Hegel H80 Balanced vs Unbalanced Inputs

Based on pics, I would say the Hegel H80 is not balanced internally. That being said, I am going to assume that the balanced inputs would be a benefit because the XLR would (typically) drive both the positive and negative lines on the input circuit (possible an opamp). The input circuit would convert the signal to "single ended" internally inside the Hegel.

That being said, it would really only be truly beneficial if the DAC you chose had real balanced (differential) output circuits. There are DACs that do have an XLR output, but the negative polarity pin is not really generating any signal -- usually it is just shunted to ground, possibly through a resistor.

We can only assume stuff on the Hegel balanced input. It’s entirely possible that it is using all pins on the XLR. This means that it will use both the positive and negative polarity signals on the XLR, as shown in this op amp example:

https://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Op-Amp_Differential_Amplifier.svg/300px-Op-Amp_Differential_Amplifier.svg.png

However, I highly doubt that the signal is balanced after this. The op amp will convert the balanced (+/-) signal to a single-ended "unbalanced" signal internally. The amplifier part of the Hegel is not going to be fully balanced/differential. It’s difficult to see, but it appears that there are 4 transistors mounted to the amp heatsink. This means it’s only single-ended. The amp will use 2 transistors per channel (one transistor for positive side of waveforms and a second transistor for the negative parts of the waveforms.  There aren't that many amps that are truly balanced internally. They are usually monoblocks, but ATI and Theta have models that use balanced amp cards.

http://2.bp.blogspot.com/-d9V_PoFrbx4/UzHRUZXW_RI/AAAAAAAAXLw/wzgZdKol-Ok/s1600/HegelH80-07.jpg

That being said, I have always had superior results using balanced connections, even though the source/preamp device is not truly balanced.