A system for generating waveforms or sounds by combining basic waveforms or sampled sounds prior to further processing with filters and envelope shapers. ...
OB-Xa
An enhanced version of the OB-X, the OB-Xa also was "available in four-, six-, and
eight-voice configurations, offered 32 program memories, polyphonic portamento, and
polyphonic sample-and-hold", and in addition to that, it "offered the ability to split the
keyboard, or double up the voices so that two voices would sound for each key that was
depressed."