I wanted to create custom mixer for that device, because I can't get recording to work. I've fiddled with mixer controls, but that seems totally pointless and stupid solution for the problem. Open Sound System recognizes my soundcard as High Definition Audio ALC888, but lspci -v and program for retriving system information (i-Nex) shows it as nVidia Corporation MCP55 High Definition Audio (rev a2):

$ lspci -v
00:06.1 Audio device: nVidia Corporation MCP55 High Definition Audio (rev a2)
       Subsystem: Giga-byte Technology Device a002
       Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 21
       Memory at fc100000 (32-bit, non-prefetchable) [size=16K]
       Capabilities: <access denied>
       Kernel driver in use: oss_hdaudio
       Kernel modules: snd-hda-intel

I've compiled and run both mixgen and mixgen2. I've pasted the output on pastebin.

I wonder does recording work with that card. I can record, but the result is barely audible and ossrecord doesn't show anything on volume meter of ossxmix.

I also want to thank you for creating Open Sound System and still working on improvements. OSSv4 with production quality enabled is absolutely the best sound solution for Linux and BSD.