Moog Little Phatty w/softsynth input, MOTU Ultralite

[GrangeGrover]

I've been doing the fun with the Moog Little Phatty's external audio input, turning my old analog-modeling synths into monsters with the use of the Phatty's beast of a filter. Sure enough the time came when I wanted to do the same to softsynths, and I'm having serious problems. It seems that the output on my MOTU Ultralite MK2 doesn't send the right format of sound, or something. Maybe it's the fact that I'm running the Phatty's output right back into it. At any rate, here's what I've tried so far:

In Ableton Live I created a channel with an instance of Arturia CS-80V. I've tried all kinds of other plugins too, but this is the one I've been hoping for. I create an external effect box with the in and out channels set correctly. However, when I play notes on the Little Phatty, I get instead of the output of the plugin, either nothing, or a bunch of feedback whose pitch is controllable with the filter controls. The filter controls do not seem to control the filter itself. I've tried it in the standalone version of the Arturia synth as well, just changing its output from main outs to the aux out I'm using, and I have the same problem. Has anyone else tried this?

Also, I can't seem to find any way to configure the volume or any other parameter on the MOTU's outputs, even though the inputs I can easily do that to.

Please Help!!

Walker

[GrangeGrover]

Update: It is not feedback in my interface, I know because I tried monitoring the Phatty through headphones only, and have the same problem.

Someone please help!