Abstract: A method and apparatus are disclosed for the dynamic control of a MIDI synthesizer filter. A digital filter controlled by a plurality of filter coefficients is preferably coupled to the output of an excitation signal source within a MIDI synthesizer. The excitation signal source is typically controlled by a MIDI data file comprising a sequential series of program control commands and matching note on and note off commands. A plurality of filter coefficient factors are stored in memory and periodically accessed in response to variations in the program control commands and matching note on and note off commands. The selected filter coefficient factors are then utilized to calculate appropriate filter coefficients so that the center frequency and filter Q of the digital filter may be dynamically and optimally controlled.

Abstract: A system and method automatically providing wrap interconnections for wrap diagnostic capability of analog-digital conversion systems obviating the need for wrap cables. A connector system has a first state wherein DAC outputs are automatically internally routed to corresponding ADC inputs thereby closing a wrap loop whereupon automated DAC to ADC loop tests are performed. A second switching state is provided automatically by insertion of connector plugs into the connector system whereby the loop is broken and DAC outputs and ADC inputs are made available externally to respective output and input connectors. In one embodiment the switching system has application to an audio digitizing capture and playback adapter card. In the first state the card is automatically configured for a wrap diagnostic test.