What you can record simultaneously greatly depends on your computer type and your selection of hardware.

Hardware is moxf8 alongside ur22 audio device.
The computer is a more than adequate desktop.

So?..

What type of computer was what I was asking.

If you wish to record MIDI from the MOXF and audio via the UR22 there is no problem, whether you use a Windows computer or a Mac. If, however, you wish to record audio via both interfaces at the same time you would need a Mac (where you can construct an aggregate audio device which would allow both interfaces to function simultaneously for audio.

The Yamaha Steinberg USB Driver should be used to select the UR22 as your ASIO device, the MOXF will function by setting the UTILITY mode MIDI I/O = USB. Both the UR22 and the MOXF can connect to the computer via USB. Or if you are out of ports connect the MOXF using standard 5-pin cables through the UR22 (be sure to set the MOXF USB In/Out = MIDI.

Returning with a new question on the subject:
What if I want to play sounds from the moxf8 banks recording midi, alongside an audio recording of a microphone plugged on the ur22?
What is the configuration to use?

The MOXF can record to a DAW both a microphone and your playing simultaneously, (with nothing extra).
Connect a dynamic mic to the Left A/D Input jack on the MOXF back panel
Set the MOXF MIC/LINE = MIC
Set the AD IN to "Lmono"

When the MOXF is set to "2StereoRec" (dual Stereo record) mode, the microphone is recorded via USB1/2 while the MOXF synth PARTS are recorded via USB3/4. So it is possible to discreetly record vocals and yourself playing simultaneously. All without an external audio interface.

You would only need an external audio interface to use a condenser microphone (that requires 48V phantom power). if that is the case you can record using the UR22 separately, then setup to record the MOXF, or vice versa.

Using either one as your audio interface means it will be able to playback data recorded to the computer.
So you can setup the MOXF as a VST - this will allow you to record the MOXF as MIDI, then use the FREEZE function to render temporary audio files, this will allow you to playback your MOXF music tracks while you add signal via the UR22 as audio interface.

I am assuming that you want to use the UR22 because you have a condenser microphone that requires Phantom power, otherwise what Bad Mister suggests (plugging a dynamic mic into the MOXF) is far and away the easiest way of doing what you want. Personally, I've never had success with freezing the MOXF in Cubase 9 and then trying to switch to my audio interface's driver - Cubase throws up an error (can't remember what it was now - it has been months since I last tried - now I know that it *should* work I might try again). But also, you can't record a fully live performance with it - it does require you to record the MOXF first, then play it back while recording the Mic input separately which obviously isn't suitable for capturing a fully live performance or just jamming session.

What I do - and I do it frequently - is to use ASIO4ALL as the driver, which enables you to simultaneously use the Yamaha driver and your audio interface's driver. It works very well *however* it doesn't let you see all 4 of the Yamaha driver's channels - it only lets you see USB1&2 so your MOXF has to be in "1 stereo rec" mode. You need to download and install ASIO4ALL first, obviously.

I'm sure some people will advise against it but it has worked well for me so far in doing what I want to do - record a live performance of simultaneous singing and playing.

David.

Bad Mister's solution works fine and is actually quite simple. No, I don't need Phantom power, at least for now. Before trying Bad Mister's solution I did this: I connected a mono line out from moxf8 to the line in of ur22. Thus cubase read midi via usb and audio via line in from moxf8. I used the other in-port of the ur22 for the microphone. Only problem is that the audio from moxf8 sounded a little distorted. Is that because it was a mono connection?

Another thing is when I try to have more midi channels. As far as I understand it, with the way described here (by Bad Mister) I can only load one sound from moxf at a time. I guess that in order to have a multichannel layout (with different moxf sounds collaborating at the same time) I have to use the vst configuration of moxf. That brings me to my next question: Suppose I want to work alongside Kontakt, by switching between the two drivers (Yamaha for moxf, ur22 for kontakt). Problem is, I can’t find out how to do that manually. I changed the driver from Yamaha to ur22 from cubase device setup, as well as the vst connections, but I get no sound from Kontakt. What else do I have to change?

Thank you!

P.S. Also, it seems that withouth the moxf audio vst I can't render the midi to audio.

Silly as it is, I didn't get any sound because I forgot to switch my headphones from the moxf to the ur22. There is one more thing though: I get a return-piano sound, after a few seconds a press a key on the keyboard of moxf. So there is still some setting missing for the configuration to work (that is, after switching to the ur22 as the main driver). All the while Kontakt is working fine. But what is the second sound?

Which now mysteriously stopped appearing 😮 (the second sound)

P.S. Also, it seems that withouth the moxf audio vst I can't render the midi to audio.

Well, certainly the MOXF VST makes it extremely easy to render MIDI (virtual audio) to (real) audio. It depends on the routing capability of your DAW. If you are using Cubase Pro 9, you can setup an EXTERNAL INSTRUMENT routing situation so that you can. You have possibly selected to use a less flexible workflow. What version of Cubase 9 are you using? You don’t say.
Cubase AI 9 you’ll need the MOXF VST to render MIDI to audio
Cubase Pro 9 you can configure the MOXF as an External Instrument and then render MIDI to audio.

The big deal about Cubase AI as the free entry level version (Advanced Integration) specifically refers to the the audio routing scenario VST makes available for even the entry level user. The full (Pro) version of Cubase allows External Instruments to export audio using the Export Audio Mixdown function to render MIDI to audio.

Good to know! Still cubase 8 artist here.