Input issues

Hello
So I have a new problem that hopefully someone can shed some light on ..
I only seem to have one input working
In preferences , audio , the top drop down tab where I select drivers
There is 3x drivers
U46mk2 ch12
Uk46mk2 ch 56
U46mk2 ch34
Plus various others
What one should I be using ?
Basically want 2 turntables to work on separate channels
Someone give me an idiots guide to what options and tabs should be on or off please
Thanks in advance
Carl
So I have a new problem that hopefully someone can shed some light on ..
I only seem to have one input working
In preferences , audio , the top drop down tab where I select drivers
There is 3x drivers
U46mk2 ch12
Uk46mk2 ch 56
U46mk2 ch34
Plus various others
What one should I be using ?
Basically want 2 turntables to work on separate channels
Someone give me an idiots guide to what options and tabs should be on or off please
Thanks in advance
Carl