Pure Sound (was A 435 or A 440 ?)

[Gene Nelson]

  ----- Original Message ----- 
  From: Stéphane Collin 
  To: Pianotech List 
  Sent: Wednesday, July 26, 2006 2:39 PM
  Subject: Re: Pure Sound (was A 435 or A 440 ?)


  Hi Gene.

  I suppose that the long bridge on that Knabe makes a "hockey stick" shape in the tenor section (reducing the speaking lengths in that area compared to the logarithmic progression).  Is it so ?
  Not really, the low tenor only slightly curves and foreshortens - not even close to a hockey stick but certainly not straight - nor is it a continuation of log scaling.

  In pianos with plain wire trichords on the tenor end of the long bridge (did I understand that this is your intend ?  replace the long bridge wound bichords by plain trichords ?), the use of shorter speaking length induces a drastic drop in tension for those wires, causing an increase of inharmonicity. 
  The piano has 5 wound bichords in the low tenor. My thoughts are to use Pure Sound wire (unwound) in place of wound strings - they would remain bichords.

   My understanding (following Wolfenden) is that this is meant for the tenor end of the long bridge's notes inharmonicity to meet that of the high notes on the bass bridge, ensuring a smooth transition between the two bridges.  I understood that many redesigners on the list don't like that drop in tension and try to bypass the need for it.  
  The scale plotted on PScale is very typical with low tension and high inharmonicity in these low tenor wound bichords. The match with the upper bass notes is not very pleasing.  I hope to raise tension and lower inharmonicity with the use of Pure Sound bichords on the end of the long bridge and eliminate the wound bichord strings.

  How do the wound bichords on the long bridge sound ?  Too much inharmonicity ? 
  The strings were too dead to tell but on PScale this is certainly true.

   Maybe the Pure Sound trichords could be a good idea there, as you suggest. 
  I have not considered Pure Sound trichords but this is possible.

   But if they sound better, wouldn't the transition between those and the bass bridge be more obvious ?  And also, the volume of the Pure Sound notes would be a concern.  Maybe choosing a thicker gauge would help. 

  I have worked this scale using an imaginary third bridge with very good results on paper. 
  The Pure Sound is just a desire to solve this problem very inexpensively and labor in-intensively.
  Thank you for your response.
  Gene

  Best regards.

  Stéphane Collin.


  ----- Original Message ----- 
    From: Gene Nelson 
    To: Pianotech List 
    Sent: Wednesday, July 26, 2006 10:13 PM
    Subject: Re: Pure Sound (was A 435 or A 440 ?)


    Stephane,
    Thank you very much for this information.
    I do not have any experience with Pure Sound but had entertained the idea of using it in place of wound bi-chords in the lo-tenor of a 5'8" Knabe rather than try to get a string maker to wind the ultra small wrap or make a 3rd bridge.
    Sounds like I could indeed get a bit more tension and less inharmonicity. 
    Any thoughts?
    Regards,
    Gene Nelson

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