Create a new 'Instrument' track in your arrange page, launch EVOC PS instrument. Choose whichever audio track you wish to feed through the vocoder and mute it in the arrange window
or select in its channel strip,
'no output'.
The actual analysis input is on the top right of the Evoc (where it says 'side chain') - from the drop down list, select the above chosen audio track. In my image attached, this shows track 10 'The Riff' (In classic vocoder terms, this is called 'the modulator')
Set a cycle range and then put the instrument track into record ready so it can receive midi. Select any preset vocoder effect you desire from the central drop down menu ('teutonic electricity' is chosen in the image), start the sequencer and play some chords on your keyboard.
After this, it's just experimentation and fun with the instruments modulation and sound design parameters (alongside the midi input, this is known as: 'the carrier') - BTW, page 221 in the 'Logic Studio Instruments and Effects' pdf (available from the
help menu within Logic 8) is of particular interest (and IMO importance) - you'll see why when you read it..
Enjoy!
