The iFi iUSB Power Supply - Neat Tweak & Upgrade for USB DAC

[Raym87]

While on the subject of cables, is there a requirement to use cables of a similar quality for the input and output of the iFI USB.

I'm currently using a Cardas USB from my Mac Mini into the Stello U3. Say I used this as output ( iFi to Stello), Would I need to get another of similar quality for the input ( Mac Mini to iFi). If that is the case then that raises the cost somewhat.

[ted_b]

iFi provides a generic blue "umbilical" (i.e short 18 inch USB cable from computer to iFi) which I'm using. I don't think anyone has "rolled" that side yet, but your point is well-taken.

[tubesound]

In addition to a USB cable, iUSB now comes with an USB to DC cable as well, which was talked about in earlier posts:

 

[Liam]

I received my iFI USB Power yesterday morning. Had a quick refresh with a few familiar tunes using the Aqvox USB power supply first of all and then connected up the iFI USB Power. Initially the ground was not lifted with the provided switch. The bass notes became more differentiated during heavy electric bass passages, the soundstage receded to a more believable and more preferred position and gained more dimension and inner space. The voices also found their appropriate new position within the soundstage. Glare was reduced and there was more sweetness to the upper registers, violins etc. On moving the switch to the ground lift position there were further improvements along the same lines.

 

I got a brainwave then and thought to myself could I ever have too much of a good thing, so I reconnected the Aqvox PSU and then connected the iFI USB cable to the output of the Aqvox connector? I perceived an increase in weight of the sound in general, but it seemed to be at the expense of characteristics I perceived as advantages with the vanilla iFI USB alone. For the moment at least I have reverted back to the iFI alone. Internet Radio via iTunes is also sounding particularly good today, even in another room from the system, being dynamic, crisp and musical from top to bottom. Recommended.

 

The company has announced that the first production run have been sold out, but Stephen at Select Audio who are the distributors for the UK and Ireland, and I think for part of Europe steered me in the right direction for a unit and told me that a number of his other dealers have stock also.

 

Oh and another thing. I made a posting above about the requirements of the USB input of the m2Tech Young dac. I can confirm that there was no adverse issue in lifting the ground with this dac in my system.

 

Edit: Weds. 19th, Dec. 2012.

Like I said above I perceived an increase in the weight of the sound with the Aqvox PSU in tandem with the iFI PSU, but what made me revert to the iFI alone was that with the increased weight there was a loss of transparency, stage depth and inner space. The soundstage also took a step forward and was less focused.

 

Nevertheless I liked the extra weight to the sound and wondered if I could tweak an improvement. Going through my head was to check if inverting mains polarity of the Aqvox might bring about any improvement. I quickly discovered that the earth connection and screen of the homemade mains cable I was using was unconnected. I had done that when it was formerly used with a CD player, and forgot to restore it when I sold the CD player with original lead. Slap on the wrist...ouch! The outer screen on this cable is connected to ground at the mains socket end only, and with the screen and ground connection restored I reintroduced the Aqvox PSU immediately at the USB output of the Mac Mini, as before, and followed with the iFI PSU. For those unfamiliar with the Aqvox PSU it works by causing a discontinuity of the USB power from the computer and replacing it with cleaner power from it's linear supply. However, the claimed noise suppression of the Aqvox is not as good as that claimed for the iFI PSU. It does mean though that the iFI is offered a cleaner supply than otherwise and the data within the iFI supplied feeder USB cable is possibly subjected to less power noise. There is continuity of ground through the Aqvox PSU USB adapter and the iFI offers the option of raising that also. I wonder if a USB cable which split the power and data cables apart to feed the iFI might bring benefit.

 

This time it was a different story. Again the music gained in weight and richness, but now the image retreated, as preferred, and formed a deeper, wider soundstage and the space into which performers played was more obvious. Another layer of glare was removed with the increase of timbre. I think now that the two PSU will run in tandem as standard, though I usually like to listen to the system following any tweaks for a week or so before coming to more settled conclusions.

 

For anyone who has already got an Aqvox PSU I feel it is worth checking out before deciding on parting with it or not. Perhaps for the benefit of other forum members reporting on your own findings would be of interest and I would certainly like to know how you get on if you try it.

[wisnon]

As I reported, the AR 1.0SP works fine (great blackness, great depth, a little too lean for me), and a buddy says the Kingrex u-art works (not sure which one).

 

"The reason why some "handmade" USB Cables do not work with the iUSB is simple, they are not of sufficiently accurate impedance.

 

With a single short cable this is less damaging and the makers of such contraptions often can almost get away with murder.

 

However, as with the iUSB Power you in effect couple two cables together. In this case, if one cable has correct USB Impedance (e.g. the short blue tail included in the box) and the other has a different impedance additional reflections (on top of those at both ends of the cable) will be generated.

 

And even a robust system data transmission system like USB will eventually experience packet loss...

 

Sadly, the more expensive and exotic a cable is the less likely it is to be mass produced on machinery made for precisely mass producing USB spec cables.

 

It's not that people do not know how to make better USB cables, the problem is modifying standard cables for improved performance in ways that are compatible with industrial production methods and then finding someone to make such cables in moderate quantities."

[Liam]

"The reason why some "handmade" USB Cables do not work with the iUSB is simple, they are not of sufficiently accurate impedance.

 

With a single short cable this is less damaging and the makers of such contraptions often can almost get away with murder.

 

However, as with the iUSB Power you in effect couple two cables together. In this case, if one cable has correct USB Impedance (e.g. the short blue tail included in the box) and the other has a different impedance additional reflections (on top of those at both ends of the cable) will be generated.

 

And even a robust system data transmission system like USB will eventually experience packet loss...

 

Sadly, the more expensive and exotic a cable is the less likely it is to be mass produced on machinery made for precisely mass producing USB spec cables.

 

It's not that people do not know how to make better USB cables, the problem is modifying standard cables for improved performance in ways that are compatible with industrial production methods and then finding someone to make such cables in moderate quantities."

 

Ah I see that my surmise at the end of the third last para of my review above about a split cable to feed the iFI might not be such a good idea after all....unless of course iFI saw any benefit in it and built one with correct impedance if that was possible.

[wisnon]

Here's the kicker...It IS possible and quite likely coming to a shop near you soon.

[Liam]

I guess you mean the split iFI cable from the iFI PSU to the dac. I was told about a week ago what they intend to call it, but mum's the word :-) I do have one on pre order. I'm wondering though about whether there would be a benefit in separating the power and data leads in the single lead from the computer to the iFI. From what the spokesperson you quoted said though the impedance matching tolerances are tighter when this is done because the chances of reflections due to impedance mismatches increases with additional cables if not manufactured to industry impedance standard.

[ted_b]

There is no mums the word, the cable is called the Gemini, has been on their website for some time, is a dual conduit design, and will be introduced to the public at CES. I should have one soon thereafter; pre-orders may well beat me to it, of course.

[Dicky]

Perhaps I missed it but can someone please provide a link to purchase this?

[tubesound]

Perhaps I missed it but can someone please provide a link to purchase this?

 

Here's the list of their dealers: iFi-audio Sales

 

If you're a Canadian, Excel Stereo in Toronto just recently became an iFi dealer: About us

[Liam]

There is no mums the word, the cable is called the Gemini, has been on their website for some time, is a dual conduit design, and will be introduced to the public at CES. I should have one soon thereafter; pre-orders may well beat me to it, of course.

 

Ah I hadn't seen the name referred to on their site Ted. I thought I had inadvertently seen it on a dealer document. :-)

[wisnon]

LoL.

 

Dont you imagine that the "spokesman" would know too?

 

I gave a lot of useful techie info there, more than that, i do not know.

 

As an aside, I would love to see iFi offer a straight USB cable of the same quality as the Gemini. I expect it would provide unbeatable value, both in terms of appearance and performance.

 

So much market disruption. I love it.

[wisnon]

Correct. I'm having trouble keeping them in stock but am ramping up to keep up with demand.

 

Brian Walsh

Essential Audio

 

The good kind of problems to have....

[Jud]

I'm very curious to hear from anyone has listened to the iUSBPower with a DAC that plugs into the wall (or power strip, etc.) and thus does *not* get its power through the USB connection. Doubling the number of USB cables does not appeal to me, but I wondered if insertion of the iUSB between computer and DAC would make a countervailing difference.

[ted_b]

Jud,

First off, the 5V requirement of a DAC has NOTHING to do with it plugging into a wall. Battery powered DACS may require 5V, and wall powered DACS may not. It has to do with how the USB chip to DAC chip is programmed (simplified). My Meitner plugs into the wall and needs 5V from the USB cable; my Mytek plugs into the wall and doesn't.

 

Second, the galvanic isolation (iEarth is not pure galvanic, but does help ground loops) is one area it may help, as some with internally powered USB chips have reported back. I agree that the extra cables and connections are (hopefully) necessary evils, in this case.

[Liam]

How the iFI and Aqvox PSU's are joined in tandem in my review above. Note the cable I received with my iFI is not the same as the one pictured at the start of the thread.

 

[Blake]

I'm very curious to hear from anyone has listened to the iUSBPower with a DAC that plugs into the wall (or power strip, etc.) and thus does *not* get its power through the USB connection. Doubling the number of USB cables does not appeal to me, but I wondered if insertion of the iUSB between computer and DAC would make a countervailing difference.

 

I am using the iUSB and my DAC plugs into the wall (my DAC does not get its power through the USB hub). My positive comments appear earlier in this thread.

[tubesound]

Is this adapter better than using a quality USB cable?

 

 

I'm buying one to try out ... (It's very cheap on eBay).

[Jud]

I am using the iUSB and my DAC plugs into the wall (my DAC does not get its power through the USB hub). My positive comments appear earlier in this thread.

 

Thanks, Blake, I've now read through the older comments in this thread I hadn't looked at before. Definitely educational. Encouraged by your results, though your setup differs a bit from mine (no USB powered USB-to-SPDIF converter, actually no converter at all, for me).

[wisnon]

From: iFi Audio

 

iFi Audio Ultra Low-Noise AC/DC Adapter

Not all Adapters are created Equal Note: This article focuses on the iFi Ultra Low-Noise AC/DC Adapter, NOT the iFi iUSB Power ...

[agentsmith]

Just found out about this bulletin that indicates that the iUSB can also be used to power the SB Touch supplying it with clean power.

 

USB Audio Device upgrades with iFi-Products | Facebook

 

Has anyone tried it? It seems too good to be true!

 

My questions are:

 

1. How does the iUSB know to supply the correct voltage/current to the Touch direct from its USB outlet?

 

2. When this feature is used, does it mean that USB that requires external power will not work? And I guess one will not be able to use twin head USB cables?

 

Can't wait to try it when I get home.

[ted_b]

Just found out about this bulletin that indicates that the iUSB can also be used to power the SB Touch supplying it with clean power.

 

USB Audio Device upgrades with iFi-Products | Facebook

 

Has anyone tried it? It seems too good to be true!

 

My questions are:

 

1. How does the iUSB know to supply the correct voltage/current to the Touch direct from its USB outlet?

 

2. When this feature is used, does it mean that USB that requires external power will not work? And I guess one will not be able to use twin head USB cables?

 

Can't wait to try it when I get home.

 

I talked about this about 50 posts ago

http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/ifi-iusb-power-supply-neat-tweak-and-upgrade-usb-dac-13832/index6.html#post191926

 

The USB-dc plug cable turns the iFi into a generic 5V power supply, good for things like Logitech SB, etc.

1) 5V is what the Squeezeboxes need, so no real issues other than making sure the dc plug is the right size (size adapters are only a few $$)

2) the iFi cannot be both things at once, of course. Either a generic 5V supply (using the USB to dc plug cable), or a USB power supply (using a single or dual conduit cable).

[agentsmith]

I talked about this about 50 posts ago

http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/ifi-iusb-power-supply-neat-tweak-and-upgrade-usb-dac-13832/index6.html#post191926

 

The USB-dc plug cable turns the iFi into a generic 5V power supply, good for things like Logitech SB, etc.

1) 5V is what the Squeezeboxes need, so no real issues other than making sure the dc plug is the right size (size adapters are only a few $$)

2) the iFi cannot be both things at once, of course. Either a generic 5V supply (using the USB to dc plug cable), or a USB power supply (using a single or dual conduit cable).

 

Thanks Ted. How's your experience with using it to power a Sb Touch (if you have done it already?)

[dallasjustice]

I love this little iusb! Even if you think your USB DAC is well designed, it's worth a listen. My DAC uses the XMOS board and vbus only powers the DAC's USB receiver. Once you become familiar with the effects of a lower noise floor, it's easy to identify. It's well made and smartly designed by AMR. Step aside AQVOX!