Introduction
 
As a long time portable audio enthusiast, I was ecstatic when a Chord representative invited me to participate in the Chord Mojo review program. Given that my review has been long overdue, and others have already thoroughly covered the general operation and background of this unit, I've decided to focus this review on the Mojo's ability to drive the various headphones in my extensive collection. I will also touch on the Mojo’s function as a standalone DAC, and how it stacks up to the top-of-the-line DAPs and mid-price desktop amplifiers that I currently enjoy.
 
Disclaimer:
 
As part of the U.S.A. review team, the Mojo is free for me to keep. I’m thankful to Chord for this wonderful gesture, but would have paid full price for the review sample given how much joy I received from the Mojo during the past several weeks. Additionally, English is not my native language so I would like to apologize in advance if I'm not clear, or in case of any grammatical error on my part. I would also like to thank my friend and a headfi buddy Mulveling for his assistance on grammatical review/editorial work. 
 
Reviewer Background & Bias:
 
I have been heavily into headphone listening since my early teens. My love affair with personal/portable audio began when I received an Aiwa portable cassette tape player as a gift in the early 1990’s.  From that day on, I have been smitten with portable audio and headphones, and in a way I would choose high-end headphones over a high-end speaker system. As you can probably tell, I'm simply a headphone geek at heart.
My musical preference ranges from the usual audiophile titles to classic rock, jazz, pop, folk, and classical. I am a strong believer that a great sound system should excel at resolving inner musical details, and be able to render them realistically in the soundstage. Soundstage depth and imaging are often more difficult to execute properly compared to the width of soundstage.  When these the aforementioned traits are executed properly, music sounds more “alive” and “real”. I am also a recovered bass head (aren’t we all?), and now have a strong dislike of systems with muddy and overly bloated bass response. My listening preferences lean toward gear with a sense of clarity, neutral tonal balance, and a grain free presentation. For example, I gravitate toward the sound of the Sennheiser HD-800 (with upgraded cable) and Stax SR-009 over lusher sounds like the LCD-3.
 
Setup:
 

 

 
 
Throughout my listening session, the Sony NW-ZX2 & ZX1 were used as a high quality digital transport feeding a digital audio signal to the Mojo's USB input, via the Sony WMC-NWH10 adapter. The music catalog consisted of lossless hi-resolution PCM files (mostly FLAC) ranging from 16-44.1 to 24-192. I also utilized the Astell & Kern AK100 as another transport feeding a digital signal to test the Mojo's optical input. However, I never had the chance to hook up the Mojo via computer, so I will not make any comment regarding the Mojo’s ability to handle the DSD playback.
 
The sound of Mojo
 
Generally I find the Mojo to sound exceptionally clean, grain free, and very impressive for a DAC/Amp of this size. The overall tonal balanced is very close to neutral with a slight emphasis toward clarity. Bass hits hard with plenty of articulation and tightness. There is no bloated, over emphasized bass here to speak off. The treble is nicely extended without any apparent harshness that often plagues badly designed amplifiers. Midrange is clean and clear, but could also use a slightly stronger presence. Soundstage is moderate in size with good width and decent depth. Spatial cues are discernable but fall a little short compared to high quality mid-range desktop gear. In short, I find the Mojo to be transparent and musical, with punchy dynamics and a good sense of power behind the sound. In my opinion, the Mojo has been voiced very well and is definitely in line with my sonic preferences.
 
Pairing:  Mojo + JH13 pro FP
 

 
 
The Mojo has no problem dealing with easy to drive and efficient portable earphones such as the JH13 pro. Throughout my listening test, I did not detect any unwanted background hiss/noise coming from the pairing -- but perhaps that's possible for someone with younger, more sensitive ears. The Mojo powered the JH13 with plenty of authority at a fidelity level similar to – or slightly better than -- the headphone outputs of my Sony NW-ZX2, Questyle QP-1R, and a loaner FiiO X7. However it falls a little short in soundstage width/depth and imaging when directly compared to the Sony PHA-3’s balanced headphone output. If you already own a top-of-the-line DAP and primary use IEMs, adding the Mojo to your setup may not be a top priority unless you want to drive full size headphones. However, I think the Mojo will be better utilized for someone who would like to significantly enhance the sound from their ipods and smart phones.
 
Pairing:  Mojo + Sony MDR-Z7
 
A stock Z7 -- Sony's current flagship -- is a decent sounding closed headphone that's exceptionally well built and comfortable to wear. In stock form, I find the Z7’s bass to be loose -- lacking in focus -- and a bit wooly overall. The bass notes also bleed into the lower midrange, affecting lower treble and overall sense of transparency. This results in a relatively dark sound, with somewhat rolled-off treble. I was able to greatly mitigate these shortcomings thanks to the highly regarded Moon Audio Silver Dragon cable. I'm happy to report that the Mojo is able to drive this Sony headphone very well. In fact, it was able to handle the Z7 with ease; in many ways it bests Sony's very own PHA-3. With the Mojo, the bass is tighter and also better defined. Treble energy is more alive, while midrange is cleaner and more engaging to listen to. The Mojo’s sense of power and toe-tapping dynamics really wake the Z7 up in a good way.
 
Pairing:  Mojo + Sennheiser HD-800
 
This Sennheiser dynamic flagship is a favorite of mine. As my go-to critical listening headphone, it's often my first choice to evaluate sources and amplifiers. The HD800 is notoriously difficult to drive properly, and will sound anemic and relatively lifeless out of many amplifiers -- but it is very much capable of sounding world-class with the right amp. The Mojo surprised me at how well it is able to drive the HD800. Out of this little DAC/AMP, the HD800 sounds authoritative and musical. This is impressive, given that I was not able to get the same results out of my trusty Sony PHA-3 and Denon DA-3000USB desktop amplifier. My only nitpick here is that the pairing can get slightly fatiguing on a long listening session, due to a slight emphasis on treble.  This is likely not a fault of the Mojo alone, given that the HD-800 is well known to have an uneven treble response around 6 Khz. The Mojo was nearly able to go toe-to-toe with my Geek Pulse X here, loosing out ever so slightly in width/depth of soundstage and overall sense of refinement.
 
Pairing:  Mojo + LCD-3
 
Many thanks to Mr. Joe Saxson of Headphoneaudiophile.com for lending me the LCD-3 to audition with the Chord Mojo. The LCD-3 is a relatively dark sounding high-end headphone with a smooth, liquid presentation. The sound is more forward, with generous bass output compared to the Sennheiser HD800. This headphone is more difficult to drive properly out of most portable devices, and adding the Mojo to the chain makes a world of difference. The Mojo drove the LCD-3 with a good sense of dynamics and plenty of headroom to drive them to unsafe listening levels (if you so choose). Given that the LCD-3 isn't my cup of tea, I'm not going to delve into fine details; suffice it to say that the Mojo in fact works very well with the LCD-3, and earns my strong praise for its ability to drive this headphone.
 
Pairing:  Mojo + HE1000
 
The HiFi-Man flagship is very well liked by many, and is one of the best sounding headphones currently available. The sound quality is smooth, warmth, musical, and relatively fatigue free. It has a huge and tall soundstage, with a good sense of depth and solid spatial cues. The bass is generous, with good texture but slightly loose for my tastes. It can also sound a little soft and diffused around the edges; it lacks that sense of "focus" compared to the Sennheiser HD-800. In my experience, the HEK must be paired with a high quality solid state amplifier that is transparent and snappy sounding, with a good amount of driving power to address those shortcomings. The Mojo’s sound signature is just that, and it has mated well indeed with the HE1000. I found the pairing very enjoyable to listen to. I personally recommended the Mojo to any HE1000 owners who are looking for a portable solution to drive the HE1000. 
 
Comparison with Headamp Pico DAC/Amp
 

 
 
Back around 2010, Headamp's Pico was the gold-standard for anything portable DAC/AMP listening. The Pico was able to drive wide-range of headphones including my Sennheiser HD-800 surprising well given its minuscule size -- however, these headphones now sound noticeably better and more dynamics on the Mojo. I was not able to identify any area where the Mojo can't outperform the still-impressive sounding Headamp Pico DAC/Amp.  This is quite a treat on the Mojo given that the Pico DAC/Amp has noticeably less driving power & headroom and its internal DAC is only capable of 16/48 signal.  Also the Pico is lacking in features such as a dedicated line out and inability to charge while playing given its $499 pricetag.  Lastly,I have to admit that I still love look & feel of the Pico more but I would take the Mojo over the Pico any day of the week.
 
Comparison with Sony PHA-3
 

 
 
The PHA-3 was my reference DAC/AMP unit before the Mojo arrived. The PHA-3 is a liquid, but relative dark sounding amplifier. Its single-ended headphone output doesn't quite measure up to the Mojo's sense of dynamics and resolution. The PHA-3 was able to drive the HD800, LCD-3, and HIFIman well -- however, it lacks a sense of power compared to the Mojo.  Switching to the PHA-3's balanced output, the PHA-3 still lacks a tiny bit in power compared to the Mojo, but it more than makes up for this in its size of soundstage and imaging. There is a better sense of decay, as well as noticeably more weight to the sound, along with more layering. In my opinion, the PHA-3 was able to render a more "refined" presentation, but the MOJO still rules in clarity and punchiness. Given that the Mojo is nearly half the size of the PHA3, and able to operate while charging, I have to tip my hat to the Mojo. Still, the Sony is able to save the day somewhat thanks to its balanced drive amplification.  So how does the two compared as a DAC?  I personally prefer the DAC output on the PHA-3 by just a hair thanks to its better representation of depth cues and musical details within the soundstage..
 
Comparison with Headamp Pico Power Amplifier
 

 
 
True to its name, the Pico Power is a portable amplifier with enough power to drive both the Sennheiser HD-800 and HE1000 very well. It provides roughly the same level of performance as the Mojo's amp section, but with slightly better resolution, as well as featuring a dead-neutral sonic character. Therefore I would rate the Power as having a slightly better amplification section overall, but note that having to carry another portable amp (as well as spare 9 volts batteries) along with the Mojo will greatly affect the portability factor, and thus is less than ideal in my mind.  Again, the Mojo's do-it-all appeal win me over the Pico Power here as well.     
 
Comparison with mid-range desktop amplifiers with DAC options
 
 

 
The Mojo performed admirably against several mid-price desktop DAC/amplifiers in my possession -- namely the Questyle Q192, Headroom Ultra Desktop Amplifier/DAC, and Geekpulse X. Overall, the Mojo fell just short compared to the Q192 at driving the HD800 -- losing out slightly on the depth of the soundstage, bass impact, and overall tonality. The Mojo's presentation is more upfront and neutral compared to the Q192. However, the HD800 tends to thrive with a warmer/bassier amp, and here the Q192 is able to supplement the HD800 better than the Mojo. After all, the Q192 was designed and voiced for the HD800 in mind.    
 
Next I put the Mojo up against my Geek Pulse X. Yet again, the Mojo didn't get embarrassed next to the more expensive Geek Pulse X. In fact, the Mojo delivers more authoritative bass impact, providing a better sense of speed on both the single-end and balanced outputs with my beloved Sennheiser HD-800. I prefer the Mojo over the Geek Pulse X in single-end operation, but the Pulse X manages to pull away from the Mojo once its balanced headphone output is utilized. With balanced output engaged, the X pulls ahead in soundstage and layering, while also providing a more effortless and laid-back performance. Despite falling a little short compared to these mid-priced desktop units, I still came away extremely impressed with the Mojo's overall sound quality and ability to compete in a higher weight class. The Mojo is the only truly portable DAC/AMP device of this group.  
 
Sound Quality as a DAC
 

 
 
In this test, I compared the analog output of the Mojo against that of the Geek Pulse X, Questyle Q192, and Denon 300USB DAC. Again, the Mojo stood up well to the full-sized desktop AMP/DAC competition. Tonality wise, the Mojo is the most neutral of the group, with the Q192 being the most lush. The Mojo managed to edge out the Denon, due to the former's lack of grain. The Mojo's only shortcoming is its inability to match the depth cues and layering portrayed by both the Q192 and Pulse X. Overall, I found these four devices to be relative close in performance, with the Pulse X & Q192 tied for the first place, following by the Mojo and then the Denon. 
 
Last Words
 
At $599, the Mojo offers tremendous value for the money, given that it surpasses all of the high-end DAPs and portable AMP/DAC in my collection. It works well with a wide range of different headphones, and has proven to stand up well against the bigger and pricier mid-level desktop models in my possession. Sonically, I find a lot to love and very little to fault with the Mojo. Sure, I wish that the Mojo could be a little more resolving, with a better sense of layering, but this is a whole lot to ask from a portable device roughly the size of a cigarette box! Additionally, it can be used as a DAC to feed your secondary system. I think the magic in the Mojo is its voicing and the tremendous work in its DSP. Chord has done it again, and this little Mojo has earned my strongest recommendation – in my opinion it's become a new benchmark in the portable DAC/Amp segment.