Pianotech

  • 1.  Haddorff Bridge Connector

    Posted 12-29-2021 17:21
    Anyone want to guess its purpose? And does it accomplish its purpose? I have no idea.

    https://www.youtube.com/watch?v=wqr4Ja_OTgw
    -chris

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    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    https://www.youtube.com/channel/UCqIJud92EW7YI8La8OyY1nA
    Lenoir City, TN
    865-986-7720
    ------------------------------


  • 2.  RE: Haddorff Bridge Connector

    Posted 12-30-2021 04:26
    How does it connect/attach to the tenor portion of the long bridge? It looks like it just sets on top of the bridge pins, etc. (certainly that can't be the case!)? Probably some silly effort to duplicate the Steinway bass/tenor continuous bridge.

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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    Original Message


  • 3.  RE: Haddorff Bridge Connector

    Posted 12-30-2021 08:18
    I did something similar on an old Bechstein grand to stabilize the bass. I called it a sub-bridge. It coupled the bass and tenor bridges, I think bringing the bass vibrations more toward the middle of the board. There were no adverse affects. There was a section of board behind the bass bridge that required filling with epoxy. This was also done in an effort to reduce the bass apron's canitlever-effect.

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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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    Original Message


  • 4.  RE: Haddorff Bridge Connector

    Registered Piano Technician
    Posted 12-30-2021 15:40
    Jon,

    I'm curious as to what you mean by "stabilize the bass"  Can you describe the tonal issue(s) prior to vs after application? Again just curious as i might attempt using riblets for similar reasons. 

    Thx

    Peter Grey Piano Doctor

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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    Original Message


  • 5.  RE: Haddorff Bridge Connector

    Posted 12-30-2021 16:29
    I looked at my old photos and the bass bridge did not have an apron. But there was a good size portion of the sounding board behind the bass bridge which got filled in with epoxy. The sub-bridge was to add support for the board and bridge in that area. It worked because the system is still working well after 20+ years.

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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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    Original Message


  • 6.  RE: Haddorff Bridge Connector

    Posted 12-30-2021 23:06
      |   view attached
    I think this just got a little more interesting. The instrument i have is a Vertichord and there is suppose to be a patent, but i haven't found it yet. Haddorff has what was called a Homo-Vibrating Soundboard that also included an acoustic coupler. The ads i saw all claim of a soundboard formula that produces an even and rich tone. The formula was suppose to include panel thickness and taper as well as the proper rib dimensions. 

    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    https://www.youtube.com/channel/UCqIJud92EW7YI8La8OyY1nA
    Lenoir City, TN
    865-986-7720
    ------------------------------

    Original Message


  • 7.  RE: Haddorff Bridge Connector

    Posted 12-31-2021 00:00

    That post is a keeper, Jon.

    Thanks.




    Original Message


  • 8.  RE: Haddorff Bridge Connector

    Registered Piano Technician
    Posted 12-31-2021 11:13
    The shape and markings on that piece also look as if it's designed to brace against the cabinet somehow. 
    N. Salmon
    LaVale, MD



    Original Message


  • 9.  RE: Haddorff Bridge Connector

    Registered Piano Technician
    Posted 01-01-2022 00:54
    Chris, thanks for posting this. Fascinating!!

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    Kevin Fortenberry
    Registered Piano Technician
    Longview, TX 75602
    806-778-3962
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    Original Message


  • 10.  RE: Haddorff Bridge Connector

    Posted 01-03-2022 10:24
    Over the weekend, i searched for and through Haddorffs patents. He only filed 3, none of them on the Homo Vibrating soundboard or his Acoustic Coupler.
    Soooo, i thoroughly measured his soundboard and then made an interesting discovery of a subtlety of design which are - An evenly tapered panel and an even rib scale that provides an even stress curve.  I made a video of it. When i install a new board, i will play the piano with the acoustic coupler on and off and listen to see if there is a difference. Its only screwed on so it will be easy to do.
    -chris
    Enjoy:
    https://www.youtube.com/watch?v=i0BMfxe7PvM

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    https://www.youtube.com/channel/UCqIJud92EW7YI8La8OyY1nA
    Lenoir City, TN
    865-986-7720
    ------------------------------

    Original Message