Dead frets after shimming

[PennyroyalWe]

Yesterday I shimmed the neck pocket of my de-fretted Squier VM TB with a Stew Mac .5 degree angled shim. The bridge was bottomed out and I wanted the strings a little lower, so shimming seemed the right answer. While it did fix the issue of the bridge being bottomed out, I now have “dead spots” where the note sounds buzzy and choked out on the D and A string in the 17-18 fret range. It has a 2 barrel bridge, if that matters. Measured with my string gauge, all the string are nearly even height from the fretboard, at 1.75mm @12th fret. The only things I can think of are either the shim did something funny to it, or the fretboard there is more uneven than I thought...or the shims are making whatever unevenness there much more apparent. The bright side is that at least it’s way up on the neck where I nearly never play, so it’s not ruining any of my playing, but I would like to have the bass play well over the whole instrument.

 

[Turnaround]

It has nothing to do with the shim and everything to do with the height of the strings over the frets. That clearance at the 12th fret is quite low - I assume you are measuring between the bottom of the string to the top of the fret, not the top of the fretboard as you stated. Assuming you meant top of the fret, you will need very even frets to get it buzz free with 1.75mm clearance and you will need a light touch.

 

[PennyroyalWe]

It has nothing to do with the shim and everything to do with the height of the strings over the frets. That clearance at the 12th fret is quite low - I assume you are measuring between the bottom of the string to the top of the fret, not the top of the fretboard as you stated. Assuming you meant top of the fret, you will need very even frets to get it buzz free.

It’s fretless, hence measuring from the fretboard. You’d call that too low? That’s about where I have all my basses, any higher is about where I’d start calling it “medium action”. Guess it’s just what I’m used to, I’d like to stay below 2mm if I can.

 

[two fingers]

It has nothing to do with the shim and everything to do with the height of the strings over the frets. That clearance at the 12th fret is quite low - I assume you are measuring between the bottom of the string to the top of the fret, not the top of the fretboard as you stated. Assuming you meant top of the fret, you will need very even frets to get it buzz free with 1.75mm clearance and you will need a light touch.

The bass has been de-fretted, as he said early on in his post.

 

[David Jayne]

You have indeed discovered that your fingerboard needs work up there. You've likely got a bit of a 'ski jump' happening. The cure is to level and maybe even (my preference) cut in a bit of upper-level 'fall-away.'

 

[Turnaround]

It’s fretless, hence measuring from the fretboard. You’d call that too low? That’s about where I have all my basses, any higher is about where I’d start calling it “medium action”. Guess it’s just what I’m used to, I’d like to stay below 2mm if I can.

Sorry - misread the original post. 1.75mm is still quite low. And you will need a really level board at that height. It can be done, but fretless is even more demanding than fretted - on a fretted instrument the space between frets doesn't need to be level, just the fret tops. On a fretless every mm along the length of the board must be level. And as with a fretted instrument, the lower you want the action, the more critlcal it is that the board is really level. And the shim is still not contributing to the problem.

 

[PennyroyalWe]

You have indeed discovered that your fingerboard needs work up there. You've likely got a bit of a 'ski jump' happening. The cure is to level and maybe even (my preference) cut in a bit of upper-level 'fall-away.'

That’s what I’m afraid of :/
Did the shim cause the ski jump, you think?

 

[JKos]

Did the shim cause the ski jump, you think?

Nah, you just discovered your fingerboard isn't as level as you thought when you lowered the string height.

In @Turnaround 's defense, the title of the thread does say "Dead frets"!

 

[PennyroyalWe]

And the shim is still not contributing to the problem.

There’s one less thing to troubleshoot. I’ve heard the micro-tilt systems have caused ski jump, wasn’t sure if that was what’s going on here

 

[Turnaround]

There’s one less thing to troubleshoot. I’ve heard the micro-tilt systems have caused ski jump, wasn’t sure if that was what’s going on here

Neither shims nor micro-tilts cause ski jumps - it's a myth.

 

[lz4005]

This is why measuring is pretty meaningless.
Use your ears. Raise your strings until you don't have an unacceptable buzz on any frets. That's the lowest you can go without leveling those frets.

 

[David Jayne]

That’s what I’m afraid of :/
Did the shim cause the ski jump, you think?

Bloody unlikely. But if you want to be sure, use a thick full-length shim instead. Rather that tilting the neck it will raise the neck evenly. A little harder to pull off but will give the same result (lowered action) as a back shim.

 

[JKos]

use a thick full-length shim instead

He did use a full-length shim.

 

[PennyroyalWe]

Neither shims nor micro-tilts cause ski jumps - it's a myth.

There sure a lot of myths.

 

[Turnaround]

There sure a lot of myths.

You bet!

 

[micguy]

I agree with others that you've now pushed your action lower than the flatness of your neck allows. You need higher action and/or a flatter neck. 1.75 mm is about .068", which is quite low.

.080" or so is about where I run my D and A strings.

 

[PennyroyalWe]

I have raised the saddles a smidge and it seems to have alleviated the issue. Thanks all, I feel silly for asking about such a simple issue.

 

[Zooberwerx]

There sure a lot of myths.

Down here in SE Virginia, if you pull your car onto a railroad crossing and kill the engine, the ghosts of Confederate soldiers will push your vehicle out of harm's way.

Riis

 

[David Jayne]

He did use a full-length shim.

I said thick.... not tapered. But I suppose it doesn't matter either way..

 

[RSBBass]

I said thick.... not tapered. But I suppose it doesn't matter either way..

Pretty sure StewMac shims are all full length.