Let’s get something out of the way first. You might be saying something like “Another 5-star review? Seriously? Does this guy ever give anything but 5-stars? Is this dude on happy pills or something? Geez Louise…” Guilty as charged. Another review, 5 more stars given to another piece of Head-Fi gear. Why? So here’s the skinny (and the reason I don’t write for anyone but myself) – I only invest the time (which is non-trivial) in writing these reviews for gear I feel incredibly strongly about. And as an optimistic person I tend to feel the most for things I love. So yes, I tend to write mostly 5-star stuff. Will this always be the case? Who knows, but for now it is. Also I only write a handful of reviews but I (luckily) get listen to and play with a bunch of gear. Okay, now onto the reason we are here, the review of the CDM.
 
Actually, let’s pause another second first. In writing this review I had a bit of an observation/inspiration, which is included towards the end of what surely is going to be yet another very long review. So if you’re not all that interested in the CDM review but you want to read a bit about my “observation” (dare I say a new “law of HF audio”?) jump down to the part that starts with “***” (it’s easy to search for this string) and see what you think. Now, back to the regularly schedule review, I promise this time!
 

 
So after buying and reviewing the ALO Rx (http://www.head-fi.org/products/alo-audio-the-new-rx/reviews/13219) and getting to know Ken Ball, the main-man behind the magic at Portland, Oregon based ALO Audio, I had the chance to try out his other new headphone amp, the Continental Dual Mono (or “CDM” as its friends call it). The CDM can be thought of as the big brother to the Rx, sharing a similar design philosophy, aesthetic and to some degree sound signature. However, when you pull out the birth certificates and compare them you will see that they’re more like half-brothers for a number of reasons, including: 1) there are two fathers to the CDM, both Ken Ball and Vinnie Rossi (who tag-teamed on its design), 2) they have different amplification lineage, with the Rx running solid state while the CDM utilizes tubes (as would befit an “older” brother), 3) the CDM has more tricks up its sleeve in being able to power both full-sized and sensitive IEM’s as well as acting as both a DAC and amp, and 4) the CDM lives in a richer neighborhood, coming in at $1,495 USD to the little brothers $299. So actually, when you look at it they’re quite different – something along the lines of ‘brothers from another mother’. But Dad had a strong blood-line when it came to his external appearance, and you’ll see the similarities in the Rx and CDM casework.
 
So let’s cut to the chase. Is the CDM a worthy big brother to the CDM? Will the family be happy when it shows up to Thanksgiving dinner with a “hot” date? (Sorry for the pun, the meaning of which will become clear later.) The answer is “damn-straight” – if the CDM was my brother I’d roll out the red carpet for him (good thing I only have sisters so I should be safe in making this statement) and pour him a nice glass of 30 year old single malt. This is one amazing piece of gear. Is it worth the ~5x price-tag? Again I would answer in the affirmative. For all that it can do, and how well it does it, the CDM is IMHO an amazing value. For while I said in my other ALO review that the “Rx is clearly not a Swiss-Army type of amp” the CDM actually is. Amazing tube amp? Check. Rock-solid DAC section as well? Check. Portability? Most of a check. Ability to power all sized cans? Check (at least for my transducers, with the Noble K10’s and the Audeze LCD-3’s monopolizing most of my listening time). And the CDM is clearly a sexy beast, with almost everyone I’ve shown it to in person saying “Wow!” when they first see it. I’ve also had a number of people ask me “what’s that?” when I’ve been using it on planes or trains. In fact one person who asked me about it turned out to be a potential client – so the CDM is a good business development tool as well!
 

 
More details you say? Okay, we’re getting there. First of all (my first minor gripe) the setup process was a bit of a bitch in getting my computer to recognize the CDM. However, I blame that more on CMedia than ALO. Turns out I had to do some updating of drivers and also removal of other DAC’s drivers (which also used CMedia) in order to get it working. And actually in full transparency the issues with the PC are the reason I have my CDM. I got a random call from Ken asking if I was a PC user (clearly they’re more MAC than PC’s guys out in the Pacific Northwest, with I guess is a bit ironic given the proximity of Redmond versus Cupertino, but we’ll save that discussion for another time). I have to admit I felt a bit awkward in answering “yes, I still use a PC”. It was kind of like admitting that you were one of the AV-nerds in school who the teachers called on to get their gear working (I have a sneaky suspicion there might be more than one of us here at HF with that background, right Brian?). Ken asked if I would be willing to help trouble-shoot and write some of the user’s guide/FAQ stuff for the CDM, and after having heard the CDM prototype at CanJam SoCal I was like “heck yeah!”. And without any pre-arranged agreement, and with no strings attached, Ken (who’s a total mensch by the way) told me after all was said and done with the work I had volunteered to do to keep the CDM in recognition for the time I invested in helping get the CDM up to speed.
 
So now that the PC and the CDM were talking, we were off to the races, and the CDM was hot out of the gates. Yes, hot. The CDM is hot stuff, literally and figuratively – like Shannon Elizabeth in American Pie (sorry, I have to put in a movie reference every paragraph or two). This tube powered unit sure pumps out some thermal energy – even the volume knob gets pretty warm! I recommend picking the CDM up by the sides around the vent holes, which by design stay cooler. I’d guess from touch (I actually used to have my touch calibrated to temperatures – the fun stuff you learn working in a chemical plant) that it gets up to around 140F maximum, which I think is similar to what Ken measured. Some can hold onto something this hot for a number of seconds, while others will find it hard to even touch for all but the shortest times. This CDM gets hottest in my experience on the part of the chassis between the window and the volume knob, and gets the hottest when you are playing the CDM while it is plugged in to the wall charger and also are using it for both DAC and amp duties. This heat also makes the vent holes very important – so my advice is not to throw the CDM into a bag or pack – let it breathe man! However, once you are aware of it and get used to the heat I didn’t find it to be an issue.
 
How do you tame the heat? Well, as I already said you keep it well ventilated. And you can also try changing out the tubes. Yes, this bad-boy is on a roll, a tube-roll that is. With the purposeful design the two tubes in the CDM are easy enough to swap out. One Allen wrench, some static dissipation and a few minutes of your time and you can significantly change not only the heat-generation of the CDM but more importantly its sound signature. First the heat. The “pencil tubes” that the CDM uses come in two different types – single and dual triodes. What does that mean? Google it if you want details, but essentially the duals can do stereo duty, handling two signals at once, while the singles are well, just single. Since it is a dual-mono design (the “DM” in CDM) the amp only uses one channel, but has to power both sides of the tube, even the one not being used. So more power equals more heat, oh and less battery life as well. So there is benefit to the single triodes, although you do have to be careful when installing them as the green-PCB boarded single-triodes are chiral, which is chemistry-speak for they have right-and left-sided versions. So be very careful when you’re installing them to put them on the correct side of the CDM or else bad things can happen (I’ve heard of one Head-Fier who already made this mistake and ended up doing some damage to their CDM). To play it safe be sure to watch Ken’s video on how to swap tubes in and out of the CDM, which can be found on the ALO site (http://www.aloaudio.com/cdm-faq). Oh, and two more hints – 1) getting the volume knob off the first time can be a challenge. It can get a little stuck, even after loosening the nut, so just give it a little extra “oomph” the first time after you’ve unscrewed it, and 2) there are little squares of tape holding the back sides of the tubes to the PCB (nothing worse than tape stuck on your backside!), so be careful and apply constant pressure on the tubes after you’ve disconnected the ports to the PCB and the tape will let go. After the first time it’s all easy-peasy.
 

 
So what are my thoughts on the different tubes regarding sound? Well our friend Lieven wrote an in-depth CDM tube-rolling review on Headfonia recently which I will point you towards here (http://www.headfonia.com/review-tube-rolling-the-alo-cdm/) as he did a really great job on it. I’ve only tried three tubes so far, but they are three of the biggies, and the first three in his review – the stock Sylvania 6111’s, the Mullard 6112’s and the Sonotone 5719’s. First, the stock NOS Sylvania 6111’s are a very solid and well-rounded performer (and easier to source) hence why Ken includes them with each CDM. I could have been happy with just leaving them in the CDM and going on with my business, but hey, this thing is built for rolling and who am I to stand in the way of progress? The Mullard 6112’s are IMO simply amazing – the clear choice for wonderful, tube-typical warmth and emotion. Sucky part is that they cost quite a bit more and are very hard to source, so they’re not often available. If you get the chance I highly recommend you pick them up. So my thoughts on those two tube-types (try saying that five times fast!) match with Lieven’s take. Where we diverge somewhat is on the Sonotone 5719 single triodes. I found the 5719’s to be a bit thinner and not quite as engaging, especially compared to the Mullards. However, YMMV, and the 5719’s do run cooler, so they are worth trying out. Now with the Mullards in place I feel like I don’t have to do a lot of swapping around. Whew, at least that’s one element off the audiophile merry-go-round (at least for now!).
 
“Damn it man, you haven’t talked about how the flippin’ thing sounds yet! Get on with it already!”
 
Okay, okay – I get the hint. Let’s talk about the all-important SQ. First the soundstage is wider and taller than the Rx – although their depth is similar to my ear. The CDM provides clearly the best soundstage I’ve heard my K10’s throw that I can remember. For example on Eiji Oue’s amazingly recorded “Reveries” the haunting “Gymnopedie No. 1” is broad and nuanced at the same time, with the clarinet solo seeming to hang in space, suspended by who knows what. On R.E.M.’s “Laughing” from “Murmur” the bass has real depth while the symbols seem to sprout out of your ears and eyebrows like the errant hairs on a mad-scientist. This is good stuff.
 

 
Like well-designed tube gear the CDM allows you to see the delicate nature of instrument images. It’s not that you’re overtaken by additional detail, which there certainly is, but rather the way the details and instruments are portrayed that is so impactful. It’s like looking a painting by a master and realizing that while the overall image is stunning, that the fine brushwork is so nuanced and refined and that this extra texture makes the whole picture better. The delicate nature of the note is delivered with great power where needed. It’s like switching between a compound bow and a crossbow. They both can be incredibly accurate but when you move from an arrow to a bolt the difference in mass makes the impact much stronger (as Tywin Lannister found out that fateful night on the commode for you GOT fans out there). When the source tells the CDM to punch it, the CDM says “how high?”, even when going high means reaching low, hitting you deep in the gut (again, reference Tywin Lannister…). And talking about impact, if you want to see what a good DAC/amp really does for you then get a CDM and an iPhone camera adapter (Lightning to USB). Then listen to the same track via the iPhone’s (mine’s an iPhone 6) headphone jack and then through the CDM. Wow. Anyone who isn’t knocked over is either: 1) deaf, 2) not anyone who should be reading a review on Head-Fi, or 3) really, really loves Steve Jobs and thinks Apple products are bullet-proof in every way. The impact, the resolution, the pure musicality is night and day.
 
After listening to the CDM using the standard 3.5mm TRS cable I moved to a balanced cable (ALO Tinsel 2.5mm TRRS to silver barrel “custom IEM” 2-pin). This added even more to the soundstage and detail retrieval. In terms of the soundstage it takes what is impressive and gives it more depth, while the resolution also bumps up a notch, with more air between the instruments and micro-details. So for fun I switched from the K10’s to the LCD-3’s (the F model) and flipped the CDM’s switch to higher gain. OH MY EFFIN LORD. The CDM powered the LCD-3’s much better than I thought it would, bringing plenty of power to the party. It clearly needed the High gain setting, maxing out on Low gain, but then it only used half of the volume range to play the Audeze’s plenty loud. Seriously, if I was told I could only have one piece of gear to drive both my CIEM’s and full-sized cans I would take the CDM in a heartbeat and be perfectly happy, knowing that I wasn’t giving up much in performance to a much larger and more expensive desk-top system.
 
For more SQ information here are some of my notes for specific artists and titles:

1. The Eagles, Hotel California: The bass line is much more “alive”.
2. London Grammar, Strong: The squeak on guitar strings, the space of her voice, the impact of the keyboard bass line – completely more 3-dimensional.
3. REM, Laughing: The bass line and kick-drum both have real texture and nuance, even though they are roughly in the same frequency range, a nice trick.
4. The Chieftains/Diana Krall, Danny Boy: So amazingly emotional!
5. Peter Gabriel, The Barry Williams Show: Incredible bass section, both the bass line and the kick drum and CDM is the best I’ve ever heard it sound on my K10’s – again real texture and impact without drowning out the high hat or Peter Gabriel’s fine vocals.
6. Coldplay, Always in My Head: The texture and tone of the bass line is fantastic. This is a strong bass line no matter what you play it on, but on the CDM it’s like it adds another dimension, moving from 2D to 3D as you can now hear and almost feel the texture of the notes coming off the bass. Also the duration of the notes is like they’re hanging in midair.

Clearly lots of good stuff on a bunch of different types of music.
 
So some downsides to mention – hey, I roll transparently my friends! First the extra resolution comes with the typical price – you get to hear the stuff you weren’t necessarily supposed to. A number of times I’ve sworn that I hear a “hiss” from the amp, but each time I stop the music and fiddle with the CDM I realize it’s not the amp, it’s what has been recorded on the track. Bad recordings sound, well, not so hot. Second, and most importantly, the CDM is highly susceptible to outside interference. ALO wisely points out that you should keep your cell phone away from the CDM, and they’re right. Interference is such that you want to make sure your CDM is not near your phone or anything else giving off a lot of noise or is actively transmitting. I don’t have any issues with hiss when nothing is playing, but I can hear some interference quite often if I’m not careful with where I place the CDM. Seeing how hot it gets, you’re going to want to be careful where you put in any way! So keep your smartphones away, and also be careful with some computers how close you put it, as I found that to be an issue with my computer since it has a built-in broadband card as I got the same cell-signal interference. One the plus-side if you want to get all Jason Bourne you could potentially wave the CDM around and see if there are any listen devices hidden in your room. Third, while the CDM is technically and practically portable, it’s pretty big and not that convenient to hike around. On flights of ~2 hours or less I just use my trusty Rx stacked on my Fiio X3. For longer flights where I’m going to settle in for a bit I’ll pull out the CDM and the related cables and watch people get nervous as they wonder what they hell I’m powering up as it starts to glow. However, once I’m at the hotel (yes, I travel a lot) the CDM is my go-to source of audio bliss.
 
*** (Yep, observation time – talk about a total non-sequitur!). Okay, I’m now naming what I believe to be core element of head-fi, which came to me as I was reviewing the CDM and that I’ll very humbly call “Michael’s Law” (yes, that’s what the “m” stands for in mscott58 if you didn’t know). My observation is this – the better something sounds the less you pay attention to the equipment in the moment. This last part is important. When we get drawn into the music, at a basic and almost spiritual level (almost) everything else seems to go away – you are just one with the music. At some point thereafter, whether it be a few seconds or a whole night’s worth of reference tracks later, you snap out of it and say something like “holy crap, that (insert equipment name) sounds amazing!” (just like I did with the CDM on a few occasions). I think this is also a key element of audiophilia (is that even a word?), that to listen best we must listen with our hearts and souls. Forget about the numbers of drivers, the bit-rate, the composition of the cable, the age of the tube, whatever (and yes, even the price of the component) and just listen - let yourself get taken away. The further and deeper you go, the better. And I don’t give a rats-ass if that piece of equipment cost you $5 or $5,000 - enjoy the experience, wallow in it like you’re Wilbur after winning the county fair, lose some sleep, write silly reviews that use too many pop-culture references, call your friends over – whatever it is that makes you happy. And then be willing to accept that this experience that was so important to you will likely not be replicated for a good percentage of your friends/fellow HF enthusiasts. This happens so often that “YMMV” should be tattooed on the back of all of our hands so that we see it when we start flaming each other on the boards, using phrases like “it can’t” and “you don’t get it” and “zip-it Lachlan” (sorry, couldn’t resist). Back to my point, which is getting quite long I know, but the more you’re looking for a difference (like the damned and dreaded double-blind test), the more you want to find something and you risk focusing so hard on this that you lose the music, that you move away from the thing that we all should really (IMHO) be seeking – that true musical bliss. So the harder you have to try, the more you are focused on the equipment the less that piece of gear is really doing it for you.
 
Time for a very snobby analogy (but hey, we never judge each other here right? Ha!). Anyway I have been lucky enough to drive a fair number of very nice cars, and I had a similar “observation” driving something that costs so much it makes my head spin (and you think we have an expensive hobby?). So as a kid I always loved Lamborghinis. Heck, who grew up in the 80’s and didn’t have a picture of a Countach somewhere in their room? (I had both a picture and a model I had made and painted to look like the coolest cop car ever). So fast-forward a few decades and I got to drive a Lambo for the first time, and really drive it on a private 1.7 mile road course along with a Ferrari and a few other TOTL cars. Now I’ve always respected Ferrari’s, but the Lambo was my first real car-crush as a teenager. And guess what – I found myself wanting to like the Lamborghini (a Gallardo) so much, that this was what I was thinking about, not the driving experience. And like most ‘first-time’ things, it wasn’t all that enjoyable – likely for either of us. Juxtapose that with the Ferrari, where I wasn’t all giddy about the manufacturer (although they are “so choice” as Mr. Bueller would say) but I soon found myself completely lost in the driving experience. I became one with the road as that Italian beast slid around the track at speeds that I’m glad my wife didn’t see me post. I wasn’t thinking about the car or how much it cost or anything else really, I was lost in the moment, becoming one with the machine, experiencing and enjoying what it was built to do, and how I interfaced with it. This is how we should be with audio gear – lost in the music, letting the gear help us get there versus having the gear be the destination. For those who agree with “Michael’s Law” (okay, I admit the name is stupid, we can surely find something better and no, Warren or Wata, you don’t get to just put your own name it) let’s never forget to keep our focus on the music.
 
Okay, now back to the review – this is a review, right? Wait, what was the product again? Oh, yeah, the red-hot ALO CDM. I think it’s about time for a conclusion (as we rapidly head towards 4000 words and beyond). The CDM is an amazing amp/DAC on almost any scale, but is even more amazing when you consider that it is portable, it uses tubes and allows for easy rolling. Pricey? Yes. Worth it? Definitely. Ken and Vinnie, well done my friends, well done. 

 
As my wife will tell you, at just about every major audio show I attend I buy something (shocker right?). There’s something cool about looking at my pieces of gear and thinking about the show where I got them. For example my Noble K10’s make me think of Denver and RMAF/CanJam and working feverously with the Head-Fi crew to build all the banners before the show started (good times Joe, Jim, Jude, Warren, and Andres!). SoCal this year was about finding the best portable amp for my wonderful Kaisers, and I think I tried almost every one out there. When I worked it down to the two finalists I was wondering how to best do the final A/B comparison. I got Ken Ball’s attention at the ALO table and asked him if it would be okay if I wandered off with one of his new Rx amps for a while. He said no problem at all. Nice! (in full disclosure I did volunteer to leave my travel case containing my LCD-3’s with him as collateral, so it was very low risk to him!). However, I think that Ken might have even let me even without leaving him ~$2K in gear – he’s just a good guy. Off I went to the other amp manufacturer’s table, and many swaps of amps later I had a winner. I wandered back to the ALO table and told Ken his Rx had won the portable IEM-amp cage-match against the also very good Oppo HA-2. “Great” he told me, “and thanks for supporting Portland!”. So what won me over and what do I think of the ALO Rx? This is a review, so that’s what comes next. Geeze, why ask such a silly question…
 
So Ken’s ALO Rx is clearly not a Swiss-Army type of amp, this baby is purpose-built, and what it does it is awesome at. This amp is no decathlete, it’s a one-trick pony. “My name is ALO Rx and I’m an portable headphone amplifier for IEMs and that’s all I have to say about that.” Stand proud my friend, for you do your duty and you do it well.
 
In fact I realized that the portable amps I had been using before had bells and whistles I didn’t need and wasn’t using, and that was okay, but they made the amps bigger and meant I was paying for stuff I wasn’t using. Built in DAC? Nope, that’s part of my DAP’s duty. Ability to change gain ranges? Sorry, my K10’s are my CIEM’s for travel (and everything else currently) and when I’m home my LCD-3’s have their own dedicated amp and the Rx has just the right gain for my CIEMs. Adjustable treble/bass/etc.? Not needed – the combo of the K10’s and Rx is just the blend I need for the sound I like. Balanced output? Well, that would actually be cool, but hey, that’s outside the remit for this value-packed, option-light amp. Ability to make me an extra-hot skim latte? Hey, that’s why by law we have Starbuck’s every two blocks!
 

 
Also the Rx is lightweight, but not in a cheap way. This is custom milled metal people. For those of us who have fallen in love with titanium (my bottle opener on my keychain is titanium – guess that isn’t what the material scientists were thinking about when they developed that alloy) know that Ti is super light, but not cheap. It’s light on purpose – same with the Rx, although it’s not made of titanium, but nickel-coated aluminum (and now is available in black anodized as well). Actually the ALO Rx is like a sports car that has ripped out all the excess weight to help it go faster. This is a stripped-down, purpose-built IEM amplification machine. Don’t ask it to make you a latte or shine your shoes (wait, didn’t I already use the latte line? That’s a lot of latte). It doesn’t slice or dice, it amplifies, and it does it wonderfully – the best of any portable amp I’ve heard to date. Size-wise it’s almost a perfect match to my Fiio X3. The Rx is about ¼” shorter (when you include the volume knob) and essentially the same width and depth. A few straps/rubber bands and a nice patch cord (ALO of course!) and you’re good to go. Since I just mentioned the volume knob it’s the right time to tell you that I find it to be one of the best implementations of volume control on a portable piece of gear I’ve ever used. It’s conductive plastic potentiometer has a great range of motion and is both smooth to turn, with no degradation of the music during adjustments, and is firm enough to not get turned inadvertently during normal use. Ever almost blown out your ear-drums when you bump against a volume knob? No worries on that with the Rx in my experience.
 
One very cool thing is that Ken picked an orange LED to show the amp is powered on. Why is that cool? It’s not Halloween after all. Well, with the drilled grills on the sides of the amp the LED gives off a nice warm orange light, making you think of the glow of a tube, which is a theme of Ken’s work and reminds you of his other new portable, the Continental Dual Mono (which is an awesome piece of gear in itself). Was this done on purpose? I’m not sure – but it looks really cool (warm actually). The ALO Rx is made in the USA and looks hand assembled (because it is!) - almost bespoke.
 

 

 
Okay, so what does it sound like? Well, like most reviews I waited until near the end to talk about that (why do we all do this? Are we afraid that people won’t keep reading our lame prose and stupid coffee jokes?). The Rx has a deeply engaging sound and offers amazing resolution and decay that goes places I didn’t know a portable setup could go. One of the great things about my current reference desktop amp (the Bakoon HPA-21) is its ability to pull apart the finest details, seemingly let you identify not only the type of guitar being played, but possibly even the manufacturer of the guitar! The Rx is similar, in letting you hear great levels of detail and in a way that doesn’t distract from your overall listening experience. One example of the ALO Rx’s ability to show the texture of the notes is in the bass line in the intro to Hotel California. The Rx shows a great level of detail and emotion in these low notes while not taking away anything from the detail of the plucking of the guitar strings being played at the same time. The more you zoom in the more details you can see as you focus on a specific part of the music. This reminds me of the Sydney Opera House, but not because of that venue’s great acoustics, but rather the fact that what looks like smooth white sails on the external surface of the incredibly designed building are in reality millions of small white tiles. Pay attention in life and it’s amazing the additional things you can see and hear.
 
The amp is also voiced in a way that I really like. What is that voicing? I would call it neutral, with maybe a slight tick towards warm. What does that mean? Well, describing this stuff is always the hardest part. Let’s say I love the K10’s, I love the Bakoon HPA-21 and I worship my LCD-3F’s – none of which are analytical, but are a bit warm and skewed a bit towards the lower end (IMHO). The Rx doesn’t add much, if anything on its own, but allows this sound signature to shine through. And speaking of not adding anything, this amp is like a black-hole in terms of background noise – it’s just black, which is one of the reasons it is able to resolve fine details so well.
 
As far as the other bits go, everything works as it should. The battery is great and I’ve never run it all the way down, although I am a stickler on charging it between trips. The plugs are solid and well built, the unit itself is very well constructed and has given me no issues at all. As a bonus you even get an ALO Green Line micro USB cable with the nickel version of the Rx, which is quite a deal seeing that this cable’s retail price is about half of the total cost of the Rx. No cheap after-thought cable here my friends.
 
So what’s the downside of Mr. Ball’s little Rx-reboot wonder? Well, as mentioned before it is only optimized for this one use, so don’t expect it to do more. Also be sure to ensure that the range of amplification fits your IEM’s well. It should most, but there is a chance it might not be quite powerful enough for some, depending on how loud you want to listen. For example on my K10’s the Rx powers them perfectly in the range I normally listen to, but if I really wanted to blow my eardrums out the Rx won’t go that high. Actually, this is a kind a safety mechanism for me, protecting me from hurting my hearing by playing at stupid-high levels of volume. That’s the only thing I can say about the Rx that isn’t totally positive, and it actually is not a downside for me. Ken’s done a great job on this unit.
 
Okay, I don’t usually go for the cheap humor (“that’s not true!” you’re likely shouting) and I’ve bit my tongue to not say it until this point, but the ALO Rx is just what the doctor ordered for this audiophile who has it bad for great sound while on the go. At the list price this is an awesome deal – at the show discount it was a no-brainer. Highly recommended and my current portable reference.

 
If you told me that my review of a pair of headphones would somehow combine golf, science-fiction, sorcery and a supersonic jet I’d say you’re crazy. But then again if you told me I would spend $1,599 on a pair of IEM’s and consider them a bargain I’d also say you were off your rocker (and my wife would agree). But that’s where I find myself, so here we go…let’s jump into the seemingly random (and long) walk that is my review of the Noble K10’s.
 
But first, let’s go back in the time machine. In the late 90’s I had the honor of attending the Western Open at Cog Hill Country Club outside of Chicago. I was still in a field sales job and got to go see a major golf tournament and call it work – good times! At this tournament I saw Tiger Woods during his prime when he was winning majors left and right. He just made it look easy – showing true mastery of his skill. Golf is an incredibly difficult sport, and playing at that level and winning consistently is nearly impossible, but somehow Tiger did it, almost effortlessly (well, back then at least he did). The Noble K10’s are like Tiger in this regard, they’re effortless in their ability to do their job nearly perfectly. Taking 10 BA’s per channel and making them work together so coherently and precisely is a nearly impossible task, but somehow Dr. John has done it. You would never be able to guess the number of transducers in these IEM’s, but in the end all that matters is that they combine into one graceful and cohesive world-class package that makes beautiful music. The K10’s exhibit Noble’s true mastery of the craft of IEMs, reflecting the many years their key players have worked in this field. Like Tiger (at least back in the day) Dr. John and team rule their game. Add on top of this the detailed artistry of the “Wizard” and it’s a one-two punch of audio impact, both sonically and visually.
 
And speaking of Wizardry, how many of you remember the small handbag that Hermione Granger carries at times in the Harry Potter series? Through the use of an “undetectable extension charm” (yes I’m a geek, in case you didn’t know that already) her little bag can carry anything, no matter the size or weight. A complete library of books? Check. Dry clothing to change into after getting wet by jumping off a dragon into a lake? Check. Anything fits in there. The same appears to be the same with the K10’s. Besides being able to fit 10 BA drivers into each earpiece, which is a bit of magic itself, listening to the Kaiser’s makes you feel like the whole spectrum of instruments, even the largest ones, have somehow been crammed inside these gems, against all laws of mechanics (maybe quantum tunneling?). Queuing up “Life During Wartime” from the Talking Heads’ amazing album “Stop Making Sense” I was hit out of the blue by the kick-drum that enters suddenly during the keyboard intro. Even though I’ve heard this track hundreds of times, I was still struck by it - the drum as portrayed by the K10’s rocks you both in terms of impact and texture, but somehow doesn’t overpower the great stereo imaging of the keyboard riff. Putting on my LCD-3F’s for comparison I find the ability of the K10’s to convey this passage to be very nearly (but not quite) at par with the Audeze’s. How the heck do they do that? How does Dr. John fit that much musical magic into such a tiny space? Instead of quantum mechanics does he use the same charm Ms. Granger applied to her purse? He is a Wizard as well after all.
 
Anyone who looks at my hard-drive of FLAC files or my list of most-played Tidal tracks (hey, get off my computer!) knows that I listen to a very wide range of music, alternating between Rammstein’s “Sonne” to Miles Davis’ “So What” to Royksopp’s “Skulls”  to Duncan Sheik’s “Whispering” from Spring Awakening to The Chieftains “The Magdalene Laundries”. I love them all, and many, many more. The K10’s play them all well. I don’t find myself reaching for a different HP when I want to listen to a certain type of music. In fact another reviewer of the K10’s talked a lot about their ability to show the “space between” (which I agree with in terms of special sense), but be clear there is no space between the frequency bands. This is one coherent whole, and playing all of these different genres highlights that whatever is in the recording the K10’s will show – good or bad. In fact the times I’ve been disappointed by a sound coming out of the K10’s I’ve gone back and confirmed that the recording or other equipment was at fault (or my body, as one time I was sure I had a problem with my right earpiece, but it turned out to be a piece of ear wax rattling at a certain frequency – gross but it can happen!). The K10’s just show (their version of) the truth. Why the qualifier? They are voiced, so don’t expect “reference” neutrality, but boy-oh-boy are they fun to listen to.
 
Back to the Audeze’s for a moment. Why am I using them as my primary point of comparison? Why not other IEM’s? Well, a few reasons. First the K10’s simply left my trusted old Etymotic ER-4S’s in the dust – no comparison (although at $300 the Ety’s are still a great value). Secondly I know my LCD-3F’s very well. Third, how crazy is it to compare the K10’s with a full-sized (oversized some would say) open HP such as the reference LCD’s? This is no David versus Goliath. This is Goliath versus Goliath’s slightly younger and smaller brother – it’s a fair fight. Although to be clear, the use-case of these two TOTL offerings are completely different. The K10’s are “closed” (they’re deep in your ear canal!) versus the LCD-3F’s “open” structure. Both clearly have their strengths and weaknesses. I can easily travel with my K10’s (in case you didn’t know the LCD-3’s are not really portable – and yes I’ve seen it done) and not bother anyone (well, besides people wondering what those things stuck in my ears are!). But then again at home I’m am completely in my own little universe and cannot hear anything that is going on around me when wearing the K10’s, which can be good and bad. What? The kids were crying? Sorry honey – I had my Noble’s in. With the LCD’s I radiate a lot of sound from the cans, but then again I can still hear a bit of anything that is going on around me, assuming it’s pretty loud or the music is pretty quiet.
 
While on the subject of using the K10’s while traveling, one quick piece of advice: when you’re on a plane and listening to the K10’s be sure to let those sitting next to you know that you’re going to be off on another dimension, oblivious to anything and anyone around you and to poke you if they want to talk to you or warn you of any impending doom. Simply put with the K10’s on you will be off the grid. This is actually a great thing during boarding as it makes the process so much more enjoyable. Put an audio-induced shield up around you to repel the stress radiating from everyone else trying to cram a 150 pound duffle bag into the overhead bin or deal with a screaming 10 month old with an ear infection. Leave me a message, I’m not here - I’m in my “happy place” thanks to my friends from Santa Barbara.
 
Let’s jump once again back to the K10 vs. LCD-3F in terms of SQ comparison and specific tracks. The mids on the Nobles are very good, although they lack that certain fine “magic” and deep emotion of the LCD-3’s that made me pick the -3’s over the –X’s. But hey, I don’t know of any HP for under $5K that matches the LCD-3’s in this area. On the whole I’d say the Kaiser’s are quite close to the LCD-3 experience, around 90% of the SQ on whole. I could easily live with the K10’s if I had to (and I would pick them as my only headphone if I could only have one) but luckily I don’t have to. J Getting this close to Audeze’s  TOTL is an amazing feat given the difference in size and portability. Regarding a few of my reference tracks. On Peter Gabriel’s “OVO”, Track 12 “Make Tomorrow Today” has an intro that builds with keyboards and then the bass kicks in, followed by an acoustic guitar and then some type of whip-like sound comes out of nowhere. This jolted me out of my work, even sitting in a busy and loud Starbucks in Manhattan. Moments like this happen all the time and the K10’s again excels across the audio spectrum. Similarly on Gabriel’s “Growing Up” from “Up” the stings in the intro grab deep into your soul and then the rest of the sounds layer on with great texture and refinement. Great stuff. On Nirvana’s “Smells Like Teen Spirit”, there is a slight difference in drums, with the K10’s being just a little less textured than the LCD-3F’s, but still highly engrossing. Again this is saying something given the size difference and also Audeze’s reputation for kickin’ bass (pardon the pun). However, on “Lithium” the K10’s reproduction of the cymbal shows a bit more air and space than the LCD’s. Score one for little brother Goliath. On the bass line in the second half of the song was awesome on the K10’s, but on the LCD-3’s it was exquisite – we’re really splitting hairs here. The LCD’s and the K10’s each have their own type of magic, but only one has a “Wizard”!
 
Also be forewarned and ready to jump back on the equipment merry-go-round once you land a pair of the Kaiser’s. In my progression up the portable chain, I started with the Dragonfly, then boosted that with the addition of the Headstage Arrow 4T. Then I got the Fiio X3 and was happy with that. However, when I plugged the K10’s into the Fiio I was left wanting more. After researching all sorts of portable amps I had the brain-fart that I still had the Arrow 4T in my drawer. Pairing the Arrow with the X3 was much better, and then when I added an ALO SXC22 mini-mini cable things tightened up even more. Most recently I swapped out the Headstage for a Leckerton UHA-6S.MKII and once again the K10’s showed the jump forward in SQ. If you’re not familiar with the Leckerton, look up Nick’s little masterpiece – it’s really amazing (at least as an amp, I don’t utilize the DAC section of the UHA-6S/MKII). Others have said it, and I’ll wholeheartedly agree – the K10’s scale beautifully and will take advantage of whatever you throw at them up the chain. I’m now more eager than ever to get my LH Labs Geek Wave XD128 Ultimate Signature DAP as I’m sure that whatever Larry Ho’s portable wonder ends up being my Nobles will keep up and take full advantage of their Geeky goodness.
 
But wait, you say, you haven’t talked about the super-sonic jet yet! (assuming you were paying attention at first and haven’t given up his death-march of a review yet). So where’s the analogy? Like the SR—71 Blackbird super-jet the K10’s appears to gain power with time, moving faster and faster (or in this case getting slightly louder and louder) when they’re in the zone. This is the first headphone where I find myself turning the volume down slightly versus turning it up while listening. Many headphones sound good when played at a higher volumes (hence the importance in dB matching during comparison tests) but it takes real engineering and finesse to make something sound good at lower levels. And that’s just what the “No-bull” team has done.
 
Finally, I would be remiss if I didn’t send a shout out to Dr. John, Brannan, Sunny and the rest of the Noble team. They’re not only great at what they do, they’re also good people. All of my experiences with them have been first rate. No rock-and-roll divas here. Just solid people making and selling extraordinary audio gear.
 
And yes, as I’m finishing writing this review I’m wearing my K10’s and my LCD-3F’s are staring at me with a little hint of jealousy, awaiting their turn. Don’t worry kids, daddy has enough love for both of you.
 
Well done Noble, well done. Very highly recommended.