Cream of Tartar for scones?!

Cream of Tartar for scones?

I love scones but hate the metallic taste baking powder leaves in my mouth. Can I replace it with Cream of Tartar or do I have to mix the two? If so, in which proportion? Do you know any foolproof recipes?
Thank you for your help!

19 hours ago
We don't have self-raising flour in Switzerland..

I don't know of a way to make scones without any baking powder, but why not try a recipe with a smaller amount of it, that also uses baking soda and cream of tarter. This one uses only 2 teaspoons of baking powder for 4 cups of flour. Much less than many scone recipes I've seen:

1 cup sour cream
1 teaspoon baking soda
4 cups all-purpose flour
1 cup white sugar
2 teaspoons baking powder
1/4 teaspoon cream of tartar
1 teaspoon salt
1 cup butter
1 egg
1 cup raisins (optional)

In a small bowl, blend the sour cream and baking soda, and set aside. Preheat oven to 350 degrees F (175 degrees C). Lightly grease a large baking sheet. In a large bowl, mix the flour, sugar, baking powder, cream of tartar, and salt. Cut in the butter. Stir the sour cream mixture and egg into the flour mixture until just moistened. Mix in the raisins.

Turn dough out onto a lightly floured surface, and knead briefly. Roll or pat dough into a 3/4 inch thick round. Cut into 12 wedges, and place them 2 inches apart on the prepared baking sheet. Bake 12 to 15 minutes in the preheated oven, until golden brown on the bottom.