LSR
Locking Guitar Tuners reviewed
Traditional stringed
instrument tuners wind the string around a rotating post to control
string tension. The introduction of headless instrument designs
spawned a different approach, where tension is applied through
the linear, in-and-out motion of a threaded rod. The LSR tuner
is a clever adaptation of this principle of linear thread tuning
to a design that can be mounted on conventional headstocks.
Advantages of the
LSR design
The great advantages
of the LSR design are that the strings are locked to the tuner
and there are no extra loops of string to shift and cause tuning
drift during vibrato. Because of the locking design, the string
starts at minimum length so only a few turns of the tuner are
required to bring it up to pitch and the fine thread pitch of
the tuner screw results in a tuning ratio of 40 to 1 (conventional
tuners are 18 to 1 at best and often less) so tuning is very fine
and precise. Compared to many other tuners the LSR’s are
also light in weight, so they don’t throw off the instruments
balance by making it neck heavy and the tuners low profile means
that string trees may not be needed. In use the LSR’s are
extremely stable and they cannot be knocked out of tune like conventional
buttoned tuners.
Disadvantages of the
LSR design
The disadvantages are
that the string hole in the tuner post is smaller than often found
on conventional tuners so the maximum string gauge is limited
to 0.06 inches. Also the top E string often needs more stretching
to get up to pitch, so much more of the tuners limited travel
is used when tuning the top E. This makes it essential that the
top E is held as tight as possible when locking the string to
the tuner, otherwise it won’t tune all the way up to pitch.
This is complicated by the fact that the string lock mechanism
often seems to have problems securely gripping the smallest diameter
strings. When installing a fresh set of LSR's it may be necessary
to swap around tuners for the top string, from others in the set,
to find a tuner that grips well on the top E.
The finite travel of the tuner post does mean that, with tremolo
guitars set up with a floating trem, it is necessary to temporarily
shim up the tremolo plate to its desired rest position, whenever
all six strings are removed, before fitting a new set. If this
isn’t done the tuners may not have sufficient range to tension
all the strings to pitch.
Fitting and use
Unlike conventional
tuners, all the mechanism of the LSR tuner is mounted on the front
of the headstock, an integral bolt passes through the headstock
and engages with a keyed plate and a nut, to hold each tuner in
place.
Early versions of the
LSR design used a central hex screw, which had to be tightened
using a separate wrench, to lock the strings in place. The current
design has a built-in clutch that allows the tuner barrel to do
double duty, first to tighten the string lock and then to tension
the string to pitch.
Strings are fitted
by first rotating each tuner barrel clockwise until the string
post or hub decouples and pops out of its housing by about 2mm.
At this point the built in clutch engages the tuner barrel with
the locking screw. A further two turns will back out the locking
screw and allow the string end to be passed through the hole in
the tuner post. With the string pulled taught, turning the tuner
barrel anticlockwise will tighten the locking screw and lock the
string to the post. With the string tightly locked, the locking
clutch is disengaged by simultaneously pushing the string post
back into its housing, while turning the tuner barrel in an anticlockwise
direction. Once the tuning thread has engaged, the tuner barrel
is turned until the string is up to pitch. A grooved channel in
the body of the tuner guides the string around a 90 degree turn,
after it emerges from the locking point on the end of the tuner
post. This allows the tuner barrel, threaded post and housing
to protrude at right angles from the guitar headstock, in the
fashion of normal tuner buttons.
Conclusion
Once a set of strings
has been installed and tuned to pitch the LSR tuners perform very
well indeed. Tuning is extremely stable, they are unaffected by
the sort of occasional tap that would throw conventional tuners
out and tuning adjustment, when required, is free of backlash
and very fine and precise.
Copyright 2006 Terry
Relph-Knight |
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Locking
guitar machine heads (or tuners)
A successful design
for a stringed instrument tuner must allow for the string to be
easily and securely attached to the tuner mechanism. If the strings
slips or moves on the tuner, the instruments tuning won't be stable.
Traditional tuners
rely on wrap friction, which is adequate if string tension, once
brought up to pitch, remains constant, but isn't reliable for
modern guitar technique that involves a lot of extreme string
bending and tremolo (vibrato) arm use.
Locking tuners, designed
for these modern playing styles, incorporate some form of clamping
mechanism to positively secure the end of the string to the tuner,
before any tuning tension is applied.
This clamping mechanism
usually involves tightening a screw, that bears against the string
and holds it in place against a surface inside the tuner. For
early designs, string locking was a separate action from tuning
the string. A common drawback of these designs was that they were
unnecessarily complex and heavy. The extra weight in the tuners
tended to make instruments more neck heavy, so they didn't balance
as well for playing. Early designs also had parts which tended
to unscrew, fall off and get lost.
Recent locking tuner
designs like those from Gotoh and Grover are lighter, simpler
and use the action of tensioning the string to pitch to automatically
tighten the locking mechanism. These locking tuners look almost
indistinguishable from non-locking designs. Since the locking
mechanism is hidden the designers have been able to produce a
range of retro styles that can be fitted to older instruments
without changing their appearance.
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