Ok, I have recently started jamming with a group in my sister-in-law's basement. A fun 5 piece classic rock kind of thing, mostly for fun but we might entertain the odd summer gig or party kind of thing. Anyways, not wanting to lug my good amp back and forth all the time, I brought my spare ampeg BA-108. Love the tone on it but it's isn't quite loud enough (almost but not quite), anyways I just picked up a Line 6 Studio 110. Got it used really cheap and man this little guy packs quite a punch. My question is this, on the back is an XLR out jack which I assume is to connect to a PA or direct to record. The other is a preamp out and pardon my ignorance but what does that do for me? Also is it possible to connect both amps together to fill in the room a little more? and what would be required? Cheers.