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


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It's then that he said the Acoustic Revive would definitely work with it... but suggested that I wait to try theirs before investing a grand.

 

After Thorsten Loesch posted his comments, that's the decision I made -- to try the iFi cable first. Still waiting for the iUSB Power to arrive.

“We don’t like their sound … and guitar music is on the way out!”

– Decca Records, 1962

 

Taiko Audio Extreme | Vinnie Rossi L2i SE and L2 DAC | Omega Super Alnico Monitors | JL Audio Fathom Sub

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Hi,

 

 

It is also a possible proposition to take two pcs of normal USB Cables, chop off the "B" type plug and get a new one (10pcs USB Male Type B Plug Connector Socket for DIY | eBay), solder together the two cables into the new plug (make sure to do this neatly, cleanly without long tails of wire curled up) and cover the plug assembly with heatshrink sleeving.

 

 

I wonder - given that Acoustic Revive charges almost double for their USB with separate "A" plugs, just how much superior that version is to the the one with separate cables but a shared plug. (The SP vs. the PL model) When I say "superior" just how audible and distinct are the differences? Obviously the former offer further isolation... but can you hear it? Anyone?

Alex

Always on the learning curve...


MBPro i5 > Audioquest Coffee USB > Emotive Audio Customized Valve Preamp > Emotive Audio Custom E-Linear 6L6GA Amp > Modified Custom Quad57s (Wayne Piquet)
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Hot off the press.... this review was just posted a few minutes ago on AudioStream:

 

 

iFi iUSBPower: Taking the Audioquest Dragonfly DAC Up A Notch | AudioStream

 

 

Looks like iUSB has another fan.

Speaker Room: Lumin U1X | Lampizator Pacific 2 | Viva Linea | Constellation Inspiration Stereo 1.0 | FinkTeam Kim | Revel subs  

Office Headphone System: Lumin U1X | Lampizator Golden Gate 3 | Viva Egoista | Abyss AB1266 Phi TC 

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I wonder - given that Acoustic Revive charges almost double for their USB with separate "A" plugs, just how much superior that version is to the the one with separate cables but a shared plug. (The SP vs. the PL model) When I say "superior" just how audible and distinct are the differences? Obviously the former offer further isolation... but can you hear it? Anyone?

 

Thanks for link. I'm already using the Aqvox usb psu, but have arranged to hear this unit when available.

LOUNGE:- Qobuz Studio>TP-Link RE650 WI-FI Extender>AfterDark Ethernet Cable>EtherREGEN/Farad Super3 PSU/Furutech AC input/Level2 DC cable/SR Purple fuse>AfterDark Ethernet Cable(1/2 Metre)>Lumin U1 Mini Streamer/LEEDH volume/External PliXiR BDC Elite 12v/4amp PSU>Oyaide DB-510 bnc-bnc Digital cable>MHDT Orchid Dac>Townshend DCT300 Interconnects>Airtight AMT-1S Amp>Townshend Isolda EDCT Speaker Cables>Speakers Revival Atalante 3.

LIVING ROOM:-Qobuz Studio>Bluesound Node2i (streamer only)>Oyaide DB-510 bnc-bnc Digital Cable>iFi Retro 50 Dac-Amp>iFi LS3.5 Speakers.  Various tweaks in both systems - tubes, footers, grounding, Shakti devices, Nordost QK1, Furutech fuses, resonance generators.  

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Do you think this "iFi twin-headed USB cable" uses a design similar to the Acoustic Revive SPS, or the KingRex uArt and uCraft cables? The KingRex cables also have an optional uPower battery supply, which may be a similar concept to the iFi iUSB Power.

 

I was informed that the iFi cable is not yet available, so I'm wondering if the Acoustic Revive or KingRex cables could be used instead?

 

I just ordered the KingRex uArt "Y" shaped (twin-headed) USB. This is actually a Wireworld cable that is modified by KingRex and apparently it is a very time-intensive modification process. A KingRex technician will only be able to complete around 3 of these cables per day. Will post feedback when it arrives.

Speaker Room: Lumin U1X | Lampizator Pacific 2 | Viva Linea | Constellation Inspiration Stereo 1.0 | FinkTeam Kim | Revel subs  

Office Headphone System: Lumin U1X | Lampizator Golden Gate 3 | Viva Egoista | Abyss AB1266 Phi TC 

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I just ordered the KingRex uArt "Y" shaped (twin-headed) USB. This is actually a Wireworld cable that is modified by KingRex and apparently it is a very time-intensive modification process. A KingRex technician will only be able to complete around 3 of these cables per day. Will post feedback when it arrives.

 

Looking forward to your analysis Blake.

LOUNGE:- Qobuz Studio>TP-Link RE650 WI-FI Extender>AfterDark Ethernet Cable>EtherREGEN/Farad Super3 PSU/Furutech AC input/Level2 DC cable/SR Purple fuse>AfterDark Ethernet Cable(1/2 Metre)>Lumin U1 Mini Streamer/LEEDH volume/External PliXiR BDC Elite 12v/4amp PSU>Oyaide DB-510 bnc-bnc Digital cable>MHDT Orchid Dac>Townshend DCT300 Interconnects>Airtight AMT-1S Amp>Townshend Isolda EDCT Speaker Cables>Speakers Revival Atalante 3.

LIVING ROOM:-Qobuz Studio>Bluesound Node2i (streamer only)>Oyaide DB-510 bnc-bnc Digital Cable>iFi Retro 50 Dac-Amp>iFi LS3.5 Speakers.  Various tweaks in both systems - tubes, footers, grounding, Shakti devices, Nordost QK1, Furutech fuses, resonance generators.  

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Just on the iUSB, I got nice insight from the designer...

 

 

Why a USB Power Supply?

 

by iFi Audio on Thursday, November 1, 2012 at 11:43am ·

We get asked this a lot. Why would anyone need this Box?

It is simple. USB carries audio AND power. Many USB Audio devices power at least some part, often all of the Audio Device from the power supplied by the Computer via its USB Port. The power supply from USB Ports on PC’s is variable in quality, but always contaminated by noise. Have a look here comparing the noise from the best (lowest noise) USB Port on a PC optimised for audio idling… When playing music this is worse.

This is a lot of noise! Many common Laptops and PC’s put out tens of millivolts of noise. That is as much noise as you often get music signal and much more noise than the delicate, small details and nuances in a musical performance. Another issue is the presence of a ground connection between the Computer and the USB Audio device. This can create earth/ground loops that even if they produce no audible hum or buzz, sound quality can be impaired.

So it is little surprise that computer based audio often fails to live up to the expected and possible excellent sound quality.So why do manufacturers keep relying on USB Bus Power? Cost plays a role, as does portability and practical considerations.

Adding the iUSBPower USB Power supply and breaking the ground loop using the IsoEarth gives a major improvement in clarity, detail and musicality. Any audio device starts with the power it receives and with the iUSBPower USB Power supply your USB Audio device gets power so pure, it has even lower noise than a battery!

But the true secret weapon is the ability to break ground loops. We have measured an improvement of over 10 times even in system that are already optimised and have no audible noise.

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>>>>This is a Critical part of ANY highend USB based music server!

November 4 at 4:38pm · Like · 1

 

>>>>> is the power supply galvanic isolated, pardon my ignorance.

November 6 at 10:01am · Like

 

iFi Audio Not sure in which way you mean this? In order to keep compatibility with high speed USB2 (480MBps) to allow multi-channel use at high sample rates/resolution we cannot employ USB isolators. All current isolators are limited to 12MBPS or 2 Channels at 96KHz, which we felt was not acceptable for modern audio. So we cannot fully, galvanically isolate the DAC and PC.

 

However, full isolation is not strictly needed. USB Signalling is differential, so in theory only the two signal lines are required. In practice we need somehow a ground reference. If this ground reference comes only through the USB cable, all is well.

 

If there additional path through other equipment and mains wiring things become problematic.

 

So our "IsoEarth" feature allows breaking the ground connection in a way that is reliably safe for attached equipment (sorry to be vague, but we consider the precise method a "trade secret") and does not require "earth lift" or "cheater" plugs.

 

As we also interrupt the power line from the computer and substitute our own super regulated very low noise supply from the Computers power we essentially only leave the two USB signal lines active and connecting between PC and DAC is IsoEarth is engaged.

 

I have measured differences in of around ten times (20dB) with IsoEarth engaged in systems we use for testing - that is they are already quite well treated regarding the ground noise problem!

 

When testing a USB Isolator marketed for Audio in the same setup I observed similar gains in ground noise levels as with the iUSBPower, suggesting that in our system at least breaking the ground line and full isolation perform comparable, objectively. I did observe that the 5V output from the USB Isolator was quite noisy due the use of an isolating DC-DC converter, which basically a small switched mode supply.

 

Sorry for the lengthy missive, but it is not a simple subject.

November 6 at 10:29am · Like

 

>>>>> how does this device actulaly work? I am not sure how it is to be used. It is not a USB-Spdif converter, so what actually is it? How would it be used with such a converter? Is the iUSB powered by a SMPS?

Wednesday at 12:20am · Edited · Like

 

>>>>> Is there a manual online?

Wednesday at 12:17am · Like

 

iFi Audio ,

 

First, you can find more details and manuals etc. On-Line.

 

Secondly,the iUSBPower plugs into the USB connection between the PC/Mac and any USB Audio Device. Some of the more extreme High End gear does not draw power from the USB, the vast majority of USB Audio Devices, including USB to SPDIF Converters do.

 

In recent times we have seen some attempts to for example split up USB Cables and Lithium Polymer batteries to substitute the power supply, however most batteries when actually supplying are quite noisy (see our AP2 measurement which includes a 9V Dry Cell, rechargables are worse).

 

The iUSBPower contains noise filtering using multiple LCR filters and a so-called super regulator (as opposed to a simple cheap 3-pin regulator) which is similar but not identical to the one described by Walt Jung under this name.

 

As a result you isolate the USB Audio Device (including USB to SPDIF converters) from the computers power supply and you give a power supply much cleaner than that from the Computer.

 

Additionally we have also build in some ground impedance management and the option to break the USB ground connection entirely. This can help a lot with noise loops.

 

Third, you ask is it powered by an SMPS, plugtop type which we supply, however any source of around 9V DC may be applied (at your own risk, mind you). As we wanted a simple way of being able to sell and use the iFi worldwide and we wanted to avoid wasting power, we had to use a custom low noise SMPS.

 

In basic principle an SMPS is a much better choice power supply than using 50/60Hz rectified. The high frequency at which they produce their AC means transformers can be small and thus minimise noise leakage from the mains, they always use choke input filtering and the high frequency means relatively small components are required to filter any noise.

 

Another factor, such a supply may be made universal (runs on any mains voltage/frequency current, even DC) and if well designed efficiency will be very high, well over 90%.

 

However, many common inexpensive examples are build so badly they barely pass FCC requirements. This means they radiate a lot of noise back into the mains and often have very large levels of noise on the output.

 

The first examples we bought straight in shops like Radio-shack were horrendous. The noise on both the mains input side and the output side was sufficiently high to be visible easily on cheap oscilloscopes. output ripple went from 10's to 100's of millivolt.

 

Opening them up revealed that the RF filtering was not fitted, that the chokes and capacitors where of insufficient value and that several parts that would have produced low noise where missing, even though there where spaces provisioned on the PCB to fit them.

 

So we worked with a factory to produce our own plug-top power supply, which not only has all the extra parts fitted but goes beyond this. The result is a power supply that leaks very little noise into the mains (you can measure it, but it needs an expensive analyser, scope traces are clean).

 

Overall, a common linear supply using a transformer, common rectifiers and a 3-Pin regulator will produce more noise (including noise radiated into the mains) than our SMPS. Do not expect most SMPS's to perform similarly.

 

Finally, why don't you just try it? Ask our US distributor for a loan unit.

Wednesday at 4:43am · Like

 

>>>>> Thanks for the detailed and thorough explanation. I can now see more clearly the benefits and I do agree that a properly made SMPS is actually an advantage.

Yesterday at 7:33am · Edited · Like

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Alex,

 

Thorsten and I had a good chat today and this is the following of what came out. We also sent this to AudioStream.

 

IsoEarth 2 pins or 3?

 

“IsoEarth" works by breaking earth/ground loops that can occur in and around the computer itself or other items in the system (e.g. USB Hard Drives). This can lead to audible hum or buzz or if it is not audible, may degrade sound quality.

 

As the power supply of most MacBooks do not have an Earth Connection on the power supply this particular feature will not provide any benefit as such (the earth connection giveaway is if the 'power brick' has 2 or 3-pins). Desktops being of the 3-pin variety are almost all certainly earthed.

 

Interestingly from tests conducted, even a computer with no earth can benefit if the external HDD connected to it is earthed. We came across one such instance where a WD USB MyBook (earthed) connected to a MacBook (not earthed) with the addition of the iUSB removed severe levels of hum."

 

So, the bottom line for me is that it is worth a shot... as your YMMV. And why not, if there is a chance of the sound being cleaner and blacker.

Alex

Always on the learning curve...


MBPro i5 > Audioquest Coffee USB > Emotive Audio Customized Valve Preamp > Emotive Audio Custom E-Linear 6L6GA Amp > Modified Custom Quad57s (Wayne Piquet)
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Alex,

 

Thorsten and I had a good chat today and this is the following of what came out. We also sent this to AudioStream.

 

IsoEarth 2 pins or 3?

 

“IsoEarth" works by breaking earth/ground loops that can occur in and around the computer itself or other items in the system (e.g. USB Hard Drives). This can lead to audible hum or buzz or if it is not audible, may degrade sound quality.

 

As the power supply of most MacBooks do not have an Earth Connection on the power supply this particular feature will not provide any benefit as such (the earth connection giveaway is if the 'power brick' has 2 or 3-pins). Desktops being of the 3-pin variety are almost all certainly earthed.

 

Interestingly from tests conducted, even a computer with no earth can benefit if the external HDD connected to it is earthed. We came across one such instance where a WD USB MyBook (earthed) connected to a MacBook (not earthed) with the addition of the iUSB removed severe levels of hum."

 

So, the bottom line for me is that it is worth a shot... as your YMMV. And why not, if there is a chance of the sound being cleaner and blacker.

 

And, why "IsoEarth" may not work for some?... as in my case.... …if your ground is lifted, there is nothing for IsoEarth to lift! ;)

No more... no less complicated than that

Alex

Always on the learning curve...


MBPro i5 > Audioquest Coffee USB > Emotive Audio Customized Valve Preamp > Emotive Audio Custom E-Linear 6L6GA Amp > Modified Custom Quad57s (Wayne Piquet)
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I'm waiting for an iFi power module. They are currently out of stock at the Canadian distributor.

 

In the meantime I figured I'd order a Y cable but I find the prices, even for the Kingrex, a bit steep for my budget.

I did however stumble upon this one Elijah Audio - Products from an Australian manufacturer and was wondering if it could be a more economical alternative.

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They have invited and asked any and all of us who have questions regarding thier iUSB or other iFi products to post them on

ifi-audio.com

 

This will allow them to gather and collate our questions/inquiries - allowing them to produce a more thorough response in the form of a 'note(s)."

 

That they are more than happy to answer and wish to make themselves available.

 

I know they have just updated some of their tech papers in the "Notes" section of their Facebook Page in an attempt to make them as readable as possible

 

https://www.facebook.com/iFiAudio/notes

Alex

Always on the learning curve...


MBPro i5 > Audioquest Coffee USB > Emotive Audio Customized Valve Preamp > Emotive Audio Custom E-Linear 6L6GA Amp > Modified Custom Quad57s (Wayne Piquet)
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I've read this thread with great interest. Would the iUSB be a credible alternative to the SOTM Card?

 

I would definitely ask that on the iFi-audio site. Thorsten is extremely knowledgeable and experienced on both the audio and pc arena.

Alex

Always on the learning curve...


MBPro i5 > Audioquest Coffee USB > Emotive Audio Customized Valve Preamp > Emotive Audio Custom E-Linear 6L6GA Amp > Modified Custom Quad57s (Wayne Piquet)
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  • 2 weeks later...

My iUSB Power arrived last weekend. It was not a small improvement at all, I had to call my friends over (very bad move) to confirm just to be sure it was not my imagination. The iUSB Power made my digital setup much more analogue like, much much enjoyable. At the end of the night, my friends actually ripped the iUSB Power out of my rack and took it home ... I am again now without a iUSB Power ... :-(

Digital Sources: Optimised HP TouchSmart PC/CEC TL-1X CD Player/AMR DP-777 DAC/Theta Digital DS Pro Basic II (old)

Analogue Sources:Koetsu Jade Platinum MC Cartridge/Tri-Planar arm/Kuzma Stabi Reference turntable/AMR PH-77 Phono Stage

Amplifiers:The Gryphon Elektra Preamplifier/Convergent Audio Technology JL2 Signature Mk 2 Stereo Amplifier

Speakers:Kharma Grand Ceramique Midi[br]Cables:Nordost Valhalla (interconnect and speaker cables)/Shunyata Research power Snakes power cables

Portable: Sony PHA-1/PHA-2; Dragonfly 1.0/1.2; Meridian Explorer, Director; iFi nano iDSD, micro iDAC, micro iDSD; Geek Out; Hdta Serenade DSD

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DM... I'm curious what your "optimised HpP touchsmart" is? How has it been optimised? Which touchsmart model is it?

 

Perhaps you would start a thread and describe it?

 

Eloise

Eloise

---

...in my opinion / experience...

While I agree "Everything may matter" working out what actually affects the sound is a trickier thing.

And I agree "Trust your ears" but equally don't allow them to fool you - trust them with a bit of skepticism.

keep your mind open... But mind your brain doesn't fall out.

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While I'm waiting for my iUSB to arrive, I made this USB cable last week - a Belkin cable replaced by CAT6 wires:

 

DSCF6414.jpg

 

How does it perform? Well, I don't have expensive USB cables to compare but this one sounds better than the Audioquest Cinnamon I bought a while ago: more details and overall livelier.

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While I'm waiting for my iUSB to arrive, I made this USB cable last week - a Belkin cable replaced by CAT6 wires:

 

[ATTACH=CONFIG]2942[/ATTACH]

 

How does it perform? Well, I don't have expensive USB cables to compare but this one sounds better than the Audioquest Cinnamon I bought a while ago: more details and overall livelier.

 

Hi Tubesound,

 

Just a pair of signal cables, no 5v? Very tidy job, regardless, I shall follow in your footsteps. My Young DAC doesn't require power at the USB input. I would like some pretty gold plugs like yours though...

 

QNAP > MACMini 2015 > Audirvana+ > M2Tech Young DAC > Magnum MP250 Class A pre > Wonfor designed Single Ended Class A Monos > modified Triangle Antal ESW (Tellurium Q Black).

 

 

 

 

 

 

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Hi Tubesound,

 

Just a pair of signal cables, no 5v? Very tidy job, regardless, I shall follow in your footsteps. My Young DAC doesn't require power at the USB input. I would like some pretty gold plugs like yours though...

 

One twisted pair carries power and the other twisted pair carries signal. The CAT6 wires are better than the wires used in generic USB cables. Also, not having the signal wires and power wires inside the same cable would reduce the interference between the two.

 

The two headed version, from my understanding, is intended to ensure drawing more power from the computer since not very USB port has the same power output level in a computer. I don't think this version is critical for use with iUSB because iUSB will recreate the clean 5v power for you.

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While I'm waiting for my iUSB to arrive, I made this USB cable last week - a Belkin cable replaced by CAT6 wires:

 

[ATTACH=CONFIG]2942[/ATTACH]

 

How does it perform? Well, I don't have expensive USB cables to compare but this one sounds better than the Audioquest Cinnamon I bought a while ago: more details and overall livelier.

 

Wow, great work tubesound. Very neat and tidy construction.

Speaker Room: Lumin U1X | Lampizator Pacific 2 | Viva Linea | Constellation Inspiration Stereo 1.0 | FinkTeam Kim | Revel subs  

Office Headphone System: Lumin U1X | Lampizator Golden Gate 3 | Viva Egoista | Abyss AB1266 Phi TC 

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