Article: Lumin U1 Streaming Transport Review

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Thank you for the clear and straightforward review.

A few observations:

(1)
"Bits are bits" is for simpltons devoid of basic understanding how digital media is rendered into sound. The bits are one part of the signal; the other is timing. When the latter is off--due to jitter or electrical pollution--the sound is off. In fact, when reviewers describe the SQ of various transports, they actually describe the effect of jitter, or lack theteof. There's nothing more to it.

(2)
The sonic difference among AES/SPDIF/USB is very simple to explain. USB doesn't carry any clock information, so it's up to the DAC to implement the timing. That sets it apart from AES/SPDIF, which have the clock information embedd.

Being balanced, AES isn't susceptible the EMI, whereas SPDIF will pick them up. The longer the cable, the more so.

Furthermore, different implementations of the digital output/input stages (transmiter/receiver) will contribute to sonic differences.

(3)
Upgrading the power supply of the U1 Mini to LPS will boost the performance close to the U1 level. sBooster and Plixir sell such kits, and they'll set you back $500 to a $900--overall, much more economical than U1. In essence, those kits reduce electrical pollution and thus jitter.

(4)
The U1 direct competitor is ARIES G2, which has lower jitter and better construction, including dual LPS driving separate circuitry boards, galvenic Isolation, suspension footspikes and a uni-chasis. All that for 2/3 the price. If one can live with only iOS support, the G2 is the wiser option.

(The U1 benefits from a BNC output that the G2 is missing, but that's not enough to tilt the balance. Regardless, if possible, one should use AES)

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6 hours ago, One and a half said:

 

Comments to (3)

The two mini Lumin variants have a single output SMPS to drive the whole system. Yes, you can buy a linear supply to fit out, provided the regulation is such that over voltages do not occur.  Warranty is then a tricky issue. All other models have separate power supplies in their own enclosure and have dual linear voltages from two transformers for analog and digital circuits. 

 

Comments to (4)

Before purchasing the U1, an audit was made of the Aries G2 as alternative. What put me off purchasing that unit:

 

a) The G2 iLink is useful only with other Auralic product

 

b) Several users reported bugs with the on screen display artwork or other details relating to the screen on the Auralic support forum. The conversations went on for too long I thought and a fix was underway, but needed more time. I would have expected software issues like this to be well put to bed with limits (?) placed on metadata for example. The bugs were on production machine released 10 months after they were officially released for sale.

- A quick scan of the support forums of both camps will reveal which site has less user problems, the site a AS (CA) is example.

 

c) There's different methods for galvanic isolation, some work, some don't.

 

d) The U1 is also a single block aluminium body, with footers, so don't see advantage in construction, since both are similar.

 

As for pricing, there's room to negotiate in a civil manner directly with the suppliers, the sticker price isn't the final outcome.

 

Thank you for commenting. Allow me to relate.

 

Warranty is then a tricky issue.

Those changes are easily reversible and cheap to do, especially if you're handy with the soldering iron. 

 

All other models have separate power supplies in their own enclosure and have dual linear voltages from two transformers for analog and digital circuits. 

I haven't seen any reference that each external PSU powers a different board. But learn and live.

 

The G2 iLink is useful only with other Auralic product

The G2 iLink isn't a channel to input anything into the ARIES G2. It only facilities streaming from it into the VEGA G2.

(The latter's streaming capabilities are more limited). So as a stand-alone streamer, your point is actually moot. 

 

Several users reported bugs with the on screen display...

I believe AURALIC has outsold Lumin by a fat margin, given the relatively affordable prices, so you'd find more users with issues in general. As a rule, every vendor in the field has occasional software/hardware issues, so customers always take a chance when they take the plunge. But if Lumin is truly more robust than AURALIC, then more power to them and to you. And I write that with sincerity. 

 

There's different methods for galvanic isolation, some work, some don't.

What's your point? That AURALIC galvanic isolation is questionable? You need to substantiate that assertion, or be accused at merely floating vague innuendoes.  

 

The U1 is also a single block aluminium body, with footers, so don't see advantage in construction, since both are similar.

Lumin hasn't made any claims its chassis blocks EMI. Maybe it does, then I'll be stand corrected again. The G2 has suspension footspikes that dampens a certain range of frequencies so the oscillators aren't disturbed. I didn't see such feet on the Lumin.

 

 

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7 hours ago, One and a half said:

@Sonis, the reason I thought for the overhang for the rear connectors is protection from the atmosphere. Unless audio components are in air conditioned environment 24/7, dust, moisture and corrosive air (even lived close to the beach?)  can settle on connectors and cause corrosion. Witness a 15 year old AVR, the RCA connectors are not the same material any more. Having a cover, slows this process.

 

Once a method is settled on the output of the U1, it stays in place unchanged for, well, years. The U1 can be turned upside down to access the connectors better, there are usually only three cables, Ethernet, power and the output. 

 

For the review in general, it would have helped a little more if the music to evaluate was listed and any differences heard between what was existing and with the DUT, where it stood out or worse. 

 

Anyway, the U1 at home is with me for a month now with some solid listening hours under the bridge. Still happy with what I hear, a substantial improvement over anything else I tried, such as:

USB, ifi Micro USB, Mutec MC-3+USB, RME HDSPe AIO, USB extenders, plain USB cables, Curious USB cables, Nordost USB Cables, Mutec MC-1.2- AES3, Intona, ifi Galvanic 3.0, the list is extensive, all blown away by the Lumin U1. 

 

Anyway, the U1 at home is with me for a month now with some solid listening hours under the bridge. Still happy with what I hear, a substantial improvement over anything else I tried, such as:

USB, ifi Micro USB, Mutec MC-3+USB, RME HDSPe AIO, USB extenders, plain USB cables, Curious USB cables, Nordost USB Cables, Mutec MC-1.2- AES3, Intona, ifi Galvanic 3.0, the list is extensive, all blown away by the Lumin U1. 

 

I auctioned the G2 and U1 side by side. To my ears, the Lumin was slightly bloomier, which is an indication of more jitter (again, to me). In that regard, I think the U1 shows its age (3 years to date), and could benefit from an upgrade.

 

As for the improvements that you tried, cables don't reduce jitter, so I would't expect anything from them.

MC3+USB: I appreciate the G2's low jitter, but I still can't retire my chain of 3 x MC3+USB + REF10. If you've never tried such cascade--and able to put your hands on one--you're in for a serious treat. 

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52 minutes ago, John Yow said:

It would be cool to have a comparison review of the different streamers.  I would love to read how my dCS Network Bridge compares with other streamers.  A blind listening would be quite interesting.

 

Candidates could include low end players like the Squeezebox Touch, Chromecast Audio and may be direct from a Mac Mini.  And of course between same class players like the dCS, Linn, Naim, sonictransporter, etc.

 

Hell Mr Yow,

 

Your first comment on the matter of HKK vs China don't have room in the politically correct West. But I'm with you

 

Chromecast Audio is unlistenable. The jitter levels of the optical output renders the sound a thick mash. 

Mac Mini is merely a a notch or two above. Still pretty dismal.

Naim and Linn don't offer pure digital transports. Their products are streaming DACs. In fact, having phoned up Naim numerous times, it became patently clear that their SPDIF output is an afterthought with no jitter reduction mechanism whatsoever. Later, I  did a little audition with the ND5-XS-2 to discover how much had been left to be desired.

dCS  makes sense only if you have compatible dCS gear. Otherwise, their bridge is a waste, since the dual AES and dual clocks can only be used with dCS systems. Furthermore, if you insist on purchasing their equipment, having all that unused electronic inside might increase jitter levels (in theory of course; that has yet to be proven).

 

 

 

 

 

 

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2 hours ago, gmgraves said:

It kinda makes sense if you think about it. If bits weren't just bits, then computers wouldn't work. You code an application and when you open it, you expect it to work. You expect the bit stream that makes up that application to remain the same throughout the computer and the app's life. Is that not so? Why should a bit stream representing music or video not be the same? In fact video should be more sensitive to changing bits and clock timing than audio. So you can't blame people, especially those who work with digital signals in their jobs every day, for being skeptical. And we also know that hearing is not always believing. People hear things in their audio systems that aren't really there every day. A healthy skepticism for things that should not be is probably a good thing...

 

The video portion had been addressed below. Maybe not fully, but I'll leave it as is. 

 

Let me attack the fallacy of the "bits are bits" from a different angle.

 

Let's assume you sampled an analog wave and now wish to recreate it in the Cartesian world. The bits (i.e., different voltages) you plot along the y-axis; the timing, along the x-axis.

 

Now, what happens if the points along the x-axis deviate from the originals? Would the result be identical to original analog wave? Certainly not. Thereby, the new curve wouldn't sound exactly the same. Throw in random jitter, and the sound will be pretty terrible. 

 

In summation, for applications that operate in a single dimensional space, e.g., a word processor file system, "bits are bits". On the other hand, the demand of applications that operate in multi-dimensional space is precision in all plains. 

 

 

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1 hour ago, One and a half said:

I envy your position to audition the G2 and the U1 side by side. For that opportunity in this country, well, I have better chances at sweeping rocking horse poo. Age - 3 years? the more time a product is on the market, the more chance to prove itself. The G2 has bugs, the U1's are already fixed and gone. Whats there to upgrade? Less jitter, s'pose.

 

I had the two MC-3+USB in cascade for a time, quite good results, but not enough to keep them. The REF10 came out a few months later, by then the horse had bolted.

 

Yes, lucked out a bit  Two long running demo units.

 

You make a good point: stability vs progress. I haven't encountered any glitches with the G2 yet, but I mainly use AirPlay to stream off SoundCloud.

 

 

 

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1 hour ago, One and a half said:

Last 12-18 months I purchased Intona and ifi Galvanic (x2) devices. Both claim to isolate USB, one using the Silanna chip the other something else, can't remember now. Found out later there's leakage across the barrier anyway.

 

The ifi Galvanic disconnected itself from the host USB controller ad nauseum. Depending on the cables, would work, sort of. Returned to the supplier.

Intona worked after a firmware upgrade, but sometimes failed to connect too. When the music played it wasn't bad, but not enough to warrant it in the system. The Intona benefited the MC-3+USB, but in the wrong way, in that the top end was too artificial, depending on the music sounded hard. Both Intona are now in a drawer.

IIRC, @Superdad identified the Silanna chip in the G2. Yes, it's all in the implementation I'm told.

 

The isolation in the MC-3+USB series is very good and that's how it should be.

 

There's my evidence of floating innuendo, happy now?

 

Actually, I'm quite happy, because it's clear you haven't covered the entire galvanic insolation inside the G2.

 

A.

Yes, there's the USB galvanic treatment, which  @Superdad actually commended in the 'AERIS G2 Review,' comment section. You can find it on this site.  Personally, I never use the USB so I have no idea.

 

B

There's galvanic isolation between the dual LPS. A good move of course. 

 

C.

Lastly, a dual circuitry isolation, both for signal and ground, that blocks noise from traveling into the digital output stage. You can detect telltale signs of that mechanism in the marketing photos of the innards. AURALIC has gone the extra mile here. I believe  UpTone is going to employ a similar design in their up-and-coming network switch, but it's beyond my pay-grade.