OPPO HA-1

摘要

Anyone looking for a headphone amplifier able to drive the least sensitive cans on the market or, indeed, a high sensitivity horn-loaded loudspeaker then Oppo's new HA-1 fits the bill perfectly. Unloaded, distortion's a low 0.0006-0.0009% from 20kHz-20kHz but this increases to a remarkably uniform 0.04-0.045% under load [see red infills on Graph 2, below]. There's a further increase beyond 100mW to its maximum 8.5W output level at 0.25% THD at which point Oppo's electronic protection kicks-in [see Graph 1]. Via its analogue inputs, the HA-1's response extends from 10Hz-100kHz (-0.1dB) while, via S/PDIF and USB inputs, it reaches 20kHz/-0.09dB (44.1kHz/48kHz media), 40kHz/-0.15dB (96kHz files) and 90kHz/-0.45dB (192kHz files). The A-wtd S/N ratio is very wide - 93dB (re. OdBV) via the analogue inputs and 109dB (re. 2V) via the digital inputs, increasing to 120dB (re. full 9V balanced output).