Can i play a Gallien krueger backline 112?!
 

Well my band is about to have our first gig and i only got a Gallien krueger backline 112. We're going to play on a small club!

The Backline 112 has a output jack on the back of it (the speaker is not hardwired to the amp), so you could use the amp to drive a different cabinet if you wanted. It's only 100W though, and as bass amps go, that's not a lot. You could certainly try it.

Does the club have a sound guy or will your band be running the mix yourselves (how small of a club are we talking)? You could mic the 112 so that it will go through FOH, that would make up for any issues you might have cutting through the mix with a 100W amp.

Even small clubs can be plenty loud, so I would mic it. When I used to run sound at a church my wife and I attended, one of the guitarists had a little 15W practice amp that we miced and ran that line signal through FOH.

After the gig you'll have a better idea of what you're going to need power wise.

I could use it on some of my jazz gigs, assuming you are playing rock music, nah, you'll break it.

Things shift gears at shows. You may have made it through rehearsals but enthusiasm plus background crowd noise and a bigger space = more bass required

It's not so much the 100W but the single 12.

Eh, give it a shot. If it doesn't work out, deal with it, but 100w into a 112 isn't loud but it's not quiet either. 50/50 whether it'll work, but what are you going to do? Go out and buy a new rig? Well, you could, I guess ;)

Then he could use the output jack on the back of the amp to drive another cab (2x12 or a 2x10 perhaps?) the speaker in Backline combos is not hard-wired, but connects via the 1/4" output jack.

if you do find that you can go to the PA, you might do a little better for yourself to snag a chair or bring something to set the amp on to lift it up. this will help you hear it better. you could borrow or rent a bigger cab. 100w through 2x15 can sound pretty big. watch that eq if you don't get a different cab, though. you'll most certainly have the amp loud enough to hurt the speaker if you're careless with the low end settings.