@Luckbad Why do you want to use a transformer with your SFD-1 MKII anyway? That only makes the signal path more complicated. The XLRs are just a convenience feature as that DAC is a single ended design unlike the SFD-2 / SFD-2 MKII where such an aproach might make sense. My former Audiomat Maestro 1 MKII was similar in a way. While it had two PCM1704 per channel, they weren't used in a differential layout but in parallel. What followed was the usual Audiomat output stage with only three transistors per channel for the single ended output - one for I/U conversion, one as a voltage reference and one as buffer. The balanced output used the output from that buffer and added four transistors to that - to generate a balanced signal and to buffer it. Guess what sounded better! The newer Audiomat DACs on the other hand use one PCM1794 per channel with a three transistor output stage for each positiv and negative signal. Here the balanced output makes sense in the same way as with the SFD-2 / SFD-2 MKII.