Tested via its variable balanced XLR outputs (ie, with the volume engaged), the Libra makes for a superb line-level analogue preamp. Capable of delivering a full 20V from a moderate 46ohm source impedance (rising to 63ohm at 20Hz), it offers a combination of low 0.0001-0.0002% bass/midrange distortion (rising to 0.0024% at 20kHz), a decent 92dB A-wtd S/N ratio (re. OdBV) and a spectacularly flat and extended frequency response that stretches from 1 Hz to 100kHz ±0.1 dB. Its performance as a DAC fits within this envelope although with mildly superior results via USB than S/PDIF as the former's asynchronous operation demonstrates a lower jitter (＜ 10psec) than the clock-recovery of its S/PDIF input (～250psec). Tested via its fixed balanced output, the DAC section offers a maximum 4.15V at OdBFs and a wide 111dB A-wtd S/N ratio and where distortion -through bass and midrange at least - remains a low and consistent 0.0006-0.001% over the top 30dB of its dynamic range [see red/black traces, Graph 1, and red trace, Graph 2]. There's some stress in the analogue output at peak frequencies/peak level, but the 0.026% THD at 20kHz quickly drops back to 0.003% at -1 OdBFs [blue trace, Graph 1].
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