One
of the most overlooked components, in terms of guitar, is
the ball end of a string. The concept of a string’s ball-end
is simple. Its purpose is to anchor the string to the body,
bridge or neck of the instrument. Are all ball-ends created
equal? At a glance they all look alike, but they are not.
Let's take a look...
Perhaps
the most common ball-end has a barrel shape with a groove
in the center. They are often made of brass.
There
has been a series of manufacturers who have used stainless
steel ball-ends, or chrome plated ball-ends. The purpose
of this is more cosmetic, than functional. In some instances,
this can be a cost reduction for string companies. The
cost of raw materials such as steel, brass, and copper
has sky rocketed in recent years. This has been due to
world market demands created by many countries continuing
to enter the market in manufacturing and free trade. The
trend is likely to continue.
As
an effort to eliminate the "loop" commonly found
on ball-ends, the bullet shape gained popularity amongst
tremolo bridge users. The loop often contributed to tuning
issues. The bullet shape was a break through in traditional
thinking about string termination. It eliminated many
of the issues with the ball-end loop. The selection of
strings with this type of termination is still fairly
limited on the market.
In
more recent years, manufacturers have powder coated and
painted the ball-ends. This allows for various color coding
schemes. In some cases, this enables brand recognition
for string manufacturers. Notice the inside of the barrel
is lacking pigment as it is difficult to get full coverage
into the barrel. This is purely a cosmetic issue, and
has no effect on the string’s performance.
Sloppy
workmanship, poor tooling, and cheap materials are apparent
in this unrefined ball-end. This is how the ball-end
looked, brand new, out of the package. This was part
of a free set of strings a major guitar retailer was
giving away. This particular string was made in Korea.
String sets given away for store promotions will have
this type of low quality ball-end. When we checked the
material hardness of the brass ball-end, we found it
to be considerably softer than most other ball-ends
we checked. Notice the wrap termination was not secured.
Upon further examination under the microscope, we found
the outer wrap-end to be "pinched" off rather
than a clean sliced cut. This is an indication of a
dull, or worn cutter needing replaced or sharpened.
Everything about this string screamed cheap and low-buck.
This
string is brand new, and demonstrates another ball-end
loop with poor workmanship. The ball-end is contoured
brass that has been nicely powder coated black. This
is a string that was made in the USA by a very well
known string company. Notice the excess string winding
resting against the ball-end. This is perhaps one of
the worst types of errors in terminating
the outer winding. In this case, the ball-end potentially
will never seat properly in the bridge due to the excess
winding being in the way. As a result, the string may
not stay in tune properly. In short, this string should
have been rejected at the factory. Unfortunately, we
have found many string companies are not inspecting
for this type of error.
This
ball-end is from a string set made in China. It is a
low grade brass that allows for ultra low cost strings.
Although we found this particular string to have other
issues, the twist in the loop is fairly tight and well
done. This makes it friendly to bridges with narrow
string channels.
As
you can see there are many differences in the ball-end.
What does a ball-end accomplish in terms of tone and playability?
The answers can vary as there are many things, bridge
related, to the performance of a ball-end. The first place
to look is the loop and twist.
Loop
Patterns
The
loop is the portion of string where the wire has been looped
back onto itself and “twisted” around the ball-end. The loop
pattern has always been a point taken for granted by the majority
of musicians. Many glance at the twist and visually acknowledge
whether or not there is enough wrap to hold the ball-end in
place while the string is under tuning tension. Take a look
at the two twists below. Notice how the Loop Pattern 1 on
the left is tighter than Loop Pattern 2 on the right. In Loop
Pattern 3, there is no loop. The ball-end loop has been eliminated
in this particular design. Depending on the bridge or tailpiece
design, the ball-end loop will have a profound effect on tuning.
Loop
Pattern 1
Loop Pattern 2
Loop
Pattern 3
Spring
Effect
As
previously mentioned, the loop can have a profound effect
on tuning. Some bridge/tailpiece designs require the ball-end
and twist to be completely cut off. Such tailpieces eliminate
the issues found with ball-ends and loops. The majority of
tailpieces and bridges on the market utilize the ball-end
and loop. When dealing with a loop such as Loop Pattern 2
(above), there is a drawback to having excessive tangential
slack in the loop. To illustrate how the loop effects tuning,
we are going to examine one particular scenario we call the
"Spring Effect" in the loop.
Figure
1
In
this illustration we are seeing a cross sectional view
of the bridge or tailpiece. We are also seeing a properly
seated ball-end. The ball is resting on the bridge as
it is under tension. Notice how the string loop is not
in contact with anything on the bridge. The loop is
isolated via suspension from the instrument. In effect,
the loop and string are floating.
Figure
2
In
this illustration, again we are seeing a cross sectional
view of the bridge or tailpiece. In this design, the
string channel is much narrower. The loop is about to
touch the bridge, before full tension is reached. In
this situation, the loop is not going to be floating.
Figure
3
As
the string is tensioned to a tuned state, the loop begins
to compress. The compressing of the loop makes the ball-end
want to spring back against the string. We call this
the Spring Effect. It effects the tuning of the string.
Figure
4
Once
the string is fully tuned, the ball seats against the
bridge. At the same time, the loop retains its Spring
Effect. In some cases the Spring Effect is so strong;
the ball never anchors to the bridge.
Results
In
the figure Loop 1, below shows a brand new string with a fairly
loose ball-end loop. This is a string from a company with
a very well known brand in the industry. The core string has
good uniformity in its shape. In addition, you can see the
normal extrusion marks, or lines, from when it was drawn into
the proper gauge diameter and hex shape. In Loop 2, the same
exact string was installed on a guitar. The guitar had a tailpiece
bridge with narrow string channels. As you can see, there
were dig marks created on the core string from the Spring
Effect. In fact, a small tiny metal burr has developed on
the string. The marks are created by the bridge digging into
the ball-end loop. This occurs once the string has been tightened
to tuning tension. Additional micro-movement by a string being
bent or stretched can create deeper marks potentially creating
a stress point that can cause the string to eventually break
at the loop. Aside from poorly twisted ball-end loops, bridges
and tailpieces that have narrow string channels, without good
chamfering and port holes, some string brands are notorious
for causing the Spring Effect.
There
has been a series of manufacturers who have used stainless
steel ball-ends, or chrome plated ball-ends. The purpose
of this is more cosmetic, than functional. In some instances,
this can be a cost reduction for string companies. The
cost of raw materials such as steel, brass, and copper
has sky rocketed in recent years. This has been due to
world market demands created by many countries continuing
to enter the market in manufacturing and free trade. The
trend is likely to continue. 
As
an effort to eliminate the "loop" commonly found
on ball-ends, the bullet shape gained popularity amongst
tremolo bridge users. The loop often contributed to tuning
issues. The bullet shape was a break through in traditional
thinking about string termination. It eliminated many
of the issues with the ball-end loop. The selection of
strings with this type of termination is still fairly
limited on the market. 
In
more recent years, manufacturers have powder coated and
painted the ball-ends. This allows for various color coding
schemes. In some cases, this enables brand recognition
for string manufacturers. Notice the inside of the barrel
is lacking pigment as it is difficult to get full coverage
into the barrel. This is purely a cosmetic issue, and
has no effect on the string’s performance. 
Sloppy
workmanship, poor tooling, and cheap materials are apparent
in this unrefined ball-end. This is how the ball-end
looked, brand new, out of the package. This was part
of a free set of strings a major guitar retailer was
giving away. This particular string was made in Korea.
String sets given away for store promotions will have
this type of low quality ball-end. When we checked the
material hardness of the brass ball-end, we found it
to be considerably softer than most other ball-ends
we checked. Notice the wrap termination was not secured.
Upon further examination under the microscope, we found
the outer wrap-end to be "pinched" off rather
than a clean sliced cut. This is an indication of a
dull, or worn cutter needing replaced or sharpened.
Everything about this string screamed cheap and low-buck. 
This
string is brand new, and demonstrates another ball-end
loop with poor workmanship. The ball-end is contoured
brass that has been nicely powder coated black. This
is a string that was made in the USA by a very well
known string company. Notice the excess string winding
resting against the ball-end. This is perhaps one of
the worst types of errors in terminating
the outer winding. In this case, the ball-end potentially
will never seat properly in the bridge due to the excess
winding being in the way. As a result, the string may
not stay in tune properly. In short, this string should
have been rejected at the factory. Unfortunately, we
have found many string companies are not inspecting
for this type of error.
This
ball-end is from a string set made in China. It is a
low grade brass that allows for ultra low cost strings.
Although we found this particular string to have other
issues, the twist in the loop is fairly tight and well
done. This makes it friendly to bridges with narrow
string channels. 
