Dante:  We've all heard of 'balanced' cables, being the ones with 3 wires, one more wire than unbalanced.  That's right isn't it?  Well, yes but there's more to it than that as Music Manic raised the question 'Is there any benefit in using balanced cables?' and GaryB took up the question:

GaryB: Basically a balanced signal has a positive and negative conductor along with an additional shield (earth ground).  Unbalanced connections combine the shield and negative together.  An unbalanced cable has two conductors, a balanced cable has three.  Balanced signals generally have less noise and isolating ground between two pieces of gear is easier.

Typically most balanced audio signals are at a level called +4.  Most unbalanced audio signals are called -10 or -20.  This is about loudness measured in millivolts so obviously a +4 signal is much louder.  Audio loudness is expressed in decibels (dB) and the scale is logarithmic.  This is important for understanding why the input level on the A16 might be low when receiving a signal from an unbalanced device or why the signal from the A16 might be hot going into a piece of unbalanced gear.  It's not a problem, just something to be aware of.  Actually, the A16 Ultra has dip switches to change levels for the first 8 channels and also the second 8 channels, so it can have both levels running at the same time depending on what it is connected to.

For a 1/4" phone cable end usually balanced is wired tip positive, ring negative and sleeve shield or ground=unbalanced is tip positive and sleeve negative/shield.  There is no standard, however. 

GaryB and Dante October 2014