Network Audio Players/Servers

As with the ES9038PRO-based digital section of the partnering 9000A amplifier [HFN Aug '23] the 9000N also offers a choice of five digital filters although these are only enabled when the 'upsampling' option is switched off. With 352.8kHz/384kHz 'upsampling' on, the 9000N defaults to a gentle minimum phase filter offering a –0.4dB/20kHz, –9.6dB/45kHz and –14.8dB/90kHz roll-off with 48kHz, 96kHz and 192kHz inputs, respectively. Jitter is fabulously low at <18psec (PSU-induced) with 24-bit inputs regardless of whether 'upsampling' is engaged or not [see Graph 2, below]. The five digital filters include fast and slow roll-off linear and minimum phase types plus a fast roll-off mixed/hybrid option, these offering responses of –0.0dB, –3.5dB, –0.05dB, –5.0dB and –12dB (re. 20kHz with 48kHz files) traded against stopband rejections of 112dB, 16dB, 93dB, 21dB and 98dB, respectively. With 96kHz media the 45kHz responses are –0.5dB, –5.0dB, –0.2dB, –7.2dB and –23.7dB, respectively.

Low-level resolution is true to ±0.1dB over a full 110dB range (and only +0.5dB adrift at –120dBFs) thanks to the 4.2V peak-level output and very generous 115.0dB A-wtd S/N ratio, all from a 115ohm balanced/XLR source impedance. Distortion settles out at 0.0003%/1kHz at peak level (re. 1kHz) falling to a lower 0.00005% with upsampling switched off [see Graph 1]. Similarly, peak level digital inputs cause a digital clip of ~0.4% at 20kHz (falling back to 0.00035%/–10dBFs) when 'upsampling' is engaged, though this is highly unlikely to occur with typical music data. Otherwise, the 9000N's post-DAC analogue stage offers a fine >105dB stereo separation and 0.01dB channel balance (all re. 20Hz-20kHz). PM