First thing I always notice in any audio setup is the soundstage, imaging and instrument presentation & separation.
All of the above are the `forte` of Chord Mojo. Really amazing. Since these things are so so important to me, I was damn impressed and even depressed that I didn't buy these. I gave it more days. By the end of the week I had my thoughts clear. I loved the Mojo, enjoyed it. But in the long run, I like my XD-05 or for the matter the Fulla 2/Opus #11 more than Mojo. Indeed Mojo is technically superior. But it doesn't reproduce the instruments as purely as others do.
The low end & bass on Mojo are really tight. I didn't find it deep enough. It may be able to reproduce very eep bass tones but they are well rolled off. Deep bass is there, but it is rolled off and laid back and under represented compared to mids and lower treble. Now, it excels in detailing. Low end is clean and detailed. You can hear all the details. If the roll of was controllable it would really add to the awesomeness. Mids are what I like Mojo for. The vocals sound very nice due to excellent mids. It is this part of the spectrum where Mojo kills others. Excellent, just excellent. Very smooth, detailed, attack and decay of notes overall is spot on. There is nothing to complain in this part.
Now treble is where my major complain lies. It is very very clean and clear. It isn't natural though. The treble/highs on the Mojo sound (here I'm struggling to find proper words) somewhat unnatural. Also, the treble extension can feel artificial sometimes. I am still confused whether it had enough trebles extension or it was just a result of the sheer cleanliness of sound and somewhat thin unnatural highs. Not a lot of people are going to notice things in such detail. The sweet n smooth sound coupled with immensely precise soundstage and instrument clarity makes you forget everything else. You don't actually notice the few flaws that it has.
The flaws are not really a deal breaker for me. If I had not bought the XD-05 I would buy the Mojo for the clarity and try to mitigate the flaws using an appropriate AMP. Btw, headphone out on Mojo is cleaner than line out on most DAC's.
Given the price, for a portable setup there are still competitors like iFi Nano iDSD Black Label.
For the desktop setup, though Mojo is pretty powerful and great DAC, for the price I would rather consider the refurbished (discontinued) Audeze Deckard (Pure Class A) or the Matrix M-Stage HPA-3U+ (Not really a pure Class A, it uses op-amp in gain stage, IIRC).
Interested enough to check the CHORD MOJO? Click here.
Check out my review of the Astell&Kern Billie Jean wherein I explain in detail various aspects of the headphone including its design, comfort, and performance. Has Astell&Kern outdone itself with the quality and performance with its Billie Jean. Click to find out!