Acoustic Guitar Construction

This will be a long sequence of posts before it is over. Ken's gypsy mold arrived a couple of days ago and my first step will be to modify it slightly to accommodate a slightly wider fingerboard than is standard for this style guitar. People have bigger hands today than they did 100 years ago. I am also in the process of modifying the Michael Collins plan to create a sound that is darker and warmer. This design is influenced by John Monteleone's version of the Maccaferri-Selmer instrument as well as some ideas I have picked up from Trevor Gore's book.

Monteleone observed in an interview that it is 10 times harder to get string energy to travel across the grain of the top than with it. For that reason and because I am so impressed with a 1920's Oscar Schmidt Ladder Braced parlor guitar I recently acquired, I am changing the design of the top to get the energy out to the edges and to hopefully let it release there. Thus there are far fewer braces on the top than one normally finds on a Maccaferri-Selmer and they will be constructed like that of a ladder braced with a pinned bridge (like Monteleone used on his version of the gypsy design). Current plans call for only the upper most brace to be coupled to the sides, and it will be firmly coupled.

The sound hole will be slightly larger than the standard gypsy small mouth but much smaller than most 15 3/4 inch guitars. This favors lowering the natural frequency response of the sound box, as it does in the original design. But it is moved to the upper side of the upper bout so that the top does not have a hole in the middle of its main region of stress. This is to make up for the reduction in bracing. I will also leave this "spine" thicker than the "wings" in an effort to more rapidly convert string energy to top movement as it crosses over the top towards the sides, again without sacrificing integrity of the top and its ability to withstand the pull of the strings. I hope that the displacement of the sound hole will also enable a larger monopole and increased bass response and volume (though gypsy guitars are known for volume anyway).

I speculate that part of the reason for the dry, quick attack of the typical gypsy is found in the stiffness induced not just by multiple interconnected braces, but the arching of the extreme pliage as well, so I may use a much milder arching instead - make the top more compliant as one would do in designing a bass speaker.

The saddle placement approximates a 14 fret neck. It could wind up being 13 or 12 frets to the body.

I will post my first draft drawing and welcome comments. I plan on getting some input from Brian Burns too.

Oh boy - looks like a whole lotta fun!!!

It will be fun. I consider the value of laminated sides well established. I also believe the thousand or so Macaferri-Selmer instruments have established the worth of laminated backs as well, but that is not so well regarded and I look forward to checking out how they work in this build. They are tough, light, require no joining strip, and bracing is a sonic issue, not a durability one.

Other parts I have assembled for the build are:

1. Michael Collins back and side set laminated from East Indian Rosewood and Honduran mahogany thick veneers using urea formaldehyde glue, 3 ply.
2. Red Cedar top that I got from Dan Minard 10 years ago. Very stiff, very light, and perfectly quartered. Rings like the bells of Rhymney themselves.
3. Gaboon ebony fingerboard, well quartered, very dark, very old, needs no dye.
4. Honduras Rosewood bridge blank, well quartered, sounds like a marimba bar, with matching veneer on head stock.
5. Red Spruce brace blanks.
6. Michael Collins laminated solid mahogany linings, 7 ply. I did not know how strong they would be until I had them in hand.
7. Fully compensated elephant ivory saddle.
8. Elephant ivory nut with traditional zero fret that I will somehow make work together visually.
9. Heart logo carved into cutaway face with ebony background, opposite sound hole which will be lined with ebony.
10. Gold position markers on edge of fretboard, gold plated tuners.
11. Flamed maple bindings. I designed custom black and white minimalistic "roping" to go inside the bindings and am waiting on a quote from Michael Gurian.

I am making my own plywood from second grade spruce tops for the end blocks, fingerboard support, and foot. I will use a Spanish style neck joint that is forever. The neck will be CF reinforced with a double action adjustable neck rod and a scarfed joint between the neck and head stock.

Some primo materials!!

One ingredient I forgot is the brass plate under the spruce bridge pad. Even though I plan to use a pinned bridge, I think having the strings anchored in brass is part of the Maccaferri-Selmer sound. In the Benedetto DVD there is a segment of a workshop Bob did at one of the meetings in which he stressed the difference between the sound of strings anchored by a wooden tailpiece and a brass one. Bob asserted the wood sounded far better. To my ear they sounded quite different, for sure, neither better than the other. I can hear that sharper sound in the gypsy guitar recordings too. I don't know how John Monteleone approached the underside of his gypsy interpretation's bridge, but I plan to go with brass, both to sharpen the sound and to eliminate the wear problem.

Here is a pix of Monteleone's Hot Club model (top instrument). You can see his pinned bridge, wider fret board, and relatively large sound hole. I don't believe he used pliage on the top either. Once Mario Maccaferri moved to America he and Monteleone became and remained very close, both professionally and as friends.

http://www.monteleone.net/images/galler ... 11x563.jpg

Final detail, while I am thinking about it.

The "standard" sound hole for the small mouth is a 2 1/2 x 2 1/8 inch ellipse. The one in my first draft is 3 1/2 x 2 5/8 inches.