which constitute this TDA7377 subwoofer circuit.

Integrated Circuit (IC)
  • TDA7377 (X 1)
NPN Bipolar Junction Transistors
  • C2383 (X 1)
  • C2655 (X 1)
Electrolytic Capacitors (Polarized Capacitors)
  • 2200µF (X 2)
  • 1000µF (X 1)
  • 220µF (X 1)
  • 47µF (X 1)
  • 10µF (X 5)
Ceramic Capacitors (Non Polarized Capacitors)
  • 100nF i.e. 104 (X 1)
  • 22nF i.e. 223J (X 1)
Fixed Resistors
  • 10KΩ (X 1)
  • 3KΩ (X 1)
  • 2KΩ (X 1)
  • 100Ω (X 2)
  • 22Ω (X 1)

Mounting the IC on a heat sink is necessary for cooling it while operating. Also, you should apply thermal paste between the IC and the heat sink. This makes heat leaves the IC faster, transferring it to the heat sink.

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TDA7377 Subwoofer circuit diagram


TDA7377 subwoofer circuit

7 thoughts on “TDA7377 Subwoofer circuit”

      1. I need some clue on how and which point one can put the variable capacitor (volume) on the above project

        1. Hi, for volume control use 50K potentiometer.

          Step 1: Connect the wiper (middle pin-2) to the input point where the -ve terminal of 10uF and the other terminal of 223J capacitors met

          Step 2: Pin_3 of the pot becomes the audio input

          Step 3: Pin_1 to the ground (0V).

          That’s it!

  1. Thanks so much, I’ll inquire more incase I get stuck.
    But in the meantime, I really get some challenges in determining which terminal of the input is L, R and the ground. Some light please

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