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    Lumin U1 Streaming Transport Review

    Lumin advertises the U1 as a “Network Transport” for those audiophiles who already have a DAC with which they are satisfied. It is compatible with all the major services and formats including PCM from 44.1 KHz sampling rate all the way to 768 KHz and bit depths from 16 to 32-bit and DSD 512 to 22.5.

    The U1 joins a growing lineup of high-end products from this Chinese-based company that includes a line of full “Network Players” that contain a Network Transport as well as a built-in DAC. Lumin also has a pair of power amplifiers in its “stable” as well as a Music Library Storage solution and a Smart Application which allows the user of the transports and players to completely control them form a tablet or smart phone running either the Apple iOS or Google's Android OS. 



    Physical Characteristics


    The U1 comes in two units: The main “Transport” and a separate PSU (Power Supply Unit). Both units are available in either a brushed silver aluminum finish or a black brushed aluminum finish. Our review sample is black. 



    The Power Supply

    A separate power supply unit is unusual these days and requires an umbilical cord to connect to the main transport unit. The PSU contains two toroidal power transformers. Lumin believes that separating the power from the signal circuitry results in better audio performance. 

    The PSU measures 100mm (4 inches) W X 315mm (12.4 inches) D X 55mm (2 inches) H and weighs 2 Kg (4.4 pounds). There is but a single button on the front which is illuminated to show that the unit is switched on. The back contains but a round multi-pin connector for the umbilical to the main unit.



    LUMIN-A1-psu-angled.jpg LUMIN-A1-psu-inside.jpg




    The Main Transport

    The main unit or “transport” as Lumin calls it, is characterized as a “monolith-like” enclosure with an elegantly curved front and a recessed cutout in the center for a vacuum fluorescent display. There are no controls on the front panel of the U1. The enclosure measures 350mm (13.7 inches) W X 345mm (3.16 inches) D X 60mm (2.37 inches) H, and weighs in a hefty 8 Kg (17.64 pounds).  

    The rear panel of the Lumin is rather inexplicably recessed a good 2 inches (55mm) making it unnecessarily difficult to get to when installing the U1 into one's system. Aside from that the unit is very well laid out in back. Starting from the left, we have a small reset button, then for the input to the unit, an RJ45 jack for CAT 5 or CAT 6 Ethernet cable, then a gold-plated “earth” (ground) post. The ouputs, ostensibly to a DAC, consist of two Type “A” USB connectors, a Toslink SPDIF, a gold-played RCA coaxial SPDIF, and a BNC coaxial SPDIF. These are followed by a Cannon/XLR AES/EBU output. Finally there is a circular 7-pin connector for the DC umbilical cable from the PSU. 





    Streaming Protocols


    Since the Lumin U1 is a music transport, it naturally must conform to and support the major protocols available to today's “digital audiophiles.” These include the UPnP A/V protocol with the streaming extension. The unit is Roon Ready and supports TIDAL, can connect directly to Spotify, supports Apple AirPlay, gapless playback as well as the on-device playlist. 

    The U1 has full support for MQA from TIDAL, Qobuz, and Tune-in Radio. On the separately downloaded (but free) smart application, the unit supports both TIDAL and Qobuz icons to indicate high-resolution programming. It also allows for the control of volume in the digital domain, sports a sophisticated search function, allows for high-resolution artwork from one's sources and artwork caching. The application will handle multiple file tags and allows multiple tags and composer tags. The app also enables albums to be grouped together in response to several grouping options in the playlist and provides automatic internet links to either artists, albums or individual works/songs. Playlists can be saved and restored in case of an accidental deletion.

    I cannot emphasize too strongly that the app, which is available for both iOS and Android devices and downloaded from Lumin's website is de rigueur rather than optional as it is on many such devices. It would be impossible to operate this device without it. 







    Connecting the Lumin U1 to one's system couldn't be more straightforward. I connected a 50 ft CAT6 cable to my wireless router next to my main computer. The other end, I plugged into the RJ45 connector on the back of the U1. I then connected the umbilical cable from the PSU to the back of the Lumin, and connected a 0.5 meter XLR cable from the AES/EBU output connector on the rear of the U1 to the AES/EBU input on the Schiit Yggdrasil DAC. I then downloaded and installed the Application on my Android tablet (the app will run on most Android devices and any Apple iPad or iPhone manufactured since 2014).


    feature-ipad.jpgUpon launching the app it connected immediately with the Lumin and the interface is so intuitive that it becomes immediately apparent what needs to be done to access one's locally stored music on one's computer or NAS (Network Attached Storage) device. At this point it is advisable to explore the app (there are no instructions that I can find for the application). You will soon figure out how to access TIDAL, Spotify, and Qobuz and your own locally stored music files. I had pre-USA rollout access to Qobuz and I have a Spotify account. I was able to quickly setup a playlist containing a combination of streaming files from Qobuz (Tchaikovsky's Piano Concerto #1 in B minor, Sviatoslav Richter, Herbert von Karajan and the Berlin Philharmonic) and Spotify (my favorite Roy Orbison songs) and a number high resolution files from my main computer: Albinez “Iberia” and piano works from Debussy on the PlayClassics label. I was able to queue these disparate sources and change their playing order at will as well as save the playlist to be able to repeat it at any time. Any single playlist will support up to 2000 tracks with “cover art” icons and icons to indicate the files' streaming source such as TIDAL MQA or Qobuz “Sublime High-Res.”


    The app allows the operator to drag files around to re-order them and to edit individual tracks or even entire albums. One's personal library can be arranged by track title, album title, artist, composer, genre, date added to library, etc. The app contains a search function that allows the library to be searched in two ways: a simple “find” function or using a set of filtering criteria. It also enables the user to search both TIDAL and Qobuz catalogs directly. There are many more features of this remarkable interface, too many to list here. But one will quickly find them by merely poking around.



    Sound Quality


    feature-u1-inside.jpgOK, I'm firmly in the “bits-is-bits” camp when it comes to talking sound quality from what is essentially a purely digital signal. And I would have said that the Lumin U1 would have the same sound as a NAD or a Pioneer or any other music server “client.” After all, the only thing that comes out of the device is “bits!” Well, I was wrong. I have two other devices in my system that do (to a certain extent) what the Lumin U1 does. I have an Oppo 205 and a Logitech Squeezebox Touch. Both feed the Yggdrasil DAC so the only difference should be the source component. If bits were indeed bits then the same program material would yield the same sound from each source. It ain't so!


    Compared to the digital output  of the Oppo or the Logitech device, the U1 was, well, just better! First of all, the top octaves were cleaner and more delineated. The 24/96 PlayClassics files of  Albeniz' Iberia played by  Luis Grane and Angel Cabrera playing Debussy are exemplary performances of solo piano. The recordings are both first rate and with a decent system the sound is almost as if the pianos are in the room with the listener. When streamed from my Mac Mini where the files are stored, they can be played through the Logitech, the Oppo or the Lumin. While excellent through any of these devices, the Lumin seem to delineate the transients better than the other two and the pianos seem to have more “space” around them.


    To make sure the digital interface wasn't making differences where none actually exist, I re-connected all three devices via coaxial SPDIF to the DAC. The noted differences as well as the sonic superiority of the U1 was still there. Another further improvement over the other digital server clients that I noticed was that while the other two units threw an image that started at the speaker plane and went back beyond the wall, there was nothing forward of the speaker plane. The Lumin U1 somehow brought the entire presentation forward as well as back, giving a three dimensional quality to the imaging that simply was absent from the others. I do not know to what to attribute this, but a friend of mine noticed the same phenomenon and mentioned it before I had said anything. It's there alright. 





    The Lumin U1 is a beautifully made superbly engineered “music transport.” It supports basically all formats and streaming service in use today. While it supports MQA on TIDAL, I don't have access to that service and therefore wasn't able to test that function, but none-the-less, the sound the U1 elicits from these ones-and-zeros is definitely a cut above many other similar devices. 

    The Lumin application is the best of its type that I have encountered. With it loaded on a tablet or a smartphone, the world of streaming music is a real joy. It works so well and is so intuitive that once you use it, you'll wonder how you ever got by without it. I was sorry to delete it from my Android tablet but the Lumin had to go back.

    My only real complaint is the machine case top's extreme overhang in the rear. It makes it very difficult, once the unit is installed in a system to access the rear connections. If I owned one I'd be very tempted to take a band-saw to the machined CNC case top and I encourage Lumin to re-think that particular design decision.

    The Lumin U1 is not cheap at close to US$6000, but it is definitely a very high performance unit. Luckily, Lumin sells a smaller unit with less expensive casework, a built-in power supply and with LPCM support to only 384 KHz instead of 768. Capabilities, otherwise seem similar and its only US$2000. 





    Additional Information:


    Manufacturer: Lumin

    Product: U1 Audiophile Streaming Transport ($5,900)

    Quick Start Guide: LINK

    Hardware Settings: LINK

    App Usage: LINK

    Contact: LINK













    User Feedback

    Recommended Comments

    6 minutes ago, wklie said:


    If DSD to PCM has to be done due to the DAC accepting PCM only from an AES / SPDIF / Toslink input, from a mathematical point of view, I would suggest converting it to 176.4kHz instead of 192kHz.   DSD64 is 2822400 Hz, divided by 176400 Hz it gives an integer value 16.  If divided by 192000 Hz it results in 14.7.  So if a DAC plays 176.4kHz and 192khz equally well, I think the former may be better.  An exception would be a DAC (hypothetically) hardware only has a base clock which is a multiple of 48kHz, with a 44.1kHz derived from the 48kHz, then one will have to listen to find out which sounds better.


    As for DSD512, the story is this: Linux based streamers such as Lumin U1 (MINI) and several other streamers popular in this forum require a Linux native DSD compatible USB DAC for DSD512 to be played.  Recent XMOS based DAC and recent Esoteric models do.  Those DAC using Amanero USB board running older stable firmware and SaviAudio USB chip do not support native DSD256 or native DSD512 with Linux.  Users of such DAC are limited to using Windows USB (with a required driver, typically ASIO) as a source if they desire DSD512 playback.


    For DSD256, it has another possible condition of working even if a DAC is not Linux native DSD compatible - if it supports DoP256 it will still work with Lumin U1 (MINI) - however, not all DSD256 DAC support DoP256.

    Roon complicates the process a little bit which I should have elaborated on. DSD64 for example is converted to 352.8 PCM (8 x 44.1) internally, and then to 176.4 ( 4 x 44.1) PCM for the coax to the DAC. 


    This is the custom table in Roon for other frequencies above 192. 




    This is the chain for a Mutec connected locally to the machine ASIO driver playing a DSD256 file . The U1 is asleep for now, powered off.





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    I'm using a windows PC connected to my T+A Dac8 and is working fine, so for now I'll stay that way. Thanks anyway.


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    On 1/31/2019 at 5:31 AM, Cgrossi said:

    Thank you One and a half. This is a very valuable information and it changes the whole approach. I'll continued seaching for an streamer that can upsample to DSD512 through my T+A DAC8. Any suggestions?

    The problem is the T+A DAC itself, not the Renderer.  T+A needs to change their USB receiver to be compatible with native DSD from Linux based Renderers.  Most (if not all) Renderers use Linux based OSs for very good reasons.

    BTW, there is firmware for the Amanero USB receiver which is now stable with DSD 256, native DSD, from a Linux based renderer, i use it every day.

    For DSD 512 via a Linux based Renderer, i would recommend XMOS based USB receivers, they are entirely capable-DAC manufacturers, are you listening?

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    5 hours ago, barrows said:

    BTW, there is firmware for the Amanero USB receiver which is now stable with DSD 256, native DSD, from a Linux based renderer, i use it every day.


    Which version?  1099c?  Thanks.


    Reading this https://github.com/lintweaker/xmos-native-dsd/issues/12

    Based on the posts there, it seems that some people still have various issues, or not able to get DSD512 to play perfectly.

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    Amusing how time flies, along with memories apparently. The reason the Lumin has a cable overhang at the rear is because the Linn Klimax DSM does. Pixel Magic started Lumin by reverse engineering the Linn product. 

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    the lumin app is not the only solution. i use the linn kazoo app and find it much better. that said, the linn app will not adjust settings on the U1, just manage playback - and for this, i find it superior to the lumin app.

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