Hello,
Unfortunately, we cannot help you with this, since we the board that you are using is not sold by us, and the BSP is different from the one that we support. You will need to go with Variscite, they could help you with this. I apologize for the inconveniences this could give you.
However, I found this information. Probably it could help you.
13.04 - How to upgrade alsamixer in ubuntu 13 - Ask Ubuntu
Best regards,
Diego.