[warp08]

 

 
 
Foreword
 
About two months ago when I have decided to increase my investment in desktop digital audio, digital cabling was on top of my list for both a portable and a desktop audio rig.  Based on my research, I have ordered both a Locus Design Polestar USB-A to USB-B mini and a Nucleus USB-A to USB-B digital reference cables from Whiplash Audio.  The Polestar--the highest grade Locus Design USB cable that can accommodate a mini USB-B connector--would serve as an upgrade from my longtime Virtua Audio USB cable to use with my iBasso DB2 Boomslang and RSA Predator, while the Nucleus would be paired with the Sonic Diverter/Antelope Zodiac+ combo.  
 

 
While we were discussing the synergies of the Polestar cable, Craig quite unexpectedly asked me if I had a chance to have listened yet to the new Qables iQube V2 DAC/Amp.  I had not, nor have I ever heard the earlier, V1 amp.  Craig then proceeded to loan me an evaluation unit for a month in exchange for posting my impressions.  That sounded good to me since I’m always eager to learn more about high-quality offerings and gladly accepted the offer.  Unfortunately, the only comparable, combined DAC/amp unit I have in my possession at present was my RSA Predator, so I decided to use that as a baseline.
 

 
Even before the unit arrived, I have done a quick scan of existing impressions of the V2 and found only one of significant value, the 6Moons review by Marja & Henk of the Netherlands. This review, located at http://www.6moons.com/audioreviews/iqube2/v2.html offers a great deal about the background, design and operational aspects of the device, yet, relatively light on what’s typically the most important measure of one: its sound characteristics.
 
So I have decided to focus only on that missing piece.   Those of you deciding to read this and not yet familiar with the iQube offerings, it is highly recommended to scan the above review first before proceeding any further, as this is meant to be strictly a complimentary reading material to their work.
 
 
Test Tracks
 

1. Bella Sonus “Enamoured”
2. High Endition Vol 11. “Melange”
3. High Endition Vol 9. “Life Stories”
4. Deep Purple “Fireball” (MOFI 24K Gold Remaster)
5. Sade “Soldier of Love”

 

 
TWag Reference X Recabled HD600/HD800 Sessions
 
The similarly recabled versions of these well-known headphones yield very similar sound signature, unlike in stock form, where the HD800s performance can be characterized as head and shoulders above its lesser sibling.  Aside from the interconnects, amp synergy plays a major role in the overall experience with both headphones.
 
It doesn’t take long, however, to discover that both Sennheisers can be driven with ease by both amplifiers, however, even at its highest gain setting, the Predator needs to operate well above its optimal efficiency and very near its max output level at comfortable listening volumes.  That is not the case with the iQube, which hardly broke a sweat with any of these two headphones, keeping up with ease even with more demanding tracks and genres.
 

 
For example, “My Woman from Tokyo” from the Deep Purple “Fireball” MOFI Gold Audio Fidelity remaster:  less sibilance, more balanced overall presentation by the iQube than the Predator.  This recording was mastered from the original tapes and it shows its limitations.  Still, the much bigger punch of the iQube due to its superior headroom capability which elevates the fluidity and overall dynamics as observed by Marja & Henk in their 6Moons review.
 
Bella Sonus “Rincon de. Espana:”  superior tonal balance and detail again distinguishes  the iQube. The Predator rolloff has become more apparent both on low and high end spectrum.  The iQube seems very composed and laid back, which is perfectly suited to the Bella Sonus listener’s relaxed state as the expert, ethereal soundscape programming crafted by Robert Smith is so masterfully intertwined by those enticing Angel Suarez flamenco riffs with the background vocals emanating from everywhere. 
 

 
 
Allan Taylor “Beat Hotel” from HEE vol. 9:  enormous soundstage, although very little emotion conveyed from Allan’s raspy voice by the iQube.  The Predator does a much better job projecting the singer’s voice into the mind by adding the enticing subharmonics in the midrange and adding an almost hypnotic quality to the experience.  I need to credit the Polestar cable with some of the difference, because the last time I had sheard this song on this amp with my Virtual Audio USB cable, it was not nearly as enticing.  In fact, I listened to this twice, because it gave me goosebumps and I can rarely get enough of that. This demonstrates that no comparison is black or white, and sometimes it pays off to keep amps of different characteristics around if one can afford it or can borrow one from time to time, like me.
 

 
Chris Jones’ “No Sanctuary Here” also from the HEE CD has clearly favored the iQube, because the vocals here were lacking that additional dimension.  His acoustic guitar riffs were rendered with a much better separation from the drums and the vocal track itself, again, at a much more expansive soundstage. 
 
 
TWag Recabled JH13 Pro Sessions
 
 
While the Predator is perfectly happy to accommodate highly sensitive, low-impedance IEMs via its 3-way gain switch, this is predictably more of a challenge for the more powerful iQube.  Still, I had no major difficulties with testing its performance using my JH13 Pro, which was more closely matched the two Sennheiser headphones’ sound signature than my JH16 Pro.
 
The only minor issue is with the iQube’s attenuator at very low volume levels affecting low-impedance IEMs like the JHA customs.  From 0 to about 2 o’clock--as I always dutifully turn down the volume all the way before switching headphones--there is a bit of a channel imbalance, which really doesn’t affect playback once the pot enters a typical listening volume range.  This artifact is not applicable to the Predator, but I have experienced a similar phenomenon with my iBasso PB1 Toucan, another powerful portable amp, primarily designed to pair with higher impedance headphones.
 
Playing the same tracks for comparison purposes the results were largely identical.  The  JH13 Pro has a bit better synergy with the RSA Predator than the Sennheisers, though, as evident in its design, more compact size and overall performance characteristics.
 
[size=medium][/size]
 
Conclusion
 
Based on my time with the iQube V2, I have grown quite fond of it.  Perhaps it is a tad too big for most to be used as a portable amp paired with IEMs on the go, but it is the perfect size for a compact desktop rig.  Despite its streamlined appearance and simple controls, everything about it exudes quality and feels solid and pleasant to touch and operate.  Decent battery life, great sound quality comes at a matching price tag ($599 retail).  The Polestar USB cable is also a must buy for those who want a portable desktop amp with a performance and sound quality to match, but in return, this amp can drive pretty much any headphone or even IEM on the market today with ease.
 
Are there any downsides?  Very few that I was able to notice.  The device charges happily from the USB port, so no charger provided in its attractive aluminum case.  Its DAC component works well with any computer, but it is not supported by the iPad (which works well with most portable DACs I’ve tested it via the USB audio Dock connector, including the Predator’s).
 
Still, unless you are among those who are considering transitioning to the new breed of balanced portable amplifiers such as the iBasso PB1/DB2 combo or even the upcoming RSA SR71B, however, I believe the iQube V2 will serve the rest of those portaphiles well, who are on the market for a neutral, balanced sounding, single-ended DAC/amp in a relatively compact size and with power to spare to be able to accommodate virtually any future headphone acquisitions.  I have grown quite fond of it over this past month, and sure will miss it.
 
If you have any additional questions about the iQube or the Polestar cable, please contact csanborn@whiplashaudio.com.  Whiplash Audio is an authorized Qables and Locus Audio reseller.
 

 

[HelloHell]

Great review Laszlo! You have successfully tempted me to buy WhipMod + Fat Boy + iQube V2 from Craig all at once
 
By the way, have you compared its amp part with Pico Slim?

 

[warp08]

I have not, because I did not believe anyone would consider the V2 for the same purpose as the Pico Slim.  The V1 is more compact and if you don't need the DAC, would be better suited as a portable, although it will still be much bigger than the Pico.
 
The 6Moons review did indicate that the sound signature was similar from the Line-in as it was from the USB DAC digital input, so if you are considering this as a multi-purpose unit (which it clearly is), you should expect pretty much the same thing.
 
6Moons did review the V1 as well, so you may want to read that.  I did not have first-hand experience with that unit, so I can't comment further.  One reason why you would want to consider either one of the iQubes is their ability to drive bigger cans that are outside the Pico's performance envelope.