| 摘要 |
<p>Modulation systems for electrical signals representing music in which synchronous vibrato and tremolo modulations are applied to a flute signal in one channel, the vibrato being produced by a bucket brigade modulator and the tremolo by a balanced modulator in cascade with the bucket brigade modulator, and in which in a second channel tones other than flute tones, and pedal tones, are separately treated to have independent vibratos, and in which balanced modulators for modifying the amplitude of the tone signals are concurrently controlled by a common expression voltage. In one modification flute signals are vibrato modulated in opposed phases, and passed via diverse filters to a common tremolo modulator. Provision is made for combining the inputs of the channels, the outputs of which are electroacoustically transduced by separated loudspeakers. Provision is made for slowly varying the frequency of a sub-sonic modulating oscillator, which is either turned off, or operates at about 1 Hz. or about 6. Hz., in proceeding from any one of these three values to any other, the rate of variation being such as to simulate the rate which occurs when the modulations are produced by rotation of a mechanical device such as a rotating loudspeaker.</p> |
