From Michael Van Dijck via our Facebook page.
Here is an example of the Hohner piano in action:
In this video, Chick Corea plays a Hohner Electra piano with Miles Davis. (Keith Jarrett is playing a different electric piano.)
Electric pianos are of course not strictly synths, as they are electro-mechanical rather than electronic. But these instruments are favorites of ours here at CatSynth.