Jack leads.
Any Mono (single black ring) leads, are by definition unbalanced.
(this also applies to Phono and any other connector that only provides +ve and a
-ve/Shield)
Any stereo (TRS,= tip, ring, shield = 2 black rings ) Jack to TRS
(stereo) Jack, or Jack to XLR leads SHOULD be balanced, but you will need to check this,
as they might, for example, be unshielded headphone leads (+,- & common ground), or some
other kludge.
XLR Leads
XLR to Mono Jack or Phono(RCA) are unbalanced.
XLR to XLR are usually balanced, unless they're speaker leads....( in which case
they're most often only using two out of three pins, and unshielded 2 core cable... which
is normally either orange (basic garden mains cable really) or has speaker cable printed
on it (under all the dirt

) )
XLR to 2 of anything is usually unbalanced/stereo
Best bet is to
buy a cable tester that shows a connection matrix, so you can see which connections are
connected to which, at either end.
Actually that's one thing behringer do quite
well, (mind you I'm told they ripped off the design) . Their CT100 cable tester is a handy
tool.
(it also provides a tone generator, and has almost every analogue
connector you're ever likely to meet.)
Max
--------------------
if you don't know who i am, i aint gonna tell you.