Hola, I just watched video 1.7 irregular verb ir. Did my ears catch correctly that all V's are said B as in bas (vas), va (va), etc. except for voy that is said Voy?
V said V and said B
B and V are generally pronounced the same (if you chat with a lot of young Spanish speakers online, you will notice a lot of b/v spelling errors). Here is a page that sort of explains the pronunciation: http://spanish.about.com/od/spanishpronunciation/a/b.htm
I also noticed that Spanish speakers sometimes say V as B, especially when the word begins with this letter. (This is how my friend who's name is V..., became B... in Spain )