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A novel way to massively improve the SQ of computer audio streaming


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Most important: please realize this thread is about bleeding edge experimentation and discovery. No one has The Answer™. If you are not into tweaking, just know that you can have a musically satisfying system without doing any of the nutty things we do here.

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On 1/5/2017 at 4:02 PM, hopkins said:

I set it up in Linux, with an Intel board running RoonServer and a RaspberryPi running RoonBridge. Took me two minutes.

 

Both have fixed IP addresses set on my router.

 

On the Intel board (Ubuntu in my case):

apt-get install bridge-utils

 

then in /etc/network/interfaces:

auto lo br0

iface lo inet loopback

iface br0 inet dhcp

bridge_ports eth0 eth1

 

Done ! Works, but have not spend time listening yet :(

 

Can you (or anyone else) confirm these are the instructions for "bridging/direct" Ethernet on Ubuntu?  Thanks.

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51 minutes ago, User471 said:

 

I have a linux based roonserver and a separate linux based endpoint both connected via the same Netgear unmanaged switch (with an iFi PSU)

 

All built and setup by me, so I have some linux skills ? (mostly being able to Google a solution and use SSH, to be honest)

 

So I'm going to be thick here  .... apologies

 

What is being advocated here is to have x2 ethernet connections to my server - one direct to the switch; one direct to my endpoint

 

Then I install bridge-utils (I'm on Debian 9), edit /etc/network/interfaces and .... hey presto !?!?

 

 

Hi,

 

I'm working with my home-built Ubuntu server and was wondering if you knew how file packets were routed with a bridge in place and the renderer directly connected to the server.  Thanks.

 

EDIT: just reread your post and saw you're using Roon; I'm not.  Not often I get a chance to converse with another Linux user.

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9 minutes ago, User471 said:

 

My understanding, imperfect as it is, is as follows

 

With x2 bridged NICs in the server, locally stored music is routed directly to the endpoint (bypasses switch) but streamed music from WWW (eg: Tidal) comes via the (?dodgy) switch first before the server routes it to the endpoint

 

Hence if (big if) this all works one should be able to discern a difference between the exact same track that's played locally versus one that is streamed from the WWW (and hence goes via the switch on its way to the

endpoint)

 

I'd be interested if anyone has done that test

 

(Happy to be corrected/educated by one of the network pros out there ?)

 

This is what I'd hoped for, which is the best case scenario.  Like you, I'm using my own server (now Ubuntu 18) with a JCAT Net card between the server and the dCS NBR (renderer), but I began to doubt this flow when experiencing a slight delay with medium to larger sized files.  May I ask the source of your understanding?  The last article I found did say the bridge functioned at Layer 2, which is consistent with what you've said.

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Thank you.  Don't hold your breath for the network engineers.  I've combed the web for days looking for definitive information on this and found very little.  Btw, one article I found said that the bridge is merely a pass-thru, to share the connection.

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14 minutes ago, Dutch said:

Yes it’s a software bridge, bridging two different network segments over L2. Hosts on both segments need to be in the same layer 3 IP network.

 

I’ve always found the bridging solution buggy and had performance issues as well so I’ve setup a routed approach which I believe accomplishes the same in a more stable and better performing way.

 

On my dual NIC server I’ve installed a lightweight DHCP server for the SMS-200 when one could not yet set a fixed IP. That binded to the second NIC.

 

In the central router of my network I’ve added a static route for the second subnet (192.168.2.0/24) in my network. This network ‘lives’ behind the 2nd NIC in my server. The gateway for this subnet is the primary interface of the server in subnet 192.168.1.0/24.

 

For this to work for applications not running on the server (e.g. The Roon Remote) the server needs to have IP forwarding enabled to transfer traffic between the NIC’s. This requires one simple registry change. See for example http://www.itgeared.com/articles/1066-how-to-enable-ip-forwarding-on-windows/ (yes this works on 2012 R2 too)

 

Since the second interface with the second subnet is local to the server it knows where to route the traffic to. Default gateway on the server is the central router so it also knows the ‘way back’ to hosts on the 1st subnet.

 

This method does not work for software that relies on broadcast traffic (e.g. For mDNS) like HQPlayer and Airplay. For Roon it works great.

 

With all this NUC/AL experimentation I’ll need to look into how to do this on Linux. :)

 

I'd be interested in what you find for Linux.  One of the reasons I switched was because bridging in Windows was such a pain.  In Ubuntu, I just use the connection editor and it's done with a few clicks and a restart (easy in Mac too).  Ubuntu 18 has a minimal install option, and I only add "Vino" to admin from my main Windows machine with VNC.

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  • 3 months later...
On 6/28/2019 at 7:00 PM, austinpop said:

Folks, we seem to have veered off-topic again. 2 pages on DSD vs. PCM, Hi-res vs. Redbook? It's an interesting discussion topic, but it is OT for this thread. 

 

Yes, the focus here is on direct listening experiences, but not about anything! As a reminder:

 

 

The reason I'm trying to rein in these OT meanderings is that this thread is already long enough, so it behooves us to keep a very high S/N ratio.

 

I really have better things to do than come in here and moderate every day. I do not want to delete posts, so please make my "job" easier.

 

I have very little time for forums as well, but something occured to me yesterday that should be within your parameters.

 

As a friend and I are working on our latest servers, both attaching to DAC/renderer via USB (a change for me), I was wondering if the second connection on our JCAT Net cards (bridged for direct connect as before) could be used for the NAS.  Why?  For the same reasons it benefited the Ethernet connection to the DAC/renderer:  better latency and lower noise.  If plausible, I would then consider how to deal with the proximity of the NAS to the server and listening position, and would consider replacing hard drives with SSDs on the NAS only (that's actually a single SSD for my current Synology DS119j for those cringing at the idea of buying several, expensive SSDs).

 

Thoughts (preferrably from those currently using bridged Ethernet)?

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12 minutes ago, austinpop said:

 

Interesting proposition.

 

Examples of on-topic follow up would be SQ reports from those who’ve tried this or similar, and their findings compared to keeping the NAS elsewhere.

 

I’ve always preferred to keep the NAS far away due to acoustic noise considerations, but I’d love to hear reports on this approach.

 

Well, I'll try it and let you know.  It's going to be several weeks until I get the new 6-rail LPS and then build the new server.  It occurred to me because my home network is about as cheap as you can get (builder wired and the AT&T U-verse router), and I've always had trouble using Windows shares.  I'm currently populating the NAS with the web API and it's slow.  Also, I read an article asserting little to no benefit replacing HDDs with SSDs in a NAS because the network is the bottleneck (for the average home network).  But we have the acoustic concern as you state.

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25 minutes ago, elan120 said:

 

I have been connecting NAS to server direct via JCAT Net Card for awhile (see below), but have not done comparison if installed far away.  When compare with external HDD, internal Optane, they seems to be very close in SQ, with external HDD appears leading slightly.  Certainly worth a try to see how well it works in different system.

 

Very cool Elan120.  For my cheapie home LAN, I'm hoping for other benefits as well, like Windows share performance.

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On 12/15/2019 at 5:37 PM, romaz said:

SGM Extreme

 

Given the knowledge accumulated through so many hours of testing and comparing, the natural question arises why I would buy an SGM Extreme?  The bottom line is as much as I would like to, I cannot build a server of the caliber of the Extreme.  I don't think anyone but Emile can.  Having communicated with Emile at length over a span of months, it became evident that Emile has spent many more hours than I have with his testing and comparing.  He even quit his day job as a university level IT professional so he can test and compare all day long.  Unlike me, he has access to measuring equipment and has spent tens of thousands of Euros measuring the noise spectra of motherboards, CPUs, chipsets, clocks, memory, storage media, and power supplies to guide his path whereas I am left to random guesses as to which CPU and motherboard might sound best.  I also do not have the gifts that Emile has with respect to hardware and software optimization capability including network allocation.  I don't think most other IT professionals do either based on the fact that no one else has come up with a server like the Extreme.  Here is an example of one of Emile's e-mails to me and I think you'll quickly get the picture as to how Emile views music server design.  I had asked Emile why he felt he needed to use 48GB of RAM in the Extreme when this seemed like overkill and would potentially be a significant source of noise:

 

"Well RAM is a topic on its own, to start with, the 2 cpu’s are split into domains (NUMA / SNC), so you really have 2 x 6 dimms, 6 for each CPU, they are not shared. Music services have their own cpu/dimms and the OS has its own cpu/dims. So its sort of a core and endpoint into a single machine going beyond just core allocations for individual processes. These Ram modules are a custom order type, similar to the Apacer types popular in the Jplay forums, but taking it just a bit further. They do create less noise and draw less current then other offerings. If more dimms reduce performance, it typically means your power supply is negatively impacted by the increased current draw. As occupying more memory channels increases bandwidth and reduces wait states, you do get better individual process performance."  "What you really want to do is reduce your hardware active processing times as much as possible. The net effect is much like a class A amplifier, you have a higher baseline power consumption, but power draw does not vary much, and this is very good for a more “natural/relaxed” sound. I hope this makes sense 🙂 But you do need a power supply which is very comfortable supplying the load. You really want the least possible variation in load, and higher cpu power / bandwidth systems are better at that with very low load music playback processes."

 

As for the Extreme being a core and endpoint in a single chassis, this was interesting for me as well.  You basically have 2 CPUs with each CPU having its own dedicated RAM bank (24GB each) and so there is a genuine distribution of tasks between 2 machines just like dual Pink Faun 2.16Xs.  While I very much like what I heard in the Aries Cerat room at Munich this past May where dual 2.16Xs were playing, this configuration costs north of $30k, has fewer cores, uses a noisy SSD, consumes more than 200 watts, and capably functions as a room heater.  I find the Extreme to be a more elegant and practical solution and at least on paper, I believe it is the most technologically advanced music server at this time.  My brief listening experience in Taiko Audio's listening room did nothing to dissuade me from this opinion.  

 

Happy holidays.   

 

 

Just now saw Mr. Romaz's holiday update.  Like everyone else here I really enjoy reading content like this, and this one was so well done, full of useful info.

 

This is the most compelling write-up I've seen for the SGM Extreme (and I've been so on-the-fence about getting it, rationalizing it will be better to wait for Emile's B lineup he says he'll have out in a few months, or to settle for a pair of PHD SR7s with my own ASRock/i7/Streacom server).  For me this year, it's either the SGM or the mono powerbases for my MSB Select 2 DAC -- I can't do both.  I wish Emile had a demo unit.

 

EDIT: I scanned the quoted post another time, and somehow keep missing the amps he liked with his Alexias.

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9 minutes ago, HeeBroG said:

If it's not at the "source" no DAC, including the MSB Select 2 DAC, will be able to recover it!🤔

That seems to be the SGM mantra anyway and I guess it makes sense.

Its just a pity that the cost of admission is prohibitive for most at €24k.

As a comparison though; how much do you think you've spent on your server inclusive of power supplies, DC cables, audiophile USB/Ethernet cards etc?

 

 

A few thousand ;)

 

One of MSB's objectives for the ProUSB input module was to take the server variable out of the equation, but a number of MSB customers are now advocating for the SGM.

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