Have you ever wondered what would happen if a high-end audio manufacturer with a reputation for sonic excellence applied itself wholeheartedly to designing affordable electronics for personal audio applications? As it happens, that very question has been answered by the British firm Abbingdon Music Research, through its subsidiary brand iFi Audio.
iFi’s first components were its compact, affordable, desktop-orientated Micro-series models that demonstrated an uncanny ability to channel many of the sonic virtues of AMR’s full-size, high-end components. I reviewed the iFi Micro iCAN headphone amplifier in Hi-Fi+ issue 97 and stated that it represented “a new benchmark in its price class and … a perfect entry point for high-enders who would like to experiment with top-tier headphones, yet without investing an arm and a leg in dedicated headphone electronics.” Lately, however, iFi has focused on developing an even more compact range of portable Nano-series models.
Given favourable past experiences with the brand, we decided to review iFi’s new Nano iDSD portable DAC/headphone amplifier (£165) and Nano iCAN portable headphone amplifier (£149, reviewed elsewhere in this issue). Candidly, £165 is such a modest sum that many might question whether it represents a viable budget for something as sophisticated as a multi-format, DSD-compatible DAC. But if you set aside such ‘it’s-too-cheap-to-be-good’ biases, you may discover, as I have, that the Nano iDSD can sound ridiculously good in many (though not all) listening contexts. In short, the Nano iDSD begs to be taken seriously.
The Nano iDSD’s list of features and functions is extensive and impressive. For starters, the iFi is an asynchronous USB DAC that uses a BurrBrown DAC chipset to provide true native decoding for PCM files (44.1 – 384kHz, 16 – 32-bit), DXD files (352.8 – 384 kHz/24-bit), and DSD files at rates of 2.8, 3.1, 5.6, and 6.2MHz. The unit’s high-speed asynchronous USB interface uses iFi’s signature “Bit-Perfect” data transfer technology, backed by proprietary “ZeroJitter Lite” clocking technology. Finally, the Nano iDSD provides a useful 130mW headphone amplifier.
Inputs, outputs, and controls are simple and straightforward. On the rear panel, one finds a USB 3.0 (2.0 compatible) jack that is used for file transfers and battery charging, a coaxial S/PDIF digital output, and a standard/minimum phase digital filter selector switch (iFi recommends minimum phase settings for listening, but standard settings for test measurements). Out front, the Nano iDSD provides a stereo RCA analogue output, a 3.5mm headphone jack, and a control knob that doubles as a volume control and power switch.
The top panel of the Nano iDSD sports a tiny, multi-function, multi-colour LED that indicates formats and sample rates for files being played, connectivity status, and battery charging status. Unlike inscrutable DACs that refuse to tell you what they are doing, the Nano iDSD’s status LED tells you exactly what’s going on (once you learn its colour code, of course).
Unlike competing compact DAC/amps such as the Audioengine D1, Audioquest Dragonfly II, Resonessence Labs Herus, or the upcoming Light Harmonic Geek Out, the Nano iDSD incorporates a 1400mAh Lithium-polymer battery and thus can be USB or battery powered. Users select their preferred power mode by following specific start-up sequences. By switching on the DAC before connecting a USB cable, the Nano iDSD will run on battery power, but by plugging in the USB cable first and then powering up the DAC, the Nano iDSD will run on USB power. This feature means listeners can use the iFi with devices (tablets, etc.) that might not be capable of supplying USB power. iFi also offers this important tip: “For Apple iPhone/iPad/iPod Touch, (or) Android devices, please use Battery Power; otherwise you may receive error messages from your device.”
According to the manufacturer, “MAC OSX (10.6 or later) has built-in native support for the iDSD.” However, Windows users (XP or later) will need to download and install driver software from the iFi website: www.ifi-audio.com. Note that iFi makes periodic improvements to its driver software and iDSD firmware to expand the unit’s capabilities and improve sound quality over time. For example, planned firmware upgrades for the Nano iDSD will soon add support for ASIO 2.2 Extensions for DSD, plus support for DSD256 (11.2Mhz/12.4MHz). Plainly it pays to keep your iDSD driver and firmware up to date.
How does the Nano iDSD sound? The answer depends, in no small part, upon the transducers you choose to use—a point I make because the Nano iDSD’s potentially excellent-sounding but relatively low-output amplifier handles certain loads far more gracefully than others. As a general rule, the iDSD responds well to earphones and headphones that offer a combination of high sensitivity, high resolution, and neutral tonal balance. On the other hand, if you choose ‘phones that are low in sensitivity or known to be ‘current-hungry,’ you may overtax the iFi and get less than ideal results (in such cases, you might need an auxiliary amp such as iFi’s Nano iCAN or the more powerful Micro iCAN). While I tried the Nano iDSD with 17 different earphones and headphones, I did the bulk of my listening through two models that yielded spectacularly good results with the iFi: namely, NuForce’s phase-coherent, quad-driver, Primo 8 earphones and Oppo’s very high sensitivity PM-1 planar magnetic headphones.
At its best, the Nano iDSD delivers a refined and decidedly musical sound that exhibits natural (not artificial) warmth, a beautifully rounded and full-bodied presentation, excellent bass, suave yet articulate mids, and smooth, well-detailed highs. I also found the Nano iDSD did a good job of conveying the three-dimensional qualities found in better recordings—even though, unlike some other iFi models, the Nano iDSD does not incorporate specialised ‘3D’ circuitry.
I was particularly impressed by the Nano iDSD’s ability to leverage the top-to-bottom phase coherency and all-around timing accuracy of ‘phones such as the NuForce Primo 8s and Oppo PM-1s. Personally, I judge qualities of coherency and timing accuracy by asking two straightforward questions. First, do the upper harmonics and overtones of instrumental and human voices sound like a natural and well-integrated extension of the fundamentals of those voices, or do they sound disembodied or ‘disconnected’? Second, do transient events have a naturally quick, clear, and incisive attack with realistic decays, or do they sound overwrought, as if artificial ‘edge-enhancements’ have been applied? The iFi answers both questions in a clear, sharply-focused, yet appropriately musical way that fosters long-term listener satisfaction.
Consider, for example, the Nano iDSD’s performance as it drives the NuForce Primo 8s on Keith Greeninger, Chris Kee & Brain’s song “Close to the Soul T2” (Blue Coast Special Event 21, DSD128). On this track Greeninger’s vocals range from a whisper on up to full song and back down again, depending upon the requirements of the lyrics, and the iFi helps the NuForce ‘phones capture every subtle shift in emphasis and inflection along the way. What is more, the iFi helps the ‘phones tap deep reservoirs of low-level sonic information, giving the harmonics of Greeninger’s voice and of his gently strummed acoustic guitar their due, while also retrieving reverberant and spatial cues as the voice and guitar interact with the acoustics of the recording space. Finally, the accompaniment from an acoustic bass is heard with appropriate weight, warmth, and a soaring, richly-textured growl. Throughout, the iFi enables the NuForce to deliver a finely focused and simply masterful rendition of the recording, in the process giving a great example of a high-end audio system that could fit easily in a listener’s pocket or handbag.
No less impressive is the Nano iDSD’s performance through Oppo’s full-size PM-1planar magnetic headphones on the Gordon Getty “Overture to the opera ‘Plump Jack’, for Orchestra” from Orchestral Works by Gordon Getty [Marriner/Academy of Saint Martin in The Fields, Pentatone]. This enjoyable yet demanding test track presents a roughly 12 minute-long orchestral obstacle course for any DAC, amp, or headphone to negotiate—a test made all the more challenging by the abrupt musical ‘mood swings’ the music presents. As an example, listen to the transitions you will hear between the 6:00-minute and 9:20-minute marks in the track. During that brief span the music swings through melancholic and pensive moods, into lighter and more wryly humourous passages, on through to a section where we hear loud, low frequency percussion statements offset against ferocious brass section outbursts. Throughout, the Nano iDSD faithfully captures not only the distinctive textures, timbres, and dynamics of each section, but also their overall feel. In my notes I wrote, “The PM-1 shows just how articulate and nuanced the Nano iDSD’s mids and highs really are, and also how soulful, punchy, and well-defined its low-end can be.”
In sum, when paired with appropriately revealing, accurate, and high-sensitivity transducers, the affordable Nano iDSD DAC/amp provides an amazingly versatile and sonically sophisticated high-end solution. The only caveat is that, for best results, you must avoid asking the iFi to drive ‘phones whose power demands exceed the Nano iDSD output capabilities. Just keep that one rule in mind and you will be in for a serious sonic treat, and one that comes at a ‘cheap thrills’ price. But, should you require additional clout, flip back a few pages, to iFi’s Nano iCAN…
Type: Battery/USB-powered, portable high-resolution DAC and headphone amplifier
Digital Inputs: High-speed Asynchronous USB 2.0
(32-bit, 384 kHz)
Formats supported: PCM from 44.1 to 384 kHz, 16 to 3- bit; DXD (352.8 or 384kHz, 24-bit); DSD (2.8, 3.1, 5.6, 6.2 MHz)
Digital Outputs: S/PDIF (coaxial RCA)
Analogue Outputs: 3.5mm mini-jack headphone output, stereo analogue (variable level, via dual RCA jacks)
Power: Depending on start-up conventions followed, the Nano iDSD can be either USB-powered or
Battery capacity: 1400 mAh
Headphone amplifier output: 130mW
Dimensions (H x W x D): 28 x 67 x 106mm
Manufacturer Information: iFi
Distributed by: Select Audio
Tel: +44(0)1900 601954