I recently purchased a upright bass, as something to mess around with when taking breaks from electric bass. being a mere uneducated slab player, I have a question about strings are most urb strings ball end? my bridge seems to be designed for strings with a loop at the end, if that makes any sense. I'm thinking of buying some thomastik spirocores, and just wondering if they are compatable or if I might eventually have to get a new tailpiece. any help would be greatly appreciated.