I'm trying to make a small audio amplifier using a TDA2822 stereo amplifier. It is working as expected, but it has some noise that will make you not hear the audio when I increase the volume on my phone connected to it through the earphone jack.

Why is it oscillating the noise when I increase the audio volume to about 30 percent upwards but I can hear it clearly when the volume is below 30?

Here is my circuit:


I tried adding a pull-down resistor to both input and output and it is still the same. I tried reducing the output capacitor value, but still get the same results.

Advise needed on how to get rid of the high output noise.

  • 2
    \$\begingroup\$ The TDA2822 isn't an op-amp. Do you have a picture of your layout? The datasheet shows 10 uF for decoupling located right on the supply pin of the device. Do you have a picture of your layout? You may need a resistor from the + input to ground to supply bias currents (again as shown in the datasheet). \$\endgroup\$
    – John D
    Commented Jan 13, 2023 at 19:15
  • \$\begingroup\$ I edited OP's text to correct from op-amp to audio amp. \$\endgroup\$ Commented Jan 14, 2023 at 2:47
  • \$\begingroup\$ Joseph, if we are done here, please take note of this: What should I do when someone answers my question. If you are still confused about something then leave a comment to request further clarification. \$\endgroup\$
    – Andy aka
    Commented Aug 18, 2023 at 10:43

1 Answer 1


What you have designed isn't what is shown in the data sheet. They typically show a connection (two channel) like this: -

enter image description here

  • You have used a capacitor on the non-inverting input when it needs a pull-down resistor
  • You have used a pull-down resistor on the inverting input when it needs a capacitor.
  • The data sheet also shows a Zobel network on the output, yours has none
  • You have used a 1 μF supply decoupler whereas the data sheet shows a 10 μF

These are all significant differences but, you could have made other notable "audio-amplifier" errors in how you wired your power source to the IC.


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