Humming noise when Playback is paused

Hi all. I'm using a Hifiberry DAC+ on picoreplayer. I always expierienced a humming noise before Playback starts or seconds After Playback is paused. Been using an old Version until this week. then I upgraded to the latest Version. now the hum starts After 10 seconds of Pause, before it was After 5 seconds. I found out that this is probably due to Power Management settings that turn off the dac+ when not playing. I tried an advice from this forum with creating a conf file under modprobe.d but this didnt Work. Can you help me to get rid of the Power Management and thus the annoying hum? Thanks