Thank you very much, Peter.

I had never heard of silver strings before, however please rest assured I don't like cutting the corners (which of course tells nothing about the final quality of the 4-5 harpsichords I made), so if an overwound string is needed an overwound string will be installed. I'll find somebody who can do overwound strings or I'll try and learn how to make them.

Your notes on the fL and on the wide tangents in Hubert are of the utmost interest, I'll come back often to your and Chris's and George's and the others's posting while making.

(this list is full of great professionals and helping guys, I think I am a member since 20 ago, it was 1996 or maybe 1997...)

Domenico

> Il giorno 06/feb/2017, alle ore 22:51, Peter Bavington <[log in to unmask]> ha scritto:
> 
> Domenico wrote:
> 
>> And BTW, the Hubert is doable without overwound strings? it has 7 notes
>> - 14 strings - less than the Silbermann in the bass, but it should be
>> about the same length, so I guess the Hubert should need about 16-18
>> overwound strings? Or am I missing something?
> 
> Overwound strings are needed when the sounding length of the string is too short for solid wire to sound well. In my opinion, and as a rule of thumb, you should consider using them when the frequency multiplied by the sounding length *in metres* - the fL as Thomas Donahue calls it - is around 105, and they are definitely needed when the fL falls to about 60. [As an aside, we really need a name for this useful measure, which gives us a handle on the scaling of any particular string. The dimensions of fL are the same as speed: could we call it 'scaling speed'?]
> 
> I had a look at the string lengths on the 1789, as recorded in Koen Vermeij's superb study of Hubert's work (*The Hubert Clavichord Data Book*, Keyword Press edition 2016). Bottom C has a sounding length of 1194 mm so if the instrument was tuned to a1=415 the fL would be about 62. I conclude that it might just be possible to make this instrument work with solid strings. You should consider red brass and, for the lowest notes, silver wire.
> 
> Incidentally, silver for strings needs to be hard-drawn: the wire sold for use in jewellery is too soft. Ask for sterling silver (not Brittania silver, which is almost pure and, like pure copper, cannot be used for strings) and get it drawn as hard as possible.
> 
> As a general rule, clavichords of a reasonable size - like this one - which go down no lower than 'cello C' can often be made to work with solid wire, but they will almost certainly sound better with twined or overwound strings. Those that go below bottom C definitely need overwound strings.
> 
> Hubert himself used them on the 1789 clavichord. He always provided the overspun notes with special tangents, forged or bent over so as to provide an extra-wide tangent top. On the 1789 instrument (which, incidentally, is the latest clavichord by C. G. Hubert to survive, made four years before his death in 1793) there are 12 of these special tangents, so we can be pretty sure Hubert thought that overwound strings were needed for the lowest octave of notes.
> 
> Now, I know that the Hass family aparently never used overwound strings, even on their five-octave clavichords, though other Hamburg-school makers did use them. The bottom bass notes of a typical Hass have an unpleasantly squashy feel IMHO and the note is only saved by the presence of the 4-foot string. I will stick my neck out and say that the Hasses would sound even better than they do now if they were fitted with overwound strings in the bass.
> 
>> how do you professionals calculate string diameter for clavichords?
> 
> The actual mathematical calculations are the same as for harpsichords. The final choice of diameters will be the result of trial and error; but one must start somewhere, and what I think most of us do is base our initial stringing on (1) previous experience; (2) guidance from the old makers by way of gauge marks on surviving antique clavichords; and (3) calculated tension graphs of the type given in the last section of the book by Malcolm Rose and David Law (*A Handbook of Historical Stringing Practice for Keyboard Instruments*, available from Malcolm [http://www.malcolm-rose.com/Stringing-Practice/stringing-practice.htm] and very reasonably priced). The subject is complicated, and both Jean Louchet and Thomas Donahue have written at length about it:
> 
> Jean Louchet, *The Keyboard Stringing Guide* 2009, available from Lulu
> 
> Thomas Donahue, *The Harpsichord Stringing Handbook*, Rowman and Littlefield, 2015.
> 
> A final word: it is a lot of hard work to make a clavichord. Why compromise, and 'spoil the ship for a halfpence of tar'? If it needs overwound strings, find a way of getting them.
> 
> Hope this is useful, Peter.
> 
> -- 
> Peter Bavington
> Clavichord Maker
> 291 Sprowston Mews
> LONDON
> E7 9AE
> www.peter-bavington.co.uk
> 
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versity of Iowa.  For a brief  summary of list  commands, send mail to
[log in to unmask]  saying  HELP .
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