balanced vs unbalanced pre amp

can somebody please explain the difference between balanced and unbalanced pre amp? I am interested in a lexicon mc8 or mc12 basically
I'm no expert but I'll try to explain. Unbalanced has one positive and one ground wire. Balanced has two positive and one ground wire. Balanced is able to uneliminate any noise by "comparing" the two positive signals and eliminating the difference which is noise. Perhaps someone can give you a more technically accurate answer. Unbalanced can be fine if you cable runs are short, for example you amp will only be a few feet from the pre-amp. Balanced cab work better if the interconnects runs are long, say your amps are in the front of the room and pre-amp is at the back of the room. Many audiophiles that I know actually prefer unbalanced and claim that is sounds better. I'm not certain. I think it depends largely on the design of the pre-amp. My pre/pro is unbalanced and my cable runs are long, 8 meters, but it sound great to me and I am one picky audiophile.
Truly balanced has double the circuitry. IF you have a truly balanced amp, then the pre-amp is a match. If you don't have a balanced amp, don't bother........
Adcom's GFP 750 pre-amp is truly balanced. Their amps are not. Although the 5802 has balanced inputs, they are just converted to non-balanced in the amp...........
Thanks for the responses. I appreciate it.