APX555B limited our measurement again The THD+N of A30Pro is no higher than 0.00006%，which means the A30Pro accurately restores 99. 9994% of the original sound, what you get is what you input. Because noise of A30Pro is low enough, so APX555B limits the noise measurement of it, resulting in the need to amplify the noise of A30Pro by 100 times for indirect measurement. 4PIN XLR+4.4mm+6.35mm output Since then, buying headphones does not have to consider whether the plug matches the headphone amplifier, because the A30Pro already provides you all in a compact body, including 4-PIN-XLR，4.4mm，6.35mm.
SE + BAL input pass through When shutting down, the input signal is directly output to RCA or TRS without amplification, which will be more suitable for active speakers/monitor speakers when the DAC has pre-amplifier functions. Even better is when used with D30Pro, the excellent noise performance of D30Pro is not wasted.
Specifications： Dimension: 17.4cmx13.8cmx4.5cm Weight: 870g Power: 100-240VAC 50Hz/60Hz Gain: L/M/H Amplifier inputs: 1 xXLR (L+R) / 1 xRCA (L+R) Headphone Amplifier outputs : 1 X 6.35mm headphone output jack 1 X XLR headphone output jack 1 X 4.4mm headphone output jack， Pass through outputs: 1x6.35mm TRS(L+R)/1xRCA (L+R) Power consumption: <9.0W
Contents list: A30Pro*1 User manua*1 AC cable*1 Warranty card*1 6.35mm to 3.5mm adaptor*1