Device for producing a vibrato effect for accoustic signals

An electronic organ comprising:

• means to generate a plurality of acoustic signals;
• output means;
• manual and foot control means for controlling selection of said acoustic signals;
• a vibrato apparatus;
• and switch means selectively providing a first path for direct transmission of acoustic signals selected by said control means to said output means and a second path for transmission of acoustic signals selected by said control means to said output means via said vibrato apparatus;
• said tremolo apparatus comprising:
• delay means having an input to which in use said switch means supplies said acoustic signals selected by the control means, and a plurality of outputs at which differently delayed output acoustic signals are developed when an acoustic signal is supplied to said input;
• a scanning matrix having a plurality of first inputs respectively connected to said outputs of the delay means, an equal plurality of second inputs, an output, and an equal plurality of signal coupling circuits each having a first input connected to a respective one of said first inputs of the scanning matrix, a second input connected to a respective one of said second inputs of the scanning matrix and an output connected to said output of the scanning matrix;
• and a scanning impulse generator having a plurality of outputs respectively connected to said second inputs of the scanning matrix and comprising signal generator means for generating pulse signals comprising individual pulses having sloping flanks, which pulse signals are successively applied to said outputs of the scanning impulse generator;
• each said signal coupling circuit comprising control means operative in dependnce on the pulse signal applied to said second input of the signal coupling circuit to control the amplitude of the acoustic signal passed from said first input to said output of the signal coupling circuit.