I recently bought some Pirastro Obligatos about three weeks ago. Prior to them I was using Helicore Hybrids. I have them on a Kay M-1. My question is how long is their break in period, if any at all? Along with teacher and even my mother, I haven't seemed to notice any difference between the two strings' sound. Is it that the Obligatos need to break in or settle down or is it that they don't respond as well to a plywood bass as to a carved?