Kawai X30

The Kawai X30 is a full sized electronic keyboard released sometime in the mid 1990s, featuring analog velocity "Touch response" keys and 16-bit PCM samples.

An interesting fact about this keyboard is that it uses almost entirely off the shelf parts except for the I/O and synthesizer chips.

ROM dumps
As the instruments are stored in a 16-bit PCM format, it should be possible to dump the contents of the keyboard's ROM to extract the samples. However, the samples are stored in the synthesizer chip itself. Unless someone is able to reverse engineer or decap the synthesizer chip, a ROM dump isn't possible.