Preamble
Thank you to @Damz87 and to Luxury & Precision for arranging the Australian tour of the W4.
The IEMs/headphones used in this review included:
- Moondrop Variations;
- Unique Melody MEST MK3;
- Sony IER-M9;
- Campfire Andromeda; and
- Symphonium Helios.
All fed with FLAC.
The audio hobby over the last several years has seen a significant growth in portable sources. At the centre of this has been the plucky "dongle". A USB-powered digital-to-analogue converter (
DAC) and amp in a pocketable form factor and intended to be used with your smartphone. Whilst the market has been filled with very affordable options for the most part, today's review concerns the Luxury & Precision (
LP) W4. The W4 comes at an eye-watering price of 480 USD and seeks to be the crème de la crème of the dongle world. But does it succeed?
The Factual Stuff
The LP W4 takes the road less travelled and implements an in-house developed DAC chip in the form of the LP5108. Housed in an angular aluminium housing with glass on the rear and on the screen, the W4 cuts a rather large and awkwardly shaped silhouette for a dongle. The W4 features an LED screen to display various metrics and allows the end-user to tweak digital signal processing (DSP) settings with the knob that doubles as a button.
Speaking of DSP, the W4 claims to utilise a field programmable gate array (FPGA) to provide the end-user with "lossless" DSP.
Otherwise, on paper, the W4 claims a SNR of 134db, power output of 110mW through the single ended 3.5mm connector and 420mW through the 4.4mm balanced connector.
Within the package, you receive a lightning-to-USB-C cable, a USB-C to USB-C cable and a USB-A to USB-C adapter.
The Opinion Stuff
Sound
It is rather difficult to ascribe any definitive sound signature on a source with some of the internet claiming it is downright impossible (“aPPlE DoNgle iS mOre THAn Enough”), but the following are my impressions of what the W4 characterises.
With a wealth of DSP settings (outlined below), I used the following settings for the majority of my review:
- EQ: Normal
- SDF: Normal
- Gain: High
- FLT: Fast
- Tune: 01
Bass
The W4 takes a quality rather than quantity approach to the bass frequencies, seemingly preferring to enhance the sub-bass rather than any mid-bass frequencies. The result is a subtle and tasteful bump in the lower end but overall taking a rather reserved approach to the bottom end in order to maintain a clean and detailed reproduction. This may be altered by the end-user using a number of DSP presets outlined below.
Mids
The W4 presents a netural and balanced approach to the midrange, which is further enhanced by its technical abilities (outlined below). There is perhaps a slight precedence given to the upper mid-range as female vocalists seem to pop out a little more in the mix compared to male vocalists. Otherwise, instruments remain crisp and detailed in the stage in a manner that is potentially bordering on a “dry” reproduction. There is a degree of thinness and clinical reproduction of sounds in this region.
Treble
The W4 provides a nicely balanced approach to this region, continuing the story of a detailed and crisp source. The W4 doesn’t lean too hard in this region in order to squeeze out a false sense of detail and airiness at the cost of coming off too bright. Rather, the W4 toes the line, maintaining a sense of sparkle throughout the treble region as harsh synths and harrowing violin solos maintained their edginess without causing inner-ear bleeding. Very well done in this regard.
Technicalities
Where I feel the W4 shines the most is its technical capabilities. Staging is wider and deeper than other peers in the dongle form-factor and this is further enhanced with its detail retrieval and resolution capabilities. Listening to the W4 creates a distinct feeling that music is being rendered in clear cut layers, allowing you to accurately place the direction and placement of each instrument in well produced tracks. The W4 resolves well and provides a textured and layered rendition of music versus a rather flat and slightly incoherent mix on lesser sources.
DSP
The W4 spruiks a field programmable gate array (FPGA) to enable “lossless DSP” and supposedly, a higher fidelity means of adjusting your sound signature. The W4 comes pre-baked with a number of settings, including, EQ, Tone settings, SDF tuning for specific IEMs, and digital filters. These are disappointingly limited to whatever LP decides to keep in the firmware with their updates but nonetheless provides the end-user with a degree of granularity in their tweaking.
I for one enjoyed toying around with the NOS digital filter to give a smoother edge to the sound signature and played around with the two tone options that LP provides you. The SDF tuning on the IER-M9 (one of a handful of IEMs supported) and it appeared to make a warmer IEM into a more neutral one. Otherwise, I did not find much use in the EQ settings but your mileage may vary.
Which brings one thought coming to my mind here, namely lessons learnt after multiple DAPs, DACs and Amps plus headphones and IEMs is synergy!
Hoping for the one and only holy grail setup is maybe just a nice wish unless buying according synergy transducers and I don't believe even the W4 is an exception here.
There's a reason why people are having multiple devices in parallel or reducing inventory and keeping only the ones with right synergy.
The DSP settings are unfortunately let down by the fact that all of these settings are reliant on LP and do not offer the same level of granularity as other forms of DSP.
Overall
The W4 builds a foundation of good quality audio with great technical capabilities that belies its diminutive size. It then builds upon this with a rather healthy suite of DSP capabilities that allow a significant level of granularity for the end-user. Ultimately, the W4 presents sound quality that punches above its size.
Comparisons
vs Cayin RU7
The most pertinent competitor to the W4 is the RU7, released around the same time and at an elevated price point (albeit still not near the price of the W4), the RU7 takes a novel approach to the digital to analogue conversion process. The RU7 converts all incoming digital signal to DSD and utilises a 1-bit DAC to convert to an analogue signal. The result is what I would term as a more analogue and smoother sound signature. The RU7 also provides some level of tinkering with the user being able to step through DSD64, DSD128 and DSD256 with subtle differences between all settings. However, despite this, the RU7 appears to be more warm and lush in its reproduction of music, with a distinct focus on the mid-bass frequencies. Notes hit harder but are not as fast as decay seems slower than the W4, it is less energetic and there is less of an edge.
On a technical point, the above notes of the sound signature would normally lead one to believe that the technicalities of the RU7 are not as capable as the W4 but the truth is somewhat more muddled. The DSD256 setting remains highly resolving and only minorly lesser than that of the W4. The soundstage of the RU7 feels wide and deep to the level of the W4 but the resolution provided by the W4 provides a more distinctive “layering” capability compared to the RU7.
Other than that, the W4 provides far greater performance in the noise floor, with sensitive IEMs such as the Campfire Andromeda, the W4 performs much better in terms of maintaining a dark background in sparsely produced tracks.
Overall, I feel this is a pick-your-poison situation, the RU7 is a smoother and warmer rendition of music more suited to laid-back listening compared to the W4 which provides greater technical performance and a more aggressive, energetic approach to music.
vs iBasso DC04Pro
Dropping a considerable number of tiers in terms of price point, one would think that the DC04Pro is a far lesser dongle and in some respects, that is true.
The soundstage is more confined compared to the W4, the imaging and detail of the DC04Pro is also similarly lesser than the W4. Switching between the two there is a lesser sense of coherency in the mix with the DC04Pro and picking out certain instruments is a more difficult experience.
In terms of perceived sound signature, the DC04Pro appears to place precedence on the upper mids and the treble, lending itself to a more sparkly upper end of the frequency response curve. However, with certain songs, the DC04Pro seems to cross into the overly bright region and may become fatiguing for some, like it did for me.
The DC04Pro was purchased solely for its impressive noise floor and in this regard, it definitely matches the W4 in presenting inky silence with the notoriously sensitive Campfire Andromedas. Overall, there are similar aspects between the DC04Pro and the W4, but ultimately the W4 comes off as a much more refined and technically capable source.
vs Chord Mojo 2
Selected for its DSP chops, the Mojo 2 is a fan-favourite when it comes to portable sources, despite being larger than the dongles that are within this review.
The tonality of the Mojo 2 is minorly warmer and having more of a euphonic quality compared to that of the W4. Less dry and more “natural” the Mojo 2 presents a more “easy-listening” experience with all the DSP turned off. Whilst not as smoothed out to the extent of the RU7 above, the Mojo strikes a nice balance between a laid-back listening experience and attacking you with detail. There appears to be a greater amount of mid-bass and increased note weight compared to the W4.
Technicality wise, both are quite impressive in their ability to resolve tracks and present detail but the drier rendition of notes and the speed at which they come and decay with the W4 presents a slightly elevated sense of technical prowess. The Mojo 2 feels minorly wider and deeper compared to the W4 but overall, both appear to be rather similar in this respect.
Moving on to the DSP chops of either sources, the Mojo 2, despite having somewhat of a learning curve provides greater granularity in terms of adjustments. You are not locked into LP determined presets but rather you are able to step through dB adjustments in certain regions of the frequency response and also utilise a crossfeed function. I feel that this presents greater tuning options to the end-user and in this respect, I believe the Mojo 2 is the much better option.
Overall, the Mojo 2 matches or exceeds the W4 in certain aspects and has the benefit of having its own power supply and a wealth of DSP tuning to ensure synergy with whatever IEM you throw at it. Combined with the recent price drop in Chord products, I believe that the Mojo 2 presents a more compelling option if you are willing to go slightly larger and deal with the quirkiness of the UK-made device.
vs Shanling M6 Ultra (M6U)
With a rather significant jump up in price, the M6 Ultra nonetheless, presents another form factor that is available for people looking at a portable solution. With the obvious differences being the much larger size, the capabilities of a digital audio player (
DAP) to surf the web, utilise Android apps and the like cannot be understated. This is a rather big bonus for those who can stomach pocketing two separate devices as one is a fully fledged audio listening device that is not reliant on a separate device such as a phone or a laptop.
The M6U sonically, provides a smoother and rolled off form of sound compared to the dry and edgy nature of the W4. The midbass frequencies on the M6U are subtly elevated compared to the W4, offering a more laid-back and warmer tonality. Vocals come across more euphonic and emotionally striking compared to the clean and technical presentation of the W4. There is a slight edge to the sss sounds on vocal tracks with certain IEMs with the W4 whereas they are not present on the M6U.
Technicality-wise I would say both are on par, with both sources resolving quite well with no lack of detail with both sources. The W4's slight dryness and speed of presentation seems to make these details jump out but as you listen more critically I would say that the two sources are more similar than they are different.
The W4 seems to have a slightly wider soundstage but feels as though it is more shallow than the M6U. This may be due to the more forward vocal presentation on the M6U but that how it sounds to me in the end.
Overall, the M6U lacks any baked in DSP but benefits from the wealth of parametric EQ apps available on the Android ecosystem. Additionally, the bonus of a screen, the ability to run apps, manage your music library and the added juice to run headphones should you require it, present some compelling factors for anyone looking to purchase their next source. In terms of sound quality however, it is closer than what the price tag would have you believe. The M6U ultimately wins for me due to my own biases towards a more smooth sound signature (within reason) but the fact that the W4 sonically trades blows in its small form factor is definitely a big bonus.
Quality of Life
The W4 is a rather well built device, however, it remains fairly large as far as dongles go. The knob provides a rather satisfying sound but the feel remains rather mushy and lacking the precise tactile feedback of “I have increased the volume by 3 steps”. With that being said, the addition of a knob is a rather welcome one as I lament fumbling with mushy buttons on other dongles in the market.
This particular W4 has an issue with Apple devices, and whilst this may not be an issue with other W4s, raises the issue that dongles seem to have with power delivery. There are anecdotal issues I have observed with certain dongles and power delivery from iPhones and this whilst this may be a moot point with the impending release of a USB-C iPhone, remains a consideration for many. Other bugbears exist in the W4 universe with a distinct lack of a readily available English manual to action firmware updates and to explain what each setting within the W4’s menu seeks to achieve.
But on a more positive note the W4's battery drain while using the device seems to stellar compared to the other dongles in this review. I am unable to measure this accurately, but anecdotally, the W4 seems to do a great job in this regard. Noise floor is also impressive, even with a Campfire Andromeda hooked up in the balanced connection, handily beating the RU7 and essentially matching the DC04Pro in their absolute silent noise floor. This is definitely a bonus for those with sensitive IEMs in their collection.
Value
Coming in a rather eye-watering price of $480 USD, there is a distinct feeling of “pick your poison”. This is likely the “best” dongle there is but $480 USD is rather significant amount of money to be put elsewhere should you not require a dongle specifically. The aforementioned Chord Mojo 2 has experienced a significant price drop that puts it pretty close to the W4. The footprint is considerably larger sure but the greater DSP granularity and overall flexibility in its role in the source chain is undeniable.
I, despite owning two dongles, do not enjoy the idea of carrying a floppy and ineffectual USB cable and draining my phone battery. But your mileage may vary.
Conclusion
This have been a lot of words for a dongle, but with the exception of perhaps the RU7, this is simply the best dongle that I have ever used. With a wealth of features to provide you with the ability to tweak the sound signature to your liking, wonderful technicalities and a rather neutral, non-offensive sound signature, the W4 would be a no-brainer buy for me except for one “but”. And that is the price. For the price, I feel that there are a number of options that become available and perhaps are far more compelling, but for the form-factor.
If money is no option and you definitely need a dongle for whatever reason, I feel that the W4 is an easy buy, but that’s between you and your wallet.