4 pins XLR socket:The dac1541 is able to output minimum 13V RMS into 50 ohm or higher, in power that is 3400mW into 50 ohm, 1700 mW into 100 ohm, 560 mW into 300 ohm or 280 mW into 600 ohm. The 4pins XLR socket pinout is the de facto standard as used by Sennheiser and others.