iUSBPower supply

[AlainGr]

Hi Juan,

It would not be a good idea to use the iUSB for that purpose... Like you mention, it would be at the USB 2.0 speed (not good).

Alain

[Flecko]

If the hard drive is usb 3.0 you will lose perfomance. In how far that influences sound quality I can not say. I guess it will not be better. Usb 2.0 devices "should" normally work on usb 3.0 outputs but that is not always the case. If the ifi USBPower works the other way around and filters noise that is coming from the connected device, then maybe yes. But I can much more imagine that if the ifi USBPower works for Alain and his NOS1, than that is the place where it should be placed first.

[juanpmar]

Thank you guys!

Regards,
Juan

[AlainGr]

Well, I am still wondering how the iUSB would do any good when coupled with the NOS1... I would like to read what Peter will say about my questions a few posts back...

Alain

[Flecko]

Here is some merchandise blabla from ifi about the USBPower:

The IsoPower system is a completely new way to connect your USB audio device. There is the standard USB connection option; but with the upcoming iFi dual-path Gemini USB cable, our engineers developed the IsoPower system which offers the option to run separate power and audio data lines. You wouldn’t place interconnects and power cables together so why should the USB connection do it?

IsoPower eliminates any pollution between data and power lines. It keeps your USB audio data free from contamination and removes the USB Signal noise from the power supply lines, to enjoy the maximum performance from your USB audio device, unhindered.
 
Our engineers developed the advanced IsoEarth technology specifically for the iUSBPower. By breaking the noisy DC ground connection between the computer and your USB audio device, this further reduces the ground noise by a factor of 10. Your USB audio device can now operate in the cleanest environment possible; allowing your music to flow.

According to this you can break the ground conntection to reduce noise. Further you can transmit the data in a different cable than the power supply. This maybe could do some good, even if there is no power supply needed by the connected device.

[Flecko]

I have listened to the ifi USBPower for several hours now and just took it out again. The same impression as before: less bright, a little more three dimensional and a more accented bass BUT I am not sure anymore if this is better. With the ifi it sounds also more grainy and there is some air and midrange detail missing. I do not know if this is the same effect that made the sound of xx without "peak extension" sounds more fresh (which turned out to be distortions)? At least I have more doubts now that there is a real improvement. I will listen without ifi now for a while and see...

[Flecko]

I will send the ifi back. I listened to some difficult records (very subtile room informations) which I have listened this afternoon with the ifi. Without it, there is all the resolution and air I know from my system. With ifi drums sounds hard and wooden. My abolute admission Peter, that you got it right away, just from my description of the sound! At least I saved 200$ and my systems sounds better than before (All that air and information I can enjoy now)

[PeterSt]

What I meant with my 3.3V remark is that the bypassing would not work because the iUSB will not output 3.3V anywhere - only 5V. However, since the text also speaks of 'isolated' - which I tend not to believe - it is still worth a try with the NOS1. The effect of isolation is a bit unpredictable because it is in the data domain - not audio.
And when you try Alain, all should be better, not only one part while others gets worse.

Thanks ...
Peter

Peter, when you mention "data domain" as opposed to "audio", I am not sure how to interpret this ? Do you mean that "data" is the signal before its arrival in the dac, as opposed to "audio" being the signal after the DA conversion ?

Here is my limited understanding:
- The power coming from the pc is replaced by a cleaner one from the iUSB (like the Aqvox, but better).

- Since the NOS1 does not really uses this power, it would not  have any effect on the quality of the transmission at this point.

- The data is not isolated, unless the "Iso Earth" feature has a positive impact on the data by breaking the ground noise ?

Alain

Alain, apologies, I completely missed this post.

The data domain is where all is still normal computer data, like the audio file is when it is sent to the DAC in asynchronous fashion and where it can be error corrected.

Isolation can happen only through a transformer when the speed is low enough - but which it is not in the NOS1 case. Otherwise digital devices exist for isolation, but they carry a jitter figure themselves. Not good, but when in the data domain this should not matter. But everything matters, so I am not sure in this case.

Peter

[AlainGr]

Thanks

Yet I thought the iUSB only goal was to provide a clean power for components requiring the USB power ? There is also that "Iso-Earth" thing, but I am not sure if it is intended to stop potential ground loops ?


Alain

[AlainGr]

I experienced some problems when I first used the iUSB power supply with my USB cable (Mapleshade Clearlink 3 foot USB cable). Since the iUSB requires 2 USB cables, I was also using the 18 inch blue cable that comes with the iUSB. I could not use the following configuration: PC > blue cable > iUSB > Clearlink > Audiophilleo... Either there was no sound or after a few seconds I got "white noise".

I wrote to support at iFi-Audio and I was told that many "audiophile grade" USB cables do not have the correct impedance characteristics that is needed (90 ohm). Their suggestion was to use a standard USB cable instead.

With the Clearlink connected between the pc and iUSB and the blue cable between iUSB and the Audiophilleo, all was good. But I always wondered if using 2 cables + 2 more connections was a good thing or not. For this, the Aqvox way of doing things seemed better to me, even if the ripple figure was not as good as the one from the iUSB. 

With the NOS1, since there is not real need for power, I preferred not to use the iUSB. The simpler path, the better...

There is something that the iUSB brings with its "clean power". With it I can power a 2.5 inch SSD in an external case (it only requires 5V). I can also replace the power that is sent from my Sotm USB 3 PCIe card to the NOS1 (a USB > DC cable is also provided with the iUSB). I would like very much to have an external power supply that would feed my pc fans and another one for my music hard drive (external enclosure actually powered with a standard switching psu wall wart). My aim is to get rid of all the "contaminated" power that can affect other components and bring noise in the signal.

All of this brings me to a conclusion: XXHE and the NOS1 are BY FAR the 2 components that improved SQ to my system. There is nothing subtle about this. I don't write this because I am here in the Phasure forum. I can only state the obvious.

Alain