The XLR 4-pin connector is used for professional balanced stereo headphone outputs on headphone amplifiers, providing a fully balanced drive for each ear with lower distortion and better crosstalk than unbalanced TRS.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | Left+ | Left channel positive | ADC |
| 2 | Left- | Left channel negative (return) | ADC |
| 3 | Right+ | Right channel positive | ADC |
| 4 | Right- | Right channel negative (return) | ADC |