The “planetary geared” peg makes tuning easier on violins, violas, and cellos. There are several additional reasons to favor them.
Geared pegs are a newer innovation when it comes to useful – some may say ingenious – stringed instrument accessories. Widely available both online as well as at the local violin shop, these pegs boil down larger points of difference – some might say conflicts – within a relatively simple, small thing.
If you’re new to what a geared peg is, here’s the simplest explanation: the tension and therefore tuning of strings on any type of stringed instrument (violin, viola, cello, bass, ukulele, etc.) can happen at either end: the pegbox at the top of the instrument, or the fine tuners at the bottom of the instrument (toward the chinrest on a violin). But for the most part, the tuning pegs at the scroll end are most frequently adjusted to achieve proper tuning.
Historically, these pegs were held in place and adjusted by friction between the peg and the surrounding pegbox wood. But a geared peg is more technically advanced. Hidden inside what appear to be traditional pegs are a set of planetary gears – so named because they involve a smaller (the “sun”) and larger (“ring,” like planets) toothed gears – that do two things. One is that they allow for more precise tuning because it takes bigger, more exaggerated movement by the hands of the instrumentalist to achieve smaller changes in the tension. Second, it makes the process of tuning easier for those hands (i.e., less pressure and strength is required).
So what’s the conflict?
For starters, Stradivari, Guarneri and all other pre-20th century violinmakers never worked with geared pegs. These are modern innovations, arguably in the category of steel (not gut) strings and composite (not pernambuco) bows. Purists may scoff, but under many conditions and circumstances these newer innovations make sense. What’s interesting is that makers of geared pegs are careful to ensure the appearance of the pegs is preserved, not visible to anyone observing the instrument even at close distance.
Another conflict that is essentially solved with geared pegs is how abrupt humidity differences require acclimatization of the instrument and therefore frequent tuning. This is because wood pegs and the pegbox into which they are inserted are made of different types of wood that respond differently to humidity and aridity. The traveling violinist, violist or cellist knows how important this can be.
But perhaps the conflict resolution that geared pegs provide that is of greatest benefit to the vast majority of players is the ease with which geared pegs are adjusted. Children and older adults, or anyone with compromised wrist biomechanics, may lack the sufficient strength to execute the somewhat awkward maneuver of traditional pegs.
Is the sound different when played on an instrument with geared pegs? As with gut vs. steel and pernambuco vs. composite, it mostly boils down to the player and their pragmatic considerations (and having a good luthier to install them). In some cases it’s almost impossible to know, since those gears are hidden within the traditional-appearing pegs.