Why does a SuperUniti/UnitiServe sound better networked?

N, maybe what you are hearing is that the output quality is better via Ethernet (using the uServe as a true UPnP server) vs. spdif (thus using the uServe 'merely' as a player). 

Hi Bart

I have not had a chance to try this for myself - I'm just trying to understand it. You may be right about the output quality though. Maybe that nice Mr Harris can explain if he ever sees this.

I didn't say that very clear -- what I meant to say that perhaps what the people are saying (if it's here on the forum) is that Ethernet is better than spdif.

UPnP (ethernet) is a two-way communication protocol (essentially error-free), while S/PDIF (direct digital connection) is a one way protocol, with no error correction.

A very good technical explanation by Ihau here (11th post down) :

https://forums.naimaudio.com/to...-year-with-the-uniti

It could be that the Unitiserve is generating RFI down the Ethernet cable.  The Unitiserve is a PC which is inherently noisy.  Going via a hub/router will help isolate this.

I know Simon (in Suffolk) has discussed this on several occasions and has also identified that certain hubs can generate different amounts of noise which can have an audible effect and noise can come into a streamer via Ethernet.

Also If you connect the UServe directly to the streamer you will not be able to control it with your iPad or use iRadio as the Superuniti and UServe will be on their own network.

Richard

It would seem from lhau's excellent technical explanation that there are some good reasons why an Ethernet implementation should sound better than  a digital link.

Although I only have experience of the former, my dealer insists that it is the superior configuration for my Userve/NDX set up in discussions both before and after I had bought my equipment.

Regards

Ray

The explanation that lhau posted is not really relevant to the question the original poster asked. lhau was talking about SPDIF connections in general from PCs and in particular an Airport Express. Neither are audio grade. UPNP in these scenarios avoids the timing issues that lhau mentioned as it is a reliable bit perfect tranfer protocol.

If the original poster is connecting his Unitiserve to his SuperUniti via SPIDIF are people really saying that one Naim audiophile unit cannot interface reliably and with audiophile sound quality  to another Naim audiophile unit by this method?

No, the UnitiServe S/PDIF output is very good and will interface nicely and in a musically satisfying way with a Naim streamer or DAC. This is how I run my UnitiServe into the Naim DAC, and it is very good. The UPnP method, though, is audibly better (not immediately on direct A/B, but over extended listening), and one day I will replace my Naim DAC with a Naim streaming client.

Ihau's explanation is relevant, as the UnitiServe is a computer.

Of course it can interface reliably using S/PDIF- but that's not really the question.

Given the two options it's worth the OP trying both to see what works best for him in his particular system as they may sound slightly different .The OP will enjoy far better control options going the UPnP route given the control functionality of the US and SU. 

(Off topic)

James, your profile shows that you have the NDX and the Metrum Octave DAC. I assume you are using the NDX just for its streaming client. Could you describe the differences between the Metrum and the DAC in the NDX ?

Thanks

Jan

Excellent - Ihau's post is really helpful.

I have come late to this party, so thanks for being so kind and supportive, especially since my questions are so basic.

Hi Jan - yes i am using the NDX as a streamer (and digital hub). I see you have an email address in your profile so i'll drop you a mail directly.  

James

If / when you go the UPnP route, do connect through a proper switch within your home network, and not with an Ethernet 'patch' cord directly from the Serve to the Uniti; you want the benefits of having the Serve on the internet.  It needs internet access to pull down data and album art, and you want to be able to control it and edit the data from a computer also on your home network.  I think that the idea of a direct cat5 connection from uServe to its client is a bad one.

I'm planning to connect them both direct to the Draytek router, rather than using a switch. Is that the same?

What is a Network Switch versus a Router?

Switches create a network. Routers connect networks. A router links computers to the Internet, so users can share the connection. A router acts as a dispatcher, choosing the best path for information to travel so it's received quickly.

http://www.cisco.com/cisco/web...rk_switch/index.html

***

Nigel, direct connection to your router will work (routers include a switch), but for best SQ, a separate switch is recommended (by Naim) to isolate your music network from the rest of your network and its traffic.

I've probably grossly oversimplified, so perhaps Simon can chime in...

Jan 

That makes sense. Any suggestions for one that looks ok and doesn't need a huge plug/power supply?

The TP-Link 5-Port Gigabit desktop switch TL-SG1005D works fine with my system, cheap and can be hidden away...

Network switch recommendations

... then there is the issue of cheapo wall wart power supplies injecting RF into the ethernet leads :

To switch or not to switch : see Bart's post (11th down) and Simon's reply (15th)

Whilst the Draytek router is called a router, most of them have an inbuilt 4 port Ethernet switch so connecting the Unitiserve and SuperUniti to two different Ethernet ports is perfectly acceptable and you do not need to purchase a switch. I would guess that you have a 2820,2920 Draytek Vigor router just connect to the two of the ports on the back. Draytek routers are excellent.

If you have a big home network with lots of devices some streaming movies, ipad, downloads etc then careful planning of the network topology and selection of additional switches to segment traffic such as music might be advisable. By the sounds of it, HungryHalibut does not have such a network and using the switching capability within the Draytek is perfectly acceptable and will work fine. I know because that is what I used to do with my draytek router before I expanded my network.

HungryHalibult, some good explanations already, but essentially when using the UnitiServe's SPDIF output, the receiver - ie the SuperUniti is using the senders transport clock to clock the data into a buffer - derive the sample clock and then send the PCM data on its way through the DSP and then DAC. I think architecturally with Naim this processing happens close to the DSP processor and so possibly the harder it is having to work to iron out the variations in the transport clock - the more chance there is a knock on effect to other sensitive functions in and around the DSP.

Now the Ethernet receiver is I believe on a separate piece of the architecture and on some devices, like the NDX, on a separate Streamer board. Although significantly more scope for electrical noise than the SPDIF receiver, they do tend to be more separated on the board from the sensitive sample clocks ands DSP memory - at least the case with the NDX. Therefore there is greater isolation and there is less likelihood of interference and perturbations from the Ethernet Streamer board affecting the sensitive DSP and DAC circuitry and clocks and one assume the PCM digital; stream from the streamer boards is clean and well behaved. However even with separate streamer boards - Naim are careful, and in the NDS for example there is quite extensive screening around the streamer boards.

Further with the NDX and nDAC the quality of the transport clock of the SPDIF sources does ultimately affect the sound quality.

With Ethernet, it is subtle and at the time using 500 Series amplification, we (my dealer, his business partner and I) could hear the difference between two uPNP servers playing the identical WAV file from a NAS. We discovered that one of the Ethernet cards on the uPNP servers was running half duplex - ie the Ethernet traffic profile was therefore different and this was slightly audible. Put to full duplex differences tended to zero. You can do this for yourself by using a hub and a switch to connect your SuperUiniti and see of you an hear any difference on the Ethernet playback. (a hub forces half duplex, a switch will try and default to full duplex if it can in most cases)

Simon

Wow, this is complex.  Basically, the router is in the sitting room, as is the Naim. Everything in the house currently connects wirelessly to the router. The only 'power user' is my son and his online computer games. So the only issue for me is whether to run two leads from the Draytek to the two Naim boxes, or run one lead to a switch and plug both boxes into the switch.

i just need to be told what to do!!

I run one lead to a Netgear "gigabit" switch, and leads from the switch to my uServe, Qute and NDS.

Super, thanks!

Hi, well the explanation might a trifle involved that you asked for... But you dont need to know why to enjoy what sounds best. If you use a regular Ethernet switch to connect your Unitiserve and Superuniti you will be fine. It' can be better to go via a cheap switch rather than switch ports on  a cheap Internet router. 

String a single Ethernet lead between your switch and your router.. Or use wifi for that connection if you know what is what.

Simon