Outboard DACs

We've come a long way since iFi Audio was started as an offshoot of high-end brand Abbingdon Music Research, building its initial reputation with its 'Purifier' products, designed to clean up digital signals. And if anyone was labouring under the delusion that these were devices designed to tackle non-existent problems – you know, the old 'digits is digits' thing – the company has since expanded into making everything from complete systems to some of the most cost-effective DACs and headphone amps around. After all, its excellent xDSD [HFN Jul '18], was a 2018-19 EISA Award-winner, following on from the 2014-15 winning footsteps of the nano iDSD [HFN Dec '14].

Headquartered in Stockport, Merseyside, and using a number of outside consultants as well as its own team to design and engineer its products in the UK, these days iFi Audio has expanded its catalogue, which now runs to some 30 components. It includes the striking-looking bamboo-clad, architect-inspired Aurora all-in-one network system alongside no fewer than eight DACs in the lineup. The most recent arrivals are the tiny pocket-sized hip-dac (£149), designed for music on the move, and the very affordable ZEN models, including the £129 ZEN DAC that we have here.

Triple Surprise
Sitting at the 'even more affordable' end of the iFi Audio range, the compact ZENs show that building down to a budget doesn't mean the company cuts corners, whether on the engineering or industrial design. Built for desktop use, both the ZEN DAC and its Bluetooth counterpart, the ZEN Blue [see boxout, p67] have a striking look unlike anything else in the company's range. They're clad in high-quality aluminium casework that not only looks good but feels remarkably substantial for products so compact. Indeed, the ZEN DAC stands just 30mm tall.

Despite the toy-like dimensions, this is actually a potent and flexible digital device, both in its handling of data and its ability to fulfil its dual functions of DAC and headphone amplifier. Actually, make that triple functions as, due to its variable-level analogue outputs, it could even be used straight into a power amp or a pair of active loudspeakers, hilarious though the combination of this tiny unit and a hulking great power amp might seem. Indeed, iFi Audio's preferred analogue output is the tiniest connection here, a little 2.5mm socket on the rear panel that can be broken out into a pair of balanced XLRs via a suitable (third party) adapter cable.

Most users are more likely to use the ZEN DAC's entirely conventional unbalanced RCA outputs that can be set to fixed or variable, the latter under the control of the front panel knob. Also on the front panel are the headphone outputs comprising a standard 6.35mm unbalanced connection or a 4.4mm 'Pentaconn' type for balanced headphones.

Power Matters
The sole input here is a USB 3.0 Type-B socket, of the 'double-decker' kind rather than the smaller USB 2.0 square design more common on USB DACs, and a suitable A-to-B cable is included.

The USB connection also carries 5V power for the ZEN DAC but there's a separate DC input on the back of the unit should you wish to upgrade with an aftermarket 5V/500mA supply. You could use a simple plug-top PSU (such as that provided with the ZEN Blue DAC), with such devices available online for around £10 or so, but iFi Audio also offers two upgrade power supplies, the iPower and iPower X, at £49 and £99 respectively. In practice the ZEN DAC's maximum (headphone) power output can only be guaranteed with an external PSU because computer USB hub reserves can vary quite widely.

Within, the ZEN DAC certainly belies its budget pricing, and not simply by virtue of that balanced topology. Designed with substantial input from industry designer John Curl, who joined the company as a technical consultant last year, it employs Burr-Brown/TI's DSD1793 'True Native' DAC, downstream of a customised XMOS USB input, enabling it to handle LPCM at up to 384kHz/24-bit, as well as DSD256/11.2MHz 'quad DSD' in native form, and also MQA-encoded data.

Firmware Options
A small LED next to the volume control changes colour to indicate the incoming file format. It glows green for LPCM up to 96kHz, yellow for 176.4-384kHz, cyan for DSD64/128, blue for DSD256, and magenta to indicate MQA. It's also possible to download different firmware options from iFi Audio's website to optimise the DAC in various ways, and experiment with alternative digital filter settings.

Some of the filters originally used in the company's Pro iDSD [HFN Sep '18] can be downloaded as part of firmware 5.3C, and it's also possible to load v5.2 'Limoncello', which removes MQA capability, but makes it possible for the ZEN DAC to handle DSD512. Such firmware changes are carried out via the USB connection.