Why a good four months rolled by between the last page and this was for two reasons. One, Wyred took much longer to ship when their supplier of essential premium parts was suddenly back-ordered. Two, once the loaner did arrive at Scottish importer Elite Audio, they kindly asked whether they could break it in for me. 'Pretty please' was my reply. Thus many more weeks passed. As to MQA, "we've discussed it internally and with MQA. Our consensus is that due to investment costs and uncertainty with how MQA will ultimately materialize, we're in wait-and-see mode." 

About I²S, Wyred have long had an external input. However, there's no standard for this non-standard interface. It's why Denafrips' Terminator sports three different I²S ports; one on HDMI, two on RJ45. It increases chances that your unusual transport fitted with one is compadre. For the vast majority of users, external I²S transmission is irrelevant. Their sources don't support it. Should yours, inquire with Wyred whether it shakes hands. A shared HDMI port is no guarantee. None of our digital transports output I²S—computer, SD card reader—so this is all boiler plate. For the rest of the i/o, the photo is sufficient. For the invisible stuff, there's Sabre's 32-bit on-chip digital volume which defeats in fixed mode; auto upsampling of all incoming signal; and support up to 384kHz for PCM, up to DSD 256 (both on USB and I²S).

More invisibles are <0.002% THD+N with the volume at 55; S/NR of >120dB; cross talk of >125dB; A-weighted noise of <7µV; 50Ω output impedance; and max output voltage of 10.5V on XLR and half that on RCA. Toslink is tested up to 192kHz but due to format variations, 176.4kHz could be the practical limit. Visible again if you crack inside and count are 115'000µF of filter capacitance, 3-stage filtering and 13 regulation points. There's also galvanic USB isolation via ICs on the I²S lines reclocked after isolation for further jitter reduction; transformer coupling on the coax inputs; fully balanced circuitry; and a clock with a claimed 82 femto-second phase jitter. Invisible again is the processor's I²S DSD path which uses auto signal recognition to process native DSD files. The 9038 Pro Sabre chip in this implementation multi-tasks as input receiver, input switcher and D/A converter. Its eight channels are used in quad-differential mode.

The small green vertical board is one of the discrete regulators. In front of it we spot two nude but numbered Vishay resistors.
The setup menu is accessed in standby via simultaneous hold of up/down, then pushing power and releasing all three buttons. Menu navigation now is via up/down and selection by brief (!) press on power to not turn the unit off. Adjustable parameters are filter bandwidth (<50K, 50K, 60K, 70K); eight digital filters; I²S left or right margin justified; remote/trigger options; display dim level; variable/fixed output; assignable volume range per input; jitter eliminator settings; and 0-240s dim delay. The digital volume works in 3dB steps from 1-9, 2dB steps from 10-24 and 1dB steps from 25-70. Depending on system gain, the assignable volume range function can subtract unnecessary steps on top or bottom to leave just the volume range which a particular system actually uses. A standard 2V output on RCA is realized at volume 67 if the minimum level remains at 0. A 1V output equates to 61. Likewise for XLR at 4V and 2V. The lower the chosen jitter eliminator values, the more critical the quality of the incoming signal. If high-jitter sources suffer dropouts, set this option higher. For Mac, the DAC appears as 32bit 384kHz DSD interface under sound devices. For Windows, it goes by Wyred4Sound USB Driver 1.0.56. Recommended break-in is 200 hours. For the full blow-by-blow tour, consult this manual.

These guts are tightly packed. Much of it eludes eye and lens. Still, we spy further Vishays, assorted caps and pulse transformers. Meanwhile the boutique fuse is wide out in the open.

A mechanical novelty is the heat-sink extension. Like a roof, it covers some of the board below and probably whisks away temps from a thermally critical chip.