Smaller 909 manual : EXS24 notes
EXS24 will cycle to the next round robin samples only when all keys have been released. Overlapping notes will prevent the round robin cycle and the same samples will play over and over. If you program MIDI sequences manually, use notes short enough so that they do not overlap. If you record a MIDI sequence from the keyboard, you might have to manually shorten the notes afterwards.
(This happens in Logic version 9.1.4 and earlier, maybe it will change in the future)
Some of the programs in this library make use of the multi output EXS24 instrument. To create additional output channels, click the small + button on the multi output EXS24 instrument's channel in the Logic mixer, below the solo button: