With the PianoDisc 128-S units the early control boxes usually need
to go back to the factory to have adjustments made in the control box
so that they will work with an external CD player.  The later ones will
work fine without any changes.

If the control box is mounted very far from the piano you will need to
add a separate power supply for the control box.  PianoDisc sells one
that you just plug the input into 120 volt house current and the output
into the back of the control box.  My experience has been that 25 feet
will work without an additional power supply, 50 feet is questionable
and may work some of the time, 100 feet won't work at all without a
separate power supply.

John Dewey