CP70PKUP.GIF is a picture of the pick-up system of the Yamaha
CP-70B Electric Grand Piano.

Each note has a separate string bridge/piezo pick-up assembly
as shown in the picture. The pick-ups are wired in parallel
with one electrode grounded and the other connected to a
common bus. The connections are made using wire-wrapping
techniques.

The audio bus is then fed to a discrete FET pre-amp.