So I am new to recording. I have been reading a bit of the Tweakheadz.com guide. I hope I'm at least asking the right questions. Feel free to point me to the answer if this is a redundant post. I am still unclear about the specifics of interface inputs and outputs. I am looking at a used MOTU 828 mkII (found on CL) to use with my Macbook Pro / Garageband (for now). So, that specific interface has 2 XLR / quarter inch combo inputs and mic pres so I can basically plug two XLR mics in the front and press record in my computer (correct?). Now what does the 8 TRS (1/4" stereo correct?) i/o's on the back do for me? Also, if I want to record drums with an interface (3 or 4 mics at once) should I look for another interface? Can you only record (at one time) with as many XLR inputs on your interface or can you add on mic pre's as you can afford them and plug them into the TRS inputs? Thanks in advance.