You may have a great sounding hi-fi system on one side, and a multi-gigahertz computing machine on the other. Bridging the gap between them is the simple but onerous task of the Musical Fidelity V-Link 192.
See: more reviews of digital audio adaptors.
This missing link is now an evolutionary step-up from the company’s first V-Link, a digital adaptor that converts, not between the realms of digital and analogue, but between one digital version of musical reality and another.
To whit, the original Musical Fidelity V-Link was a USB digital-audio convertor, taking the bitstream from a computer’s USB port and translating it into the S/PDIF format that has been the mainstay of digital audio at home and in the studio since the 1980s.
Two versions of the Sony/Philips Digital Interface Format are in popular use: an electrical bitstream delivered through a coaxial screened cable terminated with BNC or RCA phono plugs. And an optical interface, Toslink, which transmits binary data through a plastic optical wire.
Mark 1 V-Link offered just those two choices for connection with the hi-fi; the V-Link 192 removes the optical option and replaces it with AES balanced digital via an XLR socket.
To combat the problem of contamination – the leaking of sound-spoiling radio-frequency noise from the PC into a sensitive audio system – the Musical Fidelity V-Link 192 adds a pair of isolation transformers, one per output, which sit just behind connectors on the circuit board.
The other main change between original and the new model can be gleaned from the product name – the Musical Fidelity V-Link 192 is specified for operation up to 192kHz, against the 96kHz maximum sample frequency of the first V-Link.
In the digital audio numbers game, 192kHz is always going to give better performance than 96kHz, assuming that the original music was sampled at this rate. Done right, you'll have a potential audio bandwidth to around 90kHz.
And strangely, even lower-frequency sample audio, such as CD and its lowly 44.1kHz rate, can sometimes be heard to sound better when upsampled to a higher frequency prior to conversion back to analogue – even though no more ultrasonic frequencies have been sampled above the original datastream’s Nyquist threshold.
Musical Fidelity V-Link 192: Features
The Musical Fidelity V-Link 192 is built around essentially the same box as other units in Musical Fidelity’s V-Series, an extruded aluminium shell with screwed-on end plates.
It’s a simple and cost-effective case for these value-conscious audio boxes; sturdy, smart, utilitarian and effective. But where the first version was finished in black, the V-Link 192 comes in natural metal.
On one end is a USB Type B port, as you’d find on most printers. On the other, the real business end, are the balanced and unbalanced output sockets – and two columns of four indicator lights, fed from circuit-mounted LEDs within.
Counting down from top left, two lights show when the unit is powered and locked to an incoming USB datastream. These glow blue and green respectively.
The remaining six squares show outgoing audio’s sample frequency: orange lights behind 44.1kHz, 48kHz, 88.2kHz, 96kHz and 176.4kHz. And to easily show when you’re running at the unit’s peak sample rate, you get a red light for 192kHz.
Inside the Musical Fidelity V-Link 192, on-the-fly number crunching necessary for format conversion is undertake by an I2S convertor, then custom XMOS semiconductor chip. Two quartz crystals provide re-clocking reference timebases, one dedicated for 44.1kHz and its multiples, another for 48kHz and company. That’s an improvement on the first V-Link, which got by with one crystal and some silicon frequency shifting.
The Musical Fidelity V-Link 192 is a development to the first Musical Fidelity V-Link, now featuring two quartz crystals for clock references, and two Yuan Dean Scientific 30T-2521NL transformers for a degree of galvanic isolation
Power for the unit is taken from the 5V USB rail, smoothed by voltage regulators within. No additonal drivers are required for use on a Mac, since OS X’s Core Audio sub-system is battle-ready for 192kHz operation out of the box. For Windows, you’ll need to install a proprietary driver for higher sample-frequency operation.
Musical Fidelity V-Link 192: 'Sound'
Rating the sound quality of a USB-to-S/PDIF convertor is not so easy. Like all audio hi-fi components, its job is to get out of the way and pass music from input to output with the minimum amount of disturbance – adding nothing, subtracting less.
That should be an easy task, although even working entirely within the digital domain there is always scope for corrupting the signal subtly. And sometimes, not so subtly. That’s typically through the introduction of small timing errors that build up to produce jitter. This will leave an audible fingerprint on the sound – a hardening, a glassiness that’s still all-too-common in digital audio. Or sometimes a smearing, lower-frequency coloration that can mask detail and tempo precision.
Rating a CD player, for example, you can cross-reference a number of models and decide with which product you perceive the most faithful and natural rendition of music. For the V-Link, there are less references available. All we can say is that, in circuit between our computer and our stereo hi-fi system, it really was found to fullfill the essential zero-insertion loss required of such a useful component.
Our source PC was an Apple Mac mini (Mid-2011), with Furutech USB cable.
We tried both of the Musical Fidelity V-Link 192’s outputs, and usually settled on the RCA connection to the unbalanced input of a dCS Purcell D-D upsampler, or directly to dCS Delius D-A convertor.
Where the original Musical Fidelity V-Link forced us to choose between the grainless but somewhat vaguer soundstage of optical, or the well-timed but occasionally harder sound of co-ax, the new V-Link 192 was perfectly civil with either output. AES3 worked very well although we somehow gravitated more to coaxial, perhaps finding it a tad more natural sounding without being able to pin why.
As well as Apple iTunes for music playback, we used Soundbooth Decibel, one of the best-sounding music players for OS X.
With track’s preloaded into memory and audio-hog mode engaged (to temporarily disconnect other apps’ access to Core Audio) the sound can rightly be described as divine, and as close to the best CD transport sources as we’ve heard.
There was an ordered and crystalline clarity to the highest frequencies, supported by solid stain-free bass. And in use of several weeks, the unit always behaved impeccably, causing no instability in the host system.