#1
If I buy a head, I would like to know if I can use my current Line 6 Spider II 112 as a cabinet. I know I can't just plug it into the input, but is there any way to turn it into a cabinet?
Heads will roll. Throats will be slit. Blood will flow like springs of water.
#2
As long as the speaker impedance matchs the new amp your should be good to go. Just unplug the speaker from the line 6 chasis and make you a 1/4 input jack then attach the speaker to that then the new amp to the input.
#3
you plug the speaker into your new amp.

It can be done.

It probably will not sound very good. Cheap amps use cheap speakers, and 112 cabinets do not sound good in general. imo at least.
#4
Thanks for the answers. I imagine it would still sound worlds better than my current amp. The head I'm considering is the Hughes & Kettner Warp X. I had a chance to try it out at Sam Ash and it's one of the best amps I've ever heard. I'll get a good 2x12 or 4x12 eventually, but right now I can only afford the head.
Heads will roll. Throats will be slit. Blood will flow like springs of water.