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[review] Nuforce Icon2 + S-X speakers + W-1 sub + LPS power supply

Discussion in 'Headphone Amps (full-size)' started by armaegis, Sep 10, 2012.
  1. Armaegis
    As miniature 2.1 speaker systems go, for most of us it probably conjures up images of a small computer multimedia set. Yeah, not a good comparison right? I've gone through more than my fair share of speaker sets from the likes of Logitech, Altec Lansing, etc. You know the kind: two little speakers, amp built into the sub enclosure, tinny sound, one note bass, lots of garble in between, and a poor excuse for a headphone amp in one of the speakers. For many years, my main computer rig was a set of Cambridge Soundworks PCworks, which to even my uneducated ears at the time were a significant step up from the usual 2.1 culprits. In more recent years, I've also moved a step up within Cambridge Soundworks to their Model Twelve which is a nifty transportable 2.1 system. I have also experimented with a few 2.0 speakers/monitors like the M-Audio AV40, a couple older KRK models, and some Behringers. One time I even tried setting up a home receiver and biamped speakers, but this was far too cumbersome for a desktop setup.
    So now I have the Nuforce speaker set in front of me. It comprises three pieces: the Icon2 amplifier (also usb dac and headphone amp), S-X speakers, and W-1 subwoofer. How do I feel about the system as a whole? In a word: Fantastic!
    There are other reviews online that will espouse the technical virtues, so I'll forgo those here and just list my impressions.
    (pictures will follow in the next post)
    Quite neat overall. The Icon2 and S-X comes in very nice plastic boxes, which incidentally also fit exactly into a FedEx box for shipment. I mean, you're not exactly going to be showing off the packaging, but they're attractive and functional.
    In contrast, the W-1 box is really, well, just a plain brown cardboard box. It's a bit drab compared to the rest. Other than some foam inserts to hold it in place and keep it from scratching, there's nothing of note. The sub itself is wrapped in an orange cloth bag, presumably to keep it clean and to prevent fingerprints as you're lifting it out.
    It's all pretty much plug and play and all the connectors are self-explanatory. No surprises here.
    The Icon2 amp is a tiny little thing, the same size as the HDP which we here on head-fi are more familiar with. Inside the chassis lies a usb dac, headphone amp, and speaker amp (30W x 2). It has three selectable inputs: two analog (3.5mm and RCA respectively) and one USB. Along with the speaker and headphone outputs, it also has a volume controlled lineout (3.5mm) for feeding into another amp or sub. Hard to believe all that packed into something roughly the size of a paperback book.
    The Icon2 usb drivers self-installed without a hitch (I'm using Windows 7) and also named itself properly in the device menu.
    After running for a few hours, the chassis is only mildly warm to the touch. I can't see heat buildup ever becoming an issue with this thing.
    As a USB-DAC
    Compared vs: iBasso D10, FiiO e10, HotAudio DacDestroyer, Sansa Fuze, laptop
    Feeding into: Bottlehead Crack into Sextetts, vintage HK receiver into Paradigm speakers
    I've owned or heard other Nuforce gear in the past (the uDac 1 and 2, the HDP), and I would describe those as mostly neutral and leaning just a touch on the warmer side. The Icon2 to my ear doesn't have that mild warm touch as the others, but it doesn't veer towards cool either. As a matter of fact, it doesn't seem to impart much of a flavour at all, which is either good or bad depending what you're looking for. It resolves better than my DacDestroyer, the FiiO e10 gives a little more weight in the bottom but but loses in dynamic range, and I would say it sits on par with the iBasso D10 or a teensy bit higher in detail retrieval.
    If I were to pick a particular strength, it would be in the detail retrieval and instrumental separation. The clarity in classical music lets me pick out the softer instruments and their locations. I can hear foot and finger taps in some acoustic recordings. With vocals, I can practically hear the room resonances. Okay so I might be engaging in some flowery descriptors there, but I really am impressed. It's not a *huge* step up per se, but it's there.
    As a speaker amp
    Compared vs: vintage Harman Kardon 330A
    Feeding into: full sized Paradigm monitors, bookshelf NuForce S-X speakers
    - no noticeable turn on/off thump
    - chassis only warms to roughly warm temperature
    Well obviously the Icon2 doesn't have as much power on tap as my HK, but it's no slouch. More than enough to fill my basement with appreciable sound, though not enough for a loud dance party.
    The HK definitely has a more “fun” sound, with a meatier bottom end (even without the loudness switch) and a bit of blurring that takes the edge off the treble. The Icon2 on the other hand has a more neutral presentation, and a cleaner midrange through treble. If anything, I would describe the sound as a touch cool and analytical.
    It doesn't have the same authority as the HK when driving the big Paradigms, but that's really an unfair comparison. The Icon2 performs very well pushing the big speakers, and delivers surprisingly good bass, but once you crank the knob all the way those woofers are just too much for the Icon2 to handle and they lose control. Returning to the bookshelf sized S-X (since the Icon2 is a desktop amp after all) presents a much different ballgame. Here the articulation of the Icon2 is more readily apparent, while the HK now feels a bit brutish in comparison.
    Volume balance is about right. Paired with the S-X, maxing out the volume is loud but not distorted. At low volumes, I couldn't detect any channel imbalance.
    Bonus: driving the HE-6 from speaker taps
    - speaker tap 1: configured with a 10ohm resistor in parallel to maintain a low load on the amp, and a 35ohm resistor in series with the headphone
    - speaker tap 2: no resistors, HE-6 connects directly to the speaker terminals
    - compared vs some vintage amps: Harmon Kardon, Hitachi, Mitsubishi
    The Icon2 performed amazingly well driving the HE-6. It's not just a matter of having enough power, but synergy too as I've discovered the HE-6 sound signature changes quite a bit on the amp used (quite a bit more than my experience with typical headphones and headphone amplifiers). Overall sound was very neutral and clean, a little light on bass impact, but with a fantastic dynamic range and superb detail retrieval. I could turn the volume all the way up and not experience distortion unless I was running a 40Hz square wave. Comfortable listening volume for me was around 11 o'clock on the knob with classical music. Metallica's Black album at 3 o'clock was verging on painful.
    The HK amp I tried was definitely warmer with more bass thump, but blurred details. The Hitachi was actually very good, with a slightly more U shaped sound overall. The Mitsubishi had the most power at 100Wx2, but sounded terrible and congested. The only nitpick with the Icon2 was a slight burr in the treble, likely a resonant peak. I'm fairly certain this is an artifact of the headphone itself from other impressions and measurements I've read, and some amps will hide/mask this, but the Nuforce does not.
    As a headphone amplifier
    - 3.5mm connector
    - mutes the speaker and lineout upon connection
    - barely perceptible on/off thump if headphones are plugged in at start
    - very low noisefloor, only noticeable with sensitive iems
    - very very slight channel imbalance at the lowest levels
    Much like my impressions from the speaker amp section, the headphone output on the Icon2 doesn't particularly stand out in any way. While the specs aren't as powerful as the HDP, it had no problem taking most of my headphones to earsplitting levels. Even with the HE-6 in single ended mode it got reasonably loud before clipping at 12 o'clock.
    Unlike the dac and speaker amp sections where I've been describing the Icon2 as neutral leaning slightly towards cool, I would say the headphone output veers ever so slightly towards the uDac and HDP signature of being a touch on the warmer side. Just barely.
    One phrase I've been repeating a few times in this review is dynamic range. It's one aspect of the Icon2 that keeps impressing me. With the DAC and speaker output, I feel as though the amount of detail in the music is really brought out. The headphone amp is no exception, carrying through with the same trend. I would say this is the only part of the chain that imparts any of its own “flavour” so to speak.
    S-X Speakers
    - compared vs: Paradigm monitors, and whole host of other full sized speakers and computer/multimedia 2.1 sets
    - connectors are the less common RJ45
    The S-X speakers are (I believe) the update to the S-1 speakers. I've never heard the older model however, so can't make a comparison there.
    They have an interesting 45° baffle, and a slim profile body. I wonder if the tall shape is an acoustic design, or just aesthetics. In any regard, they are a flashy yet not gaudy looking, and small enough to tuck into a small space. If laid on their side, they could fit into very small spaces indeed.
    My set came are in all black, but they come in a variety of colours. The top and front panel are a matte rubbery texture, which visually add a nice contrast but make for pesky dust magnets that stick moreso than the slick metal casing.
    In their literature the baffle design is supposed to radiate sound in a more diffuse and “natural” way. I would say my impressions mostly match that. They sound better in nearfield, up to perhaps 10' away. Beyond that they start to sound weaker. I found little difference with the speakers standing upright or on their side, though if placebo were talking I thought I liked them when placed on their side closer to hand height and pointed up to my ears. I also tried them briefly from the floor and thought they were quite good from there as well as long as I wasn't on the other side of the room.
    A drawback of this diffuse sound field though, is a loss in some staging and directionality. The radiation of sound makes good use of room acoustics to make the music feel “fuller”, but in exchange for some fuzziness in the directional cues. If played in a large empty room, the sound is a bit thinner though inversely the directionality then feels a tiny bit better.
    Midrange and treble detail is somewhat relaxed. There is an airy texture, and female vocals are rendered rather soft and gentle, yet forward. If I had to draw a comparison to headphones, it would be the Audio Techncia AD series. To nitpick, the upper octaves with metallic percussion feel slightly subdued and polite. At times I wish there were some more sparkle to the treble, but again this is a single 3” driver in a small enclosure; what am I reasonably expecting from it? It doesn't have the “zing” of an electrostatic tweeter for example, though that's comparing apples to oranges.
    The weak point to these speakers is in the bass, though again that's asking something of them that they are not designed for. The specs rate these down to 90Hz before rolloff, and my ears agree with this. I would say that the use of a subwoofer with the S-X is absolutely mandatory (see the section on the W-1 below).
    In terms of design though, I really wish Nuforce could have pushed the bottom end of the S-X down to 80Hz. As it is, rule of thumb with a subwoofer crossover is roughly 10 Hz above the speaker rolloff, which means with the S-X we'd be setting the sub at nearly 100 Hz which is too high in my opinion. A subwoofer should impart heft to the music without making it sound like it's coming from the sub (so essentially it should feel like the speakers are producing it). With a crossover that high though, the directional cues from the sub are too strong to ignore, which detracts from the spacial cues coming from the speakers resulting in a blurred soundstage.
    If I sound like I'm being overly critical on the speakers, well, I'm not. I'm just comparing to my experiences with other full sized speakers. It's an unfair comparison, and they obviously do not match up, but they aren't utterly dominated either. Compared to other small computer sets though, no contest here I'd pick the Nuforce.
    The S-X are currently at a new low price of $60 (from $225) on the Nuforce website, which is ridiculously good.
    W-1 Subwoofer
    Line In: 3.5mm TRS and RCA,
    Line Out: RCA
    Controls: volume, crossover, and phase
    My settings when paired with the S-X:
    - crossover knob at just under 12 o'clock, which should be ~105Hz
    - volume knob set at roughly 9-10 o'clock; any higher and the crossover is too noticeable during anything with acoustics
    - maybe crank to 11 or 12 for electronic, but it starts to distort and sound flabby beyond that
    As mentioned earlier, pairing with a sub is absolutely necessary to get the full feeling of music from the S-X speakers. The W-1 is Nuforce's own subwoofer; it does the job of filling in the low end, but with a rated spec of 50Hz before rolloff it will feel a little weak for the thumping of modern pop songs. I hesitate to even call it a sub; it's more like a repurposed woofer measuring in at a paltry 7.5"x9.5"x10.5". I've worked with subs who's drivers along were bigger than this entire box.
    Within 60-100Hz at moderate volumes, it sounds very good. It's not overbearing, the sound is clean, and for the most part the transition is fairly seamless with the exception of directional cues which are more a factor of the crossover setting rather than the sub itself (which I've explained in the S-X section above).
    The clarity is good for the price and size (it's only a 5.25” driver), but again don't go pushing this like it's an 8 or 12” sub. While you can certainly turn the volume up, you'll get sound but I wouldn't call that mess of pulses music. It seems to be a case where Nuforce has put in more power than the driver can handle (not a bad thing I suppose; it's good to have reserves for those peaks). In any event, leaving the knob at 9 o'clock was sufficient for me. Even at that setting, playing some dubstep with the volume at 3 on the Icon2 was enough to start shaking the dishes in the china cabinet.
    When paired with the S-X, I really consider the W-1 more like a woofer than a sub. Ignoring the S-X, if I turn the crossover knob down to 80Hz or so, the bass clarity is better. When I have to bring it back up to mesh with the S-X, it loses that punch in the low end since it's trying to play the midbass as well.
    The W-1 is currently at a new low price of $125 (from $250) on the Nuforce site.
    Overall Impressions
    The Nuforce speaker system sits as a very solid all-in-one set. Much like my review of the diminutive Cube (link), I've heard individual components that perform better, but as multifunctional units in this size and price, that's a pretty good deal.
    If I've given the impression that I'm underwhelmed, that couldn't be further from the truth. I just tend to present things in a very blunt fashion. For the first little while I was indeed feeling underwhelmed, but as I continued to listen everything just settled into place. With other gear, I'd get these immediate first impressions like a really thumping bass or some spatial separation that really grabbed me, but then as time passed that initial zing wore off or I found myself actually distracted by it. With so much of my gear, I wind up listening for the idiosyncrasies of that particular piece of equipment. With the Icon2, I just listened to my music and forgot about the rest... and ultimately, isn't that what this is all about?
  2. Armaegis
    With all that stuff in the pic you'd hardly notice that there's an actual speaker amp in there eh?
    headphones: Pioneer HDJ-2000, HiFiMan-HE-6, Fostex T50rp
    iems: VSonic GR07, Nuforce NE-770X
    speaker tap to the right of the mouse
    900x900px-LL-b5acb763_Icon2SX2.jpg 900x900px-LL-1240e112_Icon2SX3.jpg 900x900px-LL-49a236f8_Icon2SX.jpg
    The boxes and contents of the S-X and Icon2
    900x900px-LL-7e82d275_Icon2SX5.jpg   900x900px-LL-e40bd3fc_Icon2SX6.jpg
    900x900px-LL-d6882684_Icon2SX4.jpg   900x900px-LL-4073f962_Icon2SX7.jpg
    The S-X speakers close up. They connect at the back with typical ethernet cables, and the Icon2 has the same connectors
    The Icon2 comes with both a set of ethernet cables and a pair of wires with rj45 at one end and banana plugs at the other
    900x900px-LL-68c501f8_SubW13.jpg   900x900px-LL-41651aea_SubW14.jpg   900x900px-LL-05bf22ec_SubW1.jpg
    The W-1 subwoofer. You don't really want to see the box do you? It's just a plain box.
    900x900px-LL-95d0307f_setup.jpg 900x900px-LL-87e34a3a_setup2.jpg
    Some more system shots. Second pic of the S-X laying on its side.
  3. Armaegis
    Review Addendum: Nuforce power supply  LPS-2U-192k
    I've had the Nuforce LPS power supply for a little while now. The basic model offers 15V(DC) with 4A on tap. The upgraded models offer a usb to coax/optical converter, and an additional 15V / 1A plug. There are jumpers inside which allow you to switch to 12V, which offers some degree of flexibility in terms of what components to match it with.
    In terms of Nuforce gear, it is compatible with the Icon family of speakers amps, HDP, Dia, and CDP-8 cd player.
    Power supplies are a topic on which people seem to waiver back and forth over the merits vs cost. The basic model here costs $330, and the highest model which converts up to 192k (non-upsampling) registers at a not-so-cheap $500. It seems like a lot at first glance, but consider that it's basically two power supplies and a digital converter and that's actually quite reasonable. The real question is: do I hear an improvement? My answer is an unequivocal yes. Is it a huge difference? Well... no, but the improvements are there, and the versatility is a big plus.
    What are the benefits of clean power? Consider that everything comes from your power supply. It starts as AC from the wall and gets converted (typically) into a lower DC value. This in of itself can be a relatively simple or very complex matter, and is not something I will go into here. The gist of it though is to know that in cheap converters there can be a lot of noise generated from the conversion. Now consider that your converted voltage rails feed the amplifier components, so you are converting this energy into the sound that you will eventually hear in a manner of speaking. If those rails are noisy, then everything that references them will likewise be noisy. The cleaner the lines, the cleaner the sound that you will ultimately here.  As for what makes a good power supply, that's something I won't get into here, but two very generic parameters are a beefy transformer and smoothing capacitors. 
    You can see some of those in the gallery: http://www.head-fi.org/g/a/713293/nuforce-lps-2u-192k/
    The unit is quite heavy for its size, and very solidly built. Out of all the Nuforce products I've handled (which is a lot), this is easily the most tank-like of all of them. It was quite a process trying to take out all the screws so I could take pictures. Note the large toroidal transformer. The green board on the far opposite side supplies the 15V / 4A output, and the middle green board is the 15V / 1A output. The small blue board in between is the usb to coax/optical converter. There isn't much to note of the case other than the little red LED in the middle to indicate that the unit is on. Even when you turn off the unit, the LED glows for a long time (I stopped timing after 5 minutes), indicative of the large amount of energy stored in the caps (this is a good thing). 
    Power Performance
    While it was not possible to make a quick change and compare to the stock power supply, to my ear there was a fairly apparent improvement in the noise floor of the amplifier. This produces the stereotypical "blacker" background and gives an apparent improvement to dynamic range. The thumps have just a little more energy, and the sparkle rings just a bit cleaner. It's not a difference that will blow you away, but as with all things audio sometimes it's the subtle things that we strive for. I've noticed the difference both in amplifier and dac duties. Clean power just makes everything, well, cleaner. 
    I will be obtaining a couple other pieces of compatible gear in the near future (and HDP and Dia) and will update my impressions as I get them. The majority of my listening so far has been with the Icon2 powering an HE-6. 
    updated impressions with HDP: The LPS makes for a noticeable improvement with the HDP. I don't think I can even listen to it without the LPS now. There's just so much more authority to the sound. The dac section improves just a little bit with an improved noisefloor (which was practically imperceptible to begin with) and slightly better microdetail, but the real winner is with the amp section which feels like it got a shot of steroids without losing any finesse. I never felt the amp was thin before, but it practically feels that way now when I go back to the regular brick supply.
    Converter Performance
    The usb to coax/optical converter requires the use of Nuforce drivers, which can be downloaded from their site: http://nuforce.com/index.php?option=com_k2&view=item&layout=item&id=374&Itemid=262
    Installation is straight forward and everything runs smoothly after that. The board is very similar to that seen in the DAC-100, and I'd bet good money is of the same architecture as their U192S, which is their standalone 24/192 USB to S/PDIF converter. It works without turning on the power supply, or even with the LPS plugged in, which means the converter is completely usb powered. On the one hand this can be good as it is simpler. On the other hand, I would have liked to see the LPS provide a separate power line for the converter in case the computer has lousy usb power on its own (which is very often the case) which would affect performance.
    In any event, the converter works flawlessly and pumps out a coax and optical signal simultaneously. Both streams were identical to my ear. This was incredibly useful as I could then use the converter to feed two separate dacs for head-to-head comparisons. The outputs are transformer coupled to eliminate ground loops, and I indeed found the outputs to be wonderfully quiet. Even feeding from my old laptop which has atrocious hum in usb lines, the outputs were nice and clean. That said, this is not a magic bullet as ground loops are notoriously difficult things to track down. Eliminating ground hum from your source input is no guarantee since it might also come from any other component along the chain. 
    Overall Impression
    I was unsure at first whether I would even want this for my system, but now that I have it I find myself wanting to rearrange things so that I can work with it. That should tell you how much I like it. The dual outputs and converter offer some nice versatility and nearly begs to be used as the backbone in a trifecta arrangement with an amplifier and source component. In fact, that's what I'll be building next.
  4. Armaegis
  5. pekingduck
    Hey there, I wonder if you've tried the HE500 from the speaker taps?
  6. Armaegis
    No, I have not. A friend of mine recently bought an HE-500 though, so hopefully I'll get a chance to try it out soon.
  7. Armaegis
    Here's my full rig at the moment, which I have dubbed the Nuforce Towers. I really like how everything all fits together. Gotta love synergy.
    From left to right...
    - Icon2 speaker amp
    - RJ45CX (essentially an RJ45 to binding post adapter, now discontinued), which I modded to include the 4-pin XLR on the front
    - HDP which outputs to the Icon2, I wish I had this in black
    On the bottom: LPS-2U-192k which powers both the Icon2 and HDP, and feeds optical into the HDP
    On the right: HE-6, modded with a more open backed grill, some damping in front, and J$ Beyer pads. You can just barely make out the 4-pin XLR plug at the bottom of the pic
  8. Armaegis
    Random bumpage, but there's a Black Friday sale at the Nuforce estore and the S-X speakers are $20, and the Icon2 for $175. The amp is a fantastic deal, and the speakers are an absolute steal.
  9. Allanmarcus
    Sorry about reviving an old thread, but anyone know why NuForce discontinued the ICON 2? They didn't seem to replace it with anything either, so I figure there must be some sort of issue with the form factor or the device. Alternatively they just could complete on price or something. Insights?
    The Icon2 is $280 at BestBuy, but I think that is too much for it at this point. 
  10. Armaegis
    I asked the same question a while ago but got a very fuzzy response. Partially the reason is that they wanted to focus more on separate devices rather than all-in-ones. They've also discontinued their desktop speakers except for that bluetooth one (which I suspect is on its way out too) and the company as a whole seems to be focusing more on their home series and the portables and leaving out the desktop speaker segment.
    The last few times I've seen a used Icon2 pop up they were around $200. A new one at $280 is a decent price and I still think they're one of the best sounding amps you can get in that form factor.

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