Duo-Art Concert Grand Vorsetzer
By Dan Wilson
Craig Brougher said:
> There was two ways a DR model Steinway could be fully utilized
> by the Duo-Art. First, as long as there were not huge chords
> played at crash levels in the music, the standard Duo-Art
> mechanism could handle it on a concert grand as long as the roll
> was coded differently to adapt to the DR's greater dynamics. This
> is how it was usually handled when the pianos toured the concert
> circuits. The second way this was done, I believe, was to have a
> large capacity remote pump offstage, with an additional device
> for reading the higher intensities required by the roll and
> providing the piano with greater power at some point ( presumably
> after the spill valve in the expression box closed).
The 65/88n Pianola pushup converted to a Duo-Art Vorsetzer by Peter Davis is used for recitals in London on, typically, Bechstein Model B (six-foot) grands in large drawing rooms, similar pianos in large churches and Steinway concert grands in concert halls. Once it was used on an Allinson grand which would not accept anything more than a mezzo forte touch (i.e. it just became unpleasantly harsh without getting louder). It has a remote pump and traditional Duo-Art grand regulation gear. (And the Pianola treble/bass crossover at E/F -- but rolls are checked for both-sides theme on middle E !)
Denis Hall is normally wheeled in to conduct the necessary adjustments and I've asked him what it is he does. There seems to be a "black art" element to it but at the least, it involves using a pump setting that will produce the right level of "ff" and then setting the two regulator springs to get firstly a proper dynamic slope to match the DA codes, secondly the interpolated theme and accompaniment levels and lastly the right touch at zero levels.
He has become very familiar with the pushup's behaviour compared to his own two critically-adjusted DA grands, and rather than use a test roll, he employs two or three well-known rolls to check sensitive mezzo forte performance and tax the Duo-Art to its upper and lower limits. (I only know that the "fast soft repetition" check is done with the four-hand version of "The Carioca".)
The difference in power needed is very great and there are occasions (as mentioned in MMD 970322) when even the top settings aren't enough to get a piano to speak out enough. In fact, I've never heard the Vorsetzer playing too powerfully for a concert grand.
Dan Wilson
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