What operating system are you running, and what is the model number of your processor?
Windows 10 x64
S1366 i7 920 2.67 Ghz
Windows 10 is not a supported O/S for this board. The last supported O/S was Windows 7. Microsoft provides compatibility drivers to support older hardware on Windows 10. The coverage is pretty good, but there are misses here and there and this may be one of them.
You could try manually installing a Windows 10 driver from Realtek and see if it contains support for the old CODEC used on the DX58SO. Here is one such driver you could try: Download Realtek* High Definition Audio Driver (64-bit) for Intel® NUC DN2820FY and DE3815TY.
Hope this helps,