Outboard DACs

Although the NEO iDSD plays second-fiddle to iFi Audio's costlier Pro iDSD model which offers a higher 450mW/32ohm output [HFN Sep '18], the more affordable newcomer harbours a couple of very useful performance advantages. Sure, the maximum single-ended headphone output is 3.25V versus 4.2V for the Pro iDSD, and the power output is a little lower too at 269mW/32ohm [black trace, inset Graph]. The headphone output also clips at full '0dB' volume with a maximum 0dBFs digital input, so '–1dB' should be your maximum setting, and this with the least sensitive headphones available should you value your hearing...

The advantage offered by the NEO iDSD comes with its better voltage/current balance, the latter able to support a full 486mW into the very lowest 8ohm loads at 1% THD [red trace, inset Graph]. The second improvement offered by the NEO iDSD comes in the form of its low 300mohm (0.3ohm) source impedance which minimises signal loss and also renders its response largely immune to the variations in headphone load. By default its response mirrors that of the line outputs while, importantly, residual noise is suppressed and the A-wtd S/N extremely wide at 107dB, so hiss and hum will still be low with sensitive headphones. PM