Tuner — Lutherie Encyclopedia

TunerType: glossaryA general term for the tuning mechanism on the headstock; synonymous with machine head or tuning machine.## Definition Tuner is the commonly used general term for any mechanical device mounted on the headstock that adjusts string tension to set pitch. It is synonymous with machine head, tuning machine, and tuning peg, though the latter technically refers to the tapered friction pegs used on violin-family instruments. Tuners for guitars use a worm-gear mechanism that provides a mechanical advantage, allowing precise, incremental pitch adjustment. Modern guitar tuners come in many styles: open-gear vintage designs, sealed die-cast units, locking tuners that clamp the string for faster changes and improved stability, and compact staggered-height designs that eliminate the need for string trees. The choice of tuner affects not only tuning stability and ease of use but also headstock weight and aesthetics. ## In Practice Tuners are selected based on several criteria: gear ratio (higher ratios like 18:1 give finer control), weight, smoothness of operation, tuning stability, and visual style. Installation involves drilling mounting holes in the headstock to precise dimensions. Some tuners mount from the front with bushings, while others thread through from the back. Locking tuners have become increasingly popular because they grip the string mechanically, reducing the number of wraps needed on the post and minimizing tuning instability caused by string slippage. For vintage or traditional instruments, open-back Waverly-style tuners or Schaller-type three-on-a-plate units are common. M…