Disklavier

The physical adjustment of the pedals is different for uprights than it is
for grand pianos.  There can never be any standardization that would work
for both models.  What started this whole thread about annoying pedal
thumping has more to do with trying to deal with MIDI data on files from the
internet rather than  Yamaha PianoSoft files optimized for Disklavier use.

It is more a difference in the physical properties of the different piano
models.  There is a reason the U1 costs more than the M500 models.  It has
to do with design.  The trade-off is appearance versus function and
stability.  The MX500 is a noisier piano than a DU1A.  The pedals have
different solenoids.  The solenoid gaps are different.   The Disklavier
software is different.  The ROM is different.  The price is different.

For upright pianos, the damper pedal must lift 66 or so damper levers from
one end of a rod suspended by 4 hangars.  Furthermore, when you press the
pedal down, you are pulling down on one end of a seesaw; the other end is
rising and pushing up a rod that lifts one end only of another rod that
swings out moving the 66 damper levers away from the strings.  In a
Disklavier, a solenoid is built into the pedal rod.

In grand pianos, the dampers are much more efficient.  To start with, they
are located at the strike point of  the hammer on an ideal node that is 1/8
the speaking length of the string.  Either the hammer or the damper is
striking the string.  (Obviously you can't do this on a upright as the
hammers would always hit the dampers on the way to the strings. Therefore
the dampers are placed below the ideal position on the node.)  When you push
the damper pedal down on a grand piano the energy follows a more direct
path.  The back of the pedal pushes up a rod that pushes a lever with a
small pitman rod connected to the center of a tray that pushes up the 66 or
damper levers.

Because of the felt bushings, wear and tear can flatten their dimensions
creating a wrong size gap in the solenoid.  This adjustment needs to be
checked form time to time to keep the pedal solenoids from overheating and
shutting down the system.

Yamaha Disklavier is the only system that uses in-line solenoids on their
pedals.  No other system works as well.  In fact, the QRS folks have
modified their MIDI files (called continuous pedaling) to hold down the keys
longer so you don't even need a pedal solenoid at all.  However, the
difference in pedal nuance would drive a DKV owner crazy!

Just remember that Yamaha is NOT responsible for whatever data is contained
in third party files.  If your Disklavier plays PianoSoft files properly,
then your DKV is working just fine!

Carol Beigel