Over a period of several years banjo legend Earl Scruggs composed several banjo instrumentals which involved the manipulation of 1 or more over tuning pegs whilst playing the tune.
This was originally achieved using two extra pegs on the banjos and a rather cumbersome looking mechanical arrangement on the head stock.
Whilst this worked well it did mean that the banjos headstock would be permanently defaced once fitted.
Bill Keith however being not only a fine banjo player (he is credited as the main driving force behind the development of the melodic banjo style) he is also a great engineer.
With a lot of thought and several prototypes Bill eventually came up with the Keith/Scruggs banjo tuner.
Schaller Keith /Scruggs tuners make it possible to adjust the pitch of a individual string to a pre determined pitch via a simple internal mechanism.
The tuned pitch is fixed with two knurled screws.
The first of the screws locks the desired higher pitch and the second knurled screw locks the desired lower pitch of the string.
The screws when loosened allow the peg to rotate freely as would a regular tuning peg to allow string to be fitted.
All string posts are made of high-grade brass and fitted into the housing with utmost precision, ensuring the best possible tuning accuracy and wear resistance.
The gear ratio of the pegs is 1:4.
The tuner is a sealed unit which is lubricated with Schaller's special grease for lifetime maintenance-free service.
As with all Schaller components all parts are precision-crafted and surface-finished, the self-locking drive ensures an even, delicate and steady tuning.
Schaller D-tuners are supplied with two different string post diameters.
This is intentional as one of them allows you to alter the pitch by a half a tone (the thin axis) and the other means you can alter it by a whole tone (the thick axis). Below is the technical detail drawing for these tuners.
To fit the tuners first remove the second and third string pegs from your banjo.
Now place the Schaller D-tuner with the larger post which has the greater diameter in the hole for the second peg*
Attach the tuner with the hexagon nut and washer so that the two side knurled tuning screws can easily be reached when tuning. Install the third tuner with the small post in the same way.
Schaller D-tuners are most commonly used for 5-string banjo and feature upper and lower thumbscrew stops for alternate tunings in the keys of G and D.
These special tuners are designed for installation in the banjo's 2nd string (B) and 3rd string (G).
A common set up in G tuning is to have the 2nd or B string tuner set with the lower note as A and the higher note as B.
the 3rd or G string tuner set with the lower note as F# and the higher note as G.
This tuning will allow you to play Auld Lang Syne, Earls breakdown and Flint Hill Special as well as many others.
In D tuning (5th string tuned to F# or A) tunes such as Texas Barbecue and Home Sweet Home can be played.
Here is how to set up the tuners for either of these configurations:
To adjust the tuning stops loosen all four thumbscrews on the side of the tuners by one-half a turn and tune the banjo to open G by, i.e. 2nd string to B and 3rd string to G.
Now tighten the chrome thumbscrew on the 2nd string tuner and the black thumbscrew on the 3rd string tuner. This way the strings can not be tuned any higher.
Now tune the strings down to D-tuning by lowering the 2nd string to A and the 3rd string to F#.
To set the low stops tighten the black thumbscrew on the 2nd string tuner and the chrome thumbscrew on the 3rd string tuner.
This way the strings cannot be tuned any lower and the tuners will function only between the high and low stops.
Switch back and forth between the D and G tuning by simply turning the appropriate pegs to the desired preset stop.
An important tip to take on board is to rub a little pencil lead (graphite) in the slots in the nut and on the bridge for lubrication.
This will ensure that the strings do not bind and "Pink" when the tuner is used.
To adjust the tuner's correct friction without slip tighten the large knurled knob on the acrylic pearl button with your fingers at first but if the desired friction cannot be achieved only then should you use a screwdriver.
Never try to turn the tuners beyond the pre-adjusted stops as this may well damage the tuner's mechanism beyond repair.
*the hole needs to be 9,9 mm or 3/8". If necessary the peg holes may need to be reamed to the correct size by an experienced luthier or banjo repair person).