Setup of a National EN Resonator Guitar

  • Biscuit bridge-saddle replacement

  • Adjust string action and spacing with new biscuit

  • Install deluxe tuning machines upgrade

  • Comparisons, comments and extra information and photos

This a photo diary of my re-setup procedures for a single cone, biscuit bridge resonator guitar. As far as I'm aware this model is identical in features and components as the Style O. The style EN show here was a special order model made for Steve James an Austin based, world traveling professional bluesman of extraordinary talent and wit. He was tired of blinding his audiences so this model has an etched nickel surface on a brass body, 12 fret neck design and slot head. Although this is one of the best built guitars of any kind that I've ever owned the super vintage design of the tuning machines is reliable and simple yet a little unrefined compared to modern versions. I ordered a deluxe set from National and hopefully will upgrade those during this article and see how they work.  I've seen a bee hive of activity and discussions on these very topics and I thought going through these procedures would be highly valuable to many players out there. It may also give you the information and confidence to do this work yourself since a basic resonator setup fee can be as much as 150.00 dollars at most shops. The good thing is once you are dialed in on these beasts you wont have to worry about setup for another decade.


Below are the tuning machines that came standard which are very reliable but I'm not thrilled with their smoothness. These will be coming off and I believe it might be a little tricky but we'll see how it unfolds.

Below are the new parts. I ordered a new maple biscuit bridge from National for 12.00 and a deluxe set of tuning machines for 70.00 with alloy gear, engraved plate and white buttons. I'm a little disappointed in them but they seem better than the stock ones and half the price of Waverly tuners. I don't like those rising weld spots on the back of the plates and the buttons are white plastic instead of ivoroid to match the binding on the guitar. The letters in the pattern spell NRP. What I really found crazy was the screw patterns don't match the stock holes but the shafts do seem to be standard spacing like most 3 on a plate tuners. Also the new maple biscuit luckily has a taller saddle piece sticking up so I can not only widen the slots and make the string spacing more comfortable on my picking hand but the action will be raised from the current setting so I can play slide a little easier and get a cleaner stronger tone. This guitar came setup like a new Collings acoustic or something and I must admit it plays like any standard guitar only about 3 times heavier.

Below is my current bridge and you can see there is enough room under the cover plate to raise my action without bumping into the cover when it gets higher. This is going to require taking the covers off and opening up the guitar but this will be a fun experience. Let me explain some more things about the action in the next photo.

First things first. I tune up to standard and then put a capo on fret 1 so all my action measurements are accurate. I know this is knit picking but it's the right way to eliminate the nut.

Now below you can see the clearance or gap from the peak of the 12th fret to the bottom of the sixth string is just about exactly 3/32" inch or 6/64". Now believe it or not this all means nothing if the truss rod is out of adjustment so let's check that in the next step.

Tip: If the truss rod is too loose and the neck is bending forward this measurement can look great but once the neck is adjusted right it will be too low. If you base all your setup on this false reading you can mess the entire guitar up and have to take it to a shop to have them straighten it out. So just take your time and read this stuff. Even if you plan on going to a shop you might want to understand these things. Just knowing this can help you to work better with a tech achieving your perfect setup. They charge about 150.00 dollars for a resonator setup by the way, ouch. As you can see though it's sometimes worth the price.

Below: There are two good ways of measuring the relief on your neck. The cheap and easy way is to press down the first fret (capo) and last fret (finger) on string 3 and then find the middle point on the neck and look at the gap. The other way is to use a metal straight edge ruler and lay one edge on the fretboard between string 3-4 then hold toward a light and look at the gap under the ruler at the 7-8th fret or midpoint of the fretboard. Look at the next several photos and you'll see what I mean.

Below I am holding the guitar up to the light and pressing the first and last fret on sting 3. You can see that string has dropped below the level of the other strings so I can see it well. The gap around the middle of the fretboard indicates how much curve or relief is in the neck. Sometimes you'll find NO gap and that is not good. In this case I have a gap that is way too large. So what that means is that I need to correct this before doing any other setup work. This is the first step in a good setup. I've got the strings tuned to standard since I use this guitar for a lot of standard tuning. I need to lessen this gap or REDUCE the NECK RELIEF. Keep reading because it gets interesting.

ADJUSTING THE TRUSS ROD - I remove the dust cover and determine what size wrench to use. My 1/8" allen head seems to fit tightly so I tap it with a wrench to make 100% sure the allen wrench is completely seated or fully inserted into the truss rod adjustment hole. Otherwise you stand a great chance of stripping it out or making it get stuck in the hole. Sounds like a stupid step but trust me on this one.

UPDATE:  Here's where National documents these opposite turning rods for specific year models. Looks like guitars with the typical truss rod adjustment have red coloring in this area under the truss rod cover. Here's their FAQ also. If you don't like flash click this alternate link.

Below: This big maple neck is very stiff plus I use medium strings so I don't want to  place too much torque on this puny truss rod adjuster.  So I am loosening the strings to make sure I dont hurt anything while turning the rod. It doesn't hurt to be cautious even though this requires more work.

Below: I discovered something tricky about the National. It works the complete opposite of my other guitars where tightening the rod clockwise usually pulls the peg head back and pulls against the string tension. But on this guitar it's 180 degrees opposite. I had to turn it counterclockwise to decrease the relief gap and pull the head backward. The way I found out was turning it a little each way and then measuring with a straight edge. Someone needs to document this little gotcha or include some kind of warning in an owners manual. This really threw me for a loop at first. I had to use a wrench to turn this allen wrench. This is not an easy rod to turn and they apparently do not lubricate these at the manufacturer. You might want to lube it to prevent problems down the road.

Below I'm tightening the strings back up to standard tuning then see how much affect 1/4 turn on the rod had on the huge gap we saw before.

Below Once tuned back up I decided to check the gap with a metal ruler and make sure I was accurate. I then checked it with the string method and they both agreed. That makes me feel like I'm getting a reliable reading. I had to go back through these last few steps a few times until the relief was perfect. The gap now is about 10/1000" or 0.010". About the thickness of a business card. This has always worked well for me but some players might prefer more or less. Too much relief makes the action feel stiff and too little makes the frets buzz and can affect tone.  

Below is the neck relief I ended up with and it's a far cry from that huge gap I had before. The neck should play with less stiffness now but the gap is not so low that it will cause buzzes. If it does I will readjust it. The trick is not getting the saddle too low. Some techs will even leave some additional height until they see what the player thinks then refine the setup again. In this case though I've been doing my setups for 20 years and I am pretty certain this will work for me.

SUPER TIP! - Below you can now see that AFTER adjusting my truss rod the action reading is LOWER on string 6. This measurement of 5/64" is far too low for me and especially when playing slide. This would be low even for an electric guitar.

LESSON LEARNED - Adjust the truss rod relief before beginning the setup process. Everything depends on this being correct first.


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