Changer
The Sierra changer is an all-pull triple raise/double lower system. This means that any string can be raised 3 separate times and lowered 2 times. To accommodate the players with more complex tuning specs, we offer additional raise-and-lower capabilities. By means of a ’Äútandem’Äù system the Sierra can easily achieve these multi-change situations and still be tunable at the endplate. In Figure 5, you can see that the two raises are utilizing shafts #1 and #2, E to F and E to F#. To get another raise, E to F# again, a rod with no bushings is threaded through a bell crank in position D. On it is a collar with set screws (X) and a two holed slide block (Y). The rod on #1 passes through (Y) with a collar (Z) which is tightened on the pull rod ahead of the slide block (Y). As #3 is moved, its collar moves the slide block which contacts the collar on #1. Since #3 has no bushings, it will not affect the changer; #3 works directly on rod #1, which in turn will affect the changer.
To tune
Turn pull rod either clockwise or counterclockwise, turning #3. Clockwise will decrease the distance between X&Y, thus raising a greater distance; counter-clockwise will do just the opposite.
Change-lok
The ’Äúchange-lok’Äù is used for locking a change or changes into place: it maintains the change until released- Change-loks are hand-operated, and usually used with the universal tunings. The E9th with change-lok on E’Äôs to E-flat gives a B6th. The player can then use all his jazz pedals without being hampered by holding a knee lever in for an extended time. When he releases it, he is back to Nashville E9lh. Fig. 13 depicts this mechanism. The change-lok is tuned as follows:
1. Adjust change-lok cam so that maximum travel is opposite knob direction.
2. Adjust change-lok and mount plate so that with the cam engaged the knee lever is pressed hard against stop.
The change-lok, when engaged properly, will put the KL cam in the same position it would be if the normal KL was engaged.