I make one bass model — an adjustable-neck 3/4 gamba that I developed back in 2000 as an effective orchestral/solo hybrid. My goal was to make an instrument with the ergonomics and projection of a solo bass without sacrificing the warmth and depth of an orchestra or recording instrument. I work alone — one bass at a time — in a workshop thirty feet from my house in Oliver BC. I am singularly focused on the quality of my work rather than productivity. Each bass is hand carved by myself; no steps are automated.
My bass incorporates a modified version of Jim Ham’s adjustable neck — a brilliant and elegant design that has proven itself over more than twenty years. Its main advantage is to allow the use of a proper solid bridge and avoid response-destroying bridge adjusters. I would never consider making a fixed-neck bass. The design is simple and rugged and allows for fine action adjustments in seconds with the turn of a single tool -- with no effect on tuning. While the purpose of the design is to allow fine action adjustment, it is reasonable to consider the neck removable for travel — although one should be skilled and perfectly familiar with bass setup and adjustment in order to set the soundpost, bridge and strings.
I make a highly arched fingerboard and narrow, Gary Karr spec string spacing of 22mm for 1, 2 and 3 and 24mm between 3 and 4. This string spacing is non-negotiable as it is critical ingredient of the design. If you haven’t played a bass with this setup, you’ll find left hand articulation and double stops easier — and your bow will enjoy the room once you get accustomed to the higher arch. The narrow string spacing reduces leverage forces acting upon the bridge and it adds to the bass’s quick response. The lower corners are well out of the way and the C-bout is narrow for bow clearance. Standard string length is 106mm or 41 3/4" but I have made successful basses with 103mm or 40 1/2" string length. The standard bass has an E-flat neck and a three-octave fingerboard.
Here is a video of Gary Karr playing my 2005 (Sarah Klein) bass. Quite entertaining.
Forward to 12:50 for the beginning of the concert.
While the bass feels small due to its sloping shoulders, it is actually a proper largish 3/4 as it carries its extra volume in the lower bout. It does fit a 3/4 medium Mooradian bag and David Gage hard case. The body is 45” long with a lower bout of about 25 1/2'“ (ish) and an upper bout of 19 1/2”. The rib depth is about 8” and the upper ribs narrow at the back bevel to allow a very comfortable fit and excellent access to higher registers. If you're familiar with Ham's bass, mine shares only the design of the upper block itself -- the entire shape is otherwise different with a longer body, fuller bouts, different corner positions, and entirely different arching and back design.
The design of my back is unlike any that I know of. I make a "domed" (or arched in all directions) flat back with deeply carved edge fluting — and most importantly — a soundpost brace made of the same wood as the back with the same grain orientation; this is very important. Traditional flat back basses use spruce braces glued across the grain of the back -- creating a structure that is inherently and unavoidably unstable with changes of temperature and humidity. My soundpost brace is positioned similarly, but the grain orientation and wood type matches that of the back. This allows all the advantages of a flat back without the downsides — stresses induced by changes in humidity are vastly reduced. The domed arch creates a very strong structure that needs no other bracing and it's very stable with changes in humidity. Having said that, it is still wood -- and wood moves with changes in humidity. You can expect my back to behave as a carved back in terms of stability. To the untrained eye, it looks like a normal flat back from the outside and not the least bit unusual — but inside, the secret is revealed. Shh.
I make my own lightweight kevlar-reinforced tailpieces and lightweight ER-16 collet-type 10mm titanium endpins.
I generally use Irving Sloane tuning machines — although I am slowly developing my own… which I will make in my metal shop some day.
I love carving — although my basses are the only thing that I carve. My edges are finely crafted with ebony and linden purfling and deep, curvaceous fluting. The edges take an amazingly long time to make. The f-holes receive beautiful fluting too.
The finish is a reddish-brown oil varnish — applied by brush. I don't care for a perfectly even application of colour and prefer a slightly “tortoise-shell” mottling. You may choose how red or how brown you’d like yours. Varnishing takes a few weeks.
The finished bass pictured is of white spruce with claro walnut ribs and back — and a western maple neck with a black ebony fingerboard.
I use this image to give wood suppliers what they need to know.