Network Audio Players/Servers

Under the mini-i Pro 3's bonnet, Matrix Audio uses a pair of TI's very capable TPA6120A2 headphone amplifier chips. However, before we discover just how capable, it's worth cautioning anyone wishing to use the mini-i Pro 3 with analogue sources. Its RCA input samples at a full 96kHz but the ADC clips at 2.1V so will not have enough headroom for all modern 'line level' sources... Otherwise, the mini-i Pro 3 is a maxi powerhouse, delivering a full 151mW into high impedance (600ohm) cans with sufficient current to support 1.55W/32ohm [black and orange traces, inset Graph]. There's some limiting above 460mW into very low 8ohm loads but the mini-i Pro 3 plugs away at ~0.2% THD until finally clipping at a full 1.2W/8ohm/1% THD [red trace, below].

Overall gain is +19.1dB and the A-wtd S/N is a very wide 96dB, so sensitive 'phones will not be burdened with background hiss. Also, while there's a steady increase in distortion when driving lower loads from 0.0008%/10mW/600ohm to 0.003%/10mW/32ohm and 0.009%/10mW/8ohm, these figures are still very low. In practice, any 'colour' associated with the mini-i Pro 3 will as likely stem from its moderate 10-11ohm source impedance. This is about 10x higher than ideal and responsible for a ~2.3dB loss into 32ohm, moderating the essentially flat native +0.0dB/–0.45dB response (20Hz-20kHz) in 'tune' with the peaks and dips of the headphone's load impedance. PM