Harpsichord string breakage

[Avery Todd]

Hi Stephen,

>Assuming overall pitch of the instrument is 440 as you said, and that,
>when you >say Bb is the problem note, you mean Bb in the A440 position...

   No, it's Bb in the A-415 position. That's where the maker's instruction
sheet says to put it. Here's a direct quote: "List for replacement of
strings and plectra, with keyboard in the middle (A=415) position."

>so length is 315 mm, dia.
>0.28 mm on Bb. It's pretty close to the max for Rose brass wire, probably
>similar for
>whatever else brass you might be using, except the disgusting phosphor
>bronze wire
>which is only suitable for plumbing repairs. Your problem string is
>sitting at less
>than a semitone to breaking, so any unusual mechanical stress might very
>well be
>causing your breakage, or even variation in wire strength. Try a size
>smaller in that
>section.

   There is more than an octave above that of the same size wire, so I
wouldn't "think" a smaller size would be the cure. Right?

Avery

>Stephen
>
>Stephen Birkett Fortepianos
>Authentic Reproductions of 18th and 19th Century Pianos
>464 Winchester Drive
>Waterloo, Ontario
>Canada N2T 1K5
>tel: 519-885-2228
>mailto: birketts@wright.aps.uoguelph.ca