tb3

Legendary Gibson engineer Lloyd Loar resigned at the end of 1924,
after designing and developing the style 5 Master Model series, including
the Master Model mandolin (F-5), guitar (L-5) and banjo (TB-5). The
name "Mastertone" was derived from the Master Model series and was
applied to the top model banjos that Gibson first introduced in 1925.

This banjo was originally a
TB-3, the lowest model in the
Mastertone line.

The neck and resonator are
maple with a red mahogany
finish, and the hardware is
nickel plated.

The earliest Mastertones incorporated a ring designed
by Loar that was hollow and rested between the calfskin
head and 20 small ball bearings set in the maple rim.
This gave the instrument a more bell-like sound.

The number "42" (serial
number 8207-42) is
stamped on the rim where
it joins the neck.

The skin heads of banjos of that era were sensitive to
changes in temperature and humidity, and the often
necessary adjustments of tension proved difficult.
Gibson engineer George Altermatt conceived the idea of
putting steel springs beneath the ball bearings, perhaps
to create more consistent head tension.

This Mastertone TB-3 has what is now
considered the first true tone ring, namely a
spring-loaded ball bearing ring.

The spring-loaded ball bearing ring on this instrument differs from that
of the earliest ball bearing banjos. The springs and bearings are larger,
and a solid rod is brazed to the top of the 60-hole tone chamber tube. A
second stamping is also brazed to the outside diameter of the tube to
keep it centered within an outside support ring.

In addition to a true tone ring, the Mastertones featured a
change in the resonator plate. The bracket and shoe
assembly was replaced by a two-piece flange, also referred to
as a "tube-and-plate" flange.

The resonator plate is made of brass, and four
hex-head screws attach it to the resonator. The
tension hoop of this TB-3 is grooved, and the
hooks are flattened. The resonator is single-bound.

The original tenor neck has "07" written in pencil
and "42" stamped on its heel.

The original instrument has donated its truss rod cover,
Grover tuners, and lag screws from the heel to the
5-string conversion neck, crafted by Jim Yarborough.

"Mastertone" is etched in mother of pearl on one of
the lower frets of this and subsequent Mastertones.
The fingerboard is Brazilian rosewood with celluloid
binding and features snowflake-and-diamond inlay.

The peghead is fiddle-shaped
and is inlaid in mother of
pearl with a diamond at the
top, the Gibson logo,
snowflake-and-diamond
cross, and curlicues.

"Mastertone" appears on the
peghead of earlier 1925 ball
bearing banjos.

The "Grover patent" tuners
are geared 2:1, as seen in this
and other nickel-plated
Mastertones until the early
1930's. Each has 2 mounting
tabs, the holes for which are
set 180 degrees apart.

The rim is 3/4 inch maple, but is 4-ply, with a machined lip to
accept the tube of the tube-and-plate flange. With the
Mastertones, Gibson introduced double coordinator rods,
which allowed easier adjustment of the action of the springs,
their height above the fingerboard. Two coordinator rods were
used on all style 3 and higher instruments from 1925 until 1942.

The previous owner, Bill Robson,
wrote, "The banjo was bought in 1926
by my father from Lyon and Healy in
Chicago. The stamp is still on the
original head."