Pianotech

  • 1.  Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-02-2022 16:11
    It's time to rethink touch weight on our university's Yamaha CF (1986).

    When I replaced the hammers, I followed the advice from David Stanwood in an online masterclass I had attended.  He had suggested that a concert piano in a performance hall should have a strike weight profile of not less than Zone 9, as defined in his protocols.  This means a strike weight of 12.4g on note 1, 11.8g on note 16, 10.5g on note 40, and 8.4g on note 65.

    Stanwood also specifies a front-weight ceiling, which works out to 41.3g on note 1, 37.5g on note 16, 30g on note 40 and 18.6g on note 65.

    Strike ratio worked out to around 5.8 on this action.  It became clear that if I followed the suggestions above, my balance weight would be a little higher than I would consider ideal, 40 to 41g in the lower notes, dropping to a little under 38g in the top half.

    I decided to go with the recommendations above, knowing that I would have easy access to the piano to make adjustments and corrections when I saw how it turned out.

    I elected to set front weight right at the Stanwood ceiling.  This meant removing some weight from the key sticks in the overstrung section, and adding modest amounts of weight above that.  I chose not do drop below the ceiling, in order to minimize my issue with excess balance weight.

    I chose to install Renner Bluepoint hammers, and manipulated the weight to achieve something very close to Stanwood Zone 9.

    The original hammers were well worn, so I couldn't establish their original weight profile.  I have them archived, so going back to measure what they were at the time of removal remains an option.

    Early user feedback indicated that the action felt heavier than expected, and that the tone was overly subdued.  I did some mid-to low shoulder deep needling with the objective of opening up the tone, then proceeded to use B72 to build the tone.  Several months of use have provided some progress in the playing in of the hammers.

    The arrival of a new piano instructor in our music department opened the door for another opportunity for user feedback.  The new instructor, in collaboration with another trusted artist in our community, spent some focused time at the piano.  The following is feedback that came from that visit:

    "A couple quick observations: the Yamaha needs to be a lot lighter of an action and perhaps brightened up, as it is quite heavy and a bit veiled in tone.  Right now it's a bit of a chore to play on and needn't be. It doesn't really feel like a Yamaha. It has some lovely sound though, and the bass is actually nicer than the Fazioli I find."

    I am considering my options.  I am leaning toward reducing hammer weight, as the hall in which the piano is used is not monstrous in its proportions.  Transgressing the Front Weight Ceiling in the bass is also a thought, since the factory front weight was somewhat higher than the level to which I adjusted it.

    "It doesn't really feel like a Yamaha."  I guess I need to learn what a Yamaha really feels like.

    Thoughts?


    ------------------------------
    Floyd Gadd RPT
    Regina SK
    (306) 502-9103
    ------------------------------


  • 2.  RE: Yamaha CF Touchweight

    Member
    Posted 11-02-2022 16:49
    Consider wippen assist springs to remove FW's inertia. That would mean new reps, I'd go for WNG. A heavy hammer lingers on the string a millisecond longer and kills the high partials. Lighter hammers thru the treble makes it more melodic. The weight of the hammers should have been geared toward the size of the space since you don't have to reach the back row on the third balcony.

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

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



  • 3.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-03-2022 01:20
    "I guess I need to learn what a Yamaha really feels like."
    Floyd, with all due respect, probably what it felt like before you decided to remanufacture it.

    ------------------------------
    Steven Rosenthal RPT
    Honolulu HI
    (808) 521-7129
    ------------------------------



  • 4.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-03-2022 07:50
    Hi Floyd,

    In my experience a 5.8 Strike Weight Ratio level is too high for a SW#9.   More normal for Yamaha would be SW#7.
    If you want SW#9 with a 38BW then you'll have to reduce the ratio by moving the capstan line.

    David







    ------------------------------
    David Stanwood RPT
    Stanwood Piano Innovations Inc.
    West Tisbury MA
    (508) 693-1583
    ------------------------------



  • 5.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-03-2022 08:48
    I'd suspect the Renner blues are a little heavier than Yamaha hammers. So reducing the hammer weight to a lower curve on Stanwood's chart will probably solve most of the problems. We use Renner blues quite often, but I've never heard them on a Yamaha. They should should very nice, but a little different than Yamaha hammers.

    ------------------------------
    Dean Reyburn, RPT
    Reyburn Pianoworks
    Reyburn CyberTuner
    1-616-498-9854
    dean@reyburn.com
    www.reyburnpianoworks.com
    www.cybertuner.com
    www.reyburntools.com
    Facebook: www.facebook.com/dean.reyburn
    ------------------------------



  • 6.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-03-2022 12:06
    Thank you Jon, Steven, David and Dean for your replies.

    The original hammers, as I found them, had been filed multiple times, thus I could not directly determine the original weight spec.

    It was also clear to me that if I ordered a replacement set from Yamaha, what I would receive would not be what was original in the piano, at least in felt composition, as Yamaha began to use Wurzen felt sometime after this piano was manufactured.  I had also come to think, through anecdotal reports, that I could not count on receiving hammers from Yamaha with the same weight profile as the originals.

    I elected to purchase Wurzen felt hammers from Renner USA.  Chip suggested a modification to my plan, which was the choice of Blue Points rather than the Blues.  I took the risk and followed his advice.  I have yet to determine if that ended up being the best choice.

    Usually the 16 pound Renners would be chosen for an instrument of this size.  I chose the 14 pound Blue Points, having received individual hammer weight data from Renner.  I use the Stanwood Precision Touch Kit in my shop, and am more confident that I can bring a hammer up to a defined spec than I am that I can bring it down if it is too heavy.  Achieving the Zone 9 spec involved some addition  of lead, and forgoing coving on some of the hammers.  This leaves me the options of removing some lead, and removing wood from the hammer molding to achieve a lower weight profile.  I understand that a lower hammer weight will also favor a faster departure from the string after strike, which will work in my favor in dealing with the rather veiled sound that has been described.

    I am more inclined to move closer to the original design than to depart further from it.  For this reason, I do not plan to install spring-assisted wippens, and I am disinclined to move the capstans.  Users of this piano in its earlier days described it has having a fairly light touch.  That suggests that my modifications are the source of the heaviness, not deficiencies in the original setup.

    If anyone has data on what the original hammer weights in this instrument might have been, I would find that most interesting.  Also, information on measured action ratio and other action specs from a CF of this vintage would be most informative.

    ------------------------------
    Floyd Gadd RPT
    Regina SK
    (306) 502-9103
    ------------------------------



  • 7.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-03-2022 14:12
    Floyd,
    I would be reluctant to move capstans on a Yamaha also, unless I was absolutly sure it would be an improvement. We do move capstans often on other makes, but almost never on Yamahas. But then, I've never worked on a CF that old so who knows.

    Whether you may want to move capstans really depends on the action ratio, key ratio and wippen ratio.  We offer a free service to analyze geometry if you fill out this form:

    https://www.reyburn.com/geometry.html

    There's a PDF with pictures you can download from the above page.  We use the same custom software to analyze your piano as we do for designing new keysets and action stacks.

    Best regards

    -Dean Reyburn, RPT

    ------------------------------
    Dean Reyburn, RPT
    Reyburn Pianoworks
    Reyburn CyberTuner
    1-616-498-9854
    dean@reyburn.com
    www.reyburnpianoworks.com
    www.cybertuner.com
    www.reyburntools.com
    Facebook: www.facebook.com/dean.reyburn
    ------------------------------



  • 8.  RE: Yamaha CF Touchweight

    Registered Piano Technician
    Posted 11-04-2022 08:56
    David, I reread your reply and realized that I hadn't picked up your indication of a typical strike weight profile for Yamaha. That is very helpful. Thank you

    ------------------------------
    Floyd Gadd RPT
    Regina SK
    (306) 502-9103
    ------------------------------