[pianotech] Tuning stability problem

[Ron Nossaman]

On 9/21/2010 10:00 AM, Ben Gac, RPT wrote:
> Lim,
>
> I've found that many Kawai grands have serious stability issues in
> the treble, the SK-7s that I've tuned are no exception. To tune these
> pianos so that they're stable, you may need to experiment with some
> alternative pin setting techniques. The ruling speculation (I
> believe) is that the wire doesn't move under the capo bar in the
> desired way--you probably have too much tension in your front duplex
> section from pulling the strings up.
>
> When a Shigeru Kawai MP visited our college to tune up our four
> Shigeru pianos, I asked him about the issue. His solution was the
> pull the notes incredibly sharp, then pound the HELL out of them
> until they went down--which they did!
>
> Until you get the hang of adjusting your technique for these beasts,
> expect to make at least two passes in the treble to get it to stay
> where you want.


No, the piano truck doesn't have anything to do with it. Hammer 
technique doesn't either. It is, once again, coming from the back scale. 
That's why pulling it sharp and pounding it makes it drop again. The 
string is pulling through the bridge. There's no way to "read" what the 
back scale tensions are during tuning, so there's no magic way to hold 
your tongue or manipulate the hammer to make the back scale move with 
the front. All you can do is try your best to knock what you just did 
out of tune. If you can, tuning it again will leave it much more stable. 
I find this in Yamahas quite frequently, for unknown reasons.

PS Note, please, the absence of 30K of past replies.

Ron N