I just realized that I misspoke about the Preamp being "fully balanced" and should have said "truly balanced". As Quoted directly from our FAQ Page at this link:
https://www.anthemav.com/support/faq.php It says:
Are the XLR connections on the amps and preamps truly balanced?
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.
What about the whole circuit from front to back - is it fully balanced?
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.
