1 Redesigned new NFCA circuit based on the same working principle as the one in A30 Pro. It provides 2x power at 300 Ohm compared to L30. 2 The new circuit shares the same 0.3uV ultra-low noise and 145dB dynamic range as well as 0.00006% THD+N. Sound quality is never a problem. With the help of NFCA, L50 easily reaches the top of the industry, and it has almost perfect performance regardless of distortion, dynamic range, and multi-tone testing. Easily match with high or low sensitivity. L50 has three gain options. Covering a wide gain range is sufficient to meet the needs of low-sensitivity full-sized over-ears to high-sensitivity IEMs. With the help of extremely low noise 0.3uV, even lEMs will not hear any background noise. Note: Please send the voltage you need after place the order (110v/220v).