Key Drive Unit; Amplifier Unit; Shank Stopper - Yamaha disklavier Mark III Series Maintenance Handbook

[Curve of change in the beam amount]
Beam amount
Rest
K1
K2
K3
K4
End

3. Key Drive Unit

This unit utilizes high-power high-efficiency solenoids. The new design provides high thrust while con-
suming only 2/3 the power required by its predecessor, allowing for a wider dynamic range.
4. Amplifier Unit
This unit provides the main switch and the master-volume and tone-control knobs, and is used to adjust
the sound output from the speakers. Setting the master volume to 0 switches off sound from the XG
generator and (in silent mode) from the piano generator, and disables control of volume from the con-
trol box and switch box.

5. Shank Stopper

The shank stopper's drive motor (MD unit) is mounted on the right rear of the key bed. The motor
drives both the shank stopper and the regulating rod.
The regulating rod is attached to the hammer rail (at the front of the regulating button). The regulating-
rod adjustment screws are accessible from the front. For more information, refer to "Maintenance"
below.
A response curve that is measured and stored on the
sensor sheet during manufacture of the key sensor unit.
Open
Rest
Beam amount that is measured at Open, Rest, and End locations
after the sensor unit is installed into the piano
2.7m/m
4.5m/m
6.3m/m
8.1m/m
10m/m (Key Stroke)
End
15
Beam closing distance