The Guitar Gallery Forums - The Guitar Legacy of Matsumoku

The modification to shorten a 5mm hex key.

Instead of my pneumatic cutoff tool or angle grinder fitted w/ a cutoff disk, I used a Dremel like the sort of rotary tool that many folks would have access to. The Dremel was bit slower, but the difference was insignificant. On the plus side, the rotary tool was much more controllable. Cooler cutting, too. Didn't generate enough heat to even singe the tape wrapped around the end of the hex key. The CR-V material cuts like butter.

Next, I will post photos and measurements of the initial neck relief and the degree to which the neck is underset.

Photos displaying initial configurations for:

• Neck relief height (7th fret)
• Action height (20th fret)
• Roller saddle height, relative to straightedge resting on first/last frets
  (Floating bridge set to bottom of adjustment range)

The guitar is strung to pitch.

After examining the String-to-Pickup Gap, my focus has shifted.

Presently I am in the midst of performing a series of small truss rod adjustments over several days in order to slowly reduce forward bow to the point where the fret board is nearly straight. After that task is accomplished, the next step will be to lower what now appears to be an excessively high saddle. Prior to examining the pick up gap, I believed I needed to address what was initially perceived to be an underset neck issue. Now I think there is a good prospect of not needing to reset the neck at all.

The target for the P/U gap is 3/32" (0.094"/2.4mm) +/-. [The target for string action height is 1/16" (0.063"/1.6mm).]

I am going to lower the saddle by removing the bridge's thumb wheel adjusters. Then the strings will be brought back up to pitch and refinements will be made to raise/lower the saddle accordingly.

In the neck pickup photo, the bass E string is pressed to the last (20th) fret. I didn't have enough hands to fret the string again while photographing the bridge pickup, but I doubt whether doing so would have reduced the size of the large gap very noticeably in the picture.

Check the neck to body angle. Many of these older Japanese full hollows had a habit of warping up at the neck pocket. Is the neck set or is it bolt? On the two Arias, Conrad and Lyle I had to shim the neck to compensate for the neck pocket warp.

The neck is a "bolt-on" (probably wood, rather than machine screws).

Following are rough measurements for use in TundraMan's "Neck Angle" calculator (http://www.tundraman.com/Guitars/NeckAngle/index.php)

24.409" - Scale Length
14 ... - Fret Number Where Neck Joins Body
0.30" - Height Of Fingerboard At The Neck Join
0.85" - Height Of Bridge (saddle)
0.40" - Increase In Top Height From Neck To Bridge

A result based on these initial numbers suggests that the neck needs a 5° correction. But that result is largely determined by the present saddle height. It seems to me that adjusting the neck to suit an excessively high saddle leads to extra work. The large 'string-to-pickup' gap still needs to be reduced somehow, presumably by fabricating spacers to be inserted between the guitar top and the pickups.

Noob question: Why not drop the saddle height first?

The saddle rollers are captured in a frame that rests on thumb wheel adjusters threaded onto studs sticking out of the top of the floating bridge's base. Removing the thumb wheels lowers the saddle height significantly. Closing the "string-to-pickup" gap so that pickup inserts are not required. Also lowering the string action at the fretboard. If the saddle height needs fine adjustments, suitable shims can be inserted between the saddle roller frame and the top of the bridge base.

If the figure used for "Height of Bridge" is reduced from 0.85" to 0.65", the calculator result suggests the neck still needs a 4° correction for proper string action, but the string-to-pickup gap has been dealt with.

Images of lower saddle height (thumb wheel adjusters removed)

It's not the saddles that are high. If you have to remove part of the original bridge to bring the action down there is something wrong elsewhere.

Why else would they have installed a bridge that incorporated thumb wheels to adjust bridge height?

Stop and think about it. The saddles didn't grow over time. The bridge didn't magically get taller. The body didn't somehow get fatter around the middle with old age (like we do). I suspect the neck pocket warped. EVERY one of the hollows I had made the way yours is had this issue. There is very little support at the neck joint in the body.

Absolutely true, especially when looking at acoustic guitars.

Three of mine are experiencing this problem (two are Vantages) and the only remedy is a neck reset which I'm not equipped to do, nor is it financially feasible to have done elsewhere.

The capo is my best friend now.

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The strings on this guitar were ALWAYS a long way above the fretboard. What you see in the photos is not something that developed over time, that's essentially the way the action was when I received this new in '69 as my second guitar. (The bridge on my first, a #7 Suzuki Parlor, lifted within a year of purchase. A likely consequence of being tuned by an adolescent using a pitch pipe and being restrung with a gauge unsuitable for the Suzuki's light construction. Have the Suzuki and am working on it, too.)

Loved the look of the double Florentine cutaway and the Dark Cherry Burst then and still do. Hated what it did to my fingers. That's why it has ZERO fret wear after 54 yrs of ownership. Couldn't bring my younger self to push through the discomfort long enough to learn how to play. For a variety of personal reasons, it wouldn't have been feasible to discard this instrument in favour of something that played better, even if I had known at the time that there were other instruments out there that were more pleasant to play.

None of which is to say that there ISN'T a problem w/ the neck pocket. Only that the issue existed from the get-go.

Just want to cure the deficiencies and get it to a state where I can play it and enjoy myself doing so before I croak. That's an accomplishment that would help fulfill some obligations ...

Could you elaborate a bit on using a capo to compensate for neck angle issues.

Thank you

I've had a couple of acoustics that the neck joint started to warp, both older Japanese. I had a Japanese Alvarez 12-string that developed a belly so I made and installed a belly bucker and it brought the action right down on the fingerboard.



That's surprising. I don't know if I could have tolerated that. A neck shim fixed the high action on all the old hollows I had. Luckily all of them had fully functional truss rods in them, a couple took a while to get the bow out of them though. I like a very small amount of relief to avoid string rattle but only a small amount.