METHOD OF DIGITALLY CONTROLLING THE ENVELOPE IN A POLYPHONIC MUSICAL SYNTHESIS INSTRUMENT, AND CIRCUITS TO PUT THIS METHOD INTO PRACTICE

摘要

Envelope curves for a large number of individual sounds to be digitally synthesized are generated by storing sample envelope shapes. The duration of the stored curves is varied by exercising control over the sampling of the stored envelopes. The smooth transition from one envelope curve to another is accomplished by sampling the new curve at a fast rate until substantially matching values of the previous and new curve are found and then proceeding with the sampling of the new curve at the desired rate.