How to fix Audio Amplifier Circuit make a lot of unwanted noise in output?

Thread Starter

Jayasanka Bandara

Joined Mar 4, 2022
13
I made an mono Audio Amp using a TDA2003 and some goods using below schematic.

Schematic_Audio Amplifier Using TDA2003_2022-09-15.png
(I used an instructubles circuits using this link)

And I used an Old 6Ohm 8W TV speaker below!

20220915_211505.jpg
Finally made the circuit on a breadboard!

20220915_214632.jpg

(Blue = 12V, Green = L in (Mono), Brown = GND)
(Please don't judge the crappy breadboard wiring; Because I had a shortage of jumpers)

Then after plugging it in; this happened!

Part 1:

Part 2: Running on 5V DC

Part 3: Running on 12V DC

So unfortunately I couldn't find any solution to smooth this out. (You may hear the HDD startup and running noise clearly in Part 3; so maybe the HDD is interfering other control circuits)

The problem is that I was thinking to mount this circuit inside the PC case. (So maybe more interference with HDD)

Any solutions? Can anyone help me to fix the interference(or the noise)? Is it not mounting this in the casing good?
 

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R!f@@

Joined Apr 2, 2009
9,826
Try using an isolated PSU first and then check
And also may be ur sound card is of poor quality
Other reason could be your audio cable is not properly shielded
 
Last edited:

Audioguru again

Joined Oct 21, 2019
5,166
The TDA2003 is very old and has been obsolete for many years. Fake or defective ones might be sold mow on Asian websites.
Its audio specs show poor high frequency response, high distortion and high noise.

I heard sound "breakup" which might be the power supply having poor voltage regulation or the breadboard is causing a very high frequency oscillation since it should be an amplifier made properly on a printed circuit board.

The speaker appears to be very poor quality and maybe is overloaded by the amplifier's 2W or maybe you are turning up the volume control too high which causes severe clipping distortion.
The speaker is missing a very important enclosure so that the sounds from its rear do not come around and cancel bass sounds at the front.
 
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