I'm try it in this way:
I make an Auxiliar track and open the MX4 (Plug in multichannel) and activate the audio imput button (and the stereo on the right).
On a Audio Track open the send bus and it doent sound.
I have touched keyboard MIDI simultaneously.
With another plug in effect all is OK but with the MX4 (V.2) I can't, what's I make wrong?

Saludetes