FW: Tuning Duplex

[Jim Coleman, Sr.]

Hi Richard:

The Baldwin vertical hitch pins are positioned to enhance the duplex
characteristics (well, almost). Since one of the three tail lengths must 
go to a second hitch pin which is shared by the next note, only two
strings per note will be in duplex relationship.

Jim Coleman, Sr.

On Mon, 15 Jun 1998, Richard Moody wrote:

> 
> 
> ----------
> > From: Don <drose@dlcwest.com>
> > To: pianotech@ptg.org
> > Subject: Re: FW: Tuning Duplex
> > Date: Sunday, June 14, 1998 7:25 PM
> > 
> > Hi all,
> > 
> > Clearly the duplex on a piano absorbs energy. Perhaps a better concept
> for
> > them is a filter to effect tone color changes in the manner a tone
> control
> > on a stereo may work if you only can *decrease* the amount of signal.
> > Regards,
> > Don Rose, 
> 
> 
> An interesting concept, but one of many to consider. The most important
> consideration of the string crossing the bridge is down bearing. This can
> only be controlled behind the bridge, where the rear duplexes are, if
> present.  The length of string behind the bridge is also a consideration,
> in that a tail length of 1/8 inch it seems would have a different affect
> on tone, than an 8 inch tail length. Perhaps there is an optimum distance,
> but only a piano maker could know, as rebuilders have limited control over
> this. That the tail length could also resonate and contribute to tonal
> quality is idea behind the rear duplexes in my understanding. 
> 	Now along comes Baldwin with the "acu-just" hitch pins. A bold concept as
> a string riding that high on a hitch pin might cause tuning instability. 
> However it doesn't. Now if these segments are not muted, might they be
> considered part of a "duplex" if so are the acu-just pins positioned in
> such a manner to enhance the duplex effect?  
> 
> 
> 
> 
> 
>