Garry, if you want to use the second power output from the Flatcap 2x to power the Stageline then you'll need a SNAIC5 and a 4-5pin DIN interconnect (see the FAQ for how to ID). Connect the SNAIC5 between either POWER OUT A or POWER OUT B and the Stageline's DIN5. Then connect the 4-5 interconnect between either SIGNAL OUT A or SIGNAL OUT D (depends on whether you are powering from POA or POB) to one of the inputs on the Supernait 2.
If it's a later Stageline you can also take signal from the Stageline itself, but generally I prefer to take from the PSU output like with the earlier versions of the Stageline.
Alternatively you can keep the FC2x on the CD5x and just power the Stageline from the powered AUX2 of the Supernait 2 via a SNAIC5.
