Hi, 
I recently purchased a nuaudio sound card in hopes of having better sound for music and gaming. my issue is i can't use headphones.  I get no sound when plugging in the 3.5 mm jacks into the card. if i want to use my headphones on my computer i have to disable the sound card even though i'm plugging my headphones into the green and pink jacks on my computer. My system is a new build i'm using a evga Z390 FTW motherboard, navidia GTX1060 graphics card, evga 280x140 closed loop cooler, I7-8700k coffee lake 3.7 Ghz processor, 48 gig 3200 Mhz DDR5 memory on windows 10. I'm using a 850 watt power supply as well. I currently have my desktop speakers plugged into the larger jack adapter not the RCA one. i also cant use the default program that comes with the card. i do have a second program that does work but the original application program errors out upon opening with the message " the request was aborted: could not create SSL/TLS secure channel."  any help would be greatly appreciated. 

if i want to use my headphones on my computer i have to disable the sound card even though i'm plugging my headphones into the green and pink jacks on my computer.

Where are these green and pink jacks? And what are they connected to?

It sound like you are connecting your headphones to your motherboard's onboard sound. If you are using your motherboard's onboard sound, why did you buy a sound card?

You should not try to use 2 sound cards at the same time. You should remove the nu audio card, or uninstall and disable the onboard sound card.

Their may be an option to disable the onboard sound card inside your motherboard BIOS. If not, you can right-click the onboard sound card in Windows Device Manager and select "disable". Either way, right click it in Windows Device Manager and click "uninstall" first.