CLAVIERS BAROQUES -- how to determine the proper replacement wire for the broken string on your harpsichord or clavichord

Method 1 -- The most reliable guide to the correct replacement wire for a broken string is the broken string. There are exceptions, of course, but in general, if the one that was there sounded OK until it broke, a new one of the same sort will do as a replacement. So, the question is, what sort was the original string?

• material -- soft iron, yellow brass and red brass are the most usual materials for historical harpsichord and clavichord wire. You may find steel wire on some revival instruments, but we recommend replacing it with soft iron where possible for better tone and sustain. If you are like most people, you will not have a metallurgical lab handy, but you can tell a lot by the colour, placement and behaviour of the wire:
  • Italian harpsichords will typically be strung all in yellow brass
  • French and Flemish instruments will typically have soft iron in the treble and mid-range, going to yellow brass in the bass and red brass in the very lowest bass.
  • Revival instruments may be strung all or partially in steel wire, but steel wire rarely breaks (although it does go black).
  • Early historical 'copies', those from the 1960's and 1970's, often have phosphor bronze wire in the bass, which goes a distinctive reddish-purple with age. It is not much used anymore as the tone goes dull in a year or two. If you have broken a phosphor bronze string you will probably want to replace it with yellow or red brass; contact us to determine a suitable replacement. You may find the tone so much better that you will want to replace all your phosphor bronze!
  • Some older (ie, early to mid 20th century) harpsichords and clavichords have overwound strings in the bass. This is a core string that has a smaller wire wound around it. We can duplicate these strings if you really want them, approx cost $50 per string, but in most cases a good red or yellow brass will do as well or better. The overwound strings were used because good, large diameter brass wire was not generally available until the 1970's, so builders prior to that copied piano bass strings.
• diameter -- you will need to know the diameter of the wire you are replacing. On stringed instruments, wire diameters are smallest in the treble, expect sizes like .0085" or .009" at the top, and get larger toward the bass. You will probably find sizes like .012" and .016" in the midrange, increasing up to .025" or even larger in the bass. A micrometer is the only accurate way to measure the diameter. Old wire, especially brass, will probably have stretched a bit, so it may be slightly smaller than when it was new. If you do not have a micrometer, you can always mail a sample to your wire supplier (that would, I hope, be us), who will have a micrometer. We will also be able to identify the material, too, if that is in question.
• loop -- the strings of most harpsichords and clavichords and their cousins are attached at the hitchpin by means of a loop. You can buy ready looped wire or buy lengths of plain wire and make your own loops. If you want to make your own loops, here is how to do it. Note: A few instruments have one wire serving two strings as modern pianos do, in which case there is no hitching loop, instead the wire is attached to two adjacent tuning pins at the near end and runs around a hitchpin at the far end. If your instrument is one of this sort, email us so we can make you up the proper replacement wire.
• length -- the replacement wire should reach from the hitchpin to the tuning pin plus enough extra to wind a substantial coil on the tuning pin; an additional 9 or 10" / 25 cm is usually lots.

Method 2 -- the other fairly reliable guide to correct replacement wire is the stringing schedule for your instrument. Most builders provide them with the instrument, they are included in the instructrions for kit-built instruments. Usually it's a piece of paper (although they often get lost, especially when an instrument changes hands) but sometimes it is pencilled in on the wrestplank, sometimes behind the nameboard. A stringing schedule will give you the material and diameter of the wire used for every note on your instrument, although usually not the length, you will have to measure that. It is worth observing that builders are constantly revising stringing schedules, they are not so much prescriptions as recipes. A good builder, like a good cook, will use the schedule as a starting point but will make his/her final choice of wire based on what his ears tell him. If you do not have a stringing schedule for your instrument, one for a similar instrument will still be useful as a guide, check out our library of stringing schedules.

OK, if you're ready to order, our wire page is here, you can order on-line or the olde-fashioned way.

Do you have a specific question? Perhaps we can help via a phone call or private e-mail, feel free to contact us.

September 1, 2010