It is balanced or not?

Op amps are not balanced when a single op amp is used.

They can be used to output a balanced signal by either outputting to a transformer os using two opamp sections.

joser9616,  you're welcome.  OPA2134 has also high current drive ability making it a good choice for an output amp (combined function of I/V converter and output driver). 

I have the Emotiva conected to a 2 mono Crown D-75 balanced.

erik_squires the Emotiva Differential Reference DAC XDA-1 have two of the OPA2134PA

After working on and rebuilding an XDA-2 DAC and looking at the XDA-1, my only answer would be "maybe?".  I see two 2134 op amps after the fully differential AD1955 DAC chip.  This suggests that the opa2134 op amps are working in fully balanced differential mode for the I/V section.  After that, it goes straight to the discrete analog output stage.  It is difficult to tell if this discrete analog stage is fully differential/balanced, but I would only assume so.

This is different than the XDA-2 dac, which has the same two opa2134 I/V op amps, but then goes through another single opa2134 op amp which acts as a low-pass filter and downgrades this to "single-ended".  Then the XLR outputs have their own set of opa2134 which convert the single-ended analog back to differential.  The XDA-2 is not "fully differential" from end-to-end, but the XDA-1 DAC might be.