Hi, Ive just got my FF 800 and I 'd like to know if there' s a way to control, via the total mix, the input level of the jacks TRS rear and/or front (I know it's possible via knobs from channel 1, 7, 8, 9, 10 so I'm using them for my microphones...)  but what about the TRS ones ? Are the TRS input reserved only for external instruments like guitars or bass guitars so it's not possible to control their respective input level?
In fact when I'm choosing these inputs in Logic, the level of my recordings is so low, because I can't control nothing, did I miss something in the Total Mix?
Thanks for your help.
Dan