No, actually I don't mean DAC. A friend of mine had this card (Vibra 16)and always had trouble setting up games, since it somehow wasn't compatible to a real Sound Blaster 16.
The Vibra card seemed to have two 8-bit DMA channels (due to its much simpler design and therefore lower price) which could be combined to one 16-bit channel. However, in games, it was only compatible to regular Sound Blaster cards due to this drawback.
At least, that's what I recall.
A Google search revealed the follwoing:http://www.ussg.iu.edu/hypermail/linux/kernel/9807.3/0811.html
I think it also applies to DOS.