VDMSound is an entirely different project from DOSBox AFAIK. It may work better for DOS games if you have Win2k or XP. I use GNU/Linux, so I use DOSBox.

I've succeeded in running both Ultima Underworlds with both OPL and wave audio. The details you posted about your particular sound card are irrelevant, since DosBox provides its own emulated sound hardware. Just tell the game that you have a SoundBlaster. These are the values I have in my DosBox …