Above photo: Sam Bush's Limited Edition Inspired By '34 Fern
Getting down with Mandolin set-up
by Roger Fritz
The key ingredients for a great playing mandolin are low action with little or no fret buzz and, with proper intonation, the ability to play in tune up the neck. Combine these things with great tone and life is good.
You may not able to do much about the intrinsic tone of your instrument, but you can get the most out of it with an easy setup procedure.
You'll need the following tools:
- Accurate 12" straight edge
- Small tape measure
- Small phillips or straight blade screwdriver
- Truss rod wrench
- Ruler that measures in 64ths of an inch
Please remember to be very careful when working on your mandolin.
Step 1. Make sure the bridge is in the proper location. Measure from the front of the nut to the 12th fret (fig 1) on the high E string. Now measure from the 12th fret to the front of the bridge (fig 2). The two measurements should be very close to, if not exactly, the same. If you need to move the bridge, loosen the strings enough so that you can slide it without scratching the finish on top of the mandolin.
fig 1: Measure from the front of the nut to the 12th fret on the high E string
fig 2: Measure from the 12th fret to the front of the bridge
Step 2. Tune up to standard pitch and check the intonation. Play the harmonic or "chime tone" with your finger touching the string at the 12th fret, but with the string not pressed to the fret. Then play the same note with the string pressed to the fret. If the second tone is higher, lengthen the string by moving the bridge toward the tailpiece. If the second tone is lower than the harmonic tone, move the bridge toward the fingerboard. (Be sure to loosen the strings before moving the bridge.)
Step 3. Using the small screwdriver, remove the two screws (fig 3) from the the truss rod cover and remove the cover, exposing the truss rod nut.
fig 3: Remove the two screws from the the truss rod cover
Step 4. Check the neck for straightness. Lay the edge of the straight-edge ruler lengthwise on the fingerboard, between the strings, on top of the frets. If there is a hump, turn the truss rod wrench (fig 4) counterclock-wise to relieve some tension until it is as straight as can be. If there is a dip under the straight edge of more than 1/64" turn the truss rod nut clockwise. Generally, we try to get the neck as straight as possible and then give it some "relief." To give it relief, turn the truss rod nut counterclockwise one-quarter of a turn and measure under the straight edge until there is a dip--but no more than 1/64".
fig 4: Measure from the 12th fret to the front of the bridge
Step 5. Check the string height at the first fret (fig 5) on all pairs of strings. You can do this without measuring if you want to. If it feels comfortable, move to the next step. If not, use the small ruler and check the height of the string (fig 6) from the top of the first fret. Standard height is 1/64". If a nut slot needs to be lowered, it will require a special file. I recommend the help of a qualified tech.
fig 5: Check the string height at the first fret on all pairs of strings
fig 6: Check the height of the string from the top of the first fret
Step 6. Adjust the bridge height. (fig 7) For the lowest playing action, lower the bridge until you hear fret buzz. Then raise the height slightly or until the buzz disappears. As you're checking for fret buzz, make sure the strings stay tuned up to pitch. If the instrument is in fair to good condition, this little procedure will help with playability as well as tone. Good luck
fig 7: Adjust the bridge height