Headphones

Having not tested the inaugural Diablo model, the closest 'relative' we've seen to the Diablo 2 is iFi Audio's xDSD Gryphon battery-powered, portable/desktop DAC/headphone amplifier [HFN Aug '22]. The former offered both balanced 4.4mm and single-ended 3.5mm analogue inputs, plus the option of four user-selectable digital filters courtesy of the integral TI DSD1793 DAC. The Diablo 2 has only a 4.4mm balanced analogue input, and a fixed linear phase digital filter (the same as the previous 'Standard' option) but benefits from a beefier 4800mAh battery (vs. 3600mAh in the Gryphon) and – more importantly – a pair of DSD1793 DACs each operating in differential mode. Tested at the same 2V output (the Diablo 2 clips in 'Turbo' or 'Nitro' modes with peak level digital inputs as the volume knob is advanced), the A-wtd S/N ratio has improved from 106.7dB to 108.1dB and distortion reduced from 0.009-0.013% to just 0.001-0.0085% across 20Hz-20kHz at 0dBFs [see Graph 1, below].

Distortion falls to as low as 0.00025-0.0008% (20Hz-20kHz)over the top 20dB of its dynamic range while correlated jitter is <5psec across all sample rates. (While iFi Audio claims 'compatibility' with 768kHz and DSD512, the DAC chip operates at a maximum of 192kHz and DSD64.) Anyway, the slight broadening of the peak in Graph 2 indicates uncorrelated/phase noise only. Low-level resolution is good to a remarkable ±0.2dB over a 110dB range while the combination of its linear phase upsampling and analogue filters results in very flat line responses reaching out to –0.04dB/20kHz, –0.28dB/45kHz and –0.79dB/90kHz with 48kHz, 96kHz and 192kHz media, respectively. PM