[pianotech] GH-1s

[Ron Nossaman]

On 12/16/2012 11:13 PM, Joe Wiencek wrote:
>
> To Dale, David, Joe and Ron et al,
> I am trying to understand what determinations are considered when
> deciding on making a scale to include trichords or bichords?  WHen you
> (all the piano re-designers out there) describe one scale as having
> better tone than the other, or you will sometimes favor tri-chords over
> bi-chords, what are talking about?  Fundamental volume over higher
> overtones, less inharmonicity, lower break %?  What is meant by "sounds"
> better?  One piano you just "felt" like installing 3-string unisons on
> one piano that particular day and 2-string unisons the next day?  I
> understand that ultimately one decision must be made in order to finish
> the job, but how does one make these determinations? You don't have to
> answer, but I am just very curious.
>
> Joe Wiencek

I can't speak for anyone else, but I personally don't much like wrapped 
trichords. It's not arbitrary and capricious. Finding three wrapped 
strings in the same unison that match well doesn't seem likely in my 
experience. Bichords are more likely to match, and be easier to tune. 
It's easier to mate strings to hammers with bichords than trichords, and 
I haven't run into an instance in which I get the opportunity to 
redesign the piano, where bichords couldn't do what trichords originally 
did at least as well.

I rescale everything I rebuild. If I'm doing a conventional rebuild and 
can't change things to my liking, I can still revise the string scale. 
In this case, if the original had wrapped trichords, I'd leave wrapped 
trichords in the scale. I'd likely make changes to tensions and 
impedance, to improve transitions as I can, but if I don't have 
permission to change the string configuration, I don't do it.

Given permission and a budget for redesign, the wrapped trichords go, 
and are replaced by bichords, along with whatever changes I make to the 
bridge layout. Bichords don't inherently sound better than trichords, 
but I find them less problematic. The improvement in sound isn't from 
any magic characteristic of either bichords or trichords, but the 
balance and smoothness of the overall scale as it matches and works with 
the soundboard. If you put a redesign together and find at the end that 
you have nearly no voicing to do, you made good choices in designing the 
scale, the soundboard, and in choosing the hammers.
Ron N