Musical instrument including electronic sound reverberation

Abstract

An electronic reverberation system for use in an electronic musical instrument comprises a random access memory wherein two or more time delay channels are defined by address allocation in a controller circuit. An input analog signal is converted to digital signals by an analog-to-digital converter and the digital signals are processed by the controller into the time delay channels. The channels defined in the random access memory are of differing lengths which can be changed by switch settings. The controller sequentially retrieves stored digital data words from the random access memory channels in seriatum and couples each data word to a digital-to-analog converter. The analog output signal from the digital-to-analog converter is delayed in time by varying amounts due to the length of the channels in the random access memory. A portion of the delayed analog output signal contained in each channel is mixed with the input analog signal to produce a combined signal. The combined signal is converted to a digital data word which is stored back into the random access memory location from which the last digital data word was read. An enhanced reverberation effect is selectively achieved by switchably connecting a low frequency signal on the order of two hertz as an auxiliary input to be mixed with the input analog and delayed analog signals.