I reccomend playing around with the modulation matrix. I find it super easy to obtain bell-like sounds from it bu modulating a sine wave by other sine waves that are at higher frequencies, and perhaps some fiddling could result in something more piano like.
Synthesising a piano sound is anything but easy. It's a very complex sound. But there are a few presets or tracks you can open with "piano" sounds for the Pulverisateur and the Heisenberg. Normally for a piano sound, sampling is the way to go. Unfortunately at the moment user samples are disabled.
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