Aune X1S 32Bit/384KHz DSD DAC Headphone Amplifier

Introduction
Aune is the high-quality HiFi brand of AO LAI ER Technology Co.ltd which was founded in 2004. In the past, they have created some iconic digital audio products. One of the most enduring is the X1s DAC/headphone amplifier. The X1s has been through several iterations over the ten years since the first model was released. While it has retained its familiar physical characteristics, with each generation, the company has continued to refine its appearance and internals and strengthened its identity. To celebrate a decade since the first release, Aune has released the 6th generation of their DAC/headphone amplifier and that's what we're looking at today. Meet the Aune X1s 10th Anniversary Edition.

Here's what the company has to say about it:

Aune X1s 10th Anniversary Edition is a special edition commemorating 10 years of the X1 series. Now in its 6th generation, the X1 series is a multi-functional DAC/headphone amplifier developed for PC HiFi and small audio systems. The X1s uses the Sabre ES9018K2M chip which has 3 filter modes and supports 32bit/384k and DSD128. The decoding capability is simply outstanding.

Disclaimer: This sample was provided for the purpose of an honest review. I am not affiliated with the company and all observations and opinions here are my own, based on my experience with the product. The X1s 10th Anniversary Edition is listed at $249 at the time of writing. You can get it from the official Aune store.



Package and accessories
The Aune X1s comes with a basic unboxing experience. It starts off with a heavy-duty black box that is unadorned except for the single Aune logo on the front.

On the inside, you'll find the X1s DAC nestled in a soft, black foam. There's also a thick sheet of the same foam covering the goods so everything should be well protected during postage/transit.

So what exactly is in the box?

• Aune X1s 10th Anniversary Edition DAC/headphone amplifier
• Power adapter & cable
• USB cable
• USB drive with user manual and drivers
• 6.35 mm adapter

So there are just the basic necessities inside but really what more could you need? As far as unboxings go there's not a lot to get excited about but of course, it's the actual device and the sound that really matter. The included USB cable is robust and high quality, with gold-plated connectors.

Build & functionality
Now onto the device itself. The Aune X1s has an aluminium chassis with a matte black finish (unless you get the silver one). It's a sleek looking piece with concave sides and a convex top. The resulting curves keep the Aune X1s from being another boring, black box and I think it looks great.

The dimensions are W145 mm x L171 mm x H45 mm which is a nice size to fit on a small to a medium desk. On the underside are 4 silicone feet that protect the surface the DAC is sitting on and they also have a very good grip which prevents it from sliding about.

On the front panel is the input select/filter mode button. To the right of the button are 4 LED indicators, showing which input is selected. In the middle is a gold-plated 6.35 mm headphone jack. I would have liked to see an additional 3.5 mm jack here - something I always miss after having it on the Audinst HUD-MX2. Lastly, on the right side is the volume pot. The pot is quite large and has very smooth tracking, with enough resistance to enable precise adjustments.



The rear panel hosts all the input and output options and has a nice, tidy layout with easy to read labels. Here you'll also find the only air vents, sitting above and below the power socket. It's worth noting that during use the Aune X1s never gets hot but only slightly warm and that's always reassuring. Right so let's take a gander at what makes up the back panel (from Left to Right):

• 5-pin power socket
• L & R Audio In RCA
• L & R Audio Out RCA
• Coaxial In & Coaxial Out
• Optical In
• Power On/Off switch
• USB In

Internals
Just like the previous generation, the Aune X1s 10th Anniversary Edition supports up to 32bit/384k and DSD128. Powering the conversion is a Sabre ES9018K2M DAC chip. The headphone output power is rated at 200mW @ 300Ω and 560mW @ 32Ω.

The Sabre ES9018K2M DAC has 3 different filter modes: 1. Fast roll-off 2. Slow roll-off 3. Minimum phase. There's very little difference between the filters but for testing, I stuck with the fast roll-off. Aune says that the X1S has ultra-low noise and ultra-low distortion and I won't argue with that since I heard neither. Another feature is the low jitter from the high-performance USB interface.

Something you might be interested in knowing is that when using the line out the headphone jack is still active. It would be nice to have a dedicated switch to change between the two (like the JDS Labs The Element) or automatically disable the headphone jack when the line output is selected.

The X1s has a fixed level line out so it can only be used with powered monitors or as a preamp i.e. when using the line out you have no control over the volume. Also, there was some channel imbalance at very low volume when I was testing sensitive IEMs but to be fair, it only happened at levels below what I would normally listen to, even during quiet listening.



Setup (Windows)
It has been a long time coming but Microsoft has finally made some improvements to Windows support for external DACs. After plugging in the X1s via USB, Windows proceeded to install drivers for the device and in just a few seconds it was up and running. However, I would suggest that you manually install the XMOS drivers to unlock the full functionality of the DAC.

Although there was a USB drive included in the package with the drivers preloaded on it, the one I received had errors and the driver file was corrupted. Not a problem. I hopped over to the Aune website and downloaded the driver there (which happened to be a more recent version) and a couple of minutes later had the driver installed.

Setup (Shinrico D3S)
This couldn't have been any easier. I connected the X1s via the optical in and was good to go - well with headphones at least. To test with my speakers I used the RCA line out and plugged into my FX Audio E1002A amplifier, which is connected to my ELAC Debut B6 monitors. Sweet sounds ensued.

Sound
Testing was done using my PC and MusicBee via USB-in and the Shinrico D3S via optical-in. All music was served as lossless flac files. The Aune X1s sounds neutral and transparent to my ears with a great sense of rhythm and dynamics.



Acoustic Research AR-H1
The X1s is a great pairing for the H1 and highlighted it's strong points. Levels were around 10-12 o'clock on the pot with this headphone. Bass is solid and punchy with that well-defined planar edge. Treble is crisp, almost clinically clean and clear without any edginess. The X1s provided excellent instrument separation and a wide soundstage.

Beyerdynamic DT990 Pro
This was another good match that brought to life that classic Beyer bass that has wonderful, tidy control and strong impact. At 250 ohm these require a bit more power but the X1s handled them with ease, leaving plenty of extra play available on the volume dial. The sound from this pairing was detailed with a wide soundstage.

Meze 99 Classics
For some reason, the 99 Classics didn't fare as well with this combination. The sound was a little muddy with a bloated and overpowering bass. This might be caused by the output impedance of the X1s but I can't be sure. The website doesn't specify what the output impedance is but if I remember correctly it was 10Ω in previous iterations.

I did notice, however, that the midrange and vocals were rich and vibrant. The soundstage was fairly narrow but it had a nice amount of depth.

DUNU DK-3001
At just 13Ω the DK-3001 didn't have any problems at all with the X1s. I couldn't detect any hissing or background noise. The sound is full-bodied with excellent detail and separation. Treble extension is stellar and the soundstage wide.

Comparisons
Audinst HUD-MX2 ($228 USD)
Compared to the X1s, the HUD-MX2 has a little more fullness in the bass and lower midrange and vocals are a touch more forward. There's a smoothness to the HUD-MX2 in contrast to the X1s which is more transparent and slightly more resolving. Soundstage is a touch wider on the X1s, giving it a larger, airier sound and more energy.

One thing I really like about the HUD-MX2 is the dual headphone jacks, one 3.5 mm and one 6.35 mm. I wish more headphone amplifiers had this feature because it just makes it so much more convenient when switching between headphones or IEMs. I'd love to see this added on a future generation of the Aune X1s.

Topping DX7 ($399 USD)
The DX7 and X1s share a very similar sound. That's hardly surprising since they both use the ES9018K2M chip. Where the X1s is transparent, the DX7 is even more so, though its extra neutrality is only noticeable when doing a direct A/B comparison. The X1s presents vocals ever so slightly more forward. The DX7 also seems to have more depth in its soundstage and overall separation is superior. Topping's unit also offers a balanced XLR headphone output and OLED display but of course, it's roughly double the price of the Aune X1s.



Conclusion
The Aune X1s performs really well for its modest asking price. Its sound is clear, transparent and on par with some of the more expensive DACs out there. It's all wrapped up in a gorgeous chassis that thankfully moves away from the common, straight-edged boxes that are so prevalent. The curved top and sides give it a prestigious appearance that is only exemplified when you feel how solid the build quality is.

Other standout points are the high bit-rate and DSD support plus the generous input and output options that adorn the rear panel. Anyone looking for a DAC/amp combo for their desktop should definitely take a look at this one. It's one of the best options available at this price point and I would gladly dedicate a space for it on my desktop.

*This review was originally posted on my blog at Prime Audio. Hop on over to see more like this.

A short review:
 
This sounds a *touch* better than a Dragonfly Red, significantly better than a Galaxy S6, and *much* better than my Dell XPS 13 (2013 model). 
 
You also get USB, optical, and coax inputs, a quality aluminum build, and a nice, big, smooth volume knob.
 
The biggest downside is that the output impedance is 10 ohms. Given that to minimise changes to the frequency response from your headphones, you should be using an output impedance less than 1/8 of your headphone's impedance, this means that the Aune X1s is best suited to headphones with an impedance of between 80 ohms and 300 ohms. (Why 300 ohms? Because the Aune X1s really isn't powerful enough to drive 600 ohm headphones properly.) That being said, I couldn't hear any changes in frequency response on my 32-ohm headphones between this and the Dragonfly Red.
 
Despite that criticism, I don't care. It still rates as the best DAC I own.