Patent GB-957949-A (GB)
Abstract: 957,949. Electrical musical instruments. A. A. VOLODIN. Aug. 4, 1960, No. 27023/60. Heading G5J. A single voice electric musical instrument (Fig. 18) comprises a semitone keyboard 1 (Fig. 1), a batten 14 extending under the keys of the keyboard along the length of the keyboard for taking up lateral movements of the keys due to quivering of the player's fingers, a transducer 15 connected with the batten 14, a circuit connected with this transducer for superimposing a vibrato effect on the output of the instrument, a sensitivity control 16 for controlling the degree of vibrato for a given amplitude of vibration of the batten, and means 19 for producing a vibrato effect independently of vibration of the batten, The instrument also includes a fingerboard 1 for free intonation. Two pedals are provided (Figs. 10,11 not shown) which can each be moved horizontally to control a rheostat and can also be moved vertically to control a rheostat. The rheostats control loudness, timbre and smoothness of transition from note to note. The keyboard 1 and fingerboard 2 regulate a D. C. input to a smoothing unit 3 whose action is controlled by vertical movement of pedal 4. Smoothing unit 3 includes a capacitor which causes extended decay of pulses. The pulses are fed to an oscillator 6 whose output is fed to a group of frequency dividers 7, 9. The number of dividers in use is controlled by switch 8. Output frequency divider 9 is fed to a monostable multivibrator 10 whose working cycle is controlled by horizontal movement of pedal 4. A circuit 12 produces output oscillations of complex spectral structure. The envelope of these oscillations is controlled by the keys 1 and fingerboard 2 acting on circuit 12 through an attack control 13. Batten 14 is physically connected with transducer 15, the output oscillations of which are fed through sensitivity control 16 and a switch 17 to an amplifier circuit 18 for obtaining frequency vibrato, circuit 18 being connected with oscillator 6. Alternatively switch 17 may connect a generator 19 with circuit 18 for obtaining automatic amplitude vibrato. The signal produced by circuit 12 passes through a filter 20 providing appropriate formants, through a volume control 22 regulated by vertical movement of a pedal 23 and to a filter 24 whose pass band is controlled by horizontal movement of pedal 25. The output is applied to loud-speaker 27. The fingerboard (Figs. 7, 8) comprises an elongate base 45 wound with resistance wire 42 whose turns can be pressed into a longitudinal groove in the base 45 to make contact with a common electrode 44, the turns of the wire being held away from the common electrode by resilient packing 49. The winding of resistance wire 42 (see Fig. 6) has tappings connected on the one hand, to rheostats 43, and on the other hand to movable contacts 35 of the keyboard. A sleeve 50 of elastic film keeps out dust and moisture from the fingerboard. On pressing a key down, the corresponding movable contact 35 (see Fig. 2) is put into contact with a common contact 34. The keys 28, 29 are broadened at their attachment ends, which are provided with strip springs 30 by which they are attached to the keyboard frame. Upward travel of the keys is prevented by a batten 32, and downward travel by the batten 14. A wound resistance wire 36 extends the length of the keyboard and is connected to the movable contacts 35 by wipers 37 which serve to tune the keys and fingerboard. Pulses generated by playing the keys are shaped by a circuit comprising two integrating circuits and a differentiating circuit (Fig. 12, not shown). The transducer 15 comprises a movable electrode resiliently held between fixed electrodes (Fig. 5, not shown). Specifications 335,997, 339,225 and 403,365 are referred to.