It is balanced or not?


Hello everyone, I am new to this page, I thank the Audiogon team for allowing me to be here with you, I have a question: I have the preamp and DAC: "Emotiva Differential Reference XDA-1" it has the following digital inputs: "S/PDIF (optical and coaxial) and AES/EBU (XLR)", the XDA-1 has balanced outputs for an speakers amplifier, inside it has the amplifier: "Texas Instruments Burr Brown OPA2134" and I want to know if it really works balanced; the XDA-1 has the DAC: "Analog Devices AD1955" inside. thanks
joser9616
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). 
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.