I don't have much experience with balanced output, but the easiest way to narrow down your list is to understand how it works. It sends power down both wires, so it has to have 2 ends, that's why the single mini XLR end of AKG headphones doesn't take balanced. You will need the headphones to take 2 inputs, one for each driver. Meze and Hifiman use 2 3.5 ports for balance, Sennheiser uses the 2 pin connectors.