Auralic Altair G2.1 Music Library/DAC Lab Report

Lab Report

This generational uplift from Auralic's G1 platform [see HFN Feb '21] sees improvements in processing speed, functionality, file format handling and technical performance. The latter is the focus of this report where the Altair G2.1 clocks-up a very high 4.9V output from a remarkably low 200-300mohm source impedance. Not only will this drive any interconnect/amplifier combination but, with a suitable adapter, would also serve as a very effective secondary headphone amplifier. This is a function of Auralic's self-titled 'Orfeo' output stage which, tag-teamed with ESS's tried-and-tested 9038 DACs, maintains a fabulously low 0.00003-0.0003% distortion (20Hz-20kHz) over the top 15dB of its dynamic range [see Graph 1, below]. Although Auralic specifies its own master clocks for the Altair G2.1, the jitter rejection performance of these ESS DACs is already well proven. Here, digital jitter is vanishingly low, with a correlated figure of <15psec across all sample rates and inputs. The lack of any uncorrelated, noise-like, jitter is reflected in the sharpness of the central J-test signal [see Graph 2, below] and this typically bodes very well indeed for the stability and focus of stereo images.

In similar vein, the S/N is a very wide 117dB (A-wtd, re. 0dBV) and resolution good to ±0.02dB over a 100dB dynamic range and ±0.2dB over a full 110dB dynamic range, suggesting an effective 20-bit resolution for the Altair G2.1. Once again both digital and analogue engineering is at play here, the latter also assisting in the super-wide 135dB midrange channel separation, falling to a still-impressive 105dB at 20kHz. The channel balance is good to ±0.03dB, as expected with Auralic's precision ladder volume control. From whatever angle you choose to view, the Altair G2.1 has no obvious blind spots... PM


Distortion vs. USB 24-bit digital signal level over a 120dB range at 1kHz (black) and 20kHz (blue)


High res. jitter spectrum via S/PDIF and USB (black, 48kHz/24-bit with markers; red, 96kHz/24-bit)

Maximum output level / Impedance 4.91Vrms / 200-300mohm
A-wtd S/N ratio (USB / Network) 117.0dB / 117.0dB
Distortion (1kHz, 0dBFs/–30dBFs) 0.00003% / 0.00012%
Distortion & Noise (20kHz, 0dBFs/–30dBFs) 0.0002% / 0.0003%
Freq. resp. (20Hz-20kHz/45kHz/90kHz) +0.0 to –0.1dB/–0.7dB/–2.1dB
Digital jitter (48kHz / 96kHz) 14psec / 14psec
Resolution (re. –100dBFs / –110dBFs) ±0.02dB / ±0.2dB
Power consumption 17W (1W standby)
Dimensions (WHD) / Weight 340x80x320mm / 9.5kg
Price £4599 (£4899 with 4TB storage)

Auralic (Beijing) Co., Ltd
Supplied by: Auralic Europe, The Netherlands
075901 06105