Input generate high volume white noise on adau1701 board

Hello!

I am so far a beginner in DSP designs and currently in the process of designing a DSP board. However, I have come across a strange noise problem as following:

I have an ADAU1701 board whit a mono output and a 3.5mm cable as input. It is programmed in sigma studios whit inputs straight to the output.

1. When the cable is not connected I have no sound and no noise. Which should be normal for a working DSP.

2. When I tap the 3.5mm cable whit my finger I get the normal low-frequency sound you get from a speaker. Which is expected and tells me that the DSP is working.

3. When I plug it into anything I get a white noise that is independent of what is playing or at what volume(the music is playing clearly in the background). This noise also appears when I just plug the 3.5mm to lightning adapter, without anything else than the adopter connected to it. This noise quite high in volume. It seems to be something related to the signal input. I wonder if anyone has any experience with this type of problem.

4. I tried subtracting the signal from itself and got complete silence. This I think is also an indication that the error is related to the input.

As I really feel stuck I would greatly appreciate it if someone can point me in the right direction! I attach my schematic which is based on the reference design.

Best regards and happy holidays!
Markus Nilsson

Audio Signal Processors

SigmaDSP Audio Processors

white noise

adau1701