I was writing not enough data to SD card. It turned out that half of data was cut off. After tune the SD service up my record sounds as expected.

You were right, I was writing not enough data to SD card. It turned out that half of data was cut off. After tune the SD service up my record sound as expected. Thanks a lot Norman for pointing me out the direction of investigation. =)

Thank you for reply. I will try to play with SD card service. I'll share results if I manage to make the record to sound clean.

Hi Som,Did you manage to fix the problem? Seems like I have the same problem with a software for my custom board. I use same configuration and get understandable but distorted sound.

Hi Norman,It seems that we have exactly the same problem. Did you manage to solve it? How did you cut off the noise? What configuration for channels and filters did you use?