what kind of "jack" cables???
Jack really just means female connector. The "jack" cables you might be referring to are either 1/4" TS or 1/4" TRS connectors (and they are male, so there are really no such thing as "jack" cables....) XLR's and TRS are balanced connections, TS is unbalanced. The connectors you use will depend on the gear you are connecting and the length of the cable run. There is absolutely no point in using balanced connections to link 2 pieces of unbalanced gear, feel me?
Also, XLR input jacks will usually have a different impedance than a TRS or combo jack. Impedance can dramatically change "the sound", but thats all going to be subjective to the material you are recording and your own personal taste.
I know a dude who runs his 8 outs from his MP into the mic pres on a mackie board. I run all my mpc outs into the line inputs on my A & H.....To each his own.
EDIT:Sorry, Im kind of a cable/connector geek.
