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Phil
iFi pitches the xDSD primarily as a mobile DAC with an onboard headphone amplifier, its 2200mAH rechargeable battery sufficient for up to 8 hours’ playtime. The line-out mode also makes it suitable for connection to the pre-amplifier section of a loudspeaker system, bypassing the unit’s volume control but also the xBass and 3D ‘tone controls’ – useful with headphones, less so with loudspeakers. A healthy 2.1V output seals the deal.
So — is this £399 / $399 / €448 xDSD DAC a true multi-tasker? Only if it distinguishes itself in both mobile and home roles and in a product segment not exactly short on alternatives. Even iFi’s own £299 xCan runs close to the xDSD’s utility: a headphone amplifier with a (Bluetooth) DAC on board.
What is it?
A flexible little beast, the xDSD includes three inputs. On USB we note a male type-A connector recessed into the body of the xDSD – unusual but the robust connection is reassuring. Here file support climbs to PCM 384kHz (and MQA) and DSD256. An alternative firmware jettisons MQA but extends file support to 768kHz and DSD512. I stuck with stock. The 3.5mm socket covers both coax and optical input duties, albeit with a 24bit/192kHz PCM ceiling and no DSD or MQA. The Bluetooth input is aptX- and AAC-capable and can store up to eight paired devices.
On outputs, a single 3.5mm socket toggles between fixed and variable, the latter operating in a pseudo-balanced mode that iFi dubs S-Balanced (tech info here). Two digital filters – Transient Optimised and Frequency Response Optimised – permit sonic seasoning. For better sound quality, iFi recommend the former (with echoes of the Allo Katana’s op-amp boards).
3D+ and xBass+ signal processing are for headphones and executed in the analogue domain. Think analogue tone controls, the former creating ‘a holographic sound field like listening to speakers’, the latter adding genuine welly heft to the bass. Here we let our inner purist go. Volume control is also all analogue.
Finally, there’s a USB-C port for charging. With IEMs in play the xDSD “should give 6-8 hours use”. In line-out mode, I ran dry a couple of times but the unit can be charged as it continues to play.
Looks, fit, finish, operation
Akin to a pack of cards, the xDSD is pocketable – for context: an LG V30 phone is longer / wider / heavier, albeit much shallower; an AudioQuest Dragonfly is smaller still but a) it’s much easier to lose and b) vs the xDSD, it’s an egg vs omelette comparison.
The xDSD’s fluted chrome finish looks smart until fingerprints take the shine off. A rear black bumper helps distinguish inputs from outputs, and the volume wheel feels nice. As does the xDSD overall – it’s a very tidy little unit.
Unlike the quirky ergonomics, where I never did get fluent in switching modes or deciphering the numerous coloured LEDs – intuitive it is not. It does get easier with practice though and a screen would probably add cost and size.
The review gang
Sources were an LG V30 phone (£400-ish) with audio extracted three ways – via Bluetooth, via USB Audio Player Pro + OTG USB cable (OTG = ‘On The Go’) and via the 3.5mm output which taps the V30’s quad-core DAC.
Headphone amp comparisons were Arcam’s rHead (£400) and iFI’s xCan (£300). Headphones were Meze 99 Classics (£280).
A Pro-ject StreamBox S2 Ultra (SB2SU – £600) was also used, connected via USB to the xDSD for a tidy Roon endpoint. In this line-out mode the xDSD fed an Ayre AX-7e amp ($3950) driving Graham LS6 (£2200) speakers via Tellurium Q speaker cable (£270). DAC comparisons were Allo’s Katana with iFi power supply (£360) and a Mytek Liberty with SBooster (£1200).
Listening – headphones
The LG V30 (with UAPP as appropriate) was primarily used as the source.
xDSD into the Meze
Thoroughly enjoyable indeed. Complex mixes such as “The Circle of Life” from the new Lion King – guilty pleasure and good test track – are resolved well, the different vocal layers clearly discernible, the weight of the drums conveyed with force and the climactic finale swirling around my head. Clarity is to the fore but not stripped-bare, just an ordered and structured sound.
There are limits though: “Unsuffer Me” from Charles Lloyd’s Vanished Gardens builds into a maelstrom of competing forces. The xDSD lets go slightly, elements bleeding into each other as things build. Arcam’s rHead maintains greater composure, organising things more effortlessly whilst also being slightly richer. These ears give the nod to the rHead, others may prefer the slightly cooler sound of the xDSD. The differences aren’t huge, and different ‘phones may give a different conclusion.
Bluetooth from LG V30 to xDSD to Meze
Bluetooth cedes a little richness, some delicacy and a degree of detail to the wired connection. Background guitars are more easily heard on Natalie Merchant’s “San Andreas Fault” from Tigerlily where things flow more evenly, bass warmer. Bluetooth is a little drier, cooler, less engaging.
Not by much though. When out and about it’s not really noticeable. Even when stationary, the extra convenience of Bluetooth might tip things in its favour. Noting of course that the LG V30 outputs aptX.
That’s with the Qobuz app. Switch to USB Audio Player Pro which integrates Qobuz but optimises the LG’s USB output and our hardwired connection pulls away, leaving Bluetooth trailing – there’s just more going on. More detail, greater ease, stronger tonal colours. It’s more engaging and by a margin that matters.
Versus LG V30 headphone output
The Meze / V30 combination works well – I have both. Ultimately, the V30 is out-gunned by the xDSD. The phone’s treble in particular develops a slightly coarse sheen when played loud – harsh, akin to a lively room reflecting too much sound. Turn up the xDSD and it just plays louder and remains tonally consistent. Again, the differences aren’t huge, unlikely to justify the cost of the xDSD alone. Factor in its additional functionality – digital inputs for example – and that decision may change though.
xDSD and xCAN headphone outputs (xDSD line-out feeding the xCan).
iFi’s xCan is a £300 portable headphone amp for when you already have a suitable DAC – an LG V30 for example. It’s not just an xDSD stripped of its USB DAC. Its output circuitry has been enhanced to deliver better quality, including a balanced option via a separate 2.5mm socket, for which we can call on the Meze’s balanced cable.
On unbalanced outputs the two iFi devices are close, the similarities more noticeable than the differences. Tonality, drive, control of the Meze’s ripe character – all good. The xCan grips the lower end better to make bass lines easier to track and reducing their domination. The xCan treble is also more detailed, the acoustic guitar on Natalie Merchant’s “San Andreas Fault” – from Paradise There (Tigerlily re-done 20 years later) – easier to discern. Generally everything’s tidier. The xCan’s balanced mode advances things by the same degree again, and in the same areas. Slight gains, but gains nevertheless.
Should we treat ourselves to both xDSD and xCan and use together? I’d err towards a ‘no’ – the xDSD is good enough in its own right, the extra gains marginal in the scheme of things.
Signal processing
For headphone-use only, the analogue signal processing is both subtle and useful on some albums.
xBass+ gives greater weight to Kei Koito’s crystalline organ playing on Back to Bach (naff title, stunning sound) without pushing the Mezes into bass overload. Impressive – they’re slightly over-ripe to start with. 3D lifts the treble but not overly so, the effect being greater detail and presence.
Again with the Mezes, it works well. Or switch both into the circuit – each adds to the party without the sum over-egging it. My initial thought was ‘gimmick’, but once heard with my own ears, the cynicism fell away, to be replaced by respect for finer tunings that add without distraction.
Listening – main system
Pro-ject SBS2U to xDSD to Ayre to Grahams
Freed from headphones, the xDSD flexes its muscles and delivers a sound that’s anything but diminutive. The bottom end, in particular, cedes little on depth or control to the Mytek Liberty. Low, solid, with a meaty edge to it – think just the right amount of marbling in a steak. Very impressive indeed.
It also pushes music forward, demanding our attention rather than letting us relax into it. Direct rather than beautiful, a slightly dry character favoured over richness and warmth, particularly in the midrange. Only when the sound hardened with certain albums played at higher SPLs could I find a weakness. The xDSD doesn’t flatter poor recordings.
Switching to the Katana brings more warmth into play. Not chalk and cheese but definitely a different tonal character. The acoustic also seems more realistic – slightly deeper but also more palpable. Both DACs deliver an impressive sound for the money, personal preferences determining which we choose in the home context.
Moving up to the Mytek / SBooster does however show its clear superiority over the xDSD and Katana, and not just because it’s a cleaner sound. More detail is portrayed, the acoustic is even more believable – wider and deeper. In short, we get closer to the musical intent.
Summary
We need to put those comments into context though. Fronting £5k of electronics and speakers, the xDSD does a fine job. Heck, I briefly ran it into £20k of MOON and Spendor kit (review soon) and it had me grinning for all the right reasons (that bass is really good).
It’s also a stonkingly good portable DAC & headphone amp, the rechargeable battery freeing us from mains power for long periods. It could be that I got lucky the Meze 99 Classics but the iFi unit and the Romanian headphones work very well together.
The xDSD is an attractive and well-specc’d DAC & headphone amp, working really well on the move, in headphone mode at home and residing very comfortably in our main system as a DAC for the Pro-Ject streamer. Jack of all trades, master of most.
Further information: iFi Audio
