Lumin X1 review from Taiwan:
My translation of some parts of it: [brackets are mine]
For the output, X1 not only has analog RCA and XLR outputs but have digital outputs as well. Therefore it can be used as a pure streamer [for an external DAC] too. Analog outputs adopt a design similar to some Lumin models before - there are Lundahl output transformers following the DAC hardware circuitry so that the amplified signal goes through the transformers before being output. Why does it need this extra hardware? This is because output transformer has a characteristic of filtering out high frequency noise. Transformers have a native bandwidth limitation, so signals outside the bandwidth do not get transmitted. This way, very high frequency noise associated with digital audio is naturally eliminated. In addition, output transformer has a tuning effect and make the sound richer.
[Fiber network vs copper network]
Before getting the X1, I'm very curious about its SFP fiber network interface: What SQ difference does the SFP fiber network offer as compared to RJ45 copper network? If we need to do this comparison [completely], both the NAS and switch should use SFP connection, so the distributor lent us their QNAP TS-251B NAS and QSW-804-4C switch. QNAP high-end models of NAS have expansion capability, including this TS-251B with a QNAP LAN-10G2SF-MLX network card with 10GbE using SFP+ interface. The QSW-804-4C contains both RJ45 and SFP+ ports, letting us conveniently compare the sound difference between the two. To listen to fiber network, use fiber cable to connect to the switch and the NAS SFP+ port. To listen to copper network, use RJ45 network cable to connect to the switch and NAS built-in Ethernet port. [Note: Unlike what this review may imply, it is not essential for the NAS to have fiber network in order to enjoy the fiber network in Lumin X1.]
This is QNAP QSW-804-4C with both RJ45 and SFP+ ports. The fiber in the left connects to the X1 SFP port. The middle RJ45 connects to [uplink] switch. The black cable in the right connects to the NAS SFP+ network expansion card.
Fiber network requires a small SFP transceiver.
This is QNAP TS-251B NAS with PCIe expansion slot filled with QNAP LAN-10G2SF-MLX network expansion card to support SFP+ 10GbE transmission.
What are the differences between the two sound? SFP fiber has a black background with a pure sound, it feels more liquid, soft, delicate, layered, balanced and open. RJ45 copper network has quite a clean background, but sounds to have a little impurity compared to fiber network, the sound has a bit high frequency frizz and is less smooth than fiber. However, RJ45 is sharp and energetic. Comparatively, fiber seems a bit softer. In terms of soundstage, RJ45 is more focused on centre and saturated with a clear theme. Fiber expands to two sides and is more open and is extremely balanced. Basically, I believe fiber and RJ45 has different personalities and each has its pros. Objectively, I believe fiber offers more details, layers and is full of potential. RJ45 is more variable depending on the cabling. X1 provides two types of connection and two sounds to choose from, letting the user to match their own equipment and tastes.
In addition, Lumin also allows for another type of connection topology: use the X1 RJ45 port to connect to the switch, then the SFP port to bridge the NAS SFP+ network card. This way, a SFP switch is not necessary to enjoy the advantage of fiber network.
The following review uses Electrocompaniet EC 4.8 pre-amp and NuPrime Evolution One amp， driving Aurum Cantus Grand Harmony speakers.
I quite like the pure sound and smooth voice from fiber, and the rich layers and contrast brought by full details. So I start with fiber listening, playing Janos Starker, Bach Suites for Solo Cello. With the support of X1 black background, rich details from SFP fiber are more obvious, letting me hear that when the bow hair stops, the chamber resonance decays gradually in the air. In double stops, the resolution between two notes is very good, reflecting the details. The cello sounds a little sticky, not deliberately polishing a bright smoothness, giving the texture of friction among the strings. In addition, the shape of the cello appears very correct, with a precise image and proper scale. Low mids sound a little wet, making the tone more attractive.
Cannonball Adderley, Somethin' Else: X1 soundstage is more focused and centred, especially suitable for a small Jazz band. Through the X1 playback, each instrument, each drum beat is shown with precise imaging, with excellent separation between each instrument, letting me "see" the band with realism. Besides, X1 not only plays with clear imaging, but different frequencies and proportion of sounds are strictly presented without blurring or exaggeration, and it does not have bloated bass.
X1 also supports Roon Ready in addition to UPnP OpenHome, letting me to listen to familiar music from my Roon Server on QNAP HS-453Be [TS-453Be ?] NAS. My HS-453Be does not have the fiber network card, so it is connected via RJ45. In this setup, Janos Starker, Bach Suites for Solo Cello plays with clearer shape of strings with even better contrast, giving deeper musical emotion.
Eric Clapton, Old Love: X1 is adept at this. Weak sounds are presented without strain. Strong sounds play with rich layer variations. It combines with transparent tonality and appropriate liquidity and wetness, listening to this feels great, and 13 minutes do not feel long at all.
Chris Babida, Tsai Chin, To Encounter - Chris And Friends track 1: X1 once again presents a focused and centered image with a clear shape as its strength, making the voice realistic with a dense texture and temperature thereby making it deeply emotional. I believe X1 will absolutely charm audiophiles who like listening to voices.
X1 is so great at Bagatelle music, Jazz and Rock, what about symphony? With 37th Tapei Int'l Audio & Art Show CD: even though the X1 soundstage is not too wide, the structure of the orchestra is very excellent - treble, mid, bass distribution is orderly and not messy. In particular, the front, mid, back separation and layers can easily be recognized. The resolution of whole frequency spectrum is equally good with a clean bass. Even complex music is handled by X1 easily.
It is not common for a source to be like X1 that simultaneously has rich functionality, convenient operation, elegant appearance, small physical size, HiFi grade design and manufacturing, and high level of audio reproduction, fitting any requirement of any demanding user. X1 also offers a rich listening experience, through its fiber or copper network, or its upsampling, bringing different tuning possibilities for sound quality. X1 is not complex to setup yet it has the most complete specifications and supported services. X1 will not disappoint.