A string buzz issue

[VifferMike]

I just bought a great-condition 1990 Fender Jazz Plus bass here on TB, and the bass plays great except for an issue I'm having with buzz on an open A string:

After I received the bass, I thoroughly cleaned it and re-strung it with D'Addario XL Nickel Wounds in 45-65-80-100 gauges. After tuning her up, the A string exhibits a nasty buzz against either the first or second fret (pretty sure it's the first) with anything heavier than a light pluck. The odd thing is if I mute the A string at the headstock with even very light pressure - not even enough pressure to fret the string if it were over the neck - the buzz disappears and the string plays fine.

I'm thinking that I've either got a bad string (noticed several small spots of corrosion on the strings when I opened the pack) or the gauge is too light for the nut (bone) and the setup (rather low). The frets are in great shape for a 23-year-old bass, and I know that the bass was set up for its old strings (looked to be Elixir Black Beauties; not sure of the gauges) fairly recently.

I'd appreciate any insight into the issue, and suggestions as to what I should try first to eliminate the problem ... ?

[JoeWPgh]

That's a very common issue that usually has a very simple fix. When stringing the A, you have to make every effort to keep the windings on the bottom of the tuning peg. You need to maximize the downward force at the nut.

[VifferMike]

Aaaah; that explains a lot ... thanks!

[JLS]

Right up there next to, "There's no such thing as a drop-in, preslotted nut".