I have never had new strings. The closest thing ive had is playing on basses at shops that probably had new strings. My first bass was a plywood rental that i bought, if the strings were new, that was for five years so i have no idea. My current bass has Helicore Hybrids on it. It was the rental bass at KC for professionals in jazz/pitt playing who came into town. Im guessing the strings are dead. I just feel like they dont give anything back when i dig into them. Sonically i have no idea if there is a change. I have tried changing my action but it just feels like a one sided relationship. I am pretty sure for pizz they are shot. What are signs/how do you tell when your strings are done?