Open G fret buzz after changing to flats

[Pimmsley]

Hi all,
looking for advice here, I'm trying to learn about set-ups in the process of sorting this out, as I've been maintaining my own basses for 20 years now and fortunately never had to shim any of my basses... but seen it done a few times and shimmed a guitar neck.

Offered to change strings and do a quick setup on one of my dad's basses (ancient MIJ Daion Performer P bass) and after seeing it in person, after about 15 years, realised it would take a bit of work as the action was ridiculous... around 12mm at the 12th fret...

My first thought after dropping the saddles low and taking some bow/relief out of the neck is that it needed a shim, as the angle of the neck in the pocket didn't seem right... after taking off the neck I found there was already a paper/card shim (factory installed I'm guessing) and, used a slightly thicker card cut to the same dimension, and put that in it's place...

after assembly I thought I had succeeded as the action was much better, but then I took of the roundwounds I was testing with and put on a set of GHS P flats, and I am getting a fret buzz up around the first to third fret on the open 'g' with the flats... not so much if I softly pluck the 'g' but if I use a reasonable amount to pluck it's rattling on something up there...

When I take them off and put the rounds back on, the buzz/rattle goes away, swap them back, buzz rattle comes back...

the saddle and nut heights seem ok, and the clearance from the g string to the frets seem ok...

is there a possible easy fix I can try ?

(bit cash strapped and trying to learn so please don't advise taking it for a setup)

thanks...

[thebandcircle]

Side to side buzz at the nut?

[Pimmsley]

Originally Posted by thebandcircle

Side to side buzz at the nut?

no, checked the nut.. it's not there. I checked the space between the string and first fret and it's pretty much identical to another bass of mine that also has the GHS P flats... hmmm... thanks though.

[Low Main]

Could be the windings have separated from the core of the string. That sometimes happens with flats if they're not installed correctly (making a 90 degree bend in the end of the string before trimming it to length, etc.).

Core separation will cause buzzing.

Some brands of flats are fussier than others about that. LaBellas especially need TLC during install.

But it's more common with an E or A string than a G. I'm not sure how common it is with GHS flats -I hardly ever use them.

GHS has been good in the past about providing single replacement strings where one string in a set is problematic.

[Pimmsley]

Originally Posted by Low Main

Could be the windings have separated from the core of the string. That sometimes happens with flats if they're not installed correctly (making a 90 degree bend in the end of the string before trimming it to length, etc.).

Core separation will cause buzzing.

Some brands of flats are fussier than others about that. LaBellas especially need TLC during install.

But it's more common with an E or A string than a G. I'm not sure how common it is with GHS flats -I hardly ever use them.

GHS has been good in the past about providing single replacement strings where one string in a set is problematic.

I thought that might be the case too, but after checking the string on another bass, it appears to be OK...