Typogram
Select the right type of Stephen Paulello wire, whatever the piano
Select the right type of Stephen Paulello wire, whatever the piano
To choose the type or types of strings suitable for each note of a piano, you should note down the scaling and enter every dimension in the Excel calculation sheet especially conceived for this purpose: the Typogram.
It is free of charge, can be downloaded and opened with an Excel program or equivalent.
According to the stress intensity, the steel does not react in the same way :
Changing the type of wire does not affect the tension of the string, it only affects the stress rate of the metal.
The stress rate of a string depends mainly on its vibrating length, the frequency at which it is tuned and the breaking load of the material.
Consult the technical files to learn more
Measuring and noting down the dimensions is an important step necessitating concentration and precision. It is easy to forget a note or to place oneself on a note on the agrafe side and on the neighboring note on the bridge pin side. It is strongly advised that two people undertake this work together. If you have a portable computer, keep it close to you so that you can enter the elements into the program as soon as you have measured them.
Measuring vibration lengths :
You will obtain the most accurate measures by using steel rules of different sizes. Take the middle of the agrafe or the middle of the capo d’astre as departure point, and the middle of the front bridge pin (situated towards the vibrating part of the string) as the arrival point.
Measuring diameters :
If there is no number on the frame or on the bridge, and the model of piano is unknown, use a micrometer to measure the diameter of the existing strings, or ask for a calculation of the scaling.