dedicated mains earth

[acg]

So if we have USB properly isolated...ethernet properly isolated...power properly isolated (LPS) then there is not really too much more isolation work to do other than obsessive compulsive amongst us to attack RFI.

Anthony, the more time it is to now attack EMI !
So I am sure it is high time to get myself a decent meter for that. We can suspect EMI to be all over the place with all this isolation stuff and it should be relatively easy to now attack *that*. But first we must see it ...

Regards,
Peter

There are a gazillion meters out there for measuring all kinds of stuff.  Is there any particular unit you have in mind?  I am keen to emulate on this side of the world.

[acg]

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Hi Anthony, yeah I could do this... and I will when I have time. Certainly with my current setup (both music and audio PCs on same 'dirty' line) I simply don't see the point in having an expensive linear PSU for the audio PC.

But what I will try first is putting the audio PC (with linear PSU) on the 'clean' dedicated audio line. I can't imagine how this could improve the SQ... but I can see how it might make it worse - no matter how good the linear PSU (and I think the Teradak is pretty good), it's still a PC that you've introduced onto the 'clean' line.

Mani.

 

One thing that I can't place though is the operation of the RAM-OS in your system.  How has it worked for you?  It has worked very nicely for me but if it made a difference for you then something else must be at work given the arrangement of your components, the supposed operation of the Intona and the reason for development of the RAM-OS being to reduce PC noise but reducing current draw in the PC.

[manisandher]

More later Anthony, but for now I'll just say that I had the whole system running off the PP2000 when I first tried the Intona. I only received the PS Audio P10 last week and that was when I set up the 'clean'/'dirty' AC lines.

It'll be trivial for me to compare RAM vs. HDD with the setup as it currently is. I'll do this this evening. And if there is no difference, I'll start playing around with the settings in XX, starting with SFS.

In a way, after all these years of XX development, I really don't want the Intona (along with a dedicated AC mains circuit) to be the 'holy grail'. But if it is, it is...

Will be back with my thoughts later this evening.

Mani.

[boleary]

One thing that I can't place though is the operation of the RAM-OS in your system.  How has it worked for you?  It has worked very nicely for me but if it made a difference for you then something else must be at work given the arrangement of your components, the supposed operation of the Intona and the reason for development of the RAM-OS being to reduce PC noise but reducing current draw in the PC.

I hesitate to jump into a thread where I am not very knowledgeable, but here's an observation/theory I've had about why the RAM-OS sounds so fantastic: when running the OS from RAM both electrical and vibration induced noise are eliminated. Prior to my RAM-OS I've had my spinning HD and fanless Seasonic PC power supply outside of the PC case on isolation footers. This step has always had a significant impact on SQ. When I first used the unplugged RAM-OS there was something very familiar with the sound that I believe has something to do with not having a spinning HD inside of the PC case. However, unplugging the RAM-OS went one step further to improve SQ because now electrical noise was also reduced. Today only my PC power supply is outside of the case and I make very specific adjustments to the sound with the type of footer underneath it.

One more observation: maybe it's my imagination, but try putting a 3.5 HD, or some other object weighing a couple of pounds, on top of your featherweight Intona. Seemed to solidify the sound a bit here.

Brian

[PeterSt]

There are a gazillion meters out there for measuring all kinds of stuff.  Is there any particular unit you have in mind?  I am keen to emulate on this side of the world.

Anthony, by now I see what you mean !!

And that is only when looking at the meters not even knowing what they exactly measure.

When I try to find out that part (what do we want to measure) then besides running into Gamma rays and such, this looks to be relevant :
http://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
but doesn't "connect" to those meters I see passing by. For example : http://www.lessemf.com/faq-mete.html (this site is way larger than it seems).

The only thing useful I came up for myself so far, is that there's a difference between the radiating device that will require near field measuring (e.g. hold meter close to Intona to find its radiating levels and eliminate other radiation sources) and the badly influenced receptor (like DAC) which requires far field masuring (hold meter near DAC and see what's going on for e.g. a radiating Intona).
And then I am afraid I don't even make myself clear.

But it starts with WHAT to measure. That requires what's bad for radiation. And that's a bit more hard to investigate because most is about human body (penetration) stuff or ghost hunting otherwise.

Anyway I feel another project coming !

Peter

[Diede]

Thank you Peter (and others) for your elaborate response, really helpful.

A few more questions come to mind:
What about using an optical HDMI or DVI connection and leaving the monitor connected to the Audio PC, thus avoiding going via RDC/RDP?

What about using shielded cable such as this one: http://www.conrad.be/ce/nl/product/1031706/Stuurkabel-OeLFLEX-CLASSIC-110-SY-3-G-4-mm-Grijs-Transparant-LappKabel-1125503-50-m?ref=searchDetail
and connecting the shield only on one side to the dedicated earth?

I’m really interested in learning more about those ‘line level isolators’ which would allow me to put the amps on the house mains.

Best regards,
Diede

[acg]

A few more questions come to mind:
What about using an optical HDMI or DVI connection and leaving the monitor connected to the Audio PC, thus avoiding going via RDC/RDP?

What about using shielded cable such as this one: http://www.conrad.be/ce/nl/product/1031706/Stuurkabel-OeLFLEX-CLASSIC-110-SY-3-G-4-mm-Grijs-Transparant-LappKabel-1125503-50-m?ref=searchDetail
and connecting the shield only on one side to the dedicated earth?

I’m really interested in learning more about those ‘line level isolators’ which would allow me to put the amps on the house mains.

Best regards,
Diede

Hi Diede,

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...and even if the monitor is one one ring and the AudioPC on another they are still electrically connected by the cable between them, so the noise has a direct path.  It is easier to galvanically isolate ethernet and usb (now) than HDMI/DVI/VGA etc., so when it comes to the AudioPC and a screen "you gotta keep 'em separated".

Cheers,

Anthony

[Stanray]

Today only my PC power supply is outside of the case and I make very specific adjustments to the sound with the type of footer underneath it.

Hi Brian,

Could you please elaborate on the footers you use underneath the psu?

I was planning to do something similar and even put the psu on the floor, but then I have to find/make longer wires.

Regards,
Stanley

[christoffe]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

[acg]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

The current version of XXHE (correct me if I am wrong Peter) does not shut down the monitor, it merely puts up a black wallpaper and the monitor is 100% still connected.



Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

[christoffe]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

The current version of XXHE (correct me if I am wrong Peter) does not shut down the monitor, it merely puts up a black wallpaper and the monitor is 100% still connected.



Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

Hi,

maybe I'm wrong  I take another route via the "energy saving options", and the monitor goes into the sleeping mode, and then the screen is dead.

I'm not convinced with the route tablet - server PC - audio PC, because I made different experiences. Shutting down ALL network services at the audio PC creates the best SQ on my system.
Maybe the last comment is better to discuss in a different thread.

Joachim

[manisandher]

It'll be trivial for me to compare RAM vs. HDD with the setup as it currently is. I'll do this this evening. And if there is no difference, I'll start playing around with the settings in XX, starting with SFS.

Well, I actually started with the latter and played around with some SFS settings. Recently, I've settled on SFS=0.07 - really nice sound with absolutely zero hiccups. I set SFS to 10 and listened. The sound definitely changed exactly in line with what we'd expect - it thickened slightly, became flatter and lost the lovely sparkle.

So, SFS still matters, even with my two AC mains lines and galvanic isolation between them via the Intona. Exactly how SFS can still make a difference is totally beyond me.

Via the mains? Well, there is no way noise could be travelling back from the PC, through its linear PSU, through the PP2000 on-line battery regenerator (i.e. batteries always connected to the inverter), through the house's consumer unit, back to the AC meter, through the dedicated low impedance AC line, through the dedicated hifi consumer unit, through the 15KVA isolation transformer, through the PS Audio P10 regenerator to the NOS1a. No way!

Via RFI? Well, the NOS1a sits in my little 'vinyl ripping studio' in the basement. This has a Faraday cage built around it (or as close to a real Faraday cage as I could get - the mobile phone signal cuts out as soon as I enter). The everything else sits outside this 'studio'.

Through the USB connection? This seems the only explanation to me. So, perhaps the Intona and the NOS1a are still not totally immune from USB noise?

Thoughts?

Mani.

Edit: Something I forgot to mention but that may be important is that the difference between SFS=0.07 and SFS=10 was much less than I expected.

[Diede]

...and even if the monitor is one one ring and the AudioPC on another they are still electrically connected by the cable between them, so the noise has a direct path."

Anthony

Hi Anthony,

Thank you for sharing your experience.

For clarification, how do you see the monitor and PC electrically connected if we use an optical HDMI or DVI connector?

Especially if they are on a separate earth, and possible even on a different phase (I have 3 phases in triangle at my house).

Thanks,
Diede

[manisandher]

I just tried Peter's original idea:

Audio Ring
- Audio PC as lean as possible and without monitor
- D/A Converter (connected to Audio PC)
- Power Amps (preferably no pre-amp)
- (connection to Music Server PC via direct LAN cable)

House Ring
- Music Server PC
- Monitor
- When wanted, external disks with switching supplies
- (Connection to Audio PC via direct LAN cable)
- Router, Modem, etc.

So essentially, I just moved the audio PC from my 'dirty' mains line to my 'clean' mains line to achieve pretty much Peter's exact setup. And the sound changed for sure... in very much the same way as increasing SFS. It became fuller, but also flatter, less dynamic and with less sparkle. The 'groove' was missing.

There is no doubt that I prefer the sound with the audio PC on the 'dirty' line, keeping the 'clean' line solely for the NOS1a and Orelo speakers, with, of course, the Intona doing the duty of galvanically isolating the NOS1a from the audio PC. (Without the Intona, this is a massive 'no-go' as potentially nasty ground loops would be created all over the place.)

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Well this now becomes very important IMO. With the audio PC on the 'dirty' line, does one really need an expensive linear ATX PSU? Might a good SMPS ATX be just as good, or even perhaps a little better? I will definitely try this... but not for a week or so at least. The only ATX SMPS I have here has malfunctioned. I'm sending it back to Seasonic because it's still within its 5-year warranty, but don't expect a repaired unit to be sent back to me for a while. (Also, I'm working out of the country all of next week.) Will report back as soon as I have a chance to try things.

Meanwhile, if anyone else has two *isolated lines, perhaps they could try my setup and report their thoughts.

Mani.

* Of course, my AC earths are not truly isolated - they can't be as there is literally 'earth' between them. I've taken some measurements between the shield of the input Clarixa to the Intona and the shield of the output Clarixa from the Intona. The DC resistance is 3.7MΩ. The potential difference is 0.345V. If there were no Intona in place, the current that would be flowing through the Clarixa shield would be 9e-8A. (Edit: I guess this is the DC flowing through the Intona.)

[christoffe]

Found this:

http://www.acoustica.org.uk/t/earth.html