search

delhatch / PiPod_ePaper

PiPod MP3 player with a 250 × 122 e-Paper screen
47 stars 1 forks source link

Lots of noise. #3

Open hokuto123456789 opened 1 month ago

hokuto123456789 commented 1 month ago

Hello. I just finished installing the parts, but there is a lot of noise, and the music is noisy, whether it is USB powered or battery powered. Is it a specification that there is a lot of noise? I have built two units and both are the same. Bluetooth and Wifi are off. Where can I check this to get rid of the noise?

delhatch commented 1 month ago

I have never seen this symptom, but I can think of a few things to try: 1) There are 2 ways to stuff the circuit board in the amplifier section. Double-check ensure that only ONE of the two methods has been done. See the main schematics (note in the lower right) or the attached snippet image. amp 2) Using probes or wires, hook up headphones or an amplifier to pin 6 and/or 7 of U5. This is the audio just prior to the headphone amplifier. If it sounds good there, but bad at the headphone jack, then you know there is a problem in the headphone amplifier section. Probably related to the 2 stuff options. Good luck!

hokuto123456789 commented 1 month ago

Thank you very much.

I did not notice the annotation in the lower right corner. My apologies. As it turns out, the noise is gone.

I made one TS482 type and one TPA6113 type. I modified it as shown in the annotation on the bottom right. However, at first the TS482 noise did not disappear, and the other TPA6113 still has noise but it disappeared a little.

The cause of the noise in TS482 turned out to be a broken 0-ohm resistor in R22. After replacing this, the noise disappeared.

TPA6113 also did not completely eliminate the noise, so at the last minute I changed to the TS482 specification, and the noise did not bother me as much.