Legacy External Instrument in Logic Pro for Mac
You can use External Instrument Legacy to route external MIDI sound generators through the Mixer, which you can then process with effects.
You can also use External Instrument Legacy to transmit and receive MIDI information through the instrument channel strip that it is inserted into. This enables you to control an external sound module—both MIDI and audio—from within one element.
To avoid constant repatching of devices, it is best to use an audio interface that supports multiple inputs and outputs. The plug-in is inserted into instrument channel strips in place of a software instrument.
If you’re new to using plug-ins in Logic Pro, see Add, remove, move, and copy plug-ins in Logic Pro for Mac.
Note: It is recommended that you swap External Instrument Legacy instances with the updated and more flexible External Instrument plug-in immediately after importing your project.
External Instrument parameters
Environment Destination pop-up menu: Choose the target environment object (often a MIDI instrument and channel).
Input pop-up menu: Choose the inputs of your audio hardware that the MIDI sound generator is connected to.
Input Volume slider and field: Move to set the incoming signal level.