I have Dell Vostro 3900 with Win 8.1 OEM Home and after upgrading to Win 10 most of Dell Audio settings are gone (I can configure only sound and mic volume). No equalizer and default sound is very primitive (i want bass and padded cell effects). Also i can not find any Win 10 driver/software updates in the Dell Support section.
Don't tell me about downloading the off-driver from Realtek site, because your Dell-build hardware was modified and isn't fully compatible with the original drivers.