ABM Adjustable String Nut


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Has anyone ever used one of these?

CD said:
Never even seen one. Who makes it?
ABM, I suppose.

I've seen similar designs from Warwick:

and Atlansia:

Actually, I believe the original Warwick adjustable nut was made by ABM.  Figures, they're both German manufacturers.  I've never used one, though.
I keep both instock for custom builds....yes they come from germany,but I don't like the metallic ping that they give to the sound over all.But as an aid to set up and electronics testing they make things real quick and easy.then i can pick from other materials that have more punch.(currentley Im using fossill mammoth ivory(real pain to work with but well worth the extra dosh and work).for this alone they are worth it ....I set up at least 1600 guitars a year...and scratch build another 25,so anything that allows me to save even 15 minutes during a job has to be cool.The same reason I love Spertzel machine heads.
I have a Warwick Streamer Bolt on 5 with a what they called a Adjust a Nut I.  The Adjust a Nut II is the graphite example above.  Works ok I guess.  The threds are a little loose but I don't get any buzz or rattle.  I wouldn't venture a guess about it's effect on tone.  With the brass frets and wenge fingerboard it's pretty zippy.  I'm not really sure about putting one on a guitar though.
TonyFlyingSquirrel said:
Doesn't Alembic in Santa Rosa use them?
I was about to answer back that I'd never heard of that but stopped on the brink and searched Google first. :)

Sure enough:

Alembic's Use and Care Guide said:
Brass Adjustable Nut
Our unique brass adjustable nut is featured on every Alembic guitar and bass. There are three adjustment screws on the string nut. The center screw locks the nut in place and must be loosened before attempting to raise or lower the nut. The two outer screws determine the height of the nut. The 5/64" hex driver supplied with your instrument is required to make these adjustments.
They use something very similar on the Chapman Stick.  I've never played with one on a guitar though.
While looking nice to the person who cannot fit their own proper nut.  That ABM nut has its drawbacks from the technical point of view.

Consider how the nut must be slotted?  Do the screws sit at a slight angle so that no matter how they're turned, you have the same break point?

Look at that one by Atlansia.  The break point, not sharp, and in the middle of the screw!  Might be ok for bass, forget it on guitar.

For the price and long life of the nut marterial out there today, why not just fit (or have fit) a proper string nut and be done with it?

I like the pre-slotted GraphTech on most guitars... BUT... I only use the slots as a guide for fitting and final placement of the finished slots.  That is, I square up the bottom, then take material off the top to fit the nut, using the slots as positioning guides.  Invariably, the molded slots will be cut away and never seen when the proper nut elevation is achieved.  The last two necks I have gotten from Warmoth have their own slots fit.  We'll see how they do.  Kens pretty much a perfectionist, so I'm sure they'll do ok.

The Warwick design is the best pictured, imho, but even so, I'd rather have a nut that rode on shims and locking screws, than screw pillars.