Just built the k8095 MP3 player and the sound is very low and full of static. All voltage readings seem to be fine. 3.3V and 5V from the regulators, 12V from the amplifier, 0V on pin 5 with the SD in and 3.3 without, and 3V at the decoder. The sound is the same with the headphone and RCA output.
Is the sound equal on both channels?
If not yet done, please try with other brand SD card.
The sound is equal. I have also tried two different SD cards with the same result. The sound is so low that I have to concentrate to hear it through the static. Because I can at least hear the music the decoder must be doing its job, which makes me think its the amplifier. I there a way to test the amplifier with a multimeter?
[quote]I there a way to test the amplifier with a multimeter?[/quote]The only you can do is to check the voltages on the amplifier pins.
The results may indicate possible problem.
Here are the voltages on the amplifier pins:
1: 2.1V
2: 0V
3: 5.8V
4: 5.8V
5: 0V
6: 5.8V
7: 12V
8: 12V
9: 2.1V
You can use the middle connector of the speaker terminals as ground reference.
I’m getting
- .86 v
- 0v
- .6v
- .73v
- 0v
- .85v
- 12v
- 12v
- .86v
Pin 1 and 2 of the decoder has 1.2 v
C22 and 23 have .8v on the + legs
Is the amplifier oriented so that the notch on the IC matches the notch on the silkscreen?
yes the notch is correct, the text on the amplifier is facing the same as the decoder
OK
It seems the amplifier may be defective.