Preheat oven to 325 degrees F.
In a large mixing bowl, cream the butter and sugar together. Add the sour cream and mix until incorporated. Sift the baking soda and flour together. Add to the creamed mixture alternating with eggs, beating each egg 1 at a time. Add the vanilla and pour the mixture into a greased and floured 10-inch tube pan. Bake for 1 hour 20 minutes.