Double Bass New A strings has a slappy sound

[Dave Koch]

I just put new Helicore mediums on my 59 Kay. All of them sound great except the A, which sounds like one of those spring wall protectors when you pull it back and let it go. The string isn’t hitting anything and I play a high action, like 3/8”. I thought about moving the post around, moving the bridge, and just playing for a while and see if it breaks in. I was hoping someone else has a solution or knows what might be the cause. Thank you in advance.

 

[Francois Blais]

What's the color of the silk at the tuner end?
Should be black.

 

[Greg Clinkingbeard]

Put a straightedge on the fingerboard along the A string. I’ve had bumps near the nut that caused that which didn’t cause a buzz on old strings.

Don’t go moving the post or bridge. Might be an open seam.

 

[Dave Koch]

What's the color of the silk at the tuner end?
Should be black.

Yup, black it is.

 

[Dave Koch]

Put a straightedge on the fingerboard along the A string. I’ve had bumps near the nut that caused that which didn’t cause a buzz on old strings.

Don’t go moving the post or bridge. Might be an open seam.

Yeah, first thing that came to mind. It isn’t hitting anything. I have thick hands and all I do is bluegrass stuff, my strings are probly close to 3/8 off at the bottom end of the fret board.

 

[Francois Blais]

What string did it replace?
If it was a string with a large diameter, maybe the new A is rattling inside the groove.
What's the space between the string and fingerboard at the edge of the nut?
Should be about 1 or 2 business cards max.