Disklavier

There is a universal "result" that any adjustment to piano pedals should
produce.  The standard adjustment should feel the same to the pianist if
they are playing an upright or grand piano.

When using no pedal, the damper should start coming away from the string
when the hammer is half way to hitting the string.  This adjustment is made
phyiscally to the piano action by adjusting the spoons on an upright piano
action, or adjusting the height of the underlevers on a grand piano.  The
Disklavier measures this distance by using hammer and key sensors.
Therefore as long as the piano key stays down there is no damping of the
string.  That is how QRS gets around using a pedal solenoid to get the notes
to sustain longer.  The Loud pedal is a misnomer.  It is really a sustain
pedal.

The Soft pedal is also a misnomer.  On upright pianos, the hammers are
merely moved closer to the strings thereby decreasing their travel.  The
power is removed through the lost motion between the key and hammer.  On a
grand piano, the entire piano action is shifted slightly to the right enough
so that the hammer is only striking 2 instead of 3 strings on three-string
unisons.  It only strikes 1 string instead of 2 on two-string unisons.
Ideally, this adjustment is made so that the hammer is striking the strings
in a different place on the hammer head than a string groove.

When using a pedal on a piano, there needs to be a SLIGHT amount of lost
motion between the pedal being pressed down and any result of the dampers or
piano action.  To adjust the pedals on any model of Disklavier, the physcal
adjustment is made to the piano first.  THEN the solenoid gap and
appropriate sensors are adjusted for the Disklavier so that it can measure
appropriately what is happening to the physical workings of the pedals.  The
grayscale, aside from being a really expensive $300 piece of plastic, is a
sensor that measures incrementally how much the pedal rod is moving, was
used on Disklaviers starting in 1989 with the Wagon Grand.  The only models
that DO NOT have this feature are some upright models:  the MX100A or B, the
MX80 and the MX500 series.

These calibrations of pedal and key movements are made in the Maintenance
Mode.  The pedal calibration is done by setting the number when the dampers
shut off at about 2 seconds.  There is also another sensor adjusted with a
pot adjustment for when the pedal "bottoms out".  When all the physical
dimensions are set, and the sensors are set properly, the Keyboard
Adjustment is run.  This calibrates how the keys play with the pedals.  If
there is a problem, Pass numbers are generated for each key or pedal that is
out of whack and the proper adjustment can be made.

I hope these explanations of the physical properties help for your software
writers!

Carol Beigel



----- Original Message ----- 
From: "Danny" <simpsond@...>
To: <disklavier@yahoogroups.com>
Sent: Tuesday, January 06, 2004 9:46 AM
Subject: Re: [disklavier] About DKV sensors and grayscale


>
> D: I realize that it would be impossible to playback accurately any
downloadable
> MIDI file. (Even a good quality one.) What I am trying to ascertain, is
possibly
> a good 'medium' that *may* help for various MIDI files on earlier DKVs.
The
> biggest problem in working on this this, is that I would need several DKVs
> sitting in front of me to try different ideas on. This may turn out to be
too
> complex to be achievable, but I am investigating it. The main thing that I
am
> looking at is the pedaling issue, and maybe how to lessen the effects on
those
> models which do not support the playback incremental pedaling and are
having
> difficulty in having it adjusted. After personally 'hearing' this thumping
on my
> DKV, I am somewhat motivated in trying to find a 'fix' for those that
cannot get
> rid of it. I will need to find an owner locally in my area with such a
model
> willing to try some MIDI conttoller ideas on their piano. This would be
> difficult to work on something as this 'long distance' by sending out MIDI
files
> for possible trial and error...
>
> D: Danny
>
>