iFi Gemini3.0 Dual Head USB Cable
Dual head USB cables have always struck me as interesting and fairly clever. Rather than a standard single-cable, source-to-DAC link, they split the power and signal connections into completely separate portions - which then combine at the DAC input. The result is a "Y" shaped cable offering a total decoupling of potentially dirty USB power from the source device. Users are free to instead use a high-quality supply on the power leg for the cleanest possible power.
If the USB stage of your DAC draws power over USB, as many of them do, one can imagine the benefits obtained - cleaner power is always a good thing. I recall being surprised when I first discovered that numerous DACs work this way, even when they have integrated or separate outboard supplies powering the rest of the system. But even in cases where USB doesn't draw any power, there's still potential for that dirty USB power to "contaminate" the incoming audio signal, which again impacts sound quality. You can read more on the topic here.
Does any of this really matter? I figured it was time to find out for myself. While various small boutique brands have offered dual head solutions over the years (Audiocadabra, YFS, and KingRex among others), I chose a more well-known firm for my little experiment: iFi Audio. Their first Gemini dual USB cable launched way back in 2013, so they've been at this for a while now. That model was what I'd call "midpriced" in the grand scheme of USB cables ($200-300 depending on length), and was well built if not particularly flashy.
The original was recently superseded by the Gemini3.0 which is what I ended up getting. It goes for $379 for a .7 meter length, or $529 for the 1.5m version. Certainly not a budget cable by any means, but build quality/materials are all commensurate with what you'll find in that price range (and beyond) from other brands. Plus, when you think about it, the Y style design actually requires twice as much cable, so it makes a little more sense in that context. Note that iFi also sells a Mercury3.0 cable which appears to be a more traditional take on USB audio (no Y split involved) but otherwise offering similar materials/design, for a substantially lower price. That may well be the way to go for the average user.
Upon opening the Gemini3.0 package, I realized why the name contains the "3.0" - this cable terminates in a USB 3.0 male type B at the DAC end. For those unfamiliar, this is a newer, slightly larger design than the typical USB 2.0 type B port you are likely accustomed to seeing on a DAC. There's a sort of backward compatibility here, in that a DAC sporting a USB 3.0 port can accept an older style cable, but not the other way around... unfortunately the vast majority of DACs out there do not have this newer style jack. So the Gemini3.0 is somewhat limited in this regard. Note that the USB Audio Class 2 standard is a totally different thing. We're strictly talking physical connectors when we talk about the USB 3.0 in this case.
As mentioned, the quality of this cable is extremely high. iFi lists it as "heavy OFHC continuous cast copper silver matrix" with HD Polyethylene and quad shielding, terminated with iFi's "Final" USB connectors machined from pure aluminum. The cable itself is a flat design, reminiscent of certain Analysis Plus speaker cables. The design features 3 "sliders" that can be adjusted to fit your system configuration. If your Data port and Power ports end up being very close, you can cinch the Gemini so it looks pretty much like a normal cable until the last little section. Or, if your ports have some distance between them, Gemini can split further down to accommodate that as well (making it more of a "V" cable if you spread them out far enough). The sliders themselves are described by iFi as being metal oxide ceramic filters, which silence RF noise by "detuning" the antennae formed by the cable. I didn't notice a difference in sound when changing slider positions, though I admit I didn't spend a bunch of time on that experiment (sounds incredibly tedious, but that's just me).
Of the many dozens of DACs (I've lost count) passing through my audio rack in the last few years, only a few had this 3.0 type B connector. Many, but not all, of the iFi DACs do - my most recent experience was the Pro iDSD which worked well with the Gemini3.0 in place. Other models include the excellent B.M.C. PureDAC and even better UltraDAC, along with the little AMI Musik DDH-1. Any model not using this newer style connection will require an adapter of some sort, which is not necessarily an ideal situation. But we'll discuss that further in a bit.
My first experience with the Gemini3.0 involved the iFi Pro iDSD DAC. I fed it with USB from my Euphony PTS music server which was powered by a Keces Audio P8 power supply. Initial listening was done with a Cabledyne Silver Reference USB, which is a very nice if more "traditional" USB cable in terms of design. I then swapped in the Gemini3.0 which drew power from the USB power output on the Keces P8 - a very useful component to have in this scenario.
After much listening, I thought I heard just the slightest improvement in dynamic grunt with the Gemini3.0 installed, plus a touch of added clarity in the treble region. The result is what I'd call improved realism, but we're almost splitting hairs at this point. The change is roughly on par with what you get by switching digital filters on a DAC - it can take strenuous listening to notice the change, and in some cases is just barely audible (depending on the DAC, the music, etc).
Next I swapped out the Euphony PTS for a Surface Pro 6 running Roon. Going back to the baseline performance using the Cabledyne Silver Reference, things took a considerable downturn. Imaging was less precise, soundstage flattened, and everything felt a dynamically compressed for lack of a better term. Treble suffered as well, with a sort of glassy feeling that I had not experienced with the Euphony PTS in the system. While still being enjoyable, the Surface-based setup was very clearly inferior - transports really do matter.
I then swapped in the Gemini3.0, using the same Keces P8 for power and Surface Pro for data. The difference was more substantial than I had anticipated. While not sounding as open and spacious as it did with the Euphony as transport, I still got a very respectable sense of where each instrument was coming from in the performance space. The treble shed its etch for the most part, which helped detail retrieval feel more natural. This sounded every bit like a high-end transport was involved, despite the pedestrian nature of the Surface Pro (from an audiophile perspective).
The Pro iDSD is unique in that it features built-in network audio streaming, and it happens to sound fantastic. If I wasn't a dedicated Roon user, I'd be more than happy omitting any external music server/transport and just stream directly. Since I do love Roon, I end up needing some external source to make that happen... which leaves me open for the Gemini option. If I mainly used my Euphony/Keces combo, I'm not sure I could justify the expenditure of the Gemini3.0 with this particular DAC - it did improve the sound, but by such a small degree as to probably not be worth the expense. But using a Surface Pro or, by the same logic, probably any regular laptop or consumer grade desktop, the Gemini3.0 plus the Keces P8 made a noteworthy difference with the iFi Pro iDSD.
I repeated these same experiments for the little-known $549 AMI DDH-1 DAC and got vaguely similar results, though with a different conclusion. In this case the cheaper device was effectively unable to resolve the change from quality standard USB to Gemini when using the dedicated music server. With the Surface Pro in place, I did hear worthwhile gains, but not enough to justify the expenditure: despite making the AMI device sound better than I had ever heard it, the ~$1100 for Gemini3.0 plus Keces P8 would be better spent on just getting a higher end DAC in the first place.
Moving decidedly up the chain in both price and performance, I brought out my ~$4k B.M.C. UltraDAC and repeated the experiment yet again. This time around the changes were more obvious in both cases - in favor of the Gemini all around. The dual-head cable really brought out a sense of musical ease, tonal richness, and rhythmic drive that only the best transports can hope to deliver. Very, very impressive performance.
I thought perhaps the UltraDAC would be immune to transport quality but the opposite turned out true... it really shows the flaws in a pedestrian source. This is likely due to B.M.C. intending users pair it with their pricey (and excellent sounding) PureMedia music server. In any case, with a budget allowing the purchase of a DAC in this league, it makes more sense that one might also be able to afford the Gemini/Keces add-on, as it really kicks things up a level or two. And to be perfectly clear - this goes beyond any difference I've heard involving a "standard" USB cable upgrade. While I think the Cabledyne Silver Reference USB is a superb USB cable and very likely on par with the more traditional iFi Mercury3.0 in terms of build quality and materials, there really does seem to be merit to the whole Y-split cable concept. I will definitely recommend it as one avenue of potential upgrade for folks already using a high-end, highly resolving DAC.
My main complaint about the Gemini3.0 is the termination on the DAC end. It just won't work with the majority of my devices. I did happen to have an adapter on hand but it converted to microUSB rather than standard USB type B. This allowed me to pair Gemini3.0/Keces P8 with the Massdrop Airist R-2R DAC, which despite its low price proved very receptive to the upgrade. In fact it may have made a larger difference than with any of the previously mentioned combinations. This DAC seems highly sensitive to incoming signal quality so I can't say I am surprised. Did the use of an adapter hold back its full potential? I have no way of knowing, but I was thoroughly satisfied with the resulting sound.
Browsing online for the appropriate adapter to convert to full size USB 2.0 type B was discouraging. Apparently that is not something many people need, so it is therefore not easy to find. I couldn't even find another example of the one I used with the Airist DAC - I picked it up a couple years ago and apparently they were easier to find back then. After browsing unsuccessfully for some time, I happened to notice iFi makes an adapter of their own.
Well, not exactly, but their iPurifier3 device happens to feature a USB 3.0 type B female jack on the input end, along with a more traditional USB 2.0 type B male plug on the other side. That's a perfect match to allow Gemini3.0 to work with the majority of DACs on the market. iPurifier3 is $129 so the price of implementing Gemini3.0 gets that much higher, though perhaps the iPurifier3 brings some benefit of its own to the chain (I have no experience with it).
That got me thinking - what does iFi want us to use for the power portion of the Gemini3.0? Surely they aren't counting on other solutions such as my Keces. This led me to browse their catalog again until I found the micro iUSB3.0, which appears to be the complementary device as it features dual outputs for power and data. Interestingly, that device ($429) plus the iPurifier3 add up to roughly the same price as my Keces P8. I can't comment on hypothetical performance from the all iFi system other than to point out that the multiple levels of filtering/regeneration/etc involved in the iFi trio may bring additional positive results... or not. These things seem very system dependent so it's hard to say for sure.
Bottom line, as far as I'm concerned: the iFi Gemini3.0 cable is an extremely high quality if slightly finicky take on the Y-split USB cable concept. I recognize that the company has almost universally embraced this newer style of USB jack on their own products, so it makes sense to find it here as well... but I still don't love the decision. I can't help but think how much more universal appeal the Gemini would have if it just featured a typical USB 2.0 type B solution.
That said, the results I got pairing it with my B.M.C. and Airist DACs were impressive enough to where I can't dismiss the Gemini3.0, even with the limitation involved. The improvement in those two cases even goes beyond what I've experienced with my favorite USB tweaks like the Wyred4Sound Recovery or BMC PureUSB, and far beyond that of even the best traditional USB cable upgrades. It's significant enough to where I do not ever want to use those DACs without the Gemini3.0 in the chain - anything else just feels second rate.
Stay tuned for my further iFi adventures: the iSilencer3.0 and DC iPurifier2 have been making the rounds in my system as well, and I'll add links to my thoughts on those once I finish writing them up.
-Addendum-
I just found out that iFi actually offers the Gemini3.0 with your choice of terminations at the DAC side - USB3.0 or the more common USB2.0 style. That makes my entire commentary above less relevant. I'm going to leave it for two reasons.
First, it shows how easy it can be even for a thorough reviewer to drop the ball on a potentially critical detail. It's a good reminder that all reviews, whether professional or amateur, paid/hobbyist/disgruntled customer/etc, are fallible. Always do your own research to verify the important details of any significant purchase.
Second, I don't think the termination choice is obvious enough. Most online shops selling the cable don't allow the customer to choose, nor do they all clearly picture that portion to at least provide a visual clue. So who knows which one they end up shipping. B&H Photo - with whom I am only affiliated as a frequent customer - is the main place offering the choice right there in the ordering menu. Unless you intend to use the iPurifier3, or your DAC has the newer style port, I'd be extra careful to order the proper version that works with your intended gear.
Having made my two points, I can now very enthusiastically recommend the Gemini3.0 cable for those wanting to squeeze the absolute maximum out of their USB to DAC connection. It's certainly not cheap, and makes things a bit complicated with the additional power supply, but the results are superb with the right setup.
Dual head USB cables have always struck me as interesting and fairly clever. Rather than a standard single-cable, source-to-DAC link, they split the power and signal connections into completely separate portions - which then combine at the DAC input. The result is a "Y" shaped cable offering a total decoupling of potentially dirty USB power from the source device. Users are free to instead use a high-quality supply on the power leg for the cleanest possible power.
If the USB stage of your DAC draws power over USB, as many of them do, one can imagine the benefits obtained - cleaner power is always a good thing. I recall being surprised when I first discovered that numerous DACs work this way, even when they have integrated or separate outboard supplies powering the rest of the system. But even in cases where USB doesn't draw any power, there's still potential for that dirty USB power to "contaminate" the incoming audio signal, which again impacts sound quality. You can read more on the topic here.
Does any of this really matter? I figured it was time to find out for myself. While various small boutique brands have offered dual head solutions over the years (Audiocadabra, YFS, and KingRex among others), I chose a more well-known firm for my little experiment: iFi Audio. Their first Gemini dual USB cable launched way back in 2013, so they've been at this for a while now. That model was what I'd call "midpriced" in the grand scheme of USB cables ($200-300 depending on length), and was well built if not particularly flashy.
The original was recently superseded by the Gemini3.0 which is what I ended up getting. It goes for $379 for a .7 meter length, or $529 for the 1.5m version. Certainly not a budget cable by any means, but build quality/materials are all commensurate with what you'll find in that price range (and beyond) from other brands. Plus, when you think about it, the Y style design actually requires twice as much cable, so it makes a little more sense in that context. Note that iFi also sells a Mercury3.0 cable which appears to be a more traditional take on USB audio (no Y split involved) but otherwise offering similar materials/design, for a substantially lower price. That may well be the way to go for the average user.
Upon opening the Gemini3.0 package, I realized why the name contains the "3.0" - this cable terminates in a USB 3.0 male type B at the DAC end. For those unfamiliar, this is a newer, slightly larger design than the typical USB 2.0 type B port you are likely accustomed to seeing on a DAC. There's a sort of backward compatibility here, in that a DAC sporting a USB 3.0 port can accept an older style cable, but not the other way around... unfortunately the vast majority of DACs out there do not have this newer style jack. So the Gemini3.0 is somewhat limited in this regard. Note that the USB Audio Class 2 standard is a totally different thing. We're strictly talking physical connectors when we talk about the USB 3.0 in this case.
As mentioned, the quality of this cable is extremely high. iFi lists it as "heavy OFHC continuous cast copper silver matrix" with HD Polyethylene and quad shielding, terminated with iFi's "Final" USB connectors machined from pure aluminum. The cable itself is a flat design, reminiscent of certain Analysis Plus speaker cables. The design features 3 "sliders" that can be adjusted to fit your system configuration. If your Data port and Power ports end up being very close, you can cinch the Gemini so it looks pretty much like a normal cable until the last little section. Or, if your ports have some distance between them, Gemini can split further down to accommodate that as well (making it more of a "V" cable if you spread them out far enough). The sliders themselves are described by iFi as being metal oxide ceramic filters, which silence RF noise by "detuning" the antennae formed by the cable. I didn't notice a difference in sound when changing slider positions, though I admit I didn't spend a bunch of time on that experiment (sounds incredibly tedious, but that's just me).
Of the many dozens of DACs (I've lost count) passing through my audio rack in the last few years, only a few had this 3.0 type B connector. Many, but not all, of the iFi DACs do - my most recent experience was the Pro iDSD which worked well with the Gemini3.0 in place. Other models include the excellent B.M.C. PureDAC and even better UltraDAC, along with the little AMI Musik DDH-1. Any model not using this newer style connection will require an adapter of some sort, which is not necessarily an ideal situation. But we'll discuss that further in a bit.
My first experience with the Gemini3.0 involved the iFi Pro iDSD DAC. I fed it with USB from my Euphony PTS music server which was powered by a Keces Audio P8 power supply. Initial listening was done with a Cabledyne Silver Reference USB, which is a very nice if more "traditional" USB cable in terms of design. I then swapped in the Gemini3.0 which drew power from the USB power output on the Keces P8 - a very useful component to have in this scenario.
After much listening, I thought I heard just the slightest improvement in dynamic grunt with the Gemini3.0 installed, plus a touch of added clarity in the treble region. The result is what I'd call improved realism, but we're almost splitting hairs at this point. The change is roughly on par with what you get by switching digital filters on a DAC - it can take strenuous listening to notice the change, and in some cases is just barely audible (depending on the DAC, the music, etc).
Next I swapped out the Euphony PTS for a Surface Pro 6 running Roon. Going back to the baseline performance using the Cabledyne Silver Reference, things took a considerable downturn. Imaging was less precise, soundstage flattened, and everything felt a dynamically compressed for lack of a better term. Treble suffered as well, with a sort of glassy feeling that I had not experienced with the Euphony PTS in the system. While still being enjoyable, the Surface-based setup was very clearly inferior - transports really do matter.
I then swapped in the Gemini3.0, using the same Keces P8 for power and Surface Pro for data. The difference was more substantial than I had anticipated. While not sounding as open and spacious as it did with the Euphony as transport, I still got a very respectable sense of where each instrument was coming from in the performance space. The treble shed its etch for the most part, which helped detail retrieval feel more natural. This sounded every bit like a high-end transport was involved, despite the pedestrian nature of the Surface Pro (from an audiophile perspective).
The Pro iDSD is unique in that it features built-in network audio streaming, and it happens to sound fantastic. If I wasn't a dedicated Roon user, I'd be more than happy omitting any external music server/transport and just stream directly. Since I do love Roon, I end up needing some external source to make that happen... which leaves me open for the Gemini option. If I mainly used my Euphony/Keces combo, I'm not sure I could justify the expenditure of the Gemini3.0 with this particular DAC - it did improve the sound, but by such a small degree as to probably not be worth the expense. But using a Surface Pro or, by the same logic, probably any regular laptop or consumer grade desktop, the Gemini3.0 plus the Keces P8 made a noteworthy difference with the iFi Pro iDSD.
I repeated these same experiments for the little-known $549 AMI DDH-1 DAC and got vaguely similar results, though with a different conclusion. In this case the cheaper device was effectively unable to resolve the change from quality standard USB to Gemini when using the dedicated music server. With the Surface Pro in place, I did hear worthwhile gains, but not enough to justify the expenditure: despite making the AMI device sound better than I had ever heard it, the ~$1100 for Gemini3.0 plus Keces P8 would be better spent on just getting a higher end DAC in the first place.
Moving decidedly up the chain in both price and performance, I brought out my ~$4k B.M.C. UltraDAC and repeated the experiment yet again. This time around the changes were more obvious in both cases - in favor of the Gemini all around. The dual-head cable really brought out a sense of musical ease, tonal richness, and rhythmic drive that only the best transports can hope to deliver. Very, very impressive performance.
I thought perhaps the UltraDAC would be immune to transport quality but the opposite turned out true... it really shows the flaws in a pedestrian source. This is likely due to B.M.C. intending users pair it with their pricey (and excellent sounding) PureMedia music server. In any case, with a budget allowing the purchase of a DAC in this league, it makes more sense that one might also be able to afford the Gemini/Keces add-on, as it really kicks things up a level or two. And to be perfectly clear - this goes beyond any difference I've heard involving a "standard" USB cable upgrade. While I think the Cabledyne Silver Reference USB is a superb USB cable and very likely on par with the more traditional iFi Mercury3.0 in terms of build quality and materials, there really does seem to be merit to the whole Y-split cable concept. I will definitely recommend it as one avenue of potential upgrade for folks already using a high-end, highly resolving DAC.
My main complaint about the Gemini3.0 is the termination on the DAC end. It just won't work with the majority of my devices. I did happen to have an adapter on hand but it converted to microUSB rather than standard USB type B. This allowed me to pair Gemini3.0/Keces P8 with the Massdrop Airist R-2R DAC, which despite its low price proved very receptive to the upgrade. In fact it may have made a larger difference than with any of the previously mentioned combinations. This DAC seems highly sensitive to incoming signal quality so I can't say I am surprised. Did the use of an adapter hold back its full potential? I have no way of knowing, but I was thoroughly satisfied with the resulting sound.
Browsing online for the appropriate adapter to convert to full size USB 2.0 type B was discouraging. Apparently that is not something many people need, so it is therefore not easy to find. I couldn't even find another example of the one I used with the Airist DAC - I picked it up a couple years ago and apparently they were easier to find back then. After browsing unsuccessfully for some time, I happened to notice iFi makes an adapter of their own.
Well, not exactly, but their iPurifier3 device happens to feature a USB 3.0 type B female jack on the input end, along with a more traditional USB 2.0 type B male plug on the other side. That's a perfect match to allow Gemini3.0 to work with the majority of DACs on the market. iPurifier3 is $129 so the price of implementing Gemini3.0 gets that much higher, though perhaps the iPurifier3 brings some benefit of its own to the chain (I have no experience with it).
That got me thinking - what does iFi want us to use for the power portion of the Gemini3.0? Surely they aren't counting on other solutions such as my Keces. This led me to browse their catalog again until I found the micro iUSB3.0, which appears to be the complementary device as it features dual outputs for power and data. Interestingly, that device ($429) plus the iPurifier3 add up to roughly the same price as my Keces P8. I can't comment on hypothetical performance from the all iFi system other than to point out that the multiple levels of filtering/regeneration/etc involved in the iFi trio may bring additional positive results... or not. These things seem very system dependent so it's hard to say for sure.
Bottom line, as far as I'm concerned: the iFi Gemini3.0 cable is an extremely high quality if slightly finicky take on the Y-split USB cable concept. I recognize that the company has almost universally embraced this newer style of USB jack on their own products, so it makes sense to find it here as well... but I still don't love the decision. I can't help but think how much more universal appeal the Gemini would have if it just featured a typical USB 2.0 type B solution.
That said, the results I got pairing it with my B.M.C. and Airist DACs were impressive enough to where I can't dismiss the Gemini3.0, even with the limitation involved. The improvement in those two cases even goes beyond what I've experienced with my favorite USB tweaks like the Wyred4Sound Recovery or BMC PureUSB, and far beyond that of even the best traditional USB cable upgrades. It's significant enough to where I do not ever want to use those DACs without the Gemini3.0 in the chain - anything else just feels second rate.
Stay tuned for my further iFi adventures: the iSilencer3.0 and DC iPurifier2 have been making the rounds in my system as well, and I'll add links to my thoughts on those once I finish writing them up.
-Addendum-
I just found out that iFi actually offers the Gemini3.0 with your choice of terminations at the DAC side - USB3.0 or the more common USB2.0 style. That makes my entire commentary above less relevant. I'm going to leave it for two reasons.
First, it shows how easy it can be even for a thorough reviewer to drop the ball on a potentially critical detail. It's a good reminder that all reviews, whether professional or amateur, paid/hobbyist/disgruntled customer/etc, are fallible. Always do your own research to verify the important details of any significant purchase.
Second, I don't think the termination choice is obvious enough. Most online shops selling the cable don't allow the customer to choose, nor do they all clearly picture that portion to at least provide a visual clue. So who knows which one they end up shipping. B&H Photo - with whom I am only affiliated as a frequent customer - is the main place offering the choice right there in the ordering menu. Unless you intend to use the iPurifier3, or your DAC has the newer style port, I'd be extra careful to order the proper version that works with your intended gear.
Having made my two points, I can now very enthusiastically recommend the Gemini3.0 cable for those wanting to squeeze the absolute maximum out of their USB to DAC connection. It's certainly not cheap, and makes things a bit complicated with the additional power supply, but the results are superb with the right setup.
