I think you'll find that all KN6500 keyboards sold in UK are fixed at 230/240volts AC with no switchable option.
Is the mains voltage not 220/230 in Geneva?

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Willum
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Willum

After silence, that which comes nearest to expressing the inexpressible is Music.
Aldous Huxley
( especially when the music is played on a KN7000....)