SanDisk Speaker Dock hiss when power turns on

Whether it is using wall socket power or battery power, hiss is audible through speakers. SDAMX-SPD 10 months old.  Any ideas to fix will be appreciated.

Are you sure the hiss isn’t in the files? What format and bitrate are the files?

Do you hear the hiss when listening to the player using headphones?

With the speakers connected, do you hear the hiss only while music is playing, or do you also hear it when the music is paused? 

If you plug the speakers into a different source, do you also get the hiss when playing music?

Hi Shelley, just curios on this. Would be nice if you can try all the steps that was given just for us to isolate the issue.