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

[jean-michel6]

On 15/10/2017 at 6:54 PM, Johnseye said:

 

See my post here:

The board I've identified, and will likely send off to SOtM for modification is the Jetway NF591.  Very similar to the DFI board Roy is using.  The Celeron proc is 6w.  It has a PCIe slot so I can use a tx-USBexp.  It has DC 2.5mm in which means I don't have to use an adapter from my SR7 anymore.  This is a big win.  But it has an M.2 slot which means I can A. use my current low power SSD and B. 

 

The M.2 slot is not capable of using the Optane stick, but I may be able to use it with the mini PCIE.

 

This board will go out to SOtM for modification this week.

Hi @Johnseye

 

I am very interested by your feedback when available about the  Jetway NF591 motherboard modified by SOTM .

Do they told you that they could modify both clock for the processor clock and also the ethernet clock ( for me as i am in a dual pc configuration ) . 

 

I have been looking also to the bios of these motherboard and i understand that there is no way to lock the CPU to a specific speed which usually has a quite significant impact on the sound quality . May be not so necessary for these processors with very low electrical consumption .

[JohnSwenson]

5 hours ago, thyname said:

 

Excellent write up!

 

For the quoted phrase above, are you saying that when connecting the endpoint / streamer (such as microRendu or sMS-200) to that switch, nothing else should go to that switch (i.e. Apple TV, Xbox, etc)?

The switches mentioned are only 1/100 switches so cannot handle gigabit Ethernet. If you need gigabit for other devices go ahead and run them through a separate gigabit switch, using the FS108 or FS105 on a connection to the audio device.

 

I did not spend a lot of time trying all kinds of different configurations, in my tests I had the FS105 etc with just two connections, one to my main gigabit switch and one to the streamer. That does not mean that is the only configuration that will work, just that I didn't test any other configurations.

 

One thing I did find is that it is important to leave an empty port next to the one going to the endpoint. For example if the endpoint is on port 1, don't plug anything into port 2. (its actually more complex than that, sometimes you CAN plug something in next to the endpoint connection, but always leaving the ports next to it free will guarantee you don't have a problem).

 

John S.

[JohnSwenson]

4 hours ago, Forehaven said:

Thank you so much John!! NOW I see why the emphasis of adding another switch and ps.  Very clear and concise that even I understood lol

 

I'll def work on this aspect.

 

The 5 port/7.5vdc ps...will the LPS=1 at 7 work here John?

An LPS-1 will probably work with this. BUT the blocking of leakage from other devices on the network ONLY works if you ground the negative of the supply feeding the switch. The LPS-1 is specifically designed so it does NOT ground the output. So if you use the LPS-1 you must also ground the output of the LPS-1 going into the switch.

 

The grounding of the negative of the supply feeding the switch is the critical part here, no matter WHAT that supply is.

 

Grounding the supply will shunt the high impedance leakage from other devices on the network, the transformers in these particular switches will block the low impedance leakage thus there is no leakage to modulate the clock in the switch and no leakage to transfer to your endpoint.

 

The transformers in other switches do not seem to block the low impedance leakage nearly as well as these do.

 

John S.

[JohnSwenson]

5 hours ago, austinpop said:

 

John,

 

Is grounding necessary if using an LPS-1 to power the switch?

YES, the grounding on the negative of the supply feeding the switch shunts the high impedance leakage coming from the network. So if using an LPS-1 you must ground the OUTPUT so the negative going into the switch is properly grounded.

 

John S.

[JohnSwenson]

5 hours ago, austinpop said:

 

Ah - you mean the SMPS energizing supply for the LPS-1 - aka Meanwell?

 

Also, @JohnSwenson - do you know what the FS105/FS108 are doing that is unique to suppress leakage through the transformers in the signal path? 

No I don't know what is special about these. Someday I MIGHT look into that, but it is complicated by many of these switches using magnetics that are very hard to find data on. The large companies frequently get custom magnetics from manufacturers in China making this task almost impossible.

 

John S.

[JohnSwenson]

6 hours ago, thyname said:

 

Thanks!

 

This one?

 

https://www.amazon.com/NETGEAR-ProSAFE-FS108NA-8-Port-Ethernet/dp/B00002EQCS/ref=sr_1_1?ie=UTF8&qid=1508161224&sr=8-1&keywords=netgear+switch+fs108

 

Then, either:

 

1 - use a 12v linear power supply, or

2 - do the grounding think on existing power supply it comes with as @JohnSwenson describes

 

Correct?

 

Then since I am using an sms-200 (soon to be upgraded to either ultraRendu or sms-200ultra), the clocking issue it taken care of by these streamers / endpoints?

 

Thanks!

 

3 hours ago, toetapaudio said:

 

https://www.computeraudiophile.com/forums/topic/35191-review-dc-power-supplies-for-aqvox-audio-grade-switch/

 

The clocking part of this is a bit unknown at this point. I am currently working on the analysis of this, which means I have to build some of my own test equipment.

 

At this point I'm not ready to give full blown details on this, but preliminary results are indicating that clocking of any data stream coming into a digital device brings along the phase noise of the clock used to produce that stream. Packet systems such as Ethernet and USB complicate this dramatically because the data comes in packets, in between the packets there is no data to pass clock phase noise. Note that phase noise is another way to look at jitter, I'm NOT talking about amplitude noise here.

 

The implication of this is that putting a very low phase noise clock on the last switch is not sufficient. The effect of the phase noise of whatever else is going into the switch also makes its way into the clocking of the switch. So just improving the local clock helps, but is not all there is to this. Ideally you should get rid of the clock influence from other sources as well.

 

Please don't ask for details about this, I have a LOT more research to do before I'm willing get into more detail.

 

John S.

[rickca]

@JohnSwenson why don't they make most SMPS with negative output grounded in the first place?  Is there a safety or cost issue?

 

[tapatrick]

On 10/15/2017 at 5:54 PM, Johnseye said:

...It has a PCIe slot so I can use a tx-USBexp.

Hi @Johnseye does the tx-USBexp only come with PCIe slot, or do you know if there is a PCI version? I'm not familiar with hacking inside PCs and am considering upgrading my Antipodes DXe which has the older slot..

[JohnSwenson]

1 minute ago, rickca said:

@JohnSwenson why don't they make most SMPS with negative output grounded in the first place?  Is there a safety or cost issue?

 

Grounding the output opens the possibility of a good old fashioned ground loop (magnetic induction from hot wires to ground wire causing voltage difference between branches of the electrical wiring or long distances on the same circuit). But not grounding lets the high impedance leakage pass through to the output.

 

Nobody else even seems to be looking at high impedance leakage, I didn't even know about it until two months ago. It is so high an impedance that normal test equipment shorts it to ground and you never see it. The problem is that its effects ARE showing up in audio systems (not all and not in the same way in all systems, of course it can't be anything simple). I had to build my own test equipment to even see it.

 

A good part of the problem is that almost all the original work on leakage currents took place many years before the advent of SMPS so they were just looking at linear power supplies, which don't have the high impedance leakage. Its a fairly recent issue, significantly exacerbated by computers and computer networks involved in our audio systems. (since these almost always use SMPS)

 

John S.

[austinpop]

35 minutes ago, JohnSwenson said:

YES, the grounding on the negative of the supply feeding the switch shunts the high impedance leakage coming from the network. So if using an LPS-1 you must ground the OUTPUT so the negative going into the switch is properly grounded.

 

John S.

 

I feel like I'm hearing conflicting things. At the risk of sounding dense, John, please help me understand. In my case, the chain is:

• AC mains > Meanwell SMPS (7.5V) > LPS-1 (7V) > switch

Should I ground the output of the Meanwell, the LPS-1, or both?

[rickca]

7 minutes ago, tapatrick said:

Hi @Johnseye does the tx-USBexp only come with PCIe slot, or do you know if there is a PCI version? I'm not familiar with hacking inside PCs and am considering upgrading my Antipodes DXe which has the older slot..

You could use a tX-USBhubEX instead of the tX-USBexp.  SOtM used to make a tX-USB which I think was a PCI card.  You can read about the differences between tX-USBexp and tX-USB in the FAQ on this page

https://www.sotm-audio.com/sotmwp/english/portfolio-item/tx-usbexp/#toggle-id-1

[auricgoldfinger]

9 minutes ago, austinpop said:

Should I ground the output of the Meanwell, the LPS-1, or both?

 

@JohnSwensonMy question, exactly.  Plus, how does one ground the output of the LPS-1?

[JohnSwenson]

7 minutes ago, austinpop said:

 

I feel like I'm hearing conflicting things. At the risk of sounding dense, John, please help me understand. In my case, the chain is:

• AC mains > Meanwell SMPS (7.5V) > LPS-1 (7V) > switch

Should I ground the output of the Meanwell, the LPS-1, or both?

To get the full advantage of using the FS105/FS108 you need to ground the output of the LSP-1 (or any other power supply you use). Grounding the INPUT to the LPS-1 will not make any difference.  You can do it if you want to, but it will not improve anything in this scenario.

 

John S.

[JohnSwenson]

2 minutes ago, auricgoldfinger said:

 

My question, exactly.  Plus, how does one ground the output of the LPS-1?

The same way as any other supply, just use one of the methods shown in the SMPS grounding thread, but in this case apply it to the output cable from the LPS-1 rather than an SMPS.

 

John S.

[tapatrick]

12 minutes ago, rickca said:

You could use a tX-USBhubEX instead of the tX-USBexp.  SOtM used to make a tX-USB which I think was a PCI card.  You can read about the differences between tX-USBexp and tX-USB in the FAQ on this page

https://www.sotm-audio.com/sotmwp/english/portfolio-item/tx-usbexp/#toggle-id-1

Thanks @rickca I will check this out. My Server has the older tx-usb which is indeed a PCI card, I'm considering the newer version combined with one of the sCLK boards....

[Confused]

50 minutes ago, JohnSwenson said:

YES, the grounding on the negative of the supply feeding the switch shunts the high impedance leakage coming from the network. So if using an LPS-1 you must ground the OUTPUT so the negative going into the switch is properly grounded.

 

John S.

I have to admit I am not 100% clear as to which output this refers to.  Let’s say I can interpret this in a couple of different ways.  Would it be too much to ask for a sketch, diagram or maybe photograph to make sure this is clear?  

[austinpop]

3 minutes ago, JohnSwenson said:

To get the full advantage of using the FS105/FS108 you need to ground the output of the LSP-1 (or any other power supply you use). Grounding the INPUT to the LPS-1 will not make any difference.  You can do it if you want to, but it will not improve anything in this scenario.

 

John S.

 

Ahhh, OK.

 

My switch is the Zyxel GS108Bv3, but it has been modified by SOtM to accept an sCLK-EX input, and better regulators and capacitor.

 

It remains to be seen if the SQ of my configuration will improve with this technique, but my terminal blocks and AC plug are on order, and thanks to Amazon Prime should be here Wednesday. Seems like a fun tweak to try!

[tapatrick]

14 minutes ago, Confused said:

I have to admit I am not 100% clear as to which output this refers to.  Let’s say I can interpret this in a couple of different ways.  Would it be too much to ask for a sketch, diagram or maybe photograph to make sure this is clear?  

See here from the Grounding SMPS thread John mentioned with photos. I tried it on the input to my Aqvox switch and helped noticeably. Thanks once again John for another  simple and effective adjustment!

 

On 9/20/2017 at 3:27 AM, JohnSwenson said:

Fortunately there is a real easy - inexpensive way to do this, it doesn't take any complex knowledge, I'm calling this the power supply grounding adapter, here are a couple pictures:

 

 

This consists of three items and some wire. The yellow item is a three pin AC power plug (shown is the US model), the black parts are male and female DC barrel connectors with screw connectors, no soldering necessary! Amazon has a whole bunch of places selling these for CCTV cameras. The spec is 5.5mm outside and 2.1mm inside. Most you will see will be this spec. The + of the male is wired to the + of the female and - on the male goes to - of the female. Look at the close up picture, in order for the wire to go straight across one of the connectors has to be upside down. This is extremely important to get right. You can use many different types of wire for this, I used solid core 14AWG wire with the insulation stripped off.

 

A green wire goes from the ground pin of the AC plug to the - pin of one of the connectors, strip a little off and just stick it in with the wire going between the two connectors, use a screwdriver to tighten the screws, you are done.

 

The green wire does NOT have to be a heavy duty high power wire. The SMPS are already designed to be double insulated so the AC cannot show up on the DC output, grounding it does not pose any electrical threat. I just used some nice silicon rubber wire I bought on Amazon, but really any green wire will do.

 

You plug the output of the SMPS into the "jack" side, and the "plug" side goes into where you would have plugged the SMPS. The AC plug goes into the SAME power strip or duplex outlet where you plugged in the SMPS. This is very important to properly shunt the high impedance part of the leakage current. If it goes into a different circuit you can wind up making it worse.

 

[d_elm]

32 minutes ago, JohnSwenson said:

To get the full advantage of using the FS105/FS108 you need to ground the output of the LSP-1 (or any other power supply you use). Grounding the INPUT to the LPS-1 will not make any difference.  You can do it if you want to, but it will not improve anything in this scenario.

 

John S.

I grounded the output of the meanwell and it made a difference listening to Barbara Streisand screaming.  Then I moved the adapters to ground only the output of the LPS-1 and Barbara was not listenable.  Adapters are now back on the meanwell.  Perhaps I should make more adapters and ground both Meanwell and LPS-1 ?

[Confused]

@tapatrick thanks for the pointers, exactly what I needed,  it is appreciated!

[ElviaCaprice]

2 hours ago, JohnSwenson said:

 

The clocking part of this is a bit unknown at this point. I am currently working on the analysis of this, which means I have to build some of my own test equipment.

 

At this point I'm not ready to give full blown details on this, but preliminary results are indicating that clocking of any data stream coming into a digital device brings along the phase noise of the clock used to produce that stream. Packet systems such as Ethernet and USB complicate this dramatically because the data comes in packets, in between the packets there is no data to pass clock phase noise. Note that phase noise is another way to look at jitter, I'm NOT talking about amplitude noise here.

 

The implication of this is that putting a very low phase noise clock on the last switch is not sufficient. The effect of the phase noise of whatever else is going into the switch also makes its way into the clocking of the switch. So just improving the local clock helps, but is not all there is to this. Ideally you should get rid of the clock influence from other sources as well.

 

Please don't ask for details about this, I have a LOT more research to do before I'm willing get into more detail.

 

John S.

Very good, thanks John.  This supports the findings on the simplifying of the audio stream and making that path as short as possible with good clocking throughout the stream.  As we have conjectured and Roy has tested, against trifecta, it would appear that regardless of how one tries to clean the audio stream outside the server, that some influence from poor clocking in the server has an effect on SQ.  Thus, addressing the poor clocking on the mobo with the sCLK-EX has a great effect on final SQ.

[rickca]

On 10/15/2017 at 11:34 AM, austinpop said:

The dCS network bridge is intriguing on that score, as it is priced at a point comparable to what I've eventually spent on my trifecta medley.

Another interesting option is the Bricasti M5 Network Player ($2400).  I particularly like that it works with A+ V3 like the Sonore streamers.  A+ is important to me for its excellent Qobuz/TIDAL integration.  The M5 also has an integrated LPS and is Roon Ready.

[austinpop]

3 hours ago, d_elm said:

I grounded the output of the meanwell and it made a difference listening to Barbara Streisand screaming.  Then I moved the adapters to ground only the output of the LPS-1 and Barbara was not listenable.  Adapters are now back on the meanwell.  Perhaps I should make more adapters and ground both Meanwell and LPS-1 ?

 

Or you can go back to "The Way We Were."

 

[rickca]

8 minutes ago, austinpop said:

I grounded the output of the meanwell and it made a difference listening to Barbara Streisand screaming.

How about Celine Dion?

[flkin]

If my Trifecta power supply (sps-500 and LPS-1's Linear Power Supply) are both connected to an isolation transformer with floating secondary, how would one ground the negative DC leg of the output from both?

 

The floating isolation transformer doesn't have a ground.