From Wikipedia, the free encyclopedia. David Warren "Dave" Ellefson (born November 12, 1964 in Jackson, Minnesota) is a bassist and founding member of the American thrash metal band Megadeth. He currently resides in Burlington, Vermont. He also has various side projects which include Temple of Brutality, F5, and Killing Machine. Description above from the Wikipedia article Dave Ellefson, licensed under CC-BY-SA, full list of contributors on Wikipedia​