Image Number 7 for United States Patent #4038896.
An organ is described in which a small number of note generators, each comprising a binary divider, a group of keyers, and an envelope generator, serves an entire keyboard. Each note generator is selectively operable by multiplexed signals from a keyboard to produce either of two adjacent notes in any octave interval. Six of these note generators are provided for each manual of a spinet size organ. A seventh note generator, which is selectively operable to produce any of the notes available from the other six, is provided together with selection circuitry which causes the seventh note generator to augment any one of the other six which is called upon to produce two adjacent, or two octavely related, notes simultaneously. The pitch of all notes is determined by a set of top octave dividers which drive the binary dividers individual to each note generator. Synchronizing circuitry is provided to control the phase relation between binary dividers, when they are driven by a common source, to avoid cancellation effects.