Integrated Amplifiers

Despite the leap from 4800mAh to 20,000mAh Li-polymer cells – this extending use time between charges – the new Valkyrie closely mirrors the already beefy performance of the iDSD Diablo 2 [HFN Feb ’24]. Ifi Audio’s colourfully-titled ‘Nitro’ mode delivers a similarly high 2570mW/32ohm – matching the rated output of the Valkyrie via its single-ended 3.5mm socket – with 9.75V or 158mW into high impedance (600ohm) in-ears, and a full 1775mW (1.8W) into very low impedance 8ohm headphone types [see Graph, right]. The Diablo 2 managed 2.2W/8ohm but at far higher distortion overall. The Valkyrie’s 300mohm output impedance is also usefully low, ensuring the system response is largely unaffected by swings in headphone load impedance, its treble rolling gently away to –0.17dB/20kHz and –2.3dB/100kHz (re. 0dBV). The Diablo 2 has a somewhat flatter response.

While the Valkyrie’s response is unaffected by loading or gain, distortion increases with reduced gain (volume) for a given output level. At full +16.9dB ‘Nitro’ gain, THD falls to 0.00018-0.0006% but lifts to 0.0015-0.011% at –6dB gain (all re. 0dBV output, 20Hz-20kHz). Neither is the Valkyrie’s residual noise quite as low as achieved by the Diablo 2 at –91.1dBV (28µV) but the S/N ratios of 94.0dB (Nitro), 99.5dB (Turbo) and 101.5dB (Normal, all re. 1V/32ohm) are only 1-2dB adrift. Arguably, the Diablo 2 might have the edge with high sensitivity earbuds but it’s the Valkyrie that keeps its cool under the pressure of driving low impedance cans. PM