The USB audio outputs from the MOXF are either Stereo (2CH) or dual Stereo (4CH).

Press [UTILITY]
Press [F5] USB I/O (USB input/output)
Set the mode to "2StereoRec" which stands for "dual stereo"
All the synth Parts will initially be assigned to USB3&4, you can isolate any Part by simply reassigning it to USB1&2 when you want to create audio. The output of any internal synth Part can be rerouted to USB 1/2 as necessary. You can record separate tracks for each Part, by multiple passes.

Please see our three part series on MOXF AUDIO RECORDING for a step-by-step tutorial on the basics:

MOXF Basic Audio Recording Part I

MOXF Basic Audio Recording Part II

MOXF Basic Audio Recording Part III

MOXF Basic MIDI Recording to Cubase

After you go through it, if you have any questions, post back here.

Thank you very much.
this was very helpful.
I finally got 4 audio channels.
but I still lose the control of the audio part signal as soon as I turn on the VST editor.
Can you point me to a guide to the VST editor similar to the ones you just showed me.
Thanks.

MOXF Editor VST

Thanks once more.
That was helpful.
I got the audition audio signal under the VST folder track. both for USB Channels 1&2 and 3&4.
But still I can't record that signal into an audio track (I can monitor it, I can send it to fx channel, but not to an audio track and record it).
There is this other guide of yours that maybe it's related
It's said that I have to route the audio signal of the VST editor through the "External instrument" tab under vst connections.
I am running Cubase 8 AI and unfortunately I can't see the external instrument tab (I only have input and output).
Looking at the comparison chart of the different cubase versions I have noticed that external instrument is given only for Motif owners and not for MOXF.
Unless to buy the full version of Cubase.
If you tell me that this is the problem I could think about buying it.
Thanks

I got the audition audio signal under the VST folder track. both for USB Channels 1&2 and 3&4.
But still I can't record that signal into an audio track (I can monitor it, I can send it to fx channel, but not to an audio track and record it).

That is correct! The "V" in VST stands for "virtual". This means the signal routing for VSTi synths is "virtual" - this means you can monitor it, you can process it, and you can hear what it WILL sound like after you render it as audio.

Rendering it as audio is a separate operation. You get the audio sounding exactly like you would like it to be printed to an Audio Track, set your Markers at the appropriate start-end measures, then in Cubase you go to FILE > EXPORT > AUDIO

A dialog box opens that allows you to create a name, and set the attributes for your audio track. You should mark the options - which you want to MIXDOWN ; you can do one or more parts at a time --- place the audio in the audio "POOL" and on a new "AUDIO TRACK"

This is how you select one or more parts to render as audio... To an audio track, it is very much a separate operation!

To be clear. You can record audio, without this VST routing... That is what the AUDIO RECORDING I, II, III were doing (no VST)
VST routing and recording adds the ability to keep you MIDI recording, while you process, and EQ, your data, then *in a separate operation* you export to audio.

VST is MIDI recording until you render the "virtual" audio and turn it into a "real" audio track.

You still will be able to export audio MIXDOWN with the free entry level Cubase AI (if you upgrade to Cubase Pro 8 do so for other reasons)

From a previous post.....
Virtual Audio is virtual, it is never seen... No audio is actually written to Cubase while you are using any VSTi... you are simply "monitoring" the audio output of that soft-synth or external VST synth. Not until you go to FILE > EXPORT > AUDIO MIXDOWN can you actually create an actual Waveform... please note: External VSTi, because they are external to the computer, will be rendered in real time. That means if you have a 4 minute composition it will take 4 minutes to render the waveform (ha, ha... This sounds odd to say, because when playing/recording music - nothing could be more real time).