Last night I tried to hook up my keyboard (Yamaha Motif ES) to my UFX using the Motif's unbalanced (line level) outputs running into the UFX's front TRS jacks. The manual says these are high impedance, and can handle levels from -34 dBu to +21 dBu, which the Motif certainly falls between. However, something is clearly not working with the signal path. When I crank the gain all the way up to 65 dB on the preamps, and the Motif is at full volume, the Motif can barely be heard (and there is more background noise than keyboard). I tried both setting the inputs to "Instrument" and not, though I'm sure it should not be set when running a line level source into it. What's interesting is that when connecting an instrument level (direct acoustic guitar, for example), and setting the "Instrument" flag in TotalMix, everything works fine... the guitar is audible at relatively low preamp gain settings. The XLR portion of the preamps (with a mic) seem to work fine as well. Driving the Motif into the rear line inputs works fine.

So is there something wrong with my unit? Or, am I missing something in how I'm understanding the functionality of the front TRS jacks?