Hello fellow forum users. I built a LM386 amplifier based on a MP3 amplifier kits instructions for use in a small stereo system consisting of dead reused CD drives. ass the thread title says my amp does not do what its supposed to do. one of my suspects is the L7805 voltage regulator circuitry i put on the same board as to save space inside the CD drive. the values of the capacitors are as follows:
C1: 10V 3300uF
C2: 16V 6800uF
C3: 400nF

 

Where does the LM386 get its power from?
If it is from the 12V, where does the 12V come from?
What components do you have connected to the LM386?
Do you have the zobel network connected across the speaker?
This is the example circuit from the LM386 datasheet:

 

You need to describe the noise you are hearing.
Audio amplifiers will emit mains hum if powered from an AC mains power supply. You need to filter the power supply heavily to remove AC ripple.

 

Where does the LM386 get its power from?
If it is from the 12V, where does the 12V come from?
What components do you have connected to the LM386?
Do you have the zobel network connected across the speaker?
This is the example circuit from the LM386 datasheet:
View attachment 138466

The LM386 gets its power from a 12V SeaSonic Power supply thats decently filtered.
Also, it seems i left out the zobel network.

You need to describe the noise you are hearing.
Audio amplifiers will emit mains hum if powered from an AC mains power supply. You need to filter the power supply heavily to remove AC ripple.

the noise is less like mains frequency and more like a strong loud hum that disappears when the switch terminals of the potentiometers are touched.

 

Also, it seems i left out the zobel network.

Stick that in and see if it helps. The LM386 does tend to turn into an oscillator rather than an amplifier without it.

 

I added it, but it still doesnt do its job as an amplifier

 

Can you give us clear pictures of both sides of the board, please.

 

i also rebuilt the board and rearranged everything a bit and replaced some components.

 

and here are some pictures of the board