Use and Operation
Sperzel

Locking Guitar Tuning Machines

I have an original Floyd Rose on my 2002 Carvin DC145 and am using Sperzel locking tuners with no locking nut and even with extreme use, my setup performs as perfect as my other guitar that employs a locking nut.

String Installation

Many people only remove and replace one or two strings at a time before going on to the next pair.  This is especially a good idea with vibrato equipped guitars or in cases where neck relief is closely monitored on guitars with low action.

To remove strings, first remove the string tension by turning the tuning key until the string is completely slack.  Once the string is slack, turn the clamp knob counter-clockwise to retract the internal pin and release the string.  The string should release immediately - after which, continue to loosen the knob until resistance is felt and then stop.  If the string fails to release, read this about release failure.

Before installing the new string, turn the tuning key to align the hole in the tuning post so that it points to the bridge.  Attach the string at the bridge end first then thread the string through the nut at the top of the fingerboard and finally straight through the tuning post hole.

Pull the slack out of the string by pulling the end and while holding it tight, lock the string into the tuning post by turning the clamp knob clockwise.  The clamp knob should only be tightened finger tight.  Over-tightening is not necessary and can cause the machine to malfunction or break.  Your string should now be secured (locked) into the tuning post hole.

Once the string is secure, tune it to pitch using the tuning key.  If the tuning post hole was lined up to point toward the bridge before threading the string, you should only have 3/4 wrap or less around the post once the string is in tune.  With locking tuners, having minimal wrap is preferred in order to take advantage of the locking tuner's stability benefits.  Try again if you end up with more than 1 full wrap around the post once the string is tuned to pitch.

The picture below shows the posts with less than revolution of string wrap.

Once you are satisfied with your results, carefully snip the loose, hanging string ends with wire cutters.

New strings will still need to be stretched.  Stretch the strings by doing 1 step bends and retune, repeating until stretching no longer leaves the strings flat.  Because the locking tuner setup has no wraps, this stretching/tuning process will be quicker than with standard tuners.

Tips

• If you are using a standard slotted nut (not locking), the best results will be obtained if the nut has been correctly slotted for the string gauge you are using.
  
  
  String slots that are slightly bigger than the strings are better than smaller because moving a vibrato bar, bending, using hand vibrato, or simply making tuning adjustments cause the whole length of the string (even behind the nut) to stretch and contract.  For stable tuning, the string must slide with little or no friction through the nut slot.  If the slot is too small, the string will hang in the nut and will not return to proper pitch once the tension on the string is released.
  
  So if you sometimes switch between 10-46 and 9-42 gauge strings, have the nut cut for 10-46.
  
  
  

• Before string installation, lubricate the nut slots with powdered graphite (pencil lead).
  
  
  

• Nut material can make a difference.  A graphite impregnated nut is ideal because of it's built-in lubrication properties.
  
  
  

• The maximum diameter string that can be used with a 3x3 or 6-inline set is .058".
  

Maintenance

• The Sperzel machine head is sealed and requires no maintenance.  Do not attempt to oil any part of it - this will attract dirt and really mess things up.
  
  
  

• If the internal pin fails to release after loosening the clamp knob, a *gentle* tap on the tuning post with a small rubber mallet or something similar (non-scratching) will usually jar the stuck pin loose.  Stuck pins have been the result of over-tightening the clamp knob during string installation.
  
  I have not personally seen a pin stick, but it has been known to happen and the "mallet tap" remedy has been reported to cause it to release.  Another trick people use is to insert a small diameter "ice pick" type tool into the tuning post hole and gently pry the stuck pin back down into the shaft.  Try a combination of moving the loosened knob and gently tapping the machine while pushing the tool into the hole.
  
  
  

• When installing strings, remember to only tighten the clamp knob finger tight.

• The only adjustment on the Sperzel is the Tension Adjustment Screw found on the end of the tuning key.  This slotted machine screw should be adjusted slightly more than finger tight so that there is a small amount of resistance when turning the key.
  
  This screw comes torqued correctly from the factory so no adjustment is normally necessary.  If the tuning key ever feels loose or seems to slip, you will need to tighten this tension screw.

Sperzel Locking Tuner Measurements