1. Using a large reamer to create holes for the ebony tuning pegs. 2. Drilling the shortened tailpiece for the tailcord. 3. Carving the tailpiece with a Swiss gouge chisel. 4. Getting ready to saw out the new bridge from a maple block. 5. The new bridge sports dual Fishman transducers. 6. It’s alive! Minneapolis musicians Billy Foster (playing the completed Gibson cello bass) and Jack Flynn jamming in the studio.We began examining a
rare, stringed instrument
in my previous column
[“Restoring a Prototype GibsonCello Bass,” February 2012].
This was an unfinished project
that was started by Gibson during
the ’70s and later sold off
“as is.” My job was to finish the
project and turn this “cello bass”
into a playable instrument.
Though the groundwork
was laid by Gibson, I still
faced many questions and had
to work through a number
of mechanical designs. Once
I understood the neck angle,
scale, body dimension, and size
of the scroll, I was able to get a
clear view of how to proceed.
There were a few cello parts
we needed for completing this
project. I purchased ebony
cello pegs, an ebony tailpiece, a
multi-fiber tailcord, and an endpin
with adjustable rod from
the Howard Core Company of
Anniston, Alabama. Core offers
an abundance of choices, which
made it easier to find parts
that required the least amount
of modification. In addition,
we used some raw ebony and
maple stock from our shop for
carving out the nut and bridge.
One of the few challenges
we encountered was finding
a gauge and length of string
that would accommodate the
scale and design of this cello
bass. Through trial and error,
I found that La Bella’s 760FL
Deep Talkin’ Bass extra-long
flatwounds were the perfect
strings for this instrument.
The extended length allows the
strings’ ball ends to seat properly
in the tailpiece and insure
that the colored thread wrap at
the other end would clear the
ebony nut and wind around
the tuner pegs.
I got out my box of violin
repair tools and blew off
the dust. It has been a good
20-plus years since guitars and
basses took over from violins
and stringed instruments in our
shop. For installing the ebony
tuning pegs, I used a large peghole
reamer (item #0343 from
stewmac.com). To limit peg slippage,
I used bow rosin that I’d
previously mashed into a powder.
This fits between the bushing
and peg, and grips very well.
After measuring out the 34"
scale and positioning a mockup
bridge, I discovered that
the Gibson tailpiece extended
beyond the front of the bridge.
After more research, I realized
the only option was to alter the
stock tailpiece to accommodate
our needs. This required shortening
it to a length of 5". In the
process, we lost all the important
cavities for mounting the
tailcord, a specialized string that
loops around the endpin and
holds the tailpiece in position
when its under string tension.
This step required an assortment
of tools such as StewMac’s
Dremel tool (item #0358), angle
Restoring a Prototype Gibson Cello Bass, Pt. 2 BY john brown
vise (#1820), and luthier’s file
set (#0842), as well as a Swiss
gouge chisel and drill press.
I had to craft the bridge
from a blank of flat-sawn maple
because there was no bridge on
the market that would work
with the neck angle. A cello or
upright bridge would position
the strings a mile off the fingerboard,
while a bass or guitar
bridge would bottom out the
strings. I wanted to give the
bridge some style, but at the
same time it needed to intonate
correctly and also support pickups.
With a smooth, warm, and
somewhat soft voice projecting
from the tonal cavity, it was easy
to conclude that the instrument
really needed to be electrified.
We decided to use a dual-element
Fishman BP-100 acoustic
bass pickup for the job. I positioned
the pickups, tested them
for balance, and finally glued
them into permanent position
using gel-like Super Glue.
After stringing up the cello
bass, I was delighted to discover
that it actually worked.
The project reminded me of
a Frankenstein movie—creating
a creature from bits and
pieces with some unknown risk
along the way. But unlike Mary
Shelley’s book, this tale has a
happy ending
John Brown is the
inventor of the Fretted/Less
bass. He owns and operates
Brown’s Guitar Factory,
a guitar manufacturing,
repair, and restoration facility
staffed by a team of talented
luthiers. His guitar-tool and accessory designs
are used by builders all over the world. Visit
brownsguitarfactory.com or email John at
info@brownsguitarfactory.com.