Mar 132014


Having bought both an iFi Audio USB Power and iFi Audio iDAC after reviewing them a little while ago I was asked by Vincent Luke of iFi Audio and also Abbingdon Music Research (AMR) if I would like to review their new – highly anticipated USB cable – I didn’t have to think about it for long and said yes almost immediately.

Having already reviewed a few USB cables awhile ago I was well aware of the difference USB cables can make in Computer Audio and one of the main factors in why USB cables might sound different over and above the cable material, plug etc is how the particular cable deals with getting the power aspect of the USB cable to the equipment and in doing so causing little or no damage in the process to the delicate audio signal.

The bottom line in my view about USB cables is that they are a deeply flawed design, as running voltage directly alongside delicate audio signals, either analogue or digital, is the complete height of stupidity, as doing so will affect the quality of the signal and thus the ultimate sound quality.


There are a couple of approaches to dealing with this design flaw that USB (Universal Serial Bus) is hobbled with and one possible approach, such as Wireworld implemented, is to separate the voltage carrying element from the signal one by spacing the two elements apart inside one flat cable. The other more extreme solution is to run two separate cables, only connected at the A and B plugs with one cable carrying the audio signal only and the other the voltage and such is the case with the iFi Audio Gemini (1)



iFi Audio have a lot to say about their cable design, so here it is, in full….

‘Audio and power cables are not laid side by side yet in the USB configuration because of its origins, transmits this way.

The iFi Gemini carries Audio + Power in two separate cables. Critically, the special geometry adheres to the 90 ohm impedance specification better than even the USB 2.0 standard. Resistance is 4x lower than textbook. The FINAL USB machined connectors provide impeccable shielding from end-to-end. The atypical silencer design spans the whole of the frequency range to totally banish all noise.

A simple, yet effective illustration is the graph below. The Gemini cable adheres to the 90ohm specification of the USB transmission protocol exhibiting just a 1% deviation from the 90ohm impedance end-to-end (ie. connector + cable together).’

‘Other expensive audiophile cables by comparison, vary as much as 15% (or 78ohm-103ohm!) This one key parameter is often overlooked yet is essential to maximise the quality of the signal transfer.

There are dual-headed designs and there is the Gemini Dual-Headed design. The following picture clearly illustrates audio and power in two separate cables. Upon closer examination, power is heavier gauge and audio has more cores. Further, signal and ground have their own respective geometry to conduct optimally. This is the Gemini difference.’


‘The signal runs through the cable and connector. Therefore, the connector must be as exceptional as the cable. Most USB Cables use moulded plastic covered connections. Plastic cannot shield the high frequencies present in the USB Data link, so noise will radiate out. Durability is also compromised. The FINAL USB connectors provides impeccable end-to-end RF shielding, being machined entirely from solid aluminium. Gold-plated connections make for years of steadfast service.’

1001175_555387381163675_597809785_a‘iFi’s proprietary machine connector looks and feels like it was hewn from a solid block of aluminium. This is not far from the truth. This is the iFi standard.’

Addressing RF issues is usually non-existent in USB cables. Even those with filters fitted, they are off the shelf and as such, work only over too narrow a range. Also, too few are fitted and common RFI filtering is placed at the ends of the cables, leaving the whole length of the cable to act as effective antennae.’

‘The Gemini cable is fitted with three custom-made metal oxide ceramic RF noise silencers. Each with different effective ranges; thus they greatly broaden the range over which RF noise is silenced. Further the middle silencer is design to be adjustable (moved along the whole length), to “detune” the antennae formed by the cable, depending on the conditions and requirements in the system. The other 2 silencers which are not affixed, should be kept as close to each respective end as possible.’


‘To reach the absolute zenith in USB audio quality, we recommend the Gemini cable (for separate audio and power transmission) AND the iUSB Power (to supply pure, clean power). This combination is unique to iFi because no one drills down to the fundamentals like we do. The use of the Gemini cable + iUSB Power is simply unparalleled when it comes to attaining the quietest and smoothest music playback from computer audio.’



The Gemini arrived a few days after my conversation with Vincent Luke – along with an iTube Buffer (3) – in a lovely quality box of similar design to the deeper iFi Audio boxes used for the iDAC, iUSB Power and iTube. As I have said before the iFi Audio packaging has a very strong streak of Apple through its look, and as is the case with Apple products it imparts a strong sense of pride of ownership even before opening the box.


When you do open the box you will  find a beautifully packed cable, nestled within a black velvet bag and the connector ends protected with both end caps and the metal parts wrapped in bubble wrap. This was certainly a good start and hopefully augured a good sonic experience with the cable.

The Gemini is sturdy, well made and imparts a strong feeling it will last a lifetime. The metal USB A and B plugs are solid with nice fit and finish and clearly gold plated parts showing. There are also three RF shield spacers on the cable and according to the literature accompanying the cable the placement of these can affect the overall sound – we shall see.

The cable itself is flexible and easy to position, I was sent a 1.5 m Gemini as a .7m was not available at the time I spoke with Vincent – this was just as well, as the set up of my system really required a 1.5 cable.

Review System


The review system comprised my current reference components: Balanced Audio Technology VK300 Se integrated amplifier (later during the review period a BAT VK52Se pre-amplifier and Music Reference RM200 power-amplifier were also used), Anthony Gallo Reference SA amplifier, AMR DP777 DAC, iFi Audio iDAC, iFi Audio iUSB Power, Acer Notebook laptop, Dell laptop, HP laptop, WD Elements Hard Drive 2TB and 3TB, with JRiver 17 and later JRiver 18 and JRemote on an iPad.



Speakers were Anthony Gallo Reference 3.1’s. All equipment was housed on Clearlight Audio Apeckt Racks, with SSC and BASE isolation platforms, Sound Mechanics M8 Cones, Telos Silver Caps. Signal cabling was High Fidelity Cables CT1 RCA to RCA cables, Altas Mavros XLR to XLR and Atlas Mavros speaker cables, QED Silver Spiral speaker cable. Mains cables were: Audience AU24, Analysis Plus Power Oval 2. No mains conditioners of filters were used except on the PSU for the laptops, where an EC Audio Pandoras box was used (very effective blast from the past used on the laptop power supply)

Review Music


Stanley Clarke – 1,2, To The Bass


Dead Can Dance – Into the Labyrinth

A lot of other types of music were used during the period of the review, too numerous to list here.


After a lot of running in (about a hundred hours or so) mostly based around casual listening and leaving music playing on the loop I finally settled down to have a serious listen and there was quite a marked difference between the cable out of the box and the cable after a prolonged period of use. A pinched, slightly lean tonal balance had fleshed out to have a full range of tonal colours but once run in was finally achieved the end result could best be described as being neutral with no emphasis in my system either towards the warm or cool end of the spectrum.

In listening to Stanley Clarkes album 1,2, To The Bass, an album I have listened to a lot in recent months the iFi Gemini cable certainly didn’t get in the way of hearing the music as many nuances and subtlety were easily heard. I particularly enjoyed I Shall Not Be Moved, a moving track chronicling the change in society attitudes re people of colour and based on the words of  Maya Angelou, spoken beautifully by Oprah Winfrey which ebbed and flowed around the clear acoustic in which Oprah spoke – her voice being rich in detail.


Switching to Dead Can Dance’s album Into the Labyrinth , merely a moments work to do via JRemote’s (4) very nifty app for the iPad, the beautiful haunting music swirled and flowed like a river in and around and outside the edges of the speakers. The Carnival is Over was as moving, haunting and magical as always with a large soundstage, with good depth of image and Brendan Perry’s voice stage centre as always and yet I felt there was just a hint of warmth and richness missing and a slightly matter of fact quality to the music.


Swapping to my current reference USB cable the WireWorld Starlight the missing warmth was now back but sadly the lovely open detailed sound the Gemini allowed through was also now missing to a degree, not missing entirely but reduced and yet being honest the slightly richer sound sat better with my listening preferences but the more closed in somewhat more homogenised sound didn’t when moving straight from the Gemini to the Starlight (5) and hearing what was lacking between the two.

More Listening an opened flower opens further.

Feeling that perhaps I had not yet achieved full burn in on the Gemini I continued using it for a month or so more – the computer audio set up playing away while I listened to other sources, during which time my listening system changed with the addition of a Balanced Audio Technology VK52 Se pre-amplifier and the return of the lovely Music Reference RM200 mk1 amplifier to regular use.

After getting used to the improvements in sound quality – after making the switch from integrated amplifier to a pre-amplifier + power amplifier combination – brought to my system and hoping the extra time on the iFi USB cable had run it in fully I returned to listening seriously once again (6).

The slight leanness I had heard before was now missing and while the presentation could still not be described as warm in anyway that previously heard slight frequency suck out was now gone, with all aspects of the frequency range now fully balanced with no lack or emphasis present.

Doing the comparison again with the Wireworld Starlight the Gemini was now in every aspect the superior conduit for all the music I listened to. The iFi cable was more open, more detailed in all areas with a wider deeper soundstage and better bass extension, nuance and phrasing, and all of this achieved without any spotlighting.


The flower had now finally opened up fully, and as such a state had now been reached I moved on to using the Gemini with its intended partners the iFi iDAC and iFi USB Power.

Gemini, iFi iDac and iFi USB Power.


So far all my listening had been done with the AMR DP777 DAC which doesn’t derive or require any power via the USB cable, so whether it was the Wireworld Starlight (which does carry power within but wasn’t used) or the iFi Gemini (I was only using the signal cable plugged into the iUSB Power (7) neither were powering anything so it was time to do so by using the iFi Audio i DAC.

The Gemini, iUSB Power and iDAC were designed to be used together as a system and frankly not using these last two items with any other USB cable other than the Gemini is I feel to miss out on what iFi;s designers ultimately intended and thus miss out on the full sound quality of what the iDAC can do.

I had previous to the arrival of the Gemini been happy using the iDAC with either a Wireworld Starlight or a Locus Designs Polestar USB cable but adding the Gemini took the whole musical experience obtained via the iDAC in a similar direction to how it had on the AMR DP777 DAC – once full run in had been achieved.

Soundstage width, depth and height improved, with better low level definition and detail being heard more easily. It was now simply easier to hear into the macro and micro structure of the music I was listening to but there was no sacrifice of coherence across the frequencies with no spotlighting evident in my system. In other words listening to music via this combination rather than using the Wireworld Starlight sounded less like HiFi and more like the real thing.


While the iFi DAC gained in performance over all via the use of the Gemini USB cable it would not be fair to the AMR DP777 to suggest that that the gap between the two, performance wise closed – as long as the USB Power and Gemini were being used with it.

While the iDAC still has much of the flavour of the DP777, being a sort of DP777 lite, it loses out overall – to a significant margin – in definition, clarity, weight, scale to make the DP777 the superior music maker/unlocking tool and sustainer of the illusion of listening to real music in one’s listening space.

RF 3 Silencers 

The iFi Gemini cable comes fitted with three ‘metal oxide ceramic’ RF filters which iFi suggest in their literature and website, that moving them up or down the cable will, ‘detune the antennae formed by the cables’ and thus change/improve the sound quality.


Having moved the silencers up and down the cable I was unable to hear any change either way, either to the positive or the negative – I guess my current environment doesn’t offer any challenge to the Gemini’s RF defence system so I heard nothing, however your mileage may vary, as I have heard improvements using Ferrite Noise absorbers on other cables in the past so trying this could well get you some extra performance.

The Elephant in the Room

iFi Audio’s marketing borrows from the Lord of the Rings, with the suggestion that the Gemini is the ‘USB lead to rule them all’, and frankly, being honest, I can’t say one way or the other if this is the case or not, as frankly I haven’t heard or used enough USB cables to form, or offer any opinion re this. I can say though that the iFi Gemini used in my system with the iFi USB Power, either into the AMR DP777 DAC or iDAC offered the best soundquality performance among the USB cables I had on hand.


Other companies do offer split USB cables in a similar way – on the face of it – to iFi Audio’s Gemini, with signal and power split via two A plugs and conducted via separate cables before being reunited at the USB B plug, such as with the Acoustic Revive (8) cable USB-1 OSPS or with the two cables coming out of one USB A plug and going back into one USB B plug like the Acoustic Revive USB-1 OPLS. So being honest I am unable to say if the superior sound the Gemini gives in my set up is unique to the materials, design and construction used by iFi Audio or the improved sound quality I heard is obtained simply by splitting the power and signal cables on separate USB A plugs and reuniting them at the USB B plug – I simply don’t know so this question must remain unanswered – frustratingly so – for now.



The iFi Gemini USB cable is a well made, well presented, on the face of it – compared to similar products – excellent value for money USB cable, that in my system offered the best sound quality I have currently had yet from my computer audio set up, and most certainly should be considered a no brainer re use as part of an iFi Audio system, with the iUSB Power and iDAC, as doing so would offer the fullest realisation of iFi’s sonic performance goal for those products.





Products – iFi Audio Gemini USB Cable

Retail Price (UK) 1.5m £235 (reviewed length) also available as 0.7m £165

Source of Loan – Manufacturer

iFi Audio


iFi Gemini USB Cable Specifications:

Dual-headed (Gemini) connection USB transmission design

Triple RF silencers (adjustable) to tune cable to environment*

Asymmetric Ground return and power line design (4x lower resistance)*

’FINAL’ USB machined Aluminium Alloy connectors

Heavy OFHC continues cast copper (up to 5A)

Double shields with different effective ranges

Custom Polyethylene insulation for lowest triboelectric discharges

*: iFi exclusive, world first.’


(1) iFi Audio are not the first company to do this as

(2) You can read more here

(3) Review to follow – soonish.

(4) Link to JRemote

(5) The Starlight USB I am using is not the current model as that is now a  Starlight 7. Not having heard this cable I don’t know how it compares to the older Starlight or Gemini so please do not take my comments above to in anyway shape or form to refer to the current cable.

(6) I was fairly certain the cable required more run in and as such I have held of finishing this review as I was pretty sure I was not hearing the cable at its best yet, and I am glad I persevered. Those who vociferously claim run in is a myth and they are unable to hear it frustrate me, as frankly I don’t understand how they are unable to hear the improvements run/burn in brings about. In saying that though I will concede that while I have always heard such improvements there have been a few occasions that the improvement has been small that was however not the case here.

(7) The plugs on the Gemini cable are labelled one as music only, a little musical note denotes this and one as power only. Pulling the power cable out of the iFi USB Power shuts the iFi DAC down as doing so robs it of power.

(8) Acoustic Revive


© Text and Photos Copyright 2013/2014 Adventures in High Fidelity Audio. Except album sleeves/manufacturers images Copyright resides with those owners.

NB No part or portion of this article may be reproduced or quoted without written permission.

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