From the Anthem FAQ
http://statement.anthemav.com/HTML/T...upport.html#Q1
Q9: Why do the power cords have two prongs instead of three?
A: To help prevent ground loops, which occur when there is more than one ground path. Often misunderstood, the ground conductor prevents the chassis from becoming live if the AC line touches it. We use double insulation instead, something that may sound unfamiliar, but you've seen it before on power tools. This method may cost a little more, but no one can resort to using a 3-prong to 2-prong adapter to open a ground loop ("cheater" plug in this case since the green wire is used for decoration instead of safety).
Q1: Are the XLR connections on the amps and preamps truly balanced?
A: Yes. All three pins of the XLR connection are part of the circuit, which means it's a real balanced connection. (If pin 3 is sent to ground or left open, as is sometimes the case, then an XLR jack is an adapter, not a balanced input.) The purpose of balanced connection is cancelling out certain types of interference and ground loops.
Q2: What about the whole circuit from front to back - is it fully balanced?
A: No. At some point the signal must become single-ended, or interference can't be cancelled. This is better done sooner rather than later in the signal chain. The purpose of a balanced stage within a circuit is cancelling out nonlinearities arising in the circuit itself, and/or to double the signal level while cancelling out some noise. This is purely a means, not an end. We use a balanced arrangement in specific areas within a circuit where it makes a meaningful difference. Doing this to an entire piece of equipment for the sake of using the catch phrase "fully balanced" may achieve nothing but a significant increase in cost, or worse if the two halves of the circuit aren't matched well.
