Noise when using stereo phono jack on CoinStation (STEVAL-BCNST01V1) board

[PPeer.1]

I use the Bluecoin starter kit to steam the audio by STSW-BCNKT01 software.

when using the micro-USB port to connect the PC the output signal does not have a noise signal but using a stereo phono jack port to connect the speaker the output signal has a noise signal.

I tested the speakers by having them turn on the music. it hasn't a noise signal.