Pianotech

  • 1.  Yamaha C2 Damper Thump

    Registered Piano Technician
    Posted 02-27-2024 16:27

    Hello all,

    I tune a 1998 Yamaha C2 for our music festival that has a noticeable thumping sound as the bass dampers hit the strings. It is not coming from the trapwork - if I hold down the keys on the bottom half of the piano, lifting the bass and treble dampers away from the string, then the sound goes away.

    I have tried adjusting the dampers so that the front and back of the dampers don't lift at exactly the same time, and I have tried reducing the amount of pedal travel, but the thump persists.

    Obviously an experienced pianist can play around the problem, and in an ideal situation the students would learn to control their feet to release the dampers slowly. However, in this particular situation, this is the recital piano, not the piano that the students get to practice on, and it really is noisier than average. The advanced teachers are annoyed that their students are getting marked down for their pedal work.

    My only thoughts are to replace the dampers and/or slow down the damper return by increasing friction in the guide bushings and/or the damper tray. Is there something I am missing before giving them a quote on damper replacement?



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    Peter Stevenson RPT
    P.S. Piano Service
    Prince George BC
    (250) 562-5358
    ps@pspianos.com
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  • 2.  RE: Yamaha C2 Damper Thump

    Registered Piano Technician
    Posted 02-27-2024 16:45
    Peter

    On a 25 year old piano, the bass dampers will have gotten pretty hard. Try voicing them first, by literally using your voicing tool to fluff up the felts. If that doesn't work, yes, replace the damper felts. 

    Wi 






  • 3.  RE: Yamaha C2 Damper Thump

    Registered Piano Technician
    Posted 02-27-2024 17:51

    Thanks, Wim, that makes sense. It seems weird to replace the felts before replacing the bass strings, but the bass strings sound surprisingly good. It's also weird to think that 1998 is over 25 years ago :)



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    Peter Stevenson RPT
    P.S. Piano Service
    Prince George BC
    (250) 562-5358
    ps@pspianos.com
    ------------------------------

    Original Message


  • 4.  RE: Yamaha C2 Damper Thump

    Posted 02-28-2024 02:02

    The upstop rail in the bass has more than a mm in clearance. 

    LaRoy Edwards said if that happens the damper lever has too much room to accelerate at the end of the keystroke. It gets "flung" and rebounds off the upstop rail instead of dropping slowly like when it has no room. If you hold the key down after the stroke, You might feel a slight bump on the key.
    Keith


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    Keith Roberts
    owner
    Hathaway Pines CA
    (209) 770-4312
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  • 5.  RE: Yamaha C2 Damper Thump

    Registered Piano Technician
    Posted 02-28-2024 12:24

    Hi Keith,

    Sorry, I should have mentioned that I already checked the damper upstop rail - it is not too high, barely above the damper height when a sharp is depressed all the way down. Also, I can make the noise by quickly releasing the pedal completely within the pedal travel. What I mean by this is that if I depress the pedal partially down, say half-way or two-thirds of the way down, and then quickly release the pedal, but not all the way up, just to the point at which the dampers hit the strings, but before the pedal hits the pedal stop felt in the pedal box, the thump is noticeable. So that should also rule out the damper stop rail.



    ------------------------------
    Peter Stevenson RPT
    P.S. Piano Service
    Prince George BC
    (250) 562-5358
    ps@pspianos.com
    ------------------------------

    Original Message


  • 6.  RE: Yamaha C2 Damper Thump

    Registered Piano Technician
    Posted 03-01-2024 00:40
    Are the lyre joints all tight, and the lyre firmly attached to the keybed? That can produce rather thumpy sounds if not all secured.

    Joe Wiencek


    Original Message