I got the Fostex FR-2LE recently (have to use this weekend for some ambient recording)...and I'm not sure exactly how to use the "mic trim" control in conjunction with the normal recording volume controls ( I have some basic understanding of audio recording...but I'm not a professional). While I can certainly figure it out by trial and error - I would appreciate any advice on how to use this control "correctly". I am using XLR mics with the recorder.