You're joking, right? The amp output is indeed balanced, when using a balanced input.
The reason only 2 pins are used on each 3-pin XLR is that each channel (aka driver) of a headphone only uses two wires. Perhaps you should read up on how balanced/bridged headphones work, before bashing something that you clearly know nothing about?
Quote:
Originally Posted by
hitoridekimasu 
Really unbelievable! A "fully balanced" amp with a single ended outup stage directly connected to the XLR connectors. Very good and clean amplification design with a very odd output stage solution. What a shame, I'm sorry for the people that bought this amp looking forward to have the best of their balanced-cable refurbished headphones and finally they realize that they wasted their money. My deepest sympathies.