This is what you want to plug into your balanced line outs from your Profire 2626, then plug the other end into a guitar amp. So you can play back dry recorded guitar through the whole pedal chain, amp, speaker, mic, mic placement, mic preamp, etc.

I hate always having to be the musician AND the technician. This will be like having a clone of myself, yet still living in my mom's basement.

http://www.jensen-transformers.com/as/as092.pdf

The chassis ground is connected to the input xlr, through the black and white wires. The black wire is connected to a screw holding down the can of the tranny which is also connected to the chassis by bracket, AND the white wire is connected to the can internally. The black wire from inside the tranny is not connected to any other lead or the can so must be an internal shield to ground out appropriately.

Two output jacks parallel. One w/ a 10k resistor to set the output impedance, one w/ a 25k pot/knob. So you should be able to balance two outputs but it's not isolated between them. I didn't really plan on using more than one at a time but it would work for some things. I'm guessing a 10k resistor or anything vaguely in the range of a guitar pickup will be fine and I won't really end up needing the knob.

The knob will reveal if that theory is correct for all the different amps I try. And let me know the exact right resistor value that it should be or if there is a useful range for different situations.