Just got a MOX8 last week and took me a while to work this out as I am not a Cubase user.So I thought I would post this here to help Cubase Newbs like me.
1:Make sure MOX is on 4 channel mode
Hit Utility,usb/io,out channel and set to 4 ch
2:In Cubase after installing the appropriate drivers and software for the MOX
Click “devices” and “Device setup” and ensure the “Yamaha Steinberg USB ASIO” is selected in “Vst Audio System”
3:This is what had me stuck
Click on “Devices","VST Connections” and in the Inputs tab select “Add Bus” and add a stereo bus.Then choose “Yamaha MOX6/MOX8-3 and 4 for left and right channels for recording The MOX sounds into Cubase and change these to “Yamaha MOX6/MOX8-1 and 2 for recording audio through the MOX audio inputs into Cubase.
Took a lot of head scratching for me to work out this one.Hope it helps someone.Cheers

Hi purcell,I really just wanted to focus attention on the problem I had (step 3)in the hope of helping people stuck on the same problem.I am very much a noob with cubase and really have no right posting a step by step setup guide.I will leave that to guys who actually know what they are doing lol.
Me I much prefer Sony Acid Pro and Im waiting for an update to that(good luck with that one)so I can stream audio to it via the MOX usb.I think I will have a looooong wait.