I don't know how Newegg can call that an "OC" supercombo. The motherboard only allows very little room for overclocking. You can't control the voltage on your own!
There are two ways to adjust CPU Vcore from UEFI in the AI Tweaker menu:
1) Manual mode: allows you to set a static voltage level.
2) Offset Mode: allows you to retain EIST functionality and offset the base VID.