duplex record

[Ron Nossaman]

>First of all I've never seen one, hence I have no idea what kind of duplex 
>scale they have. 

Dan,
Just a continuous half round, or less than half round bar, leaving all
three rear duplex lengths different for each unison. It never was intended
to be a tuned duplex.

>A second thought occurred to me in response to your "repositioned for some 
>reason" phrase. Apparently some technician thought that the tone could be 
>improved by moving the duplex, otherwise why would a tech attempt to move it. 

In this case, I think the strings had been off of it at some time in the
past (hence the brush marks in the poorly applied plate gilding), and the
duplex bar was simply allowed to fall where it may as the strings were
re-installed. I didn't see any obvious indication of anything indicating
intentional placement. Then again, it may have been carefully placed
precisely there at great expense of time and money for reasons I'm just not
equipped to fathom.


>In this case because f your appraisal method does not seem to have included 
>comparing the pitches of the duplex segments to the speaking length, there's 
>no way to know if the tech who moved the uplex was successful or not. And 
>with the condition of the tuning as bad as it was, according to your report, 
>any work on the duplex would be premature and most probably inexact. To work 
>on duplex tuning, at least in my experience, the piano must be up to pitch 
>and relatively stable.

I don't habitually compare duplex pitches to speaking length pitches on
tuning appointments because I'm normally not particularly interested in
tuning duplexes, and in this specific case I wouldn't have tried it if I
was interested. The shortest duplex segment, as I reported, was 7mm long.
The speaking length, which I didn't specify, was somewhere around 160mm. In
the highly unlikely event that a 7mm duplex would sound audibly (redundant,
I know, but nothing can just vibrate anymore without sounding), how tone
enhancing would you expect a roughly 1/20 duplex ratio to be?  


>As far as doing it "every day" is concerned, a price of a duplex tuning could 
>be anywhere from $250 to $500. I could use one of them every day.

My reference to not caring to do it every day referred to condemning one of
five pianos I had scheduled that day an hour's drive from home and only
getting a service call out of that stop instead of the tuning I was
anticipating - not to tuning the duplex.  


>PS. Would it be possible to get a picture of the duplex scale system? I would 
>like to try to analyze it to include it in my updated Duplex Scale Field 
>Manual Guide.

No, thankfully, it wouldn't.

Ron N