[CAUT] Harpsichord popping strings

[Ed Sutton]

It may not be the case that going a smaller gauge wire reduces the risk of breakage. It may even increase the risk.
According to tension/frequency formulas, it should make no difference, but Hubbard points out that during drawing, a brittle outer surface is produced. In smaller gauges, this brittle layer takes up more of the overall craoos section, so the smaller wire may have a lower breaking point than the formulas predict. If the wire is not annealed after drawing, even more so.

You might look at the angle of downbearing at the nut. Increased angle of downbearing may cause greater bending at the nut, thus stressing the wire more. Try raising the coil on the pin so the bend at the nut is less. Is there something that increases the friction at the nut? Perhaps there is a rendering problem there. I know there is a tendency to favor bringing the coil down close to the wrestplank surface, thinking that somehow it helps the sound, but I am questioning this belief.

Ed Sutton

  ----- Original Message ----- 
  From: Paul T Williams 
  To: caut at ptg.org 
  Sent: Tuesday, October 12, 2010 8:38 AM
  Subject: Re: [CAUT] Harpsichord popping strings


  They pop wherever they want.  Almost always right at the tuning pin or front "nut" area.  I've had them break on string 3 or 4 and at the very top.  8' or 4', but mostly 8' register.  This is one that tunes at 440 in the regular position, then the action moves down to one new bass string for a 415 tuning, but that would stillmean the strings are all at the same tension all the time.  Our organ professor will occasionally "touch up bad unisons, but never tunes the whole thing.  Nobody else touches it.  We used to have some organ grad students that tuned, but they've been gone for a couple years.  Richard West said this has been the situation for many many years with this instrument, and he would fix strings with a size lower than what was on there, and I do this too.  Perhaps, he thinks that the strings are just getting old and tired and it needs restringing.  (Ugh!! I don't look forward to that project!!) 

  Paul 



        From:  David Doremus <algiers_piano at bellsouth.net>  
        To:  caut at ptg.org  
        Date:  10/11/2010 04:43 PM  
        Subject:  Re: [CAUT] Harpsichord popping strings 


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    I have seen this exact situation more than once, unfortunately. I'd 
  also be curious to know if the strings are breaking at problem areas, 
  like the top of the 4' or the break between iron and brass. Sometimes in 
  building the scale varies just enough to cause problems and you might 
  need to change wire, high notes sometimes need high tensile instead of 
  low, sometimes you can't go quite as high with the brass, or maybe using 
  phosphor bronze or extending a wire size further down might make all the 
  difference. I notice that the string list from Conrad asks for Rose 
  iron, it might be worth trying the Zuckermann iron instead. The Tyre may 
  be quite a bit more historical than the others and strung in 'weaker' 
  wire to begin with. Just a few thoughts...


  --Dave

  On 10/11/10 4:20 PM, Dennis Johnson wrote:
  > Hi-
  >
  > That means also when you are in the 440 position key #1 uses wire #2.  
  > Unless the builder added one more unison set at the top then last note 
  > in the treble will not have any wire to puck so no sound.   When I 
  > first came here the harpsichord was in the low 415 position but tuned 
  > to 440 so they could get all the notes.  That could explain a lot.  If 
  > this is the case, let them know that excessive tension can also cause 
  > warping and sticking registers- or worse.
  >

  -- 


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