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Yamaha C7 Action noises

  • 1.  Yamaha C7 Action noises

    Member
    Posted 08-01-2015 23:35

    I am trying to reduce or eliminate noise coming from the action on a C7 when the keys are returning . The piano is a Yamaha C7 in a church sanctuary that has had some HVAC issues and of course the usual battle of where to set the ac in the summer.The full Dampp Chaser system had not been in use for a time but now after a full servicing and check out it is operational. prior to doing a thorough action regulation, seating and levelling strings, removing string cuts etc I was evaluating the action as I found it. the noise is about the same with the action in or out of the piano. I tried a number of things on the whippens especially and also measured the hammer flanges , rep lever pinning and jack pinning. I needled a number of things including the jack regulating felt, rep lever height felt and whippen body felt, capstan felt, knuckle core, letoff button felt, drop screw buckskin. The knuckle core felt and the letoff button felt where a little crunchie when I needled with a chopstick needle. When I did a swing test I got 9 swings on the hammer flange. The rep lever only had 2 grams of resistance when I believe it should be 5-6 to support the hammers. Knuckles are out of round, not flat but not in the round either. The springs are not overly strong but I seem to hear the noise as the knuckles contact the jack tip to slip back under. Perhaps someone has a thought what to try next. Seems like I read that the edges on the tips of some jacks need a little rounding off to help the jack return. All I have to do is get one quiet(er) and do the other 87. My plan , as a fellow tech suggested, is to return with a few newer whippens and swap them out to see what that does. However I would like to have a number of tricks in my kit.

    The piano is circa 1981 and was used for many years of concerts. I am concerned that the action noise will come through during softer play, if the piano is miked or if recordings are made. I should also mention I checked the grups in the whippens and they had the green emralon stuff. I saw a tip by Roger Jolly that suggests burnishing the slot with a sharpened shank, application of DAg followed by more burnishing and cleaning the spring end with Naptha . Anyone have thoughts on that ?

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    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------



  • 2.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-02-2015 01:28
    Hi, James:
    My first thought is the knuckles. If they are hard you'll get lots of noise from them. I'd try changing out a shank/knuckle with a new one and see what happens. Also, the jack rest felt. I'm not a Yamaha expert, but that felt can cause a slap when the jack returns if that felt is too hard. I've seen it in other brands.
    I doubt that that cleaning the wippen spring slot is going to reduce any noise, but the action will work better if they're cleaned out where there was gunk.
    Good luck.
    Paul McCloud
    SAn Diego


    I am trying to reduce or eliminate noise coming from the action on a C7 when the keys are returning . The piano is a Yamaha C7 in a church sanctuary that has had some HVAC issues and of course the usual battle of where to set the ac in the summer.The full Dampp Chaser system had not been in use for a time but now after a full servicing and check out it is operational. prior to doing a thorough action regulation, seating and levelling strings, removing string cuts etc I was evaluating the action as I found it. the noise is about the same with the action in or out of the piano. I tried a number of things on the whippens especially and also measured the hammer flanges , rep lever pinning and jack pinning. I needled a number of things including the jack regulating felt, rep lever height felt and whippen body felt, capstan felt, knuckle core, letoff button felt, drop screw buckskin. The knuckle core felt and the letoff button felt where a little crunchie when I needled with a chopstick needle. When I did a swing test I got 9 swings on the hammer flange. The rep lever only had 2 grams of resistance when I believe it should be 5-6 to support the hammers. Knuckles are out of round, not flat but not in the round either. The springs are not overly strong but I seem to hear the noise as the knuckles contact the jack tip to slip back under. Perhaps someone has a thought what to try next. Seems like I read that the edges on the tips of some jacks need a little rounding off to help the jack return. All I have to do is get one quiet(er) and do the other 87. My plan , as a fellow tech suggested, is to return with a few newer whippens and swap them out to see what that does. However I would like to have a number of tricks in my kit.

    The piano is circa 1981 and was used for many years of concerts. I am concerned that the action noise will come through during softer play, if the piano is miked or if recordings are made. I should also mention I checked the grups in the whippens and they had the green emralon stuff. I saw a tip by Roger Jolly that suggests burnishing the slot with a sharpened shank, application of DAg followed by more burnishing and cleaning the spring end with Naptha . Anyone have thoughts on that ?

    ------------------------------
    James Kelly
    Pawleys Island SC
    843-325-4357





  • 3.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-02-2015 05:42


    James

    There could be a lot of things you've mentioned contributing to this return slap noise. but the common problem with older Yamahas are hard knuckles.  I would start with deep needling the knuckles just a you would deep needle a new hammer. Yamaha's earlier knuckle core was a too dense  which contributed to that problem. Many times you can get that noise removed temporarily , but rest assured, it will come back.  Long run, new knuckles should be in the budget, or better yet ( given the age)I would use that as an opportunity to selling the idea of a full action upgrade: new set of hammers, shanks/knuckles, re-pin the wippen levers,and full action regulation.

    I know that you had mentioned return felts throughout the wippens were inspected. But take a look at the backrail cloth as well. If that has become hard and crusty, that too will contribute to a portion of that noise. 
    ------------------------------
    Tom Servinsky
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  • 4.  RE: Yamaha C7 Action noises

    Posted 08-04-2015 02:48


    The rollers are not round, you say. I go along with Paul's suggestion. Go further - get a set of Abel and be prepared to change the lot.    Michael    UK
    ------------------------------
    Michael Gamble
    semi retired
    Brighton
    01273813612
    ------------------------------




  • 5.  RE: Yamaha C7 Action noises

    Posted 08-02-2015 05:41

    Jack rest felt on the regulating button needs to be replaced, needling does not eliminate enough of the noise.

    ------------------------------
    Regards,

    Jon Page



  • 6.  RE: Yamaha C7 Action noises

    Member
    Posted 09-19-2015 21:39

    After banging my head against the wall to get at the source of the noise I finally took a very thin solid red punching and inserted it between the jack regulating felt and the spoon. The noise instantly disappeared. To test further I inserted a punching in the same place on end section whippens. The result was instant. Jon Page was correct. I had suspected this could be the problem from the beginning but the sound seemed to be coming from other places. I think the reason is sound so loud is the vibration passing down the metal spoon into the wood whippen and eventually to the flange and metal rail, What is the best way to replace these punchings and what are the best punchings to use ? I did try needling and it seemed to reduce the noise but I want a more permanent solution. Not that they are making noise but does it make sense to replace the balancier height adjustment felts at the same time ?



    ------------------------------
    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------




  • 7.  RE: Yamaha C7 Action noises

    Posted 09-20-2015 07:13

    You need to remove the wippen and use a blade to cut off the old punching. I use an Exacto with a chisel point blade. Any supplier will have the punchings. You might want to lighten the spring tension so the felt doesn't compact soon, lightening the hammers will allow for less tension on the butterfly spring.
    I've also added a thin punching to the rep lever button (on the support arm) when that was making noise. And sometimes on Renner wips where the spade screw was almost buried into the lever arm.

    ------------------------------
    Regards,

    Jon Page



  • 8.  RE: Yamaha C7 Action noises

    Member
    Posted 08-02-2015 13:43

    Thank you all for responding quickly. I had some noise in a smaller Yamaha some time back so the knuckles could be at the heart of the problem. As I said when I needled the core it was a little crunch. That plus the fact the knuckles are not completely round. I do recall a suggestion about rounding off the edge of the top tip of the jack where it comes into contact with the knuckle when it returns. I tried a fabric softener on the jack regulating felt on that smaller Yamaha and it seemed to help but soon returned. Next visit this coming week I will have some spare parts with me to try out. Any sounds in the action seem to get amplified ten fold with the metal action rails. 

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    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------




  • 9.  RE: Yamaha C7 Action noises

    Posted 08-03-2015 11:59

    Have you considered the wippen cushion cloth? Here's something to try: put a piece of felt between the capstan and wippen cushion. Play the note. Anything change? I had a lot of return noise on a Baldwin grand. I would have sworn it was key return noise from a hard back rail cloth. It was the wippen cushion. I replaced the wippen cushion cloth and that solved the problem. Thanks to Dan Mannino's suggestion for that one. If you don't have time (or there's no money) for replacement, you could try VS Profelt. This would only be temporary to get you through the recording session.

     

    Alan McCoy






  • 10.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-03-2015 12:21

    James -

    Of all the things you are fixing to throw at this piano, rounding the jack edge isn't one of them, at least, not for return noise reduction. Nor would it seem that the jack let-off punching would have much to contribute in return noise, but, at this point, it might be fun to figure out if there's anything you haven't yet needled.  

    Otherwise, you've gotten plenty of good suggestions.  It's not clear, though, where the impetus for this project is originating. Has someone specifically complained about the action noise?  How is this piano used?  Is return noise its biggest problem?  If it did, in fact, require a more major undertaking (action rebuilding), is there a receptive constituency?  


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    David Skolnik
    Hastings-on-Hudson NY
    914-231-7565
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  • 11.  RE: Yamaha C7 Action noises

    Member
    Posted 08-03-2015 20:21

    Because I hold myself to a high standard I want to get to the bottom of the noise problem. It bothers me enough and if that is the case it is sure to bother guest artists when concerts are resumed or there are special events. The church brings in a number of guest musicians and it would be a matter of time before there is a complaint. I had results on a smaller Yamaha when I rounded off the very sharp edge on the jack top but that does not mean it is the problem on this piano but never say never. so far I have not solved the issue but I think I am close. I am more and more inclined to think that the very hard knuckles are the culprit perhaps with the jack adjustment felt. That felt takes a pounding every time it slams into the spoon . When I applied fabric softener to those felts on the small Yamaha it turned the sound off.  I tracked the noise down using an electronic stethescope and found that the sound travelled through the whippen body to the flange rail and got magnified by the metal rail. Several notes playing together amplified the total volume. All of the tips are valuable in this case and in future cases. If the action is shot it would be better to lay it out now with a careful evaluation instead of getting complaints during Christmas season.  Noise troubleshooting  is something that can take quite a bit of trial and error . There is a receptive ear but as always there is always the budget issue too.

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    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------




  • 12.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-03-2015 20:54

    Let me second David S's idea that rounding the jack edge is not likely to be a remedy, and especially Alan McCoy's suggestion (with acknowledgement to Don Mannino) that you take a close look at the wippen cushions as a source of your noise. 

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------




  • 13.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-03-2015 22:10

    For knuckles, I have found one of the best noise reduction methods (besides replacement) is inserting a jeweler's screwdriver blade (a small one, like eyeglasses screwdrivers) between the leather and the core, and moving it back and forth over the curve, to make the leather more supple.

    Let off felts can also produce a slap noise, if the jack tenders hit them as the action is re-setting. It is not completely consistent, depending on the relative return speeds of the key and action, and may have to do with how fast the finger is removed from the key, but there is no question that that noise can be significant (at least heard by the player - it bothers me sometimes). Replacement of felt is best for this as well as the jack to spoon felt.

    I haven't found that needling these felts (wipp cushion, jack to spoon felt, let off, knuckle core) really leads to much noise reduction. If there is noise reduction, it is small and temporary. I think the amount of noise has much to do with the surface of the material, and needling doesn't really help there.

    1981 was a few years back, nearly 35. IOW, it is really time to replace parts. Short of that, you can replace felts and knuckles at a considerably lower cost, with very noticeable results.

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------




  • 14.  RE: Yamaha C7 Action noises

    Posted 08-04-2015 05:32

    If there's room - would gluing a length of felt along those metal rails be, in part, a solution? Deaden the sound transmission. Just an armchair thought - never done this myself.  But I do think the culprits are those out-of-shape rollers (sorry, knuckles)   Michael   UK

    ------------------------------
    Michael Gamble
    semi retired
    Brighton
    01273813612
    ------------------------------




  • 15.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-04-2015 08:53
    Once upon a time, back in the day before it was fashionable to replace everything, we would thread a narrow, thin strip of bushing felt between the leather and the felt in the knuckle to bring them back to round. A darning needle or flat metal needle works. Then clean and  brush the buckskin/ecsaine. Some used drycleaning fluid which is similar in make-up to kerosene so be careful if brushing doesn't work.

    This requires a good bit of regulation as everything from hammer blow on up is changed, but less expensive than replacement.

    And yes it sounds like knuckle noise to me also.

    Nancy Salmon, RPT
    LaVale, MD

    Frostburg State University
    Frostburg, MD.





  • 16.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-04-2015 21:26

    Michael,

    I have actually done exactly what you have suggested on a C7. The action noise was excessive, and I chose to believe that the felt I added reduced the noise. I don't think it made that much difference alone. Maybe several steps can have a cumulative effect to reduce the noise. 

    ------------------------------
    John Parham, RPT
    Hickory, NC
    828-244-2487
    johnparham@piano88.com
    ------------------------------




  • 17.  RE: Yamaha C7 Action noises

    Member
    Posted 08-04-2015 22:35

    Thank you all for the different ideas . I may have a chance to work on the piano tomorrow since there is no activity going on in the sanctuary. A have given some though about possibly trying to absorb sound that travels to the metal whippen rail. If you bought a dishwasher recently the big spec is how quiet they can be. My kitchen aid sounded like a cement mixer even when it was new. I now have a Bosch that whispers. The secret is the increased use of sound isolation and insulation materials, antivibration mounts . A few pieces of a sound absorbing foam placed in the right places may work.

    When I return I plan to try a few of your tips and swap around some new parts. Stay "tuned"



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    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------




  • 18.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-04-2015 22:46

    Instead of foam James, you might want to try some anti-vibrational rubber.

    There are lots of examples on the web where the noise decibel reduction is significant.

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    Paul Brown, RPT
    Vancouver, BC Canada
    Email: paulbrn@telus.net
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  • 19.  RE: Yamaha C7 Action noises

    Posted 08-04-2015 23:01
    The most effective thing would be the addition of mass to the rail.
    Lower it's resonant frequency and it'll quiet down.
    Ron N




  • 20.  RE: Yamaha C7 Action noises

    Registered Piano Technician
    Posted 08-04-2015 23:28

    Ron,

    Wow...cool idea. Kind of like Scotty in the first J.J. Abrams Star Trek movie not thinking that space is a variable in transporting people to an object moving faster than the speed of light.

    The mass of the rail may be the variable over which to dote.

    ------------------------------
    John Parham, RPT
    Hickory, NC
    828-244-2487
    johnparham@piano88.com
    ------------------------------