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Ken LeVan and LeVan banjos is now part of the Smithsonian Folkways series “North American Banjo Builders”
© LeVan Banjos email ken@levandesign.com
LeVan Banjos are made in the USA from sustainable, non endangered materials.
The “X” brace, with its variations has become the standard bracing design for steel string guitars. It has been used by Martin since the 1850s before the advent of steel strings. No other system has been as successful at producing as good volume and warmth / expressiveness.
The reason it works so well with steel strung guitars is that it is most resistant to distortion in the area around the bridge, and unifies the top in all directions.
My guitars use a fairly traditional X brace pattern and regardless of the wood used for the top, all our braces are made from Austrian spruce, which has the strongest structure of any spruce.
I make both bridges and bridge plates from padauk, which is a very vitreous wood, not unlike the rosewoods.
Padauk is used for marimba bars and is considered by many to be the very best wood for that—it has a very high “Q value”.
I find it to be the perfect wood for bridges.
The area around the bridge is called the “Bermuda Triangle” and is the central truss of the guitar top bracing.
The lower legs of the X cross under the bridge at a place where the bridge is thickened, creating a rigid string anchor.
The half-lap joint of the X is reinforced by a member that bridges the joint
There are a number of design differences between guitars made for flat-picking and fingerpicking. Bluegrass flat-picking is done standing up with the guitar pressed against the body, which makes the back become a reflector. Playing the guitar seated allows the back to resonate, adding an additional dimension to the sound. My guitars are designed to have a resonant back, using thinner wood and a bracing pattern that maintains
the dome of the back in three dimensions.
Of course, this works equally well for flat-picking or finger-picking. As in the top, the bracing is made from Austrian spruce. Back braces are glued with epoxy to eliminate any water from the glue process.
The bridge is the conduit of sound from the strings to the top of the guitar.
Above you see the bridge and a photograph of the Bermuda Triangle lighted from inside the guitar where you can see the relationship of the X to the bridge and bridge plate.
One reason why necks have to be reset on older guitars is a poor connection between the heel block and the body, causing the back and top to slide from string tension.
My “L” shaped heel block makes a rigid connection, not unlike the Spanish foot on classical guitars.
My necks bolt on with two bolts that thread into an anchor in the heel and a third small bolt that snugs the fingerboard extension against the top. The neck is easily removable through the sound hole.
The neck has a stiff mahogany extension that fits into a recess in the top
and keeps the part of the fingerboard that extends over the top straight.
Below you see the dome of the back,which is a 15-foot radius in all directions. The bracing prevents ripples from forming as can happen with traditional ladder-bracing.
The top transverse brace is very rigid and reinforced by braces that go up the sides from top to bottom.
This is the upper limit of the
vibrating part of the top, and
must be solidly anchored to
the sides at that point.
This brace is glued to the
tongue of the ‘L” shaped
heel block assuring a very
rigid connection.
Here you can see the top-view
of the laminated linings which
add rigidity to the sides.
Cherry is used for the “L” heel block because of its extreme stability. Cherry was used for wood type and the backing of printing plates
in the era of letterpress printing.
I It’s also less prone to splitting
than mahogany.
The top of a guitar is the sounding board,which is the primary producer of sound,similar to a banjo head.
The back resonates, reflects or both. The sides, are structural and support the top in such a way as to allow it to vibrate as much as possible when energized by the strings. Sides that are too flexible will absorb vibrations and rob energy from the top—think of the water ripples in a swimming pool with a flexible perimeter as opposed to one with a rigid concrete perimeter which keeps the energy of the water within the pool.
I make guitars with what’s referred to as double sides, which is essentially making two sides and gluing them together. Twice as hard to do, but makes a very rigid structure, and when coupled with continuous linings as opposed to kerfed strips produces a firm foundation for the sound producing parts of the instrument.
below: laminated linings
made in the same form as the guitar body reinforce the sides assembly and provide a good surface for gluing on the top and back
above: double sides—the outer lamination is a bookmatch matching the back, and the inner lamination is usually a lighter weight wood selected to produce a good stiffness / weight ratio. A center lamination can be used with opposing grain.
I make all necks as an engineered laminated assembly. The neck itself is made from two bookmatched halves with opposing grain, which makes the neck stable and prevents warping, and a center stripe of contrasting wood.
The fingerboard is a 4-part assembly with the roasted ipe fingerboard itself on the top and a three-layer lamination with cross-banding in the middle underneath. This middle layer also serves as fingerboard side-markers
Cherry neck showing mahogany and maple center stripe.
The peghead is attached with a scarf joint
Detail showing under-fingerboard lamination
acting as side markers