OM Mod - Something old, Something new
This guitar was built as a prototype and displays a number of features which drew inspiration from old principles but present themselves in an entirely new and radical way.
Inspired by the How-Orme guitars of the late 1800s/early 1900s, introduced to me by Nigel Forster, I began thinking seriously about soundboard design. How-Orme guitars featured a cylindrical dome running parallel to the strings in the centre of the soundboard. I liked this idea, but felt that there was something missing. The violin family of instruments have long adopted a carved 'belly', designed to resist the string tension and also to aid the projection of the instrument. I combined these ideas in to this guitar. Instead of carving the top, I pressed the thinner-than-usual spruce plate into a former, in a similar manner to the traditional solera methods of Spanish guitars. I painstakingly fitted each brace to the contours. It's much more work than using a radius dish. The result is a soundboard that is just as strong and stiff as a standard steel string top, but with significantly less mass. All of which lends this particular guitar a responsive touch, wonderful rich bass and an open, lively sound.
The problem of string height, high action and resulting playablity issues have been a fairly constant thorn for guitar makers and players alike. To combat this problem many early romantic 19th century guitars featured adjustable necks, one notable example being the Stauffer Legnani model. Given the unpredictable nature of how the radical soundboard design would react under string tension, I saw this as an ideal opportunity to try an adjustable neck. My design owes a lot to Ken Parker's incredible archtop guitars. But, where he uses a square post to prevent the neck from pivoting, I chose insead to use two parallel round posts. All the components in this design were machined to precise tolerances to ensure the strongest possible joint. The main post is made of carbon fibre, which helps keep the weight down with no loss in strength or stability. The adjustment is made from the rear of the guitar with a standard allen key.
Multiscale guitars have proved popular over recent years, but it is in fact a very old idea. The Orpharion, a renaissance instrument from the 16th century, featured a sloped nut and bridge. The string length is increased from treble to bass in an effort to increase the tension of the bass strings for better response and tone. Multiscale guitars are especially suited to playing in drop tunings where the extra tension on the bass strings helps keep the notes together. Most modern builders opt to follow this method, tilting both the nut and bridge. However, one of the key design concepts with this guitar was that the neck could be completely removed and replaced with another entirely different neck, maybe one with standard perpendicular frets, or even one with a much longer (baritone) scale length. As such, the bridge remains untilted and all of the offset in string length is at the nut end. This guitar's scale length varies from 656-644mm and is very comfortable to play.