Hello fellas, I have a little problem over there. While playing audio from arduino due SD card module, I get periodic noise, like pulsing, maybe yu know what could be a problem? I unsoldered dc dc module and connected power from 230/12 transfomer directly to lm7805, but noise stayed the same, maybe its 230/12 transformer causing distortions? thank you for answers, I attached my schematics and photo of my project to imagine how it looks like.
