GB1149860A - Improvements in or relating to electrical musical instruments - Google Patents

Abstract

1,149,860. Electronic musical instruments. WARWICK ELECTRONICS Inc. 28 April, 1966 [28 April, 1965], No. 18714/66. Heading G5J. In a monophonic instrument, operation of a key produces both the associated tone signal and a gating signal which allows the tone to pass to the output with a percussive waveform. As shown, operation of any of keys 11 allows the output of its associated tone generator C 2 which is in the form of a succession of rectangular waves 21 to pass through a frequency halving circuit 18 to a diode 38. This diode normally prevents the signal reaching voicing networks at the output 59, but operation of the key also removes the earth made by the normally closed top contacts of the keys and a diode 28 from a condenser 30 which begins to charge. A waveform as shown at 33 appears at its output which opens the diode 38 so that a waveform as shown at 51 passes to the voicing networks and the output, decaying as the condenser 30 becomes fully charged. A resistor may replace diode 28. In the arrangement of Fig. 2 (not shown), the note is sustained should the player release the key before the percussive pulse has completely decayed and a capacitor is provided to cut off the tone less abruptly than would be the case if the percussive signal were removed.