Since you did the update to 10, it may not have updated the Intel chipset driver. Did you look for newer Windows 10 Intel Lynx Point (Z87) chipset driver on the Intel site? Assumed you tested the Windows 10 R2.79 driver here? The XPS 8900 uses the same sound card. You could try to install it. I am not sure if it will actually know the system model when installing but worth testing.
XPS-8900_Audio_Driver_4FY5P_WN32_6.0.1.7541_A00.EXE
9/14/15
Windows 10
Version 6.0.1.7541, A00
