Headphones

Did Ifi Audio actually need to upgrade its Neo Idsd Dac/Headphone Amp? Well, change is seemingly inevitable in the fast-moving range of this Merseyside-based company, given the pace with which products - new and revised - seem to flow from its own factory in China. Indeed, there's an element of 'blink and you'll miss it' about iFi Audio's releases, which now encompass a wide range of hi-fi devices from pocket headphone amplifiers to products aimed at the pro audio market.

The £899 NEO iDSD 2 is one of its more recent arrivals and while it may look very much like the original model, launched in 2020, it follows the company's trend of sensible but worthwhile upgrades, made possible by having its own in-house design and engineering team here in the UK. So, what's new here? Well, the basic digital implementation is unchanged, using a Burr-Brown DAC from TI - iFi Audio avoiding the AKM/ESS merry-go-round that preoccupies many hi-fi brands - while offering the same file-handling capabilities (768kHz/32-bit and DSD512) as the original NEO iDSD.

Going Global

Yes, you can find DACs that go further, but then there's very little DSD1024 content available, and for most users what's on offer here is more than futureproof. Digital operations are controlled by iFi Audio's GMT (Global Master Timing) 'femto-clock', with a data buffer to tackle jitter, and inputs processed by a new low-latency XMOS microcontroller, programmed in-house and boasting both greater clock speed and a larger memory. Unusually, the NEO iDSD 2 also has an input for an external clock, enabling synchronisation with suitable digital devices.

In addition, there's an analogue input, on a 3.5mm stereo socket, alongside optical, coaxial and USB-B digital inputs, and both RCA and balanced XLR analogue line outputs, emphasising that - as well as being a DAC/headphone amp - this unit can also be used straight into active speakers or a power amplifier.

The NEO iDSD 2's analogue section is an enhanced version of the manufacturer's 'PureWave' circuit design, its balanced dual-mono topology and short signal paths ticking audiophile boxes. There's also an upgraded Bluetooth implementation using the latest QCC518x chip from Qualcomm, enabling it to handle aptX Lossless as well as aptX Adaptive, LDAC and LHDC/HWA codecs, all via a far tidier internal antenna.

Optimised layout with Qualcomm’s QCC518x BT 5.4 audio chip [top left] and XMOS USB hub [near left] feeding a Burr-Brown DSD1793 DAC [centre] and IC op-amp-based balanced line and headphone outputs [far right]

Gains To Be Had

The headline news, though, is the addition of iFi Audio's iPower2 plug-top PSU powering the unit's headphone amp to 5x the output of the previous model. Over 5W/32ohm is claimed via the 4.4mm front-panel balanced output [see PM's boxout, p75], requiring the provision of a -12dB gain setting for sensitive 'phones, alongside the normal, 'turbo' and 'nitro' options selected via one of the tiny fascia buttons.

Naturally, the NEO iDSD 2 offers the analogue tonal adjustments seen on past products - XSpace and XBass II allow the presence/soundstage scale and low-frequency response to be tuned to match your headphones and taste - plus a choice of four digital filter settings. With all that provided, and only a fairly basic remote handset [see p77], iFi Audio's Nexis Bluetooth app comes in handy. This connects to the NEO iDSD 2 to provide control, allows you to dig deep into the menu system to change settings, and facilitates over-the-air firmware upgrades.

Mind you, the rest of the accessories package is generous enough. As well as the little 'upright' stand, iPower2 power supply and remote control already mentioned, you also get a 6.35-3.5mm headphone adapter, a decent USB-A-to-USB-B cable, and good-quality analogue output cables.

Previous, long-term experience with iFi Audio's bijou DACs, amps and streamers suggests not that they just work, and very reliably, but rather that each of them delivers sound quality well beyond both their compact dimensions and price. So it is with the NEO iDSD 2 which has all the convenience of the original model, a sample of which I had to hand for comparison, but significantly elevates the performance.

Little Darling

That's especially true when used as a digital input headphone amp, but even when I started listening with it as a line-out DAC and then as a preamp, I was nothing short of amazed at what this slender silver unit could do. As a conventional DAC, outputting at fixed level via its RCA or XLR connections into a preamp or integrated amp, the Neo iDSD 2 is capable of remarkable weight and insight, but used as a preamp (albeit a minimalist one), into active speakers or a power amp, it's even more impressive.

Fed from my computer running Roon, and then - rather improbably - connected to the hefty (in every sense) Electrocompaniet AW 300 M monoblocks also on site for review [see p62], the NEO iDSD 2 demonstrated transparency, grip and wide-open tonality that made music of any genre a delight. And it sounded almost as accomplished when slotted into my second-room system, this time with a pair of 1990s Marantz Music Link mono power amplifiers.

Digital ins are shared across coaxial, optical and USB-B sockets (wireless BT 5.4 antenna is within) with 10MHz clock sync and analogue input (on 3.5mm socket) alongside. Balanced (XLR) and single-ended (RCA) analogue outs are fixed or variable

Sweet Dreams

With virtuoso percussionist Kuniko Kato's recent Kuniko Plays Reich II release [Linn CKD712, 96kHz/24-bit], iFi Audio's DAC/preamp conjured an enticing sense of soundstage focus and presence, and had real punch with the impact of mallet on instrument - this was allied to a natural decay of sound, making for an exciting listen. Meanwhile, on a different scale, Paul McCreesh's 'period instruments' recording of Elgar's The Dream Of Gerontius [Signum SIGCD785, 96kHz/24-bit] has beautiful performances and lavish instrumental textures, all of which the NEO iDSD 2 brought forth for inspection without stopping me becoming immersed in a fine rendition of what is perhaps the composer's greatest work.

Change tack to Nonetheless, the lavishly produced latest Pet Shop Boys release [Parlophone, 44.1kHz/24-bit download], and the bass extension and grip here is never in doubt from the off. The opener, 'Loneliness', pounded from the speakers in all its pomp, but also with bags of detail in evidence, especially in Neil Tennant's slightly (more) world-weary vocal. Meanwhile, with the title track of Lake Street Dive's forthcoming Good Together set [Fantasy Records, Bandcamp download], the NEO iDSD 2 did a fine job of punching out the rhythm section of Bridget Kearney's slinky bass and Mike Calabrese's crisp drumming, while allowing Rachael Price's lead vocal all the space needed to rise above the mix.

Get A Grip

However, I've saved the best until last, for while the original NEO iDSD was a very good headphone amplifier, iFi Audio's new '2' version is nothing short of sensational. There's more than enough power to drive even the most recalcitrant 'phones, and a sense of unbridled extension and very serious grip. You probably won't need the amplifier's gain-boosting facility, though you will want to dial the power back with in-ear models, as I did with a pair of AKT8iEs from Astell&Kern.

Similarly, those sound-shaping filters, XSpace and XBass II, are 'matter of taste' options rather than must-haves. I found the sound more than spacious enough, and with no shortage of low-end substance, without them in use; in practice, their effects were arguably a little too heavy-handed with many musical genres. Stick with the 'flat' settings - which are anything but dull - as I did with the ultra-revealing Austrian Audio The Composer headphones, and the NEO iDSD 2 can wrap you in the music in a totally absorbing manner.

Time And Space

Playing Blue Öyster Cult's cover of 'Kick Out The Jams' from the Ghost Stories set of 'lost' tracks [Frontiers Music FR CD 1398], the amp really got the 'phones snarling and charging with all the drama anyone could ever want. Similarly, it threw open the dense, synth-laden mix of Hawkwind's Stories From Time And Space [Cherry Red, 44.1kHz/24-bit download], the band's 36th album and the now 83-year-old Dave Brock still very much its driving force.

Kick back and let the recent LSO/Simon Rattle album of Britten [LSO Live LSO0830] wash over you, however, and the true depth and fascination of what the NEO iDSD 2

can do with good headphones is revealed. From the darkness of the 'Sinfonia da Requiem' to the sprightly 'Spring Symphony', this set-up will keep you gripped right through to the triumphant last chords of 'The Young Person's Guide', thanks to the way it fully renders the timbres of the orchestra, and the Barbican Hall ambience.