This post is the third in a series of posts about the typical maintenance a piano needs, that is in addition to piano tuning. As your piano tuner Wilmington DE, I find that many piano owners do not realize that in addition to tuning, the mechanical part of the piano, the piano action, needs periodic maintenance, as well. The piano action consists of all the moving parts of a piano, from the piano keys up to the piano hammers which strike the piano strings. The action is made primarily of wood, but there are numerous other materials, such as felt and buckskin, which are prone to wear. The tolerances on a piano action are so small, that any wear on these parts will decrease the sensitivity of touch of the instrument.
The previous two posts discussed “lost motion,” and “hammer blow” regulation, two of the three most common adjustments needed by a vertical piano. A vertical piano is one that typically stands up against a wall. This post will discuss “let-off” regulation, the third most common adjustment needed on a vertical piano. A little background is necessary to explain the importance of this third adjustment.
The whole point of the complicated mechanism of the piano action, is to make the action touch-sensitive. That is, that the pianist can control the volume of each note separately by varying the force applied to each key. This sensitivity allows the pianist to express themselves with the performance of the instrument. It seems natural to us now, to have a touch-sensitive instrument, but before the piano was invented, a harpsichord played at the same volume on each note, no matter how much the player’s touch varied from note to note. The modern piano has ten major adjustments that much be regulated within very narrow limits, in order for the the piano to have a sensitive touch. The third most common adjustment needed on a vertical piano, is called, “let-off.”
“Let-off” refers to the distance away from the string that a piano hammer stops when the key is pressed very slowly. On a vertical piano, the hammer should move toward the string, and then rebound when the hammer is 1/8″ away from the string. When the key is pushed more forcefully, the hammer travels that last 1/8″ of it own momentum. The harder the key is pushed, the louder the sound that results, hence touch-sensitivity is accomplished.
As a piano wears with use, the let-off distance tends to increase, so that the pianist must push each key more forcefully in order to get the hammer up to the string. The result is a loss of sensitivity, especially for soft playing. By restoring the proper let-off distance, the piano technician Wilmington DE can restore your ability to play softly under control.
If you have questions about the maintenance or tuning of your piano, please allow us to help. We are your Delaware piano tuning services experts, and we also provide piano services in Philadelphia, Eastern Shore Maryland and Southern New Jersey.