Chord sent me their portable DAC/amplifier combination, but I'm sure anyone reading this already knew that; the thing is near famous in its area. I've had a lot more fun with it than I expected to, and am very impressed with what Chord has put together here.
The Mojo is a small black box, which is thankfully, truly pocket-able. It's made of anodized aluminum, with some cutouts and chamfers, featuring etched logos throughout. What makes it instantly recognizable however are its marbles. They are locked in the casing by design, and essentially just sit on normal dip switches for operation. This was one of my favorite parts of the device, aside from its performance, as playing around with them is quite a lot of fun, however childish that may sound; it served to keep my hands busy when just listening to music.
The marbles light up when the device is turned on, with the power marble indicating the sample rate currently being used and the volume marbles changing smoothly as you increase and decrease the volume. I found it a little bit funny that if someone were to ask me what volume setting I used to power a certain pair of headphones, I'd have to tell them "red" or "green", not a tick-number indication. Near as I can tell, there are about 150 actual ticks of color (and by consequence, volume) adjustment, although that is just an estimate. There are certainly enough to comfortably achieve any volume that you desire for any pair of headphones, though.
The inputs available are a coaxial 1/8" port, capable of up to 768 kHz/32-bit audio, a micro-USB signal input, capable of up to 768 kHz/32-bit audio, an optical TOSLINK port, capable of 192 kHz/24-bit audio, and a 1A micro-USB charging port, capable of charging the device.
Available outputs are two identical 1/8" auxiliary ports. Neither are balanced, one is not higher gain; they are exactly the same. This struck me as somewhat odd, as I would imagine it would be fully within Chord's ability to make one of them a 1/4" port, or making one of them a balanced 1/8" port. I think that either would push this product a little bit further into the high-end range of portable DAC/amps, but it wasn't a major point of contention for me, personally. As an aside, this feature was actually great for me, as it allowed me to directly A/B (or as near as possible) the 1More Quad and Triple driver, which happened to be on my desk at the same time as this. I'm not sure whether this review will come out before those or not, but if it does, know that those are both on their way soon.
I'd like to take a moment to give out all of the specs for the Mojo, since it is an admittedly impressive list. It features a Chord Custom FPGA DAC, which is trickle-down technology directly from their very high-end products, such as the Dave. It has a listed battery life of around 10 hours, which I found was consistent with my use. In line-out mode, which can be accessed by holding down both volume buttons while turning it on, it outputs at 3.0V (to a preamplifier or what-have-you). Chord claims support of up to 800 Ω headphones, which I believe is likely true, although I don't have anything of that high impedance to test with. They powered my Cascadia Audio Talos perfectly fine, which is a modification of the notoriously hard-to-drive Fostex T50RP Mk III. It can output .720W into a 32 Ω load and has an output impedance of 75 mΩ. It's total harmonic distortion at 3.0V RMS output is a very satisfactorily low .00017%. Not as low as the Neurochrome HP-1, but certainly more than up-to-par with current, de-facto industry standards. And finally, it is DSD 256 (4x) capable via DoP. I don't personally use anything near that resolution, as FLAC serves me just fine.
Here's where I always rub a few (read: many) people the wrong way. The electrical reality of solid-state amplification is that, beyond a certain point, solid-state amplifiers will sound the same. The best that a solid-state amplifier can ever do is convey the music from the file to the listener through any headphones with no noticeable coloration or distortion. This DAC/amplifier does exactly that. Never did it introduce any distortion, clipping, jittering, or other general unpleasantness, with any headphone that I tried at pretty much any volume level. This sounds like a denigration, and I understand that, but it is the absolute highest compliment that I can give a solid-state amplifier of any kind. Sure, it doesn't have quite the absolute, unparalleled transparency that the HP-1 does, but nothing I've heard since has. This product faithfully portrays the music as the artist/producer/mixer intended it with great fidelity and no noticeable errors. I commend Chord for this. As a side note, something else that I appreciated was that this isn't a headphone amplifier that you have to carefully bring up when using very sensitive headphones; it has room to make small adjustments in volume with any headphone, and that was appreciable in use.
In sum, this product is pretty amazing. Powerful enough to handle any headphone that I can think of that is on the market right now, with a plethora of inputs, especially for a truly portable device, it holds its own with products more expensive and much less deftly designed than it. Sure, it could use a balanced output or a 1/4" output, but aside from that, it is a very solid win in my book. The somewhat retro design sets it visually apart from other devices in its class without breaching into the realm of tacky, and the technology inside, whether you agree with my standpoint on solid-state amplification or not, is absolutely rock solid.
This product was provided to me for review by Chord. I am not being paid by anyone to write this review, to endorse the product reviewed, or for the content that I put in the review.
The signal for this amp was provided by USB from my computer and by USB from my Pixel.
I have had this product for about 3 weeks, and have used it for about 50 hours.