The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Reply
 
Thread Tools
  #1  
Old 08-05-2018, 03:07 PM
Kyle76 Kyle76 is offline
Registered User
 
Join Date: Feb 2011
Location: North Carolina
Posts: 1,087
Default Do I need a truss rod adjustment?

My L-05 Larrivee has always been easy to play, but lately I’ve noticed that it is not as much so, particularly barre chords up the neck. I decided to take a ruler to it, and here’s what I found: the low E string is about 1.5/32nds above the first fret, 5/32nds above the 12th fret and 5+/32nds above the 20th fret. If I fret the low E at the first fret, it is 4/32nds above the 12th fret. If I fret the low E at the 12th fret, it is 2/32nds above the 20th fret.
__________________
Regards,
Jim
Larrivée L-05 Mahogany
Gibson Les Paul Traditional
Fender Stratocaster
Epiphone Les Paul Standard
Reply With Quote
  #2  
Old 08-05-2018, 03:33 PM
Tim Mullin Tim Mullin is offline
Registered User
 
Join Date: Feb 2011
Location: Shefford, QC
Posts: 41
Default

Translating these measurements to metric (my preferred units for setup), you’ve described height of the 6th above the 12th fret as being 4 mm, whereas something around 2.0-2.5 would be needed for comfortable barre chords. Your guitar likely needs a lot more than a truss rod adjustment, so find yourself a reputable guitar tech and let him/her do a proper assessment.
__________________
Tim Mullin
Shefford, QC
CANADA
Reply With Quote
  #3  
Old 08-05-2018, 05:45 PM
John Arnold John Arnold is offline
Registered User
 
Join Date: Jan 2009
Posts: 4,082
Default

The purpose of the truss rod is to maintain optimal relief, not adjust the action. While the measurements you give tell that the action is too high, they do not indicate relief. If the relief is correct (usually around 0.006"), then action adjustments should be addressed by changing the height of the saddle or the nut.
FYI, the nut is too high. The bottom of the nut slots should be in the same plane as the tops of the frets. You check this by pressing the string down on the second fret and note that the string should barely clear the first fret. You can check the action at the first fret if you want, but just be aware that it should always be about 12% of the 12th fret action, since the distance from the nut to the first fret is about 12% of the distance from the nut to the 12th.
Reply With Quote
  #4  
Old 08-06-2018, 05:50 AM
MC5C MC5C is offline
Registered User
 
Join Date: Mar 2016
Location: Tatamagouche Nova Scotia
Posts: 1,136
Default

I think it's time for a good setup. Nut does seem high, action is quite high, and yes, you might need a truss rod adjustment. How old is the guitar? Seems like natural settling for a 5 - 10 year old instrument. Some people do fairly complete setup adjustments every six months or so. FWIW, I look for a neck that is really close to flat, around .003 relief - but I measure it by eye fretting at both 1 and 12, and just look to see if there is any space at all under the string around the 5th fret. I look for 3/32 under the string for the low E at the 12th fret, and 2/32" under the string for the high E at the 12th fret. Yours is really quite high. Probably not neck reset time, but getting along that road.
__________________
Brian Evans
Around 15 archtops, electrics, resonators, a lap steel, a uke, a mandolin, some I made, some I bought, some kinda showed up and wouldn't leave. Tatamagouche Nova Scotia.

Last edited by MC5C; 08-06-2018 at 06:00 AM.
Reply With Quote
  #5  
Old 08-06-2018, 09:45 AM
Bruce Sexauer's Avatar
Bruce Sexauer Bruce Sexauer is online now
AGF Sponsor
 
Join Date: Jan 2009
Location: Petaluma, CA, USA
Posts: 7,525
Default

Your nut is high, but that says nothing about your relief. Set up is very demanding if the guitar is to play correctly, and although it involves just 3 major parameters (assuming heathy frets), most lay players do not seem to have a grip on it. Go see a pro.
__________________
Bruce
http://www.sexauerluthier.com/
Reply With Quote
  #6  
Old 08-12-2018, 07:29 AM
Kyle76 Kyle76 is offline
Registered User
 
Join Date: Feb 2011
Location: North Carolina
Posts: 1,087
Default

Quote:
Originally Posted by Bruce Sexauer View Post
Your nut is high, but that says nothing about your relief. Set up is very demanding if the guitar is to play correctly, and although it involves just 3 major parameters (assuming heathy frets), most lay players do not seem to have a grip on it. Go see a pro.
I do plan to take the guitar to a recommended local tech, but I’m curious as to why you believe the nut is too high when string height near the nut is much lower than the higher frets? I know there are lots of forces in play here, so I hope the tech can get it sorted out. In the six years I’ve owned this guitar it has until recently played like a dream.
__________________
Regards,
Jim
Larrivée L-05 Mahogany
Gibson Les Paul Traditional
Fender Stratocaster
Epiphone Les Paul Standard
Reply With Quote
  #7  
Old 08-12-2018, 07:57 AM
MC5C MC5C is offline
Registered User
 
Join Date: Mar 2016
Location: Tatamagouche Nova Scotia
Posts: 1,136
Default

"I’m curious as to why you believe the nut is too high"

Kyle, you said in your first post that string height at the first fret was 1.5/32" which is .047". Normal string height at the first fret for the low E string is in the range of .008" to .010", so you are around 5 times higher than normal. Now, I think that you probably measured wrong, but it bears looking at.

Brian
__________________
Brian Evans
Around 15 archtops, electrics, resonators, a lap steel, a uke, a mandolin, some I made, some I bought, some kinda showed up and wouldn't leave. Tatamagouche Nova Scotia.
Reply With Quote
  #8  
Old 08-13-2018, 08:24 AM
John Arnold John Arnold is offline
Registered User
 
Join Date: Jan 2009
Posts: 4,082
Default

Quote:
I’m curious as to why you believe the nut is too high when string height near the nut is much lower than the higher frets?
It should always be so....unless the strings are laying on the frets. That is because the nut should be the same height as the frets.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Thread Tools





All times are GMT -6. The time now is 09:51 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ©2000 - 2022, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=