Pianotech

  • 1.  Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 05-11-2022 14:58
    Dear list,
    A client has a double manual 8/8/4 Sperrhaken-Passau harpsichord that he really wants to try to get working. Since he bought it, it has never worked. I think I have located the main issue (see photos,) and I wonder if there’s any hope to get it going.

    The stops for engaging the rank of jacks are pinched by the soundboard/belly rail. My idea is to try to file, remove the section of wood that’s impinging the stop movement. My question is if this could potentially be a cure, or just a band aid until the next seasonal shift? This harpsichord had stout bracing, like a piano, so I wonder how this could have happened in the first place. Less disastrous to my mind is the hitch pin rail (terminology?) is pulling from the rim.

    Any ideas or comments quite welcome!


  • 2.  RE: Sperrhaken-Passau harpsichord

    Posted 05-11-2022 15:21
    It's total garbage. The main problem are the Jack's. They are made with an inferior plastic that now is very brittle. Plus they are not a standard sized jack, they are smaller. This means you cannot even buy a replacement jack. Better to find a more traditionally designed instrument for better tone and easy servicing.
    Chris





  • 3.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 05-11-2022 19:15
    Hi Chris,
    These jacks are actually wooden, and in good shape. Though if they need new plectra, it looks cumbersome. I was reading in the archives about putting on new plectra for this make was more effort than it’s worth.
    The owner is ready to give up the instrument, but wants to give a last shot at making it go, mostly because he doesn’t like to throw things away as useless.

    Thanks for the input.
    Joe




  • 4.  RE: Sperrhaken-Passau harpsichord

    Posted 05-11-2022 17:22
    I can't see the password but I have one of these instruments, derelict however. The main problem is a fetish for leather plectra. Ideally they need to be chopped flush and delrin inserted at the top of the leather.

    Whether your clients is the same or not I don't know but mine is, as is traditional, sealed underneath. It could be helpful to use a multitool to take out a square inspection hole underneath so as to be able to insert an endoscope so as to be able to inspect the structure inside.

    With the help and guidance of Michael Gamble we restored a 1970 Clayson and Garret and I documented it on https://www.youtube.com/playlist?list=PL98A6E31D91961DB9 if helpful.

    Your mention of stout bracing suggests that the instrument might be earlier than mine - I have a single manual which doesn't have the closed bottom which has what could be described as the stout bracing.

    https://www.youtube.com/watch?v=QLwI1FIGWJU shows the composite jack structure - in my experience there is no inherent problem with them other than a dearth of spares.

    The single manual has rather a plucky spirit (forgive the pun) https://www.youtube.com/watch?v=6bgsy05Lm2w and of its sort is a worthwhile instrument.

    Please forgive me - at the moment I'm away from home and so cannot look at the instrument itself. Some jack rails are brass whilst others are wood. Is it the mechanism that's stopping the movement or is it the jack-rails themselves? If wood, then they can be sanded to be thinner. Please email me on antespam@gmail.com any photos showing the problem.

    These instruments are deprecated as a matter of fashion but nevertheless remain worthwhile as our concert recording demonstrated.

    Best wishes

    David P

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    David Pinnegar BSc ARCS
    Hammerwood Park, East Grinstead, Sussex, UK
    +44 1342 850594
    "High Definition" Tuning
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  • 5.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 05-11-2022 21:47
    Use a digital level (wixey gauge) to compare the left and right cheek angles.
    Sperrhake used brass box registers which prevent installation of gap spacers between the belly rail and the wrest plank.
    Despite the heavy bracing, these intruments develop failure at the right cheek/bentside, causing the right cheek to bend upward, and, it sounds like in this instrument the hitchpin rail, and perhaps case liner, are coming loose from the bentside.
    Sperrhake made at least three kinds of jacks over their history. They can be repaired if you work patiently and are lucky to avoid breakage, since they are often fragile.
    You might consider simplifying the instrument to 8+8 or 8+4. This would give you spare parts, make space in the gap and reduce the tension on the frame.
    The leather plectra are probably ruined.
    There are several approaches to dealing with them. It takes great patience to remove the old plectra without breaking the jack tongue.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 6.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 2 days ago
    Thank you Ed. I have proposed to my client to remove one rank of registers to get the instrument working. I'm assuming that removing one register will require me to install some type of spacer? I have never disassembled a harpsichord to this degree, so I'm a bit uncertain what lies ahead or underneath. Something new to discover! 

     I have not inspected all the plectra for condition, though I will before plowing forward. With a little luck, the plectra may not be leather. A quick view of one jack didn't jump out as leather, but......

    Thanks for the suggestions. 

    Joe Wiencek
    NYC





  • 7.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 2 days ago
    Joe-
    You'll have to do harpsichord spelunking to figure it out. With lots of patience I have managed to remove the registers from a single manual Sperrhake without removing the strings, but it was a heroic adventure. It might be easier on a two manual. There is probably some kind of brass clip holding the registers. You may be able to pull two registers close together and omit the third.
    Artis W.'s "explanations" are way off.
    The problem is that the bone or bakelite  strips of the jacks are very brittle, and the mortises of the tongues are worse.  You may be able to scavenge parts by removing one register.
    I was given two worn out Sperrhakes, and eventually made one simple instrument out of them. It was not profitable, just something for my own curiosity.
    I think you will need to be very careful not to dig your hole deeper. Charge by the hour! Or offer to build a Zuckermann kit!

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 8.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 2 days ago
    Joe-
    My memory of working on the two manual Sperrhake, many years ago, is coming back like a bad dream.

    To pull the registers, you will need to pull all the jacks, then remove both keyboards, then detach whatever traps and levers control the registers, then, I barely remember, there are some iron support braces under the registers. When you remove these, the registers will drop down...IF...they are not jammed in between the belly rail and the wrest plank. If they are jammed, then you'll need to lower tension with hope that the case will relax a little and let the registers drop.

    That's just the start! Now you get to decide what sort of repairs are possible...with more injections of hope...and put it all back together to find out if it works.

    An alternative would be to just convert it to a 1x8' instrument. No need to remove the registers or keyboards. Just remove two ranks of jacks and two ranks of strings and use the spare parts to make one rank work.


    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 9.  RE: Sperrhaken-Passau harpsichord

    Registered Piano Technician
    Posted 2 days ago
    David,
    Thank you for sharing the Youtube documentation. Very interesting.  This Sperrhake harpsichord has brass rails guiding the jacks, not wood.  Though I may be able to file them thinner to allow the movement to occur. 

    Joe Wiencek
    NYC