KRUTZ Avant - Series 850 ViolinsKRUTZ Avant Series 850 Violins KRUTZ Avant instruments are crafted entirely in our Kansas City workshop by senior luthiers, many of whom learned the art of string instrument construction in Europe. All aspects of the making process are overseen by Anton Krutz. We hand select every single piece of European and American maple and spruce used to make these instruments. The wood is then aged for five to ten years before the instrument crafting begins.