Emu XL-7 & MP-7 User's Group

MIDI stands for Musical Instrument Digital Interface.

MIDI allows for communication between diferent devices.

With MIDI no sounds are transmitted from one device to another.

With MIDI data can be sent from one device to another. This data is 
useful insofar as it conforms to MIDI specs.

MIDI data includes note on, note off, program change, continuous 
controller, etc.

MIDI recorders [sequencers] record, store, and playback MIDI data. 
They may also let you edit MIDI data.

I am not sure what you mean by MIDI echo?  Where did you see or hear 
about it? If it is online, please post the link.

(BTW, what specifically are you trying to do with your E-Mu--other 
than use it to its maximum capabilities?)

Finally, forget about sysex [system exclusive messages]. If you are 
staying within the E-Mu and not connecting it to any other gear, you 
do not need to do anything with sysex.

If you want to create echo effects with your E-Mu, there are several 
ways to do it. The method you use depends on what you want to do. 
Three basic methods I can think of are (1) use the effects 
processor, (3) use the sequencer, and (3) use the E-Mu synth engine. 

Using the synth engine you could use envelopes and patch cords, for 
example. You could use a lfo [low frequency oscilator] to modulate 
amplitude to simulate an echo.

Using the sequencer, you could copy a track, shift the start time of 
the notes a few ticks, lower the velocity, and play it at the same 
time as the original.  In fact, if you shift the start times, lower 
the velocity, and then merge those notes with the orginal track, you 
have what might be called midi echo. (I am not sure if this is what 
you meant in the first place.)

If you then take the new track [A + A'], shift the start time, scale 
down the velocity, and merge it again, you then would have each note 
4 times [A + A' + A" + A'"].

Hope this helps.