So I was using Yamaha n 12 desk which worked a treat with control room.
The fw side of desk is no longer functioning and a I decided to purchase Behringer UMC 1820 interface.
First time I’ve even considered buying Behringer.
My thinking being if it’s no use then I haven’t thrown away too much money.
I am absolutely delighted with the pre amps,sound quality and build quality.
So now to setting it up with control room in Cubase.
I would like to use headphone channel A on behringer umc 1820 interface for Main Mix in control room and headphone channel B on behringer UMC 1820for musicians Cue Mix in control room
Can anyone point me in the direction of how this is achieved.
I have got my stereo output in studio connections as a virtual output, not connected,which I thought directed the main output signal to the control room. but I’m not hearing the main mix at all through any of the headphone channels on the behringer UMC 1820.
Obviously I’m doing something wrong
As I mentioned previously setting this up on the Yamaha n 12 just seemed to work but this is a bit more of a challenge 
Not at Cubase so the terminology might be a bit off.
Can you post screen shots of your Output & Control Room Connection tabs.
It does not. Not having the main output connected in that output tab in connections is correct. But you then have to make that available as a source in the control room tab.
In Yamaha n 12, Cubase automatically assigned the
Virtual output to the control room headphones.
So yes i would agree, I need to assign SOMETHING in control room to 2 stereo outputs.
It’s as if I need to assign the default main mix as a head phone mix.
If I create a Cue 1 and route it to say outputs 5 and 6 I am then sitting with Main mix in control room which I can’t hear but I have a Cue 1 which I can hear.
Raino I will post pics, health permitting, I can only do short periods of time on Cubase, which is killing me 
I think I’ve got the answer.
When I route a pair of monitors in control room this shares the main headphone mix with the stereo monitors out.
Then i do the same obviously for a Cue mix.
As for the Behringer UMC 1820 headphones routing different mix to different head phones is achieved by selecting your preference on buttons 1 -2. And 3-4,UMC 1820 allows your musician on say headphone channel B hear a different mix .
1 - 2 is main stereo out mix.
3-4 is the rest of your outputs.
Or you can select 1 - 2, 3 - 4, at the same time.UMC 1820 is a fantastic interface for £150.
Thanks for your replies.
As usual very much appreciated.