Yamaha Electone BK-4B Owner's Manual page 15

5. The Electone at times reproduces radio or TV sound signals.
This can occur when there is a powerful radio or TV transmitter, or an amateur radio operator located
in the vicinity. If the situation is.distracting, contact your Yamaha dealer.
6. Sound rattling (sympathetic vibration) occurs.
All materials have critical resonance
frequencies at which they vibrate.
Since the Electone
produces
continuous
tones, it is normal
that some will cause windows,
shelves, etc. to rattle.
7. Pedal notes sound too high, and upper manual notes too low.
This feeling may be especially strong for players who switch from the piano, because of the difference
in tonal construction. Each piano note is a combination
of complicated harmonics, and can be heard
only in its interaction with the surroundings. But Electone harmonics are multiples of the integral
(base) tone, and the instrument cannot be tuned in the same way as a piano.
Playing the Electone
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