Tuning the Duplex (was ...Capo)

[jolly roger]

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Hi Jason,
                 Once the hammers start to get very hard on most Yamaha's, 
the forward duplex starts to get very aggressive and zingy.  Reshape the 
hammers if needed, and deep needle the shoulders, between 10-11 
o'clock.  About 6 shots per shoulder at the start of the capo section, 
tapering to about 2 or 3 in the top treble,
If you reshape, remember to raise the hammer line to restore after 
touch.  So figure on a half days work, to shape, voice and touch up the 
regulation.
Lifting all the strings in this section can also help minimize some of the 
duplex noise.

Regards Roger

At 05:21 PM 9/2/02 -0700, you wrote:
>Gordon, thanks for the correction. I apologize for terminology slippage 
>after lo these many years (last time I tuned a duplex, it was when I was 
>restringing a Steinway in 1979, and I had the luxury of new pre-tuned 
>strings at a lower tension). The question remains:
>What's the current *best practice* regarding tuning of the duplex? Do you 
>routinely check and adjust? Can I just take a hammer and screwdriver and 
>tap it forward/back until it is in tune, and then tune the piano? Or is it 
>necessary to lower string tension first? Or should I use a different tool 
>such as a hammer shank to tap the bar?
>
>And next question: should I remove the muting felt from the c4-g4 area of 
>the duplex?
>
>----- Original Message -----
>From: "gordon stelter" <lclgcnp@yahoo.com>
>To: <pianotech@ptg.org>
>Sent: Monday, September 02, 2002 11:41 AM
>Subject: Re: Tuning the Capo
>
>
>| Sorry, Jason, but the "Capo Bar" is the solid bar cast
>| into the plate which provides the forward string
>| speaking length termination point, and downbearing for
>| the bridges ( as oppsed to the agaffes lower down the
>| scale ) I believe you are referring to the duplex
>| (or triplex) bars.
>|
>| --- Jason Kanter <jkanter@rollingball.com> wrote:
>| > Greetings, list. I have met a Yamaha C-series grand
>| > that I will be tuning next week. Took the ETD
>| > "voice-print", played it, and examined the action.
>| >
>| > This piano has a cap d'astro bar in both the treble
>| > and tenor sections. Owner complains that sometimes
>| > the piano has a "ring" that sounds almost like a
>| > telephone. I checked the tuning of the capo and they
>| > are all way off. The highest section, where the capo
>| > section is equal to the speaking section and
>| > therefore should be a unison, is off by more trhan a
>| > semitone. There is no place in the whole capo that
>| > is in tune. And there is muting string-braid-felt
>| > that has been inserted to quiet the lowest 7-8 notes
>| > of the capo (about c4 to g4).
>| >
>| > My question to you is: what's the current best
>| > practice regarding tuning of the capo? Do you
>| > routinely check and adjust? Can I just take a hammer
>| > and screwdriver and tap it forward/back until it is
>| > in tune, and then tune the piano? Or is it necessary
>| > to lower string tension first? Or should I use a
>| > different tool such as a hammer shank to tap the
>| > bar?
>| >
>| > And next question: should I remove the muting felt
>| > from the c4-g4 area of the capo?
>| >
>| > Inquiring minds want to know.
>| >
>| > Thanks in advance
>| >
>| >
>| > || ||| || ||| || ||| || ||| || ||| || ||| || ||| ||
>| > |||
>| >  jason kanter * piano tuning * piano teaching
>| >  bellevue, wa * 425 562 4127 * cell 425 831 1561
>| >  orcas island * 360 376 2799
>| > || ||| || ||| || ||| || ||| || ||| || ||| || ||| ||
>| > |||
>| >
>| >
>| >
>|
>|
>| __________________________________________________
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