This is a review of the xDuoo Link2 Bal which is a dual SE and balanced output dongle-type portable amp/DAC with up to 270mW of output power. It is priced at $149.
Disclaimer: This is a sample sent in exchange for our honest opinion. Headfonics is an independent website with no affiliate links or status. Thank you to Shenzhen Audio and xDuoo for this opportunity.
Click here to read more on xDuoo products that we have previously covered on Headfonics
Note, that this article follows our latest scoring guidelines which you can read up on here.
xDuoo has entered the dongle DAC market more than once before and they apparently sell their stock out quickly and that’s a good thing. It only means their dongles have a good general appeal. But replacing a good seller is a tricky business nowadays.
Each xDuoo dongle as they’re released carries some small improvements but still lacks refinement in certain areas.
For example, Link V1 and V2 had attached wires, less power at 32mW/82mW respectively, and a single-ended topology. The Link2 had a detachable wire and raised the power output to 150mW but still, it had no balanced topology.
So, if their older models had such appeal then their flagship dongle, the Link2 Balanced, (Bal), will also have a high level of appeal and should naturally be a step above their past dongles.
The Link2 Bal does show on the surface many visual cues that tell me more work was put into this model for certain compared to their previous models.
Tech Highlights
There’s nothing innovative about a dongle that uses dual SOC DAC chips because it seems to be the common norm nowadays. The xDuoo Link2 Bal also employs this concept.
Two Cirrus Logic CS43131 DACs sit at the heart of the Link2 Bal which is in fact a common configuration nowadays and used on other models.
The difference here is that xDuoo added a separate amplifier stage. The Link2 Bal has incorporated a Texas Instruments LM27762 chip which is a charge pump LDO that claims a power conversion efficiency of 85% which is a rather high claim.
Decoding
DSD DOP native is done on the Link2 Bal from DSD64 all the way up to DSD256 and PCM 16/24/32 bit all the way up to 384kHz. This dongle DAC does hardware-level rendering if the Cirrus Logic chip specs and features were correctly applied and implemented and I believe it is so.
The xDuoo Link2 Bal has no MQA capabilities but that’s fine with most listeners nowadays and myself included. Of course, it would be nice to have the format capability for TODAL fans and those that use local storage MQA formats.
All these formats are capable of running regardless of source since the Link2 Bal is compatible with iOS and MAC, Windows, Android, and even Chromebook compatible. But if you find it to be incompatible with a source just switch it over to UAC 1.0 and it should work.
Performance Numbers
One of the specifications that xDuoo pushes is the Link2 Bal low distortion and high SN ratio numbers which are rather good. The SN ratio for example is measured at 127dB.
The DAC chip alone carries a 130dB spec on its own factory spec sheet. So, it seems the circuitry is a well-implemented one that does not meet that specification.
The Texas Instruments LM27762 inside the Link2 Bal manages 270mW off the balanced 4.4mm connection and the single-ended 3.5mm manages 125mW, both measured at 32Ω. That’s enough power for some headphones out there but with dongle DACs, I would mostly stick to using IEMs for portability’s sake.
That amount of power is delivered with a THD-N of 0.001% on the single-ended side and 0.007% on the balanced side. Also, one obvious note in the specs is that crosstalk improves considerably on the balanced port which is rated at 120dB versus the single-ended 77dB rating.
Design
The xDuoo Link2 Bal is a good-looking dongle and feels robust as far as build. It feels good in the hand but it’s rather chunky. The xDuoo Link2 Bal body is made from a single piece of aluminum, CNC shaped, medium grey anodized finished, and finished off with 2 pieces of tempered glass.
One piece of glass displays the company logo and model number on the bottom portion while the top portion sports a format indicator short strip LED. The flip side displays the xDuoo website, a made-in-China claim, and some certifications laid in gold letters which are visible within the pitch-black tinted glass.
The I/O connection set consists of a common USB-C port for the sole input. The two output ports are a 3.5mm single-ended and a 4.4 balanced Pentaconn connection.
On one side you will find a dual button type volume control and a red button which is used as a multifunction button for pause, play, and phone call acceptance plus other functions.
The other side panel sports two switches, one is a UAC mode switch and the other is a turbo mode switch. This could have been done with a simultaneous press on both volume buttons to toggle the turbo mode.
The UAC could have been done with a long press of the red button while connecting to a USB source. I would have preferred something different on those switches like filter selectors and, or a bass enhancer.
Packaging and Accessories
I have to give praise where praise is due and although I’m not an iPhone user and personally use Android mobile devices the xDuoo Link2 Bal includes a Lightning terminated cable which is rather rare with dongle DACs nowadays and it shouldn’t be so.
Of course, you also get a USB-C cable and a full-size USB type A adapter that fits both included wires. I would consider this setup of included connectivity to be the standard but dongle DAC makers haven’t rectified this in my opinion. Rarely do they include any Lightning connectivity leaving that community to venture out to get their own cable.
The dongle DAC, the cables, the adapter plus a user’s manual and a warranty card make up the complete package list that comes in the box which is not too large. The contents come well protected inside and individually placed within some custom molds.
Sound Impressions
Summary
The first character I noticed about the Link2 Bal sonically was the full-bodied spectrum sound that is wide and tall, rather expansive but with a neutral but slight mid-centric character. It portrays overall a tonality that is rather large in scope.
The warm bass tonality tends to relax the bass and presents it in a tamed manner but with a good amount of body and low-end extension nonetheless.
The midrange takes front and center stage here, however. The high frequencies also seem to be controlled and slightly timid, somehow held back from crossing over into distortion levels.
This particular dongle DAC does well in the detail retrieval department, especially around the midrange section. You could hear distinct nuances unheard of with past dongle DAC iterations and only surpassed by modern-day models with beefier hardware implementations and of course higher prices.
I could mention a few tracks that the Link2 Bal allowed me to pick out clearly certain details when other dongle DACs made those details almost absent or hard to identify. For example, I could pick out individual notes from a piano within a vast orchestra very distinctly in a particular song, that kind of detail.
Staging and Dynamics
The Link2 Bal tends to be soft-mannered so as to not emphasize anything within a recording but it’s no mister softie either. It seems to employ a relaxed tuning but a rather spacious one and still could pack a punch at times. It also rarely sounds rushed, confused, or congested.
Imaging is almost spot on with just a very small amount of underfill but placement makes up for it and the Link2 Bal portrays an interestingly expansive capability, particularly within the midrange and high frequencies.
The balanced side does indeed have a small sonic improvement over the single-ended side, especially in the overall staging which gives credibility to the almost double and much higher crosstalk specification. It also tends to produce more detail so I would consider using the 4.4mm connection exclusively.
Synergy
Power
The xDuoo Link2 Bal actually has a pair, not only in reference to dual outputs but also that it can push my T50s and my Hifiman Arya well and I have the second release which is not as efficient as the more recent stealth edition.
The balanced connection not only will give you better staging and imaging due to the rather large difference in crosstalk specification but dynamics seem to improve considerably. You get more punch and less distortion at higher volume levels.
Pairings
I did have to kick the Link2 Bal into normal mode every time I used IEMs since the turbo mode did produce a very slight amount of hiss with very sensitive IEMs but nothing major and was barely noticeable. With the gain setting on normal, there was an absence of hiss with all my IEMs.
The first IEM I used to display this character was the FiiO FD7 which is not too prone to hiss but I also noticed some hiss with other IEMs and the remedy every time was the normal gain mode switchover.
With full-sized headphones, this wasn’t an issue on any headphones I used, and definitely not when the dongle is in normal mode but I normally kicked in that turbo mode on full-sided cans. The not-so-sensitive cans definitely preferred the turbo setting.
The Link2 Bal high gain seems particularly set for full-sized headphones and there is an app out there but it’s just a 63-step gain control.
However, I could not find it in the app store and it would be easier to find it on their website, download the kit from their website which includes the APK, and manually install it.
