Abstract: An encoder providing on a single terminal of a circuit package a composite serial data stream containing both stored data bits of a multistage binary memory and a clock signal needed for decoding the data. A parallel to serial converter serially shifts the stored binary data bits to an output thereof in response to clock pulses of an internal clock, and a logic circuit responsive to both the internal clock and the serial binary data from the converter generates first, second and third signals of amplitudes discernibly different from one another respectively in response to 1-state data bits, 0-state data bits and the termination of clock pulses. Two fixed inputs to the converter respectively provide a 1-state start bit at the beginning of the set of data bits and a 0-state stop bit at the end of the set of data bits for purposes of decoding. An amplitude discriminating decoder uses the periodic third signals and the start and stop bits to decode the serial data.

Abstract: In an audio amplifier for amplifying signals from an electric guitar or the like having a conventional tone control circuit for selectively emphasizing input signals in the bass, middle and treble frequency ranges of the instrument, a multifilter circuit for emphasizing input signals with frequencies in selected, relatively narrow, frequency bands in the upper portion of the frequency spectrum to minimize aural fatigue. The multifilter circuit comprises a plurality of parallel connected, two-pole, resonant filter sections with different, relatively narrow, resonant frequency bands separated from one another by an amount on the order of 1/4 octave and forms a signal path that supplements the signal path provided by the conventional tone control circuit. The signals produced on the output of the tone control circuit are mixed with the multifilter output signals.

Abstract: A sound effect circuit with a phase shifter producing a signal shifted in phase with respect to an input signal, a combining circuit for arithmetically combining the input and phase shifted signals to produce an output signal, an oscillator for periodically modulating a characteristic frequency of the phase shifter and a modulation control circuit. The modulation control circuit causes the modulation rate to gradually increase when modulation is manually switched on and to gradually decrease when modulation is switched off. The modulation control also causes the characteristic frequency to vary inversely with the modulation rate.

Abstract: A circuit for providing a predetermined contour for the audio signal produced by an electronic musical instrument. A reference potential which is changed under predetermined conditions, and an unidirectional reference current which may also change under some or all of the predetermined conditions, are applied to a circuit which changes the amplitude of the audio signal from its existing level to a level determined by the reference potential at a rate which is determined by the reference current.

Abstract: This invention relates to an improved bracing structure for a stringed musical instrument of the type having lower frequency or bass strings and higher frequency or treble strings, and a bridge through which the strings are coupled to a soundboard structure. The bracing structure is formed on the underside of the soundboard and serves both a mechanical-structural and a mechanical-sonic, or acoustical function. The structural function is to protect the soundboard from damage resulting from the torsional forces resulting from the pull of the strings on the bridge, which forces are transmitted through to the soundboard. This function is accomplished by a torsion bar positioned substantially in axial alignment with the bridge, torsional forces applied by strings to the bridge being transmitted through the soundboard to the torsion bar, and a framing bar structure physically connected to and acting through the torsion bar to distribute the torsional forces from the bridge area of the soundboard.

Abstract: This invention relates to a circuit for mixing a direct audio signal with a reverberation signal. The circuit includes an amplitude control for the reverberation signal and an active gain producing element such as, for example, a field effect transistor (FET). The direct signal is applied to the element in a manner such that this signal is amplified by the element. The reverberation signal is applied to the element through the reverberation amplitude control in a manner such that, as the amplitude for the reverberation signal is increased by the amplitude control, the gain of the element for the direct signal is reduced, thus maintaining uniform output volume. Thus, the output from the element has both a direct signal component and a reverberation signal component, the direct signal component decreasing as the reverberation signal component increases.