Aurender N10 music server Measurements

Sidebar 3: Measurements

With a media server like the Aurender N10, there's not much that can be assessed on the test bench. However, I did look at the properties of the N10's AES/EBU output, using a 45'-long cable to connect the N10 in the listening room to my Audio Precision SYS2722 in the test lab. Even so, with the N10 playing 24-bit J-Test data sampled at 44.1kHz, the jitter in the AES/EBU datastream was very low, at 293.3 picoseconds (average value over a 700Hz–100kHz bandwidth). The eye pattern (fig.1) was wide open, as it should be.

Fig.1 Aurender N10, AES/EBU output, eye pattern with 44.1kHz J-Test data. (50ns/horizontal div.).

All 24 bits were active in the digital outputs with 24-bit PCM files and transcoded DSD files. However, there was one peculiarity with DSD: The Aurender app offers the user the choice of transcoding DSD files either to 88.2kHz-sampled PCM or to 176.4kHz PCM, but no matter which I selected, I always got a 24-bit PCM stream sampled at 176.4kHz.—John Atkinson

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Aurender America Inc.
2519 W. Woodland Drive
Anaheim, CA 92801
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COMMENTS
music or sound's picture

I am reading quite a number of reviews of different music severs and I find quite difficult to figure out the differences between different models (e.g Aurender N100H) sound wise (except the obvious ones like price, storage capacity and type of outputs). Most reviews only state it sounds better than a Macbook. I understand it is a difficult task as there are many variables like different DACs with different inputs with various quality, different connection possibilities (but then again there are a lot different amps and speakers and I find their reviews are much more understandable - including or because of it their measurements). Would these servers sound better than a computer and a reclocking device? It is close to impossible to find a dealer who can demonstrate several different servers.
Digital audio is apparently moving away from downloads to internet streaming. So is there any advantage for this for these servers relative to computers?

spacehound's picture

Assuming your MAC is not 'broken' in some way I think this "musical mincemeat" is entirely in your imagination. Expectation bias? Dunno, I don't pretend to be a psychologist. This thing does not have a DAC so it's all 'digital'. And my 35 years in the computer industry says to me that these boxes are all the same, as it is not 'music' until it comes out of the D/A circuitry in the DAC, which this box doesn't have. Just data from a file, no different from a saved email. It's why I bought the relatively cheap (700 UK Pounds) Cambridge Audio Stream Magic. (which does include a DAC, that can, however, be bypassed, which I do).

Computer 'noise'? No. At full volume, using either streaming or USB from a cheap Windows PC, JRiver set to 'play silence', The CA streamer, which conveniently, and unlike most streamers, has a regular USB input too, a dCS Debussy ('async' so clocking is ENTIRELY from the DAC and any supposed 'computer jitter' is irrelevant - all this "it may have to work harder" stuff is pure BS, that is what DAC buffers are FOR), the latest Naim NAP250, and a pair of Tannoy Kensingtons, I can JUST hear the faintest 'transistor hiss' with the grille removed and an ear right up to the tweeter, and that faint hiss is no different if I power down the computer totally. So 'computer noise' is nonsense.

Am I a crazed objectivist with cloth ears?
No. I wouldn't have purchased the dCS, Naim, or the Tannoys if I was, would I? But I DO have sufficient knowledge to tell the boxes than can make a difference from the boxes that can't. And my powering off the computer as above proves what I say about 'computer noise', which some get pointlessly worked up about.

doak's picture

You say: "my 35 years in the computer industry says to me that these boxes are all the same."

How about giving LISTENING a try!?!

Save your $$ if YOU can't hear a difference.

What I can say because I can hear it (I won't defer to my 45+ years experience as an avid/active audiophile/music lover) is that digital music transports DO make a difference. These purpose built "digital audio appliances" make great sense and do the job better than a general purpose computer. A BIG plus is they are MUCH easier to use and deal with. I LOVE that I no longer have a "computer" in my audio system. I am spending more time listening to music and a lot less "dicking with" a computer.

BTW: It doesn't take anywhere near $7-8K to get there - plenty of less expensive choices. Check out the Auralic Aries or the Melco N1A. The future is here for those who want it.

spacehound's picture

It's why I have the Cambridge.

The rest of it is not worth an answer.
One - because how do you think I chose the dCS DAC, Naim amp, and Tannoy speakers, if not by listening?
Two. You think your 45 years (plus the years before you got interested) old ears can detect differences? Not a chance.

And as I attempted to explain, these DAC-less streamer boxes contain no 'analog' circuitry subject to distortion and are basically just 'pass through' digital switches. They don't have a 'sound quality', good or bad.

doak's picture

...that wisdom comes when we can admit how much we do not know.
From what you express it sounds like the Cambridge unit doesn't make the cut.
To truly "listen" in this case it must be with the Aurender (or something close to its quality) versus a general purpose computer, both into a quality DAC with which you are quite familiar. That's how this particular test works. "Experience" doesn't count for beans.

spacehound's picture

Do you think I haven't listened to more than one of these things? (Though I have not heard the Aurender).

Better or worse? FIRST you must hear an 'objective' difference. You can't be 'subjective' about any comparison about better or worse until you do.

What do I find:

1) I THINK I hear a difference between a basic 'computer USB to DAC USB' installation compared to a NAS-Ethernet-Streamer-DAC installation. I want to, but am not fully convinced I actually do, as I have already reached a quality WAY beyond even a top-priced (if price means much above a certain level) CD player. And there are fully valid reasons why either a computer or a Streamer should sound better than a CD player.
2) Streamer better or worse than computer? Noise level is inaudible unless I have an ear almost touching a tweeter, even at full volume. 'Jitter' is irrelevant in either case as ALL jitter comes from the 'async' DAC clock and nowhere else and it's the same DAC in both cases. Can't tell which is 'better' , not having been in the studio(s) when the recording(s) were made. This of course applies to you too. What you personally 'prefer' has nothing to do with High Fidelity, which means accuracy, by definition. No one ever comes out of a concert saying "Wasn't the bass good?"

3) If I heard a difference what was it due to?
Personally I have found that 'sound quality' depend more on my 'state' at the time than deviations between 'good' boxes.
Another one is power quality. I have a 100 Amp 220 volt, thus 22 Kilowatts 'cooker' outlet directly to the HiFi equipment rather than the standard 26 amp, 5.7 Kilowatts (the 'ring' is fed from both ends) UK 'ring main'. This is an improvement at any time. However, it all sounds best in the middle of the night when, presumably, area power demand is low.

These two things ar FAR more important to sound quality than the difference between one 'recognised' HiFi box and the next.

Quality.
You say "something close to its quality". How do you KNOW what its "quality" is compared to others such as the Cambridge? The price compared to others (worthless above a certain minimal level) or what? How many other Streamers have you personally heard? (Our 'dealer' here, audiodoctomj, has presumably heard several.)

doak's picture

... and am prone to say "There's only one opinion that counts as far as the choices I make,audio related or otherwise, and that one of course is "mine." Likewise, no doubt, in your personal decisions.

Enjoy your music system and life. In the end, that is all that really matters.

audiodoctornj's picture

As a new Aurender dealer, and as a high end dealer with over 30 years of experience, I would love to chime in.

There is a very large difference in the sound quality that comes out of a system with an Aurender in place.

My shop, Audio Doctor has been pioneering computer audio for years, and I have to say that once you hear an Aurender on a good system you will realize that there is a rather large and easily audible improvement.

I have heard modified Mac Minis, PCs, and high end servers, we had the Qsonix and the second gen with the Wadia output board was fantastic, so you could say I have played with a lot of these digital devices.

We took over our N100 to a customer with a good system: Unison Research Unico 50, Gershman speakers, Wireworld cables, NAD M51 Dac and the difference between the Mac Mini and the Aurender wasn't subtle.

The Aurender sounded was more dynamic with greater bass and an even more open sound.

The reason why does baffle me, and by the way I have heard the same results on top of the line dacs with asynchronous data transmission and re-clocking.

Why should a USB cable make such an audible difference? I don't know why we shouldn't be able to hear these things but we can.

The Aurender will bring out the best in a good dac and its difference will be readily apparent in any good system.

Even when streaming the Aurender will make an improvement.

spacehound's picture

State categorically that you are not hearing what you say you are hearing, obviously. And UNLIKE 'reviewers' you don't make a living by 'keeping the HiFi pot boiling' whether there is anything worthwhile in the pot or not, you just sell what you believe to be both good and reasonably profitable stuff. No problem with that.

But a streamer which doesn't contain a DAC (such as the one reviewed) is basically very similar to a network 'Managed Switch'. It doesn't DO anything other than implement "Take this data file from this selection of data files" (it isn't music until about halfway though the DAC circuitry) "and send it to this DAC".

It doesn't have a 'sound quality'.

SO - TO THE MEAT:

USB cables? SOME say they make a difference. But as any 'science' that might cause this is entirely unknown, it is impossible to say why. Therefore the manufacturers can't know either.

WHICH TOTALLY DEMOLISHES any nonsense about expensive USB cables being 'better'. If there is any variation at all there is no 'cost justifiable' reason whatsoever that any cable, cheap or expensive, should sound better than the next one.

The purchase price doesn't come into physics. And it doesn't come into 'unknown' physics either.

And the same applies to boxes such as the Aurender versus the Cambridge. Pick a couple of 'DAC-less streamers' at random. If there IS a difference it won't be price related as nobody, including the manufacturers, has a clue how it can happen.

audiodoctornj's picture

Your comments speak of the conspiracy minded rather than the empirical.

The fact that there many companies making servers that all sound different and many people are hearing improvements speaks to the fact that these products work and they do make an audible difference.

The concept that when you are streaming it is the same as a switch is not a valid argument, you can clearly hear a difference between two steamers on tidal as well as via NAS or hard drive.

I was present at a demo of a really expensive system $85k Dynaudio speaker, Burmester electronics, etc and we compared a Lumin to an Aurender and they both sounded different and that was on Tidal!

So you must consider that the streamer is buffering, re clocking and keeping the data stream pristine and for those reasons you can hear a difference.

The USB argument that bits is bits is also wrong. The best USB I have ever heard a $2,500.00 Enklein was tested on a device that looks at data dropouts vs lower priced high end usb cables and there was a difference that the testing devices showed, it showed that all usb cables don't allow for 100% transmission without errors.

I have also compared two $700 USB cables and they both sounded different.

So instead of looking at conceptual reasons why, get yourself into a shop and listen for yourself.

I agree that on paper we shouldn't be hearing the large differences we can hear but at this point way too many people are hearing these products and coming to the same conclusion that they work and do make an audible difference.

If you come to NJ you can visit my shop and you can compare Aurender, Lumin, Naim, Cambridge Audio, all as streamers and we do have PC's and sometimes Mac Minis as well which we compare them to we also have a sea of high end digital cables.

spacehound's picture

Most of our UK dealers are useless on this 'computer' stuff but I am 4000 miles away. Maybe when the trout fishing season starts. That gives me two excuses :)

One point I definitely disagree with. "High end digital cables". As there is no known science behind this, cable construction, as long as it is reasonable, can only be pure guesswork as the manufacturers can't know why there might be a difference either.

Thus a cheap cable of 'good' construction (which 90% plus are) is just as likely to sound as good or bad as the next cheap cable along or any randomly chosen expensive one.

So there is no reason whatsoever that as a 'group', expensive cables should sound any better (or worse) than cheap ones.

We just don't know the 'physics', if any. But I bet 'purchase price' doesn't come in to any 'physics equation', known or unknown :)

Yaman's picture

The argument "The USB argument that bits is bits is also wrong." is wrong. You completely trash all computer operation. A bank data center relies on those bits. If these kinds of data transfers are happening at random we may end up with 0 balance at any time.

One can argue that the bits are not bits because one device doesn't output bit perfect representation of the recording whereas the other one does. This is acceptable but never happens and it all boils down to voodoo

John Atkinson's picture
Yaman wrote:
The argument "The USB argument that bits is bits is also wrong." is wrong. You completely trash all computer operation.

Forgive me for daring to think I know more about digital audio than you do :-)

Yaman wrote:
A bank data center relies on those bits. If these kinds of data transfers are happening at random we may end up with 0 balance at any time.

No-one has written that the bits are changed. But unlike the bank scenario you instance, the bits in a digital-audio datastream are going to be used to reconstruct an analog signal. In which the timing with which each data word is presented to the DAC becomes critically important. The right bits at the wrong time are equivalent to the wrong bits at the right time, a phenomenon called "jitter" in telecoms theory.

John Atkinson
Editor, Stereophile

Antipodes_Audio's picture

The common mistake amongst science practitioners (as opposed to scientists) is to assume a theory that they routinely apply, completely explains reality. This leads them to foolishly claim they know all there is to know, when none of us ever will.

Theory is always a simplification that is nevertheless useful in the intended context. The theory that bits is bits is fine for the purpose of getting the right bits from point A to point B, but you still have to design a system around that need.

And you can reasonably apply this basic theory to digital audio transmission too if you don't care too much about fidelity (such as for a phone call). But for high end audio the theory needs to expand to take more real factors into account. The principle one is the effect that noise interference on the digital signal has by creating momentary uncertainty at the downstream stages, resulting in jitter. And there is the fact that the claimed restorative effects of buffering and reclocking are wildly exaggerated, and based on a misunderstanding of how they actually work.

I realise that I will be shot down for my vested interest, fire away, but I also hope some readers will see what I am saying. High end audio is not just about making something work. It is about optimising performance. And in every scientific field I am familiar with, optimisation requires more than basic theory, and typically requires a degree of art that is based on years of real experience.

larryh111's picture

This is a great site, with many quality contributions for sure. I am relatively new to digital audio in the sense I recently purchased a high performance DAC to add to my otherwise all analogue system. While investigating music servers, I ran into this thread and would like to offer a couple of comments.

First, the job of a hifi system is simple - to accurately reproduce a recorded signal. The problem with digital recording is the result will always be an imperfect representation of the sound field it tries to capture. The evidence of that is higher sampling rates produce higher fidelity ie. more data points sound better than less. Next thing that happens is the computer streams the digital file to a device that attempts to reverse the digitizing process and form a smooth voltage signal that passes to an amp and into a speaker. Best case, is the whole transaction is performed in a way the human ear can tolerate and hopefully find musical. Worst case is where there is not enough data or a ton of manipulation has been done to the computer file either while recording or during playback. Indeed there are some excellent systems out there that do the transaction quite well.

To argue about expensive digital cables versus cheap cables and expensive digital storage media versus less expensive media seems to be missing the forest for the trees. Digital files don't have feelings, they don't impart any more quality to a sound than was put there to begin with and as I have noted above is a compromise at best. Digital files don't care if they live in an mp3 player, apple computer or a high end server. They are just there and to get them out you do as any other computer program does you read them as a file. There are many ways to make sure the file is intact and not corrupted that are done much faster than the playback rate of the music feed.

Bottom line is after you have sorted out your speakers, amps, preamps, analogue cables and DAC you may want to look at the storage media or server as it is called. As a function of dollars spent for improvement I would put the other aspects of the music chain first and the choice of a server or digital cables last.

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