ive developed a problem with my decks - im getting really bad, crackly, quiet sound form one of them. after investigation ive discovered its a problem with the needle (as the problem vanishes when i swap needles). so it looks like im going to have to get a new one. my question is how often do needles go? what would have caused it to go? if i get an expensive needle what can i do to prolongue its life? i was unaware that needles could really break. any info would be good. cheers.