Hi, maybe some beginners error. The HDSP (PCI)  works fine so far. Output is on AN1+2 as standard and works fine. When playing some audiofile, I can open the Windows mixer and control the volume for the specific application. But when changing the volume or muting it for the standard device (which is HDSP speaker), it has no effect on the output at all. The mixer shows the changes, though.
Hope, anyone has an idea how to fix this or where to look for the problem. If more information are needed, I'll surely provide them.
Thanks and all the best,
Stefan