I've been playing bass for quite a while and I recently changed my strings to some rotosounds forgot what gauge I'm pretty sure light but I could be wrong. Anyways I get a buzz on the first fret of all my strings. I'm not quite sure what went wrong I wrapped the strings around the nut the right amount and stuff so Idk...thanks for the help.
check the neck hasn't been warped, if you're using a different string gague the tension will be different so it could have warped the neck

most likely though is that it's a different tension so the strings are slightly looser. you can fix this by raising the action ever so slightly till the buzz is gone.
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you need to setup your bass again. I go through this issue constantly with my Ibanez and its fairly common, esp. when you go from heavier to lighter gauge and visa versa.

Ben's done a write up in the FAQ about doing setups and there's a decent description on www.tunemybass.com as well, if I remember right. If after reading it, it still is confusing, take your bass to a good shop and have someone show you how to do it.
You may have changed your gauge. If that's the case, get it set up again. Check anarkees post.

Question though.. did you cut the tails? I used to do that until my low E string started buzzing even when open. I emailed Rotosound about the problem and they told me not to cut the tails, then sent me 3 replacement strings as a good will gesture just in case the actual string was faulty.
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