iUSBPower supply

[Flecko]

I have just receifed an ifi micro iUSBPower supply. It is 200$ and it can be connected between the PC and the DAC. It has a ultra low noise power supply for the USB input of the DAC and isolates the PC from the DAC.
The effect is clearly hearable and far from subtile. Digital brightness is removed, it sounds more threedimensional and the bass hits like a hammer. A further advatage is, one can connect a notebook and hopefully will get the same sound from it as from a PC. I will try this in the next days and see, if there is still a sound difference between PC and notebook as a source.

[Nick]

I have just receifed an ifi micro iUSBPower supply. It is 200$ and it can be connected between the PC and the DAC. It has a ultra low noise power supply for the USB input of the DAC and isolates the PC from the DAC.
The effect is clearly hearable and far from subtile. Digital brightness is removed, it sounds more threedimensional and the bass hits like a hammer. A further advatage is, one can connect a notebook and hopefully will get the same sound from it as from a PC. I will try this in the next days and see, if there is still a sound difference between PC and notebook as a source.

Hi Flecko,

The ifi psu It looks interesting and sounds like it can be heard :-). Nice specs on the 5v psu.

Which dac are you using the ifi box with ?

Cheers,

Nick.

[PeterSt]

Flecko,

All my sensors would stick out with such a description and I would be the MOST careful. Your description tells me 100℅ *more* noise. If it works for you, well, then it works ...

Regards,
Peter

[AlainGr]

Peter,

I am not sure if yout remark is aimed toward the addition of the iFi iUSB power supply, but my experience with it was different when I was using my Bryston BDA-1 DAC with an Audiophilleo. While the sound had no edges, I felt that the bass was a littlt "thinner" than the Aqvox I was using prior to the iUSB power supply. The Aqvox (first), then the iUSB were used to power the Audiophilleo USB to SPDIF then. Now that I have the NOS1, I use the iUSB to power my external SSD drive.

Have you seen the specs about the iFi iUSB ? It seems that it is even quieter than a battery...

Alain

[PeterSt]

Alain,

Thinner bass can be a good sign. Can be, not necessarily. But especially more bass in combination with less 'edgy' highs is not a good sign at all (highs are easily filtered). But you can do us a favor; please try the iUSB on your NOS1 and let us know what you perceive from it.

And btw, the combination of 'filtering' - somewhere in the text but possibly out of context - plus 'remove the USB noise' ... USB noise is 8KHz and 16KHz (for the audio band part). So, careful ...

Peter

[PeterSt]

And btw, the combination of 'filtering' - somewhere in the text but possibly out of context - plus 'remove the USB noise' ... USB noise is 8KHz and 16KHz (for the audio band part). So, careful ...

This makes no sense after all. We are in the 'data' domain, and 8KHz etc. can be filtered all right. Well, were it for in-band audio that is.
But now I'm actually wondering how in the world the data signal - which transfers at a rate of 8000 times per second can be filtered out, because we'd be filtering the 'signal strength'.
Btw keep in mind please, I am talking async USB here.

One other mistake I made - at least in my mind - is that the NOS1 doesn't use USB power at all, so (Alain) there the iUSB can not help at all; you'd have to bypass the internal supply first - which is 3.3V ...

Lastly, I would like to see 0.1uV noise from async USB - IOW hard to believe because no signal(strength) would be there. Well, sort of, because it is more complicated (it really is about the current needed for the data packets transfer).

Peter

[AlainGr]

Yes Peter, this was my thought (that the NOS1 did not require any use of the USB power for powering something) and the iUSB does not filter anything on the data side.

With the Audiophilleo the iUSB was very useful...

I could be wrong but I think that the simpler the path between the PC and the NOS1, the better (for the NOS1 at least).

Alain

[Flecko]

Which dac are you using the ifi box with ?

I use a North Star Extremo DAC with a North Star USB->I2S Interface. The interface draws its power from USB, hence a recognizable effect (good or bad) of the ifi USBPower is plausible.

Thinner bass can be a good sign. Can be, not necessarily. But especially more bass in combination with less 'edgy' highs is not a good sign at all (highs are easily filtered)

Thanks for moving the post to a new thread. It is more appropriate that way.
The bass thing could be because of the record I was hearing. I didn't heard it for a while. Maybe my new amplification was contributing here. Later I heard a record where I was expecting this new kind of bass but the bass was normal. I would take back this statement until I have done further listening tests. Whats clear is, the highs are less sharp and there is a better "order" in the soundstage. But I do not want to fool myself. I am still suspicous if everything is better or only some parts of the sound are different.
This kind of sound I am hearing, reminds me on my old usb-spdif interface, which had an own power supply. It was less sharp and had a more threedimensional sound (but other thechnical flaws and that was why I replaced it)

One other mistake I made - at least in my mind - is that the NOS1 doesn't use USB power at all, so (Alain) there the iUSB can not help at all; you'd have to bypass the internal supply first - which is 3.3V ...

It still makes sense to me. A negative effect on the signal itself should be isolated that way. If you like Alain to make the experiment, I am looking foreward for your findings!

[AlainGr]

It still makes sense to me. A negative effect on the signal itself should be isolated that way. If you like Alain to make the experiment, I am looking foreward for your findings!

Oops, I would not go that far Too much risk of breaking something for the non DIYer that I am....

For sure though, the iUSB was good with the AP2 and I expect that any component normally taking its power from a PC USB port will certainly get better with the iUSB. This was audible, even for the "not that sensitive" hearing guy that I am

Alain 

[Flecko]

Oops, I would not go that far Wink Too much risk of breaking something for the non DIYer that I am....

Sorry, I didn't want to push you into opening the NOS1 and disconnect the power supply... I meant just use it with the NOS1 as it is and see what happens. No problem if you do not like to do so. Thanks for your sharing!

[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

[AlainGr]

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

[AlainGr]

Oops, I would not go that far Wink Too much risk of breaking something for the non DIYer that I am....

Sorry, I didn't want to push you into opening the NOS1 and disconnect the power supply... I meant just use it with the NOS1 as it is and see what happens. No problem if you do not like to do so. Thanks for your sharing!

No problem Since my English is quite limited, my interpretation was wrong The NOS1 made such improvement that at this point I did not felt it was useful to try it, but I will.

I have 2 problems though: my hearring abilities does not really help me (and this is quite a problem when I try to verify if something added or substracted something in the SQ) and I tend to get things that "could" improve something. So now I have a "collection" of components: Aqvox (not in use for the moment), iUSB, Sotm USB 3 PCIe card and the last (just before I bought the NOS1) is the Ultrafi Aubisque USB filter... Not to mention the recent acquisition of the PCIe XSound card (re:http://www.phasure.com/index.php?topic=2551.0).

I have yet to find a few songs that would help me distinguish the different properties of these components alone, then eventually combine them...

This struggles with my perception that a signal path should be as simple as possible, but you don't know if something will be of some help before you try it...

Regards,

Alain

PS: About the Aubisque, I had to order also a 90 degrees angled USB adaptor to allow the connection with the NOS1, since it was not possible to connect without risking to damage the connection itself (the USB cable crosses the analog interconnects and the Aubisque + the end of the USB cable make this too difficult).

[Flecko]

...all should be better, not only one part while others gets worse.

Yes. If not, something is wrong.

The NOS1 made such improvement that at this point I did not felt it was useful to try it, but I will.

I have 2 problems though: my hearring abilities does not really help me (and this is quite a problem when I try to verify if something added or substracted something in the SQ)

A good and save way to find out if there is an improvement is to just live with the new device for a while. It takes more time than instant A-B testing but after some days of listening to only one setup you will immediately recognise the difference if you go back to the old set up. I would suggest use the motherboard usb-out and the ifi USBPower for a while and then remove it from your audio chain.
Another good indicator is the very first impression. So the first subtle feeling you get, right after installing and hearing the new device for the first seconds. This feeling most of the time turns out to be true for me. After an hour of listening and maybe A-B-ing one might to tend to mistakes, like thinking the bass has more punch as I did.

[juanpmar]

The only USB device connected to my computer (besides the NOS1) is the external Playback drive, I´ve found that I get the best sound when I connect this drive to the TeckNet USB 3.0 PCI Express Card which at the same time is filtered by the ApeXi Power Filter Card. I´ve tried all the mb USB ports and none have bettered the sound I get connecting it to the TeckNet card. As this Playback drive is externally powered and it is connected to the TeckNet card with an USB 3.0 cable I wonder if I could use the iFi-audio iUSB to power that connection between the Playback drive and the TeckNet card and if that would have any influence in SQ. The problem I see is that the iFi-audio iUSB is just for USB 2.0.

Juan

[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