Hi Paul,

There is a difference with the 'USB ground disconnection' in the current discussion. This is about the isolation from the power supply (and chassis) by removing the connection of the black wire from the USB receptacle at the power supply's end.
In this situation, the USB cable's shield remains connected to the USB circuitry at both sides.

This might not matter to you at all, but I thought it worth noticing.

regards, Coen

Great work Anthony!

I think we may conclude that the Loom does not provide for enough grounding connection to make it work without some annoyance. This must have to to with an uncertain ground potential between the card and the motherboard.

Now what if we could actively FULLY isolate the PCIE card like with some fast opto couplers....hmmm...

I wondered: why didn't you experiment with the power amps PE disconnected? Than there will be no more (redundant) ground path via the power amps. Anyway this would mimic my setup (as an alternative to 2).

regards, Coen

Mystery ground connection left aside, I do see some similarities between my setup and anthonys.

Both make use of a fully connected usb interface, that is including the usb ground.

The other is the 'single' ground. If I am correct, the pe acts as ground for Antonys setup (like a star earth) and in my setup the PCs pe is the only one connected (think bus earth). This reasoning is valid only if on the pc side the pci-e ground is connected to the chassis which is connected to the pe wire and the usb groundpoint in the nos1 is connected to the case (wich is connected to pe by 'the other' wire).

I think we are hearing a very similar improvement though through quite different methods.

Regards.

So, this all makes sense after all.

When Anthony isolates (or disconnects) the NOS1 PE (at the power cable/connector end) it does not work anymore. And be careful with static!

regards, Coen

Good for you Stanley!

If I read this well the sound stage did shift to the right !

Regards, Coen

P.s. And for Juan of course who experienced about the same!

Hi Anthony,

Thanks for the elaborate instruction.

In the diagrams I see that the data receive is not dc coupled, but the data transmit and bus clock are. Likely the are decoupled at the end of the bus.

So we can conclude that the NOS1 case connection is crucial for the ground reference. Do you have the PE connected to power earth for both the pc and NOS1? Or maybe the amps PE?

It seems like a favourable grounding scheme to reference ground at the end of the chain.

Regards, Coen

Anthony,

If you unplug the NOS from the USB 3 card, what is the voltage difference between the card (screw/parker of the bracket) and the PC's housing?

I would guess it is about 0V. Somewhere the circuit must ground itself on one or more of the active pins.
The differential inputs on the PCI-e USB chip are not galvanically decoupled from the motherboards PCI-e lines by x-formers or opto couplers. That means that the USB chip does not really allow for a 'large' common potential (like floating found) ; they must be just two single ended inputs (and feed lines).
Btw in this setup you still retain all the noise suppressing and improved transfer properties of balanced transmission lines.

Anyway I think the effort of reducing the number of possible ground return path is worth the pursuit. But this setup feels one step too far, it could potentially blow up your south bridge.

regards, Coen

Hi Pedal

This is of course true. Naturally I am referring to bass heavy instruments that I expect to be in the centre. Like a soloist's cello or practically most pop and jazz Rhythm sections.

Maybe it has always been a little on the right side but I did not notice because of the swollen sound images. OTOH I hear it typically with 1.168 so it could be an unintended feature (bug/side effect) of this version.

regards, Coen

Ok sound quality changes.

With the NOS1 side still connected and PC unconnected, there is a sharpness in the highs and the soundscape feels somewhat unstable. That is that images seem a little inflated and wandering, having lost their focus. Because of this 'bigness' you are not able to hear all details, especially on the background only 'hints'  of them remain. Highs also seem to not have a lot of nuance.
Nevertheless the sound breathes and has a natural character.

Now with the NOS1 side also disconnected, focus returns, and how! So much so that many 'background' details suddenly become clearly audible. I also hear far more into the sound ('depth' if you will) scape.
Loudspeakers have disappeared. Like Vollenweiders harp playing full power in the room. Another example is the brush that is used on drums on the Miles Davis' Kind of Blue album. You can now clearly hear it rotating over the drum's skin while the other (loud) instruments play their respective parts. There is a lot more nuance to be heard in the playing of the instruments. I almost envisioned them moving wrt the microphone. On that same album the piano has the kind of sound I recognize from the LP, rich playful and drowned in its own reverb.
Depending on the album the music stays between the speakers or moves out of them. In any case there is a natural lightness that I recognize from live performances.

So far I have not heard ill defined or sharp highs. The low end is just there like it fits, but it is not very prominent. Yet I have to start tuning the settings. They were just semi-random that was from my experiments with re-grounding the USB cards brackets.

And there is the matter of the right channel tilt. This is less noticeable in the midrange, but bass heavy instruments are constantly more to the right.

regards, Coen

Yes. from one to both sides isolated, windows 7 only. One MAJOR improvement.

Windows 8 has been a waste of time sofar.

regards, Coen

Oh,

I almost forgot about the imperfection. The sound was tilted to the right again. It did not annoy me (yet), but this is an area of concern. This must be something about 1.168 and Q setting because now I am listening to win7 or it is somewhere else in my system. We'll see....

regards, Coen

On topic again:

Last evening I did some serious listening with an isolated USB card and the USB grounding wire in the NOS1 disconnected. I did not optimize settings or anything further.

I NEVER EVER has such good sound in my room. It was completely natural and I could not locate my speakers anymore. The amount of nuances is unbelievable. I tried a few tracks from albums of notoriously bad SQ and I suddenly could follow any instrument even a male/female background vocals were clearly distiguisable. Didn't even know they were there. Its like you can hear much further in the recording I had a vision of listening to a master tape.

Dynamics do not draw your attention away or make the sound to loud or uneasy. If it is there it sounds like it ought to, big, powerful, detailed and easy. Mind you this is with a 0.8W amplifier.

Pfeww

-end of rave-

Now next is spending some time with the settings and if time permits produce a vessel for the NOS.

regards, Coen

ok!

(misunderstanding: in my NOS1 the USB grounding was attached to the PSU board with a little screw not a bolt like the PE wire)

regards, Coen

The other runs at the power connector end of the right leg (fron facing) to a screw at the top of the right side of that leg....

regards, Coen

Hi Anthony,

Did you disconnect the chassis ground wires in the NOS1 like Peter suggested in the " best sound ever"  disconnected ground thread?

If you didn't its about the USB grounding wire from the USB receptacle to the PSU and the one from the PE to the chassis.

regards, Coen