Headphone plug & Dac (x86)

Volumio Information

Volumio Version:2.882
Hardware: Raspberry Pi 3B
DAC:Digione Signature

I’ve build a Mediacenter in an ITX-Case and put a headphone socket in the front .
But when I connect the 3,5 mm plug with the rasberry , the Dac switches off .
Is it somehow possible that both will work .