I have a AudioFuse Studio, + 8x-in 8x-out.
So far i’ve been unable to route out to external effects devices using input into an x8-in port to an 8xout port:
Moog → 8X-In#1 → DAW Ext.Audio In port (?) → out 8x-out#? → external device in → external device out → 8X-In port #2 → out to speakers
i don’t know how the x8 in/out are mapped to Abeleton Live ports in the drop down.
Since the X8 In/Out are connected via ADAT, first, you need to setup your audio I/O ports (Inputs Config and Outputs Config) of Ableton Live in the Options/Settings/Audio tab to enable (and optionally, name) the ADAT inputs/outputs of the AudioFuse Studio, so they will show up in the Ext. In/Ext.Out drop-downs.
As described in the AudioFuse Studio Manual, page 31 (p 37/70 in the PDF), the ADAT I/Os of the AudioFuse Studio will be found on USB inputs/outputs 11 through 18.