Windows 8 on Dell Latitude D630: Sigmatel/IDT sound drive

I have a Dell Latitude D630 and Windows 8. The generic Windows sound driver made the sound for the laptop run, but not with the docking station. I installed the Sigmatel drivers for Windows Vista 32bit. They also worked for me on Windows 7. First, they didn't wanna install, but then I made a BIOS update from Revision A03 to A18 and it solved the problem. Now again I have sound for the laptop, but when connected to the docking station the following happens:
When I set the normal speakers as output: Sound starts to play through the speakers connected to the docking station, but aborts quickly (for example the Windows sound when changing the volume).
When I set the SPDIF out as output: No sound at all!

The Sigmatel website obviously doesn't provide drivers since it's not existant anymore. The audio business was sold to IDT, but the IDT Website sucks: Detailed descriptions of all sound cards, but no drivers at all!

There was an IDT modded drivers section on laptopvideo2go.com before, but unfortunately the project is dead. I can't even find the uploaded files anymore. Anyway, one doesn't know if it works for Win 8 at all.

Audio device:
STAC9205

Device-ID:
HDAUDIO\FUNC_01&VEN_8384&DEV_76A0&SUBSYS_102801F9&REV_1002\4&C38AAC3&0&0001

I tried the following drivers from the Dell website already which according to Windows 8 work, but give me the described sound problem:
- 2Y0VM
- R153997
- R171788
- R171789
- R218148

Any ideas how I can get this to work? Any other IDT drivers available?

Generally, only Dell supplied drivers work properly on a Dell PC. Non Dell drivers will either not work or not work properly in most cases.

Have you tried posting on the Dell Laptop forum? That would be a good place to start.
Laptop - Dell Community

Your have a super old dell laptop. I'm amased you were able to install Windows 8 on it. I would not bother finding missing drivers for the D630, the OS will not function properly. Use your license on a newer model.

AEM: You posted on this thread 2 years after it was posted. The D630 was made in 2008, so at the time, it was four years old. Hardly "super old". Anyway, it's almost 2016, and I have windows 10 on one, and it works perfectly. This is a help forum, not a place to be condescending. Posts like yours serve no purpose other than to discourage people, and give them the false illusion that newer is better. Some people like to figure things out without the peanut gallery telling them something irrelevant. Just my 2 cents.

And here's my two penneth...

I can run W10 just fine on my 9 yr Acer laptop (its running Enterprise right now). I also have a 3yr old Dell i5 Vostro laptop running 8.1 that has so far defied all attempts to get W10 to run. Clean or upgrade route, all fail in some way, often crashing out before even reaching a workable desktop/start screen.