Outboard DACs

Connecting the Sirius G2.1 to the Vega G2.1, and indeed other Auralic devices including the Aries G2.1 Streaming Transport [HFN Feb '21] and Leo GX.1 Master Clock, is the company's proprietary Lightning Link, which uses a modified version of the HDMI connector. Familiar though that may look, the design means you can't use generic AV-type cables, but must employ the cables supplied with Lightning-compatible Auralic products. Lightning Link is a combined data and control interface, described by the company as a 'low-jitter, bi-directional 18Gbps coupling that opens the door to jitter-free operation of all the devices in your system'. Clocking information is also transmitted back from the receiving device to the unit sending, for data synchronisation. It also carries system control data for everything from volume control to processor engine setup, allowing all linked Auralic devices to appear in a single, unified control interface.

From the earliest days of the standalone DAC, manufacturers have been trying to improve the integrity of data flowing between devices. Externalising the 'Inter-IC Sound' (I2S) system has been a popular method as this protocol carries the clock and data signals separately, rather than requiring the receiving device to recover and reconstruct the clock information buried within the datastream.