Melco S100 Ethernet Switch Measurements

[R1200CL]

Is that price without a 12V supply ?

[R1200CL]

29 minutes ago, jabbr said:

a 10G fiberoptic switch that costs a bit over $100

Where can I find such a reasonable priced 10G fiber optic switch?

 

I see your point with a 10G switch, and could be well worth testing with measurements. 

[R1200CL]

https://www.amazon.com/NETGEAR-Gigabit-Ethernet-Insight-Management/dp/B01NBBA1HQ/ref=sr_1_30?dchild=1&keywords=SFP%2B+10Gbps&qid=1600113626&sr=8-30
 

https://www.amazon.com/QNAP-QSW-308-1C-Switch-Gigabit-Unmanaged/dp/B07VC9T3WQ/ref=sr_1_21?dchild=1&keywords=SFP%2B+10Gbps&qid=1600114319&sr=8-21

 

So 3 possible candidates 😀

[R1200CL]

23 hours ago, plissken said:

Again here is the problem: If you start playback on the Lumin D2 and pull the plug how long does it continue to play for?

Please do your homework 😀

 

The signal from the switch with jitter, noise etc, has already been injected into the buffer. 
You should have learned this by now if you had paid attention to John Swenson’s post. 
 

Besides I think this also depend on clock in the Lumin as well. 

[R1200CL]

4 hours ago, Miska said:

One can use shielded STP cables only in very specific circumstances, where both sides of the connection are connected to the same common ground point by some other means.

This is so true, and is probably only relevant to a very few people here at AS.

The rest of us that has been discussed this here at AS the last 3 years, should keep on with un-shielded cables (like blue jeans), or use JSSG360. And fiber. 

 

If we where building professional network from scratch, indeed we could (or should) use network that applies with the official standards. 
I don’t know how this would affect etherRegen as an example in the loop, but I suppose this is when that earth screw comes handy.

I think first problem that would occur is created by the supplied modem from the ISP. They are normally not grounded. Of cause can be solved. 
 

(I read rest of your post after writing). You are so correct what you’re saying. And it can even be more complicated. If the PCB is connected to chassis etc. 

Thinking of this, does any streamer or streaming DAC comply with 10GB networking standards. Wouldn’t that one day be a requirement as well. 
 

We need to standardize on fiber (or wireless) in our audio network. 

[R1200CL]

8 hours ago, plissken said:

Jitter is time domain error. It can't exist in a buffer. John will tell you that. Buffers represent clock domain boundaries.

That’s interesting, cause then clock phase noise (which I understand as jitter) should be removed by buffers. And good clocks wouldn’t matter. But they do. I probably need to do my homework as well then 😀

Maybe I’m mixing tings. Thanks for telling me. 
I noticed the new 1.5 version of microRendu has better buffer instead of better clock, so that statement can’t just be marketing BS. 
 

Do you have equipment available to measure switches ?

And would you be interested in doing some ?

 

I just got a Cisco 2960 G version. As an example, should I expect equal measurements from the RJ45 as the SFP port ?

 

[R1200CL]

38 minutes ago, plissken said:

 

Which measurements? Ping, and throughput should be the same.

Phase noice, jitter, and what ever make sense to measure. I think you know. (Much better than me). 

[R1200CL]

36 minutes ago, plissken said:

I heard that having your wall framing made of metal stud makes your sound system better vs wood framing...

The worst is glass. Including huge TV. And not to forget bend radius of your cables. Fiber of cause most sensitive. But it can be fixed with dipping into hot water. 

[R1200CL]

33 minutes ago, plissken said:

 

How do you know it doesn't. Have you had a listening room made with metal stud yet?

Aha, a Faraday Cage. Must be perfect. 

[R1200CL]

1 minute ago, plissken said:

 

Measure jitter all you want. These are not real time systems. Jitter only appears on data transfer. The higher the speed obtainable the smaller the window of transfer.

 

You can't have jitter when the line isn't doing anything.

 

If you take 10GB and you can realize it's 1250MB/s you can transfer, on an appropriately engineered system, a CD in about .6 of a second. 

 

Even if you have a system that can only cache 30-60 seconds of audio your time on the wire at 10GB is going to scale just the same.

 

So in what way should measurements of a switch be done ? 
What parameters matters ?

[R1200CL]

35 minutes ago, plissken said:

This is simply not the way it works.

So how does it work ?

[R1200CL]

9 hours ago, plissken said:

You don't even need the switch.

Instead of me arguing, can you explain why a switch like the etherRegen won’t matter based on Alex and John’s explanations here:

 

 

[R1200CL]

@plissken

My understanding is you pull out the cable in order to eliminate leakage current, so with optical cables there isn’t a need for this. 
I suppose if a buffer is to be used in order to block phase noise (jitter), this buffer must be located after last network interface, so it can’t be inside a switch.  Maybe it can be inside the opticalRendu (I know there is one, but not sure how big, or if it does anything to reduce jitter). 
 

Where is your buffer located and what size does it have ?

 

@JohnSwenson

Would a dual design of buffers (somewhere) where the design is made a way altering between the buffers be a solution to almost totally eliminate phase noise / jitter ?

And if so yes in theory it may not be so easily done in practice. 

Or maybe the opticalRendu already eliminating phase noise the way described in white paper ?

 

I like the idea of optical 10Gbs Ethernet switches. As they most likely have higher jitter requirements. Should I expect your etherRegen or opticalRendu (and opticalModule) to work with and benefit from such switches ? I think not. 

 

I suppose the only way this can work is if those 10GB switches also do 1 GB, and I don’t think they do. So it’s up to the SFP Small form-factor pluggable transceiver maybe ?

@jabbr Maybe you can explain what’s possible with 10GB into 1GB. 

[R1200CL]

18 minutes ago, jabbr said:

10Gbe Ethernet has very low phase noise/jitter *as specified* and moreover jitter is *not allowed* to travel from one hop to the next. This is written into the compliance testing specifications. I’ve posted on this exhaustively.

And is not affected by choice of SFP ? (No problem with 1GB versions on 10GB switches). 

[R1200CL]

On 9/17/2020 at 6:06 PM, plissken said:

Here is a video I shot with an Audiophile Switch. It's short and to the point. I would love to see you tell when the switch is in and out of loop.

 

Wouldn't pulling the USB cable make same result? (You will have the same buffer there). 

[R1200CL]

5 minutes ago, plissken said:

 

You mean USB from computer to DAC? Pretty sure the DAC doesn't have 1gb of RAM buffer :-)

So you’re claiming your switch have ?

[R1200CL]

On 9/21/2020 at 4:07 AM, plissken said:

 

You watched the video?

Yes, i watched the video. I can unplug here as well. It will play quite short. 
I suppose the point with that video is only to show that there is a buffer present ?
 

So that’s why I’m asking where is the buffer ?
I also have two Cisco here. One is SMG 300, and the other is 8 port 2960G which I haven’t been able to log into yet. (But I think I know why). 
 

Can either of those two switches be set to extend the buffers ?

[R1200CL]

1 hour ago, plissken said:

My point, and it should be obvious, is that when a switch delivers data ahead of play back and you can literally pull the plug, according to the leakage current argument that a difference should be audible.

Again, where is the buffer (that will remove phase noise, “threshold jitter,”) located ?

 

[R1200CL]

On 9/16/2020 at 7:23 PM, plissken said:

I concatenated a ~45 minute album into one .wav file and flac'd it to 445MB.  I start playback and in the time it takes from clicking play to unplugging my network cable the entire song is in buffer.

Where is the buffer ?

Video only telling your plugs in and out cables. And music still plays. We dont know actually the setup. We don’t know if you’re pinging the server, or something else. And for sure we don’t know where that buffer is located. 
 

There is no need to be arrogant. 
 

I’m asking so I understand if I also can find a buffer somewhere. 
 

Also will this buffer magic work for streaming services ?

And if not, why ?

[R1200CL]

2 minutes ago, plissken said:

 

In the video the playback software is JRiver. It has a setting for up to 1GB of buffer. Tidal will buffer entire tracks. I don't know about other streaming services.

 

Sorry I thought it was readily apparent that JRiver what the application that was playing back the music without a break even with the cabling unplugged (the continuous ping).

Then we must understand that buffers only applies to those that plays directly from PC to DAC via USB, with SW allowing you to set a buffer. 
 

I must be wrong?

[R1200CL]

10 hours ago, plissken said:

Not correct. High end streamers like Lumin can have several minutes. Low end units may have just a few seconds.

This is interesting, cause let’s say you have a 5 min buffer, you would also like to be able to at lest operate stop/play from that buffer. 
This will in most cases require a network connection. 
So if you’re pulling the plug, you can’t do it in that way. 

 

With fiber this shouldn’t be an issue in any case. 
 

I notice there is a clock buffer in the opticalRendu, but I think we’re talking about another buffer here. 
Pulling the fiber cable at my etherRegen fiber side to my opticalRendu indicates no buffer. Or not more than a second. 
Pulling input etherRegen gives same results, expect establish a connection takes longer time. 
 

So maybe there still could be some improvements done by John Swenson design when it comes to buffers. I don’t know if a huge buffer is an issue working with RAAT, but since Lumin is Roon Ready, I suppose not. 
 

Then one can probably argue that buffers should be located in the DAC.

 

Understanding fully the digital chain with all sorts of interfaces and requirements for clocks and buffers isn’t easy. Maybe a tread or white paper on that would be nice. 
 

 

[R1200CL]

7 hours ago, Blackmorec said:

Perhaps its also to do with network traffic and how non-audio related packages impacts the system.

I really don’t hope that’s the case. I can’t be. It’s impossible. Then we would need a dedicated audio internet from streaming services 😀

However bad home network is another story. But still non-audio related packages shouldn’t be an issue. 
I suppose @plissken can educate us if QOS and similar technology in managed switches will help.

There must be a reason why ip-phones gets a priority, so why not audio ?

Personally I think good terminated cables and well known brands in use with router and switches will help. Probably plan for 10GB fiber. But that maybe is an overkill. 

[R1200CL]

21 minutes ago, plissken said:

You sure can with Tidal and JRiver...

I think you missed the point. (Or did I miss yours 😀). 
 

How do you communicate with your PC. Yes, of cause with mouse or keyboard, so you can do if your PC is USB to DAC.
But unless a pc isn’t your endpoint and player in one package, you can’t control the buffer (stop/start) remotely. 
 

You test has only a value in some very specific environment. And as you know there is in general accepted that a PC is the worst endpoint. With expensive exceptions. 
Maybe why you couldn’t hear the benefits of the etherRegen?

[R1200CL]

3 minutes ago, plissken said:

QoS and DSCP are traffic markup technologies for priority traffic (delay sensitive, non-bursty) normally real-time. Audio playback isn't real-time so it's delay insensitive, and bursty in nature.

Nice. So we don’t need managed switches (for whatever they offers) when it comes to audio. 
 

Thanks for clarifying that. 

[R1200CL]

@plissken

What kind of jitter is this. What causes it ? And what is an acceptable number ? Should we even bother with it ?

Speedtest.net explain like this:

Jitter: Jitter is a measure of the variability in ping over time. High jitter can result in buffering and other interruptions. Jitter is measured in milliseconds (ms).

And should my ping to external servers matter ?