if you wish to use the S/PDIF OR ANALOG ins you MUST NOT have 3 out/1 in selected. That is only for sidechaining as the USB replaces the other physical ins. If you wish to use either S/PDIF or ANALOG ins you must use 2/3 out/0 in.

This whole external FX thing is far more trouble than I am willing to work with I am afraid. Wanting to do a mono channel means I have to do some very strange panning/routing between main/surround outs to get it to work. The main problem however is the delay compensation. Cubase is doing a horrible job at best at keeping whatever comes back out of the virus in time with everything else. I am using Halion which is capable of multi outs. If I send a track from one out into the Virus for processing then back again, all is fine. If I assign a different patch to be played out of a different output of Halion all goes to hell and sounds like shoes in the dryer on playback. I click on the ping icon in the external FX and it keeps setting it back to 0ms compensation which is clearly wrong. I have to manually bit by bit fool with the compensation slider and even then it doesn't match up 100% and I still get slight phasing issues. Very annoying. Since this problem is obviously with Cubase, (not routing back as should without using external FX) and I don't expect a fix, I am just going to have to ignore processing external sound through the Virus, or mix everything down to audio first. I really wanted this to work out, but the hassles really halt my workflow.