An electronic tremolo effect producing device in which a musical sound signal frequency is deviated by as much as frequencies of two signals having different frequencies each sufficiently lower than that of said musical sound signal by means of two frequency deviation devices. Respectively a part of the output signal of each frequency deviation device mentioned above is fed back to an input side of its own frequency deviation device or the other frequency deviation device thereby to obtain a mul...

In order to facilitate bias adjustment in a single ended push-pull amplifier comprising first and second transistors connected in series between a power source and the ground, a circuit including a capacitor and load connected in series between the juncture of the first and second transistors and the ground, at least one circuit including of a plurality of resistors, one resistor being a variable one, connected in series between the power source and the ground so as to supply bias voltage to the...

A frequency-dividing circuit for signals of sawtooth waveform, comprising: a buffer transistor to the base of which an input sawtooth wave and an output square wave of a square-wave frequency divider are applied in their states of equal peak amplitude through mixing resistors having equal value, and a mixing circuit for obtaining an output of a frequency-divided sawtooth wave from the emitter of said buffer transistor, a compensating DC voltage being superposed at any point of the circuit so tha...

This invention provides an electronic musical instrument capable of carrying out bass performance conforming with chord performance by merely depressing keys in a keyboard for the chord performance. To this end, there are provided a chord detector for detecting the type of the chord including various notes, that is, root, fifth, major on minor third, and major sixth or minor seventh notes when the keys of the keyboard are depressed for chord performance, and bass selectors responsive to the outp...

Disclosed is a tone generator circuit for use in an electronic musical instrument, in which respective output terminals of a plurality of cascaded flip-flop circuits are connected to control electrodes of active elements such as transistors, said active elements are adapted to effect a switching action with their predetermined on-state resistances in response to magnitudes of signal potentials applied to the control electrodes from the outputs of the flip-flop circuits, other electrodes of the e...

In an electronic musical instrument, a sustain keyer circuit comprises a field effect transistor, a resistor and a key-operated switch all connected in series between a ground a power line. An input tone signal supplied to the gate of the FET is keyed to appear at the drain thereof. A capacitor is connected across the key-operated switch. Between the capacitor and the ground is connected another FET which is switched on and off by a rectangular wave having a supra-audible frequency and a variabl...

A frequency-dividing circuit for producing a sawtooth wave comprises at least one stage of a square wave frequency divider and a mixing circuit. Receiving a sawtooth wave or a square wave of a known frequency as a trigger input signal, the square wave frequency diver produces a square wave of half the frequency. The mixing circuit includes: resistors for mixing a sawtooth wave of the original frequency and the frequency divided square wave by equal peak amplitudes thus producing a sawtooth wave ...

A carrier wave having a sub-audible frequency is modulated in amplitude by a modulating wave of a tone signal having an audible frequency, which produces a resultant modulated output signal having first and second side band components respectively deviated above and below the tone signal frequency by a deviation amount equal to the carrier frequency. The frequency of the carrier wave is much lower than that of the modulating wave. This frequency deviation technique is utilized to provide a tremo...

An audio apparatus includes a touch detective muting arrangement. Switch actuating knobs made of metal are electrically insulated from the circuit ground and connected to an electro-static field detector circuit detecting a touch of an operator's finger with the knobs and producing a control signal. A muting circuit is provided in the audio signal path and connected to the detector circuit to be controlled by the control signal. When a finger touches the knob, the muting circuit is rendered oper...

In a keyboard electronic musical instrument having tone generators of frequency divider systems, every key is associated with and controls a plurality of tone keyers which respectively gate tone signals having frequencies being harmonically related with each other. The tone signal gated by one of the keyers is passed through a frequency shifter, while the tone signal gated by the rest of the keyers is not. Among the tone keyers, the above-mentioned one is a keyer for producing an attack signal, ...