Review: Luxsin X9, a new entry into the world of high-end DAC and headphones amplification

It's a bottomless rabbit hole when one of your hobbies is music/audio. Without some sense of self-control, things can escalate rapidly. I'd like to think I've been fairly steady for the last couple of decades with the things I've bought and/or tried out in an effort to reach "endgame" territory, but fast forward a year or two each time and a new model by brand-X gets announced, and then reviews pop up, and then the whole "I need to get one" thing happens....

... Like I said, a bottomless rabbit hole.

Luxsin Audio's algorithm must have been watching, as I only heard about the brand after an advert popped up on my Instagram feed, it was the VU Meter that caught my attention since I am a sucker for cool graphics.

The marketing made some bold claims, too: flagship AKM processing, automatic headphone calibration, a diamond-cut front panel fascia, all the input connections anyone could ever need, a slick full-colour display with smooth animations and quick touch response and more.

I reached out to see if a sample could be sent over to check out. Within a short space of time, the shipment was arranged, and a week later, I had the X9 on my desktop.

Emphasis on desktop, as my listening is primarily done in a near-field setup since I spend a lot of time at my workstation editing photos/videos, as well as writing and doing research. So, having quality audio has always been a must.

With that in mind, my existing kit consists of a FiiO K11 R2R acting as DAC and headphones amp, with an Aiyima A80 power amplifier to feed passive speakers. Whilst the price difference between the K11 R2R and the X9 is huge (€140 vs €1099), sonically I feel as though the DAC inside the K11 R2R is relatively excellent, especially once you use a clean and low-noise power supply, such as the iFi iPower2, an inexpensive switching unit that improves the sound, even if a small amount.

It is doubly an interesting comparison as it potentially can highlight the point of diminishing returns, as well as highlight key areas that actually matter for individual listening tastes. I'll try to cover as much of this as possible in this review, and as always this is a subjective take, so your mileage may vary, but hopefully with all the information presented here today, you can make a suitably confident decision on whether the X9 might be something you want to check out.

HiFiMAN Arya Stealth headphones were used via the front balanced outputs. The DAC section was tested using the X9's rear XLR balanced outputs going into the Aiyima A80's TRS balanced inputs. The power amplifier is connected to a pair of passive speakers, the TRIANGLE Comete 40th Anniversary.

First impressions

What struck me the most when pulling the X9 out of its pouch in the box was how hefty and solid it felt. The diamond-cut fascia panel has some interesting design features: an angled front that looks up with flat corner cuts that slope downwards, there's no mistaking this distinct design for a model from another brand, even from a distance.

The only physical button is the one to the right of the volume knob. This is the power button (long press for off, short press for on), which also functions as a mute button with a short press when the X9 is on.

The volume knob is suitably weighted and feels premium to turn. Not only does the internal pot ratchet sound nice, but if the X9 is turned on, then the relays actuate with each increment, and this sounds really cool to me. However, reading around after I posted the below video on forums, opinion was divided, with some saying it appears this is just an array of relays actuating instead of a full-blown R2R ladder with relays.

I reached out to Luxsin for clarification:

"The X9 features a true balanced differential circuit composed of 20 Omron micro relays and 88 precision metal film wafer resistors. This design not only ensures complete left-right channel symmetry but also effectively reduces crosstalk and impedance in the signal path. The use of metal film resistors ensures highly consistent resistance values and long-term stability, avoiding any negative impact on sound quality due to thermal drift or component variation.

The system offers up to 1024 discrete volume steps, each providing exceptionally fine granularity for near-imperceptible and smooth volume transitions. Compared to traditional digital attenuators, this analog control method delivers superior sonic transparency and dynamic performance."

That puts that to bed, then, and here is what the relays sound like in action:

So whilst the sound signature coming out of the DAC has nothing to do with R2R architecture, there are resistors in use for the volume control, and this is what is marketed as R2R volume. It's not there to improve the dynamics of the sound, but instead to provide robust and left/right balanced volume control.

Still, it's important to know the difference between common DAC architectures, so let's briefly cover that. I mentioned the FiiO K11 R2R earlier, which is an actual R2R ladder DAC and headphones amplifier. The X9 is a traditional Delta-Sigma DAC. There are several types of architecture on the market today, and I'm going to focus on the two most common ones you will encounter when shopping around, R2R and Delta-Sigma.

R2R (Resistor-to-Resistor Ladder Array):

Often found in higher-end audio equipment costing thousands, R2R architecture typically embodies a smooth and warm sound, which people usually liken to an "analogue" sound characteristic. This is the type of sound I grew up with listening to NAD C series amps decades ago. It's comprised richness and a level of charm that is neither too bright nor too mellow. A sense of liveliness in the music played back through these devices can typically be experienced.

The FiiO K11 R2R, then, isn't an expensive piece of gear, even though it carries the R2R topology, so what's going on here? Well, the it has 192 thin film resistors that have an accuracy tolerance between them of 0.1% in this 24-bit application. In a typical high-end R2R DAC, such as the Topping Centaurus, this tolerance is 0.000006% or better. These differences in tolerance should give you an idea of why the Centaurus costs around €950 and the K11 R2R is significantly cheaper.

An R2R volume controller has the potential to provide a cleaner volume adjustment than a regular potentiometer which typically suffers from channel imbalance at low volume adjustments, which then manifests as crackle or loss of sound from one channel, something that I have experienced thinking back to the analogue days.

The trade-off with R2R volume control is that there is potential for stepping noise which could be heard as clicks through speakers/headphones as the banks of relays/resistors switch over when changing volume, and this is something I will explore in more detail.

Delta-Sigma Modulation:

This architecture uses noise shaping to convert a digital signal into a high-resolution analogue one. A tried and tested solution, when implemented with some thought, can produce incredibly high-quality audio with low levels of noise and distortion.

The main issue some listeners may find is that Delta-Sigma DACs can sound a little harsh or bright, which then manifests in music as potential sibilance or muddying or upper frequency range instruments. This can often be the case on cheaper DACs where there isn't a suitable level of tuning being done to control these traits, or no tone controls are made available to the user to balance things out.

Just like R2R, the higher up the price you go, the better the output you can expect. The X9 has a THD+N (total harmonic distortion + noise) of under 0.00016% for the balanced headphones output. The other outputs are in the same ballpark, too, whilst the K11 R2R's figure is around 0.025% for comparison.

Either way, any noise or distortion differences, whichever side you take, aren't necessarily going to be audible to the human ear. What is audible, though, is the way the sound is presented to the ears, and this largely comes down to individual configurations of headphones and speakers within the DAC and amplifier chain.

The X9 uses AKM's AK4191EQ+AK4499EX two-chip solution as its Delta-Sigma architecture. This is a flagship solution which first saw its initial outing around 2022 in SMSL's products.

There are several filters outside of the EQ section to try out, with the short delay/sharp roll-off being the factory default, and is described as:

"A short delay, sharp roll-off filter in a DAC offers a balance between signal delay and frequency attenuation. It aims to minimise signal delay while still effectively removing unwanted high-frequency noise or artifacts, according to a discussion on the Audio Science Review (ASR) Forum." - Google

I could not hear much of a difference in the limited testing I did with the other filters, though due to the default one sounding great as it is, and matching the kind of sound I like, I just left it at that. It's nice to see this level initial of depth in being able to tailor the sound further should you want to.

On the back, we see all the inputs you could reasonably need, and I was impressed that whilst the X9 shipped from Korea, a UK kettle lead was included in the box. Also nice to see is that both WiFi and Bluetooth aerials are short stubby ones that don't get in the way, unlike the 4-inch long ones typically found.

The USB cables are also high quality, the terminated ends are metal, with the braiding being reminiscent of Anker Powerline USB cables.

Opening up the top panel is very easy, just some hex screws along the top row at the back and it pops right out revealing a clean PCB.

As a DAC

A/B testing between the X9 and K11 R2R was easy. A quick input source toggle on the power amp, just as I toggle the output USB device in Windows, results in a seamless switchover between DACs whilst music plays. This allowed me to hear any subtle differences in the sound without interruption.

What I noticed was that the K11 R2R had a slightly more forward presentation of vocals and centrally placed instruments. Meanwhile, the X9's presentation was pushed further back for the same areas of music. The soundstage between both appears very similar, both being well-placed in space, as well as having excellent stereo imaging for instrument locating around the music. the X9 has a more laid back and refined nature to its sound here thanks to the forward soundstage being pushed a slightly back, whilst the rest remained similarly wide.

Acoustic music especially sounds truly vivid via the X9 compared to the K11 R2R. A song that really captures the soundstage difference well is the acoustic version of King by Olly Alexander.

There are differences in vocal timbre, too, and a song that provides this in oodles is Walk on the wild side by Tok Tok Tok. If you liked that, then why stop there, check out Samba E Amor by Joel Virgel, but if something a little faster paced by highly dynamic is more to your taste, then Assembly Line by Mitch Murder cannot be recommended enough, especially for the mastering attention given to its stereo imaging. These songs are part of my curated playlist on Spotify for music that I have come across over the years that sound amazing through both speakers and headphones, tracks that can be enjoyed all day long without fatigue.

It is clear, then, that to the ears, the X9's DAC is more refined than that on the K11 R2R, which in turn is subtly more articulate than the Delta-Sigma DAC inside the A80 power amplifier. The ability to tweak the sound further through the menus means you can tailor the sound to your exact liking if your speakers don't quite make the cut in a specific area, or you fancy trying a different flavour from your music collection one day.

Using the app to set up an EQ also allows you to pick an exact frequency to adjust as opposed to a generic EQ with set frequency bands to change. Some settings are only available through the touchscreen, such as audio styles and the tone controls for bass, mids and treble.

The big question is, in bypass mode, which disables the EQ and other effects, and the very mode I prefer to use on my speakers, does the X9 sound like a DAC that is €800+ better than the K11 R2R? I'd say the answer is no for the most part, at least as far as the average listener may be concerned. There are differences between the two, though I've spent years trying different amps, speakers and headphones with the same music to be able to pick those differences out organically whilst still being fully immersed in the music. What sounds better to my ears may not transfer to someone else. Individual subjectivity needs to be factored in here for sure.

Once you start to use the EQ and other features, that's when things shift toward the X9 as the dominant choice if you want to tailor your speakers beyond their out-of-the-box capabilities, or if your speakers don't quite gel with the X9 or another part of your chain, then these features will give you room to play with and get the best out of your overall set-up. That prospect alone may be a big win for some.

This video demo was recorded using stereo lavalier microphones attached to my chair's headrest aimed at each speaker to capture binaural-like audio from the POV of someone sat in the chair:

This feature has an immediate impact on how a song is experienced, since not everyone likes a very wide soundstage, so being able to control this to preference is a big bonus.

Pockets of the online audio community have given the K11 R2R some flak in recent months, citing reasons such as it only having a resistor array tolerance of 0.1% compared to much lower tolerances in higher priced R2R DACs, I've seen comments saying the K11 R2R sounds bad as a result.

I think what those people seem to forget is that DAC, amp and speaker/headphone pairing is a missin in itself. Many factors need to align in order to get good harmony out of your equipment, this is a journey I was once on before nailing down exactly the kind of sound I like, and then keeping aligned with equipment that embodies that type of sound with each upgrade. Sometimes that meant buying and returning (or selling on) and then trying something else.

That's all part of the process, and ultimately it doesn't matter if a graph shows a tolerance higher or lower than another product that costs more (or less), the final authority in the chain is the listener, hopefully armed with some insight into why something sounds the way it does in order to be able to make an informed decision on a purchase.

I always recommend bearing this in mind because what I find pleasing may be another person's trash. That doesn't make the equipment itself bad; it's just a flavour that didn't resonate with someone else.

As a headphone amp

Here is where I noticed the biggest differences. First, when you plug in any headphone into either the 6.35mm or 4.4mm sockets, the X9 will do a quick check and set the correct impedance/gain, you can later go into the menu and adjust this if you wish, but I found the automatic feature to work 100% of the time.

There are three gain modes (16, 32 and 300 ohms) to choose from if setting manually, and between these they cover nine impedance ranges. When you manually run the re-detect option in this screen, or let the X9 auto-detect when connecting headphones via the 6.35mm or 4.4mm ports.

Here is what Luxsin said about it on Head-Fi forums:

"For the X9’s impedance detection, we have currently set 9 impedance ranges to work with our three gain modes, which should cover the majority of headphone impedance values. After detection, the X9 will display the value corresponding to the closest matching range.
For example, 14 ohms headphone will be displayed as 16 ohms."

In its default mode with HP-EQ (Headphone Equalisation) left off, the Arya Stealth headphones sounded great, but not that much better than the K11 R2R's output. Once I enabled HP-EQ, that's when the Arya began to exhibit an enhanced persona.

Now I was hearing a more detailed bass extension in appropriate tracks. For example, at 2:12, the low bassline rings through on Feel It Still by Portugal. The Man. Both with and without HP-EQ, the bassline is prominent on the X9, whereas on the K11 R2R, it doesn't have the same level of impact, regardless of whether Non-Oversampling (NOS) or Oversampling (OS) is used. With HP-EQ enabled, this improvement is emphasised further.

The headphones output ports used doesn't make any difference to sound quality, though the two balanced ports offer more power for louder volume. XLR (above) and 4.4mm are the balanced connections, they share the exact same power output and sound.

The connector you choose will typically be based on preference. Some people prefer XLR because it's a much more robust connector with pins that are parallel to each other as opposed to in sequence which inherently causes a split second short-circuit during the insertion and removal process.

The XLR cable above is by Openheart, and is available via AliExpress for around £22/$25. High quality cables do not need to cost an arm and a leg.

Just keep in mind that if using XLR, then the auto-sensing feature will not work due to the simplistic nature of the XLR connector. You must change the output manually to headphones in the menu as well, then switch back to rear XLR or RCA when disconnecting headphones connected via XLR. The 6.35mm and 4.4mm ports recognise when headphones are connected and auto-switch over and back accordingly.

Back to sound... Vocals also saw a boost in dynamics and timbre. Instrument separation was close to that of the K11 R2R, but again, there were clear refinements, and with HP-EQ enabled, the differences became clearer still.

The HP-EQ can be tailored easily using the app, which connects to the X9 using a WiFi network instead of Bluetooth. For my headphones, I found the most pleasing sound came from the highlighted HMS option above. These presets are designed to align with the Harman curve, and once applied, you can drill down and tweak individual values to then save as a custom preset.

Wait, what is the Harman curve?

The Harman curve is a target frequency response for headphones that aims to represent a sound profile preferred by a majority of listeners. It's based on research by HARMAN International and is often used as a benchmark for headphone design and evaluation - Gemini AI

Once applied in the app, the new preset is available with a single swipe to the right of the touchscreen. Several empty slots remain should you wish to add profiles for other headphones, or create different sound signatures for the same pair.

The whole process is quick, and the touchscreen is very responsive, further improving the experience. In the past, devices with these sorts of interactions between app and screen were often ripe with lag and touch latency issues, not so here.

It is of course a parametric EQ as you have control over the frequency range you are adjusting, as well as cut-off and beyond. The EQ can also be adjusted in the same way via the X9's web interface which appears to be what the app is using anyway, here's how it looks on a desktop browser:

One point to note since some folks asked about it, with headphones connected, I was able to hear the odd click around every other full rotation of the volume dial. For example, using the remote or dial to increment through to -32dB, then when dropping to -31dB or increasing to -33dB results in a split-second click through the headphones.

This only happens with headphones, I was not able to hear this through my speakers which was where I was initially testing for it. It's not a major bother, just an observation, but it does potentially contradict one part of the marketing that states that the R2R volume controlled audio performance is "...precise and distorton-free..." , leaving out the bit where the natural byproduct of a relay banked volume control circuit is the audible click noise through the headphones as the resistor/relay banks switch over.

There may be a chance that this can be tweaked with a firmware update, and as this is pre-release, I will leave the observation open-ended to see what happens.

Ease of use

I was expecting to face interface bugs with the screen, or experience app connectivity issues, but none of these presented any such problems. The touchscreen is fast with no touch latency, the on-screen keyboard feels like one on a phone, and the app responds instantly.

This experience is what impressed me the most. A new brand with its first product aimed at the high-end audience with a price to match, and whilst the X9 isn't officially available until the end of May, the samples out there seem to be going down well based on community chatter, as well as commentary from those who got a taste after attending HIGH END Munich 2025.

Here is a full tour of the touchscreen interface and menu deep-dive with the current firmware:

That's not to say everything was perfect. I experienced a few quirks that I reported to Luxsin. One of those was fixed within 24 hours via an update, which installed over the air (OTA) directly from the on-screen menu.

As I finish writing this review, a new update, v1.0.0.7, was released which tackled some of the remaining reported issues and feature requests. It's nice that Luxin's team is taking feedback on board and producing fixes so fast. the fact that it's quick to check for an OTA update via the menu is a bonus, too. The update process takes around ten minutes in my experience.

The remote offers only basic functions, but it does the job nonetheless. The main gripe is that it cannot be used to navigate the menus, that area is touchscreen only. The phone app and web interface offer another way to adjust menu settings, though some functions are only available via the screen.

The media control buttons on the remote do not control playback when connected via USB to a PC, even after installing the Eversolo USB driver (needed if you plan to use ASIO instead of WASAPI-Exclusive which is built into Windows, or view some additional connection/buffer info via the Eversolo Control Panel). These media control buttons only work on devices connected via Bluetooth.

Maybe USB media control can be added with a firmware update, too.

The volume dial looks and feels great, but it would have been even nicer to operate if the grip area was knurled instead of being smooth. Sometimes I like to adjust volume with a single finger, and because of the resistance of the stem, the finger pressure needed is higher than other amp dials, something which a knurled dial would resolve by adding more friction.

On a positive note, when using another input source, and the X9 is already connected to a computer via USB, the USB connection remains active in Windows. This is great as some DACs will cut off the USB connection when another source input is used causing any open apps on the computer to throw a fit as they can't see any sound output device any more.

The USB connection is dropped if the X9 is put into standby mode, and when only the display goes to sleep, the volume knob LED softly pulses on and off as shown above. Pressing any button or turning the volume knob wakes the screen back up.

Update: The LED pulse when the display is off can now be toggled on/off from within the knob settings manu as of firmware v1.0.0.8 released 2025.05.27.

Conclusion

The Luxsin X9 is a comprehensively featured beast, I think its high-end credentials are justified enough to warrant the cost, and whilst I have compared it for a chunk of this review against a DAC and headphones amp costing €140. It was a worthwhile comparison to make as a long-term user and community member of the K11 R2R fan club. That little device has a very capable DAC that pushes way above its price point right out of the box, and only gets improved when using a low noise/cleaner power supply.

Does the X9 do things that other DACs in this price range do not in the same way? Yes. Is there room for improvement? For sure, and thankfully much of thes improvements can be done with OTA updates. Per-output settings memory is something Luxsin has said it is exploring, for example.

The HP-EQ database contains 2500+ entries for headphones and in-ear monitors (IEM). Unless it's an obscure model, then whatever you have will almost certainly be listed there, but if it is not, then you can apply a profile from a similar model, then tweak it to your needs and save it as a custom profile.

Being able to do this effortlessly is a big selling point in my opinion, you then have additional options deeper within the menu to tweak the sound signature if you wish. The only thing the X9 lacks is the means to connect directly to passive speakers since there is no integrated power amplifier, so one will need to be added and fed a signal either via RCA or balanced XLR.

Perhaps a future X10 model could have a power amplifier stage; something like that would be a fully integrated endgame solution for someone like me. Retain all of the qualities of the X9 and just add speaker binding posts, perfect.

I would like to see Luxsin refine the touchscreen interface, it is already very good, but some UX elements could do with tweaking. For example, if I swipe left and go into 'Source In' and select another input, I then have to click the small back button which is on the top left corner of the display, I should be able to swipe right to go back to the main menu screen as well, because from the main menu screen you can swipe right to go back to the homescreen. It seems a bit of UX logic was missed when you're deeper into the menu system.

Here's a quick demo of the gesture/UX interface quirk mentioned:

This experience has given me some valuable insight into where diminishing returns can apply and where the additional cost of something like this makes sense. The Arya Stealth is not the most expensive set of cans out there, nor is it class-leading, but it scales well with better amplification, and the dynamic range is pretty incredible for the money.

Being able to upgrade or change the sound with a few clicks is convenient, being able to save multiple variations as profiles through the app and recall them immeidately on the screen is the icing on the cake.

€1099 / $1099 is still a lot to stomach for many people, it is for me just thinking about it, but I also thought about it another way... I may well have considered a better pair of headphones down the line if my existing amp had a fixed sound output signature and no EQ or means to tweak other factors. The alternative is an amp like the X9 which can upgrade existing headphones and make them sound like a better (or different) version of the same model.

Having options to tweak things whenever you fancy is the point I am making here, but is that worth such a cost increase? Only you can answer that based on an individual use-case.

Whatever headphones you use, they can undergo the same process, something that is not easily possible with fixed output DAC/amps at a hardware level. As long as Luxsin continues to keep the HP-EQ database updated as new models enter the market, then I can see the X9 having a permanent place in many homes. Endgame? The capability is certainly there.

The price is high, but then again, competing products, such as the FiiO K17, using the same AKM chips with similar features, is priced not that far apart.

Shown above, Luxsin's official page doesn't mention LDAC or aptX-HD support, I tested this on multiple Android phones and can confirm that LDAC (96KHz max) and aptX-HD (48KHz max) are indeed supported. The phone above is the HONOR 400.

Bear in mind that your phone or tablet must also support the same CODECs. If you're an Apple user, then you can only use SBC or AAC out of the box unless you buy a third-party dongle to allow other CODECs to be used, if you're a Samsung Galaxy owner, then LDAC is the highest selectable, but no aptX-HD (only base aptX, SBC and AAC), on any Windows based computer with any Bluetooth adapter, only the base CODEC will be selected by the OS, which is typically AAC or SBC unless you install the Alternative A2DP driver, which is not free. Meanwhile, almost every Chinese brand phone, such as Xiaomi, HONOR, OnePlus etc, all support the suite of aptX CODECs.

In 2025, Bluetooth CODEC consistency in the West remains a wider problem, but that's a frustrating discussion for another day.

The X9 is largely excellent, and it should only get better as firmware updates continue to roll out. As this review goes live, I have seen two new firmwares in the space of two days. These have both been after feedback was provided through the Head-Fi community to fix bugs and/or add new features in the menu system, so the developers at Luxsin are listening.

Great stuff.

Update - 2025.05.30

With more listening time under the belt, it has become clear that the X9 has three personalities, each of which unlock a new level of sound flavour. The bypass mode offers an almost transparent sound which is honest to the source material being played. I say almost because it does have some upper end roll-off, but only where it matters, though you can adjust this using the filter settings in the menu, too. Even without doing this, the bypass mode alone does a great job at removing or reducing the fatigue that is found on certain types of music, especially at the high frequency range thanks to the smoothness in its flavour or presentation of music.

That's not to say the X9 in this mode is not detailed, there is a lot of detail present which the Comete 40th Anniversary speakers are able to pick out and holographically project around the whole room. It just seems that music, especially modern pop and electronica from the 80s and 90s, are smoothed over at the top end making these genres incredibly fatigue-free at any volume level.

Whack on the Arya Stealth and a similar affair is had. The usual Planar brightness peak is under control here, I found no need to apply any tone control or EQ to balance any quirks out. For all intents and purposes, this presentation reminds me of R2R sound, without being R2R. I will be getting the upcoming FiiO K13 R2R soon, putting the Luxsin X9 against it in a head-to-head. The new K13 will almost certainly cost less than the X9, but I'm interested in seeing how it fares going up against FiiO's latest R2R model aimed at those who want a DAC and headphones amp in the high-end R2R category but without the price tag.

The tuning choice made by Luxsin in bypass mode is certainly deliberate, then. The choice to not be outright transparent has given the X9 a unique sense of character, but that character doesn't take anything away from the authenticity of the music, it is improved in my opinion, and that makes music even more enjoyable and fun. Ultimately, and as I get older, fun is what I'm more interested in when it comes to music without any fatigue during marathon listening sessions.

When you enable either the built in EQ effects or a custom parametric EQ via HP-EQ, you can unlock the second and third personalities of the X9.

Update - 2025.06.09

The question was posed to Luxsin over at Head-Fi on whether the X9 uses USB isolation. Luxsin responded with the following clarification:

"In early engineering prototypes, we did implement a USB isolation system by using an Opto-isolator chip, which able to block circuit noise introduced via the USB connection. However, we found that this approach introduced lower USB transfer speed and potential USB compatibility issues, so we decided to drop it.

Instead, we took a different approach to ensure clean USB signal integrity:
- The X9 cuts off USB bus power from the start, using only the data lines to avoid noise or coloration from USB power.
- X9 also uses two femtosecond clocks to maintain precise signal synchronization.

Overall, we believe this approach delivers better result compared to the additional Opto-isolator chip solution."

Update - 2025.06.11

A new beta firmware (v1.0.0.9) was released today. The changelog and discussion can be viewed on the Head-Fi forums.