Groovy baby. Yeah! How portable audio got its mojo back.
With reportedly more than 70,000 units sold since its October 2015 release, Chord’s Mo(bile) Jo(y) has become a personal Hi-Fi style and design icon. Immediately recognizable and passionately loved by many, the Mojo remains a staple for audiophiles on the go. Now 4-years after launch, I’ll be taking a look to see if it still lives up to all that hype and if it really can bring portable happiness.
Chord Electronics was founded in England in 1989 by owner and chief designer, John Franks. In 1989, the revolution to CDs and digital music was just getting underway. Located in an old pump house building (built in the late 1800s), in a small town called Maidstone, Chord set out to improve the musicality of digital sources.
With the addition of lead engineer, Rob Watts in 1994, the recipe for Chord’s success was in place. Over the years, Chord has garnered a reputation for British made, studio-grade audio performance in both their consumer and professional products. Their amplifiers are in use at the BBC, Abbey Road Studios, Sony Music New York and the Royal Opera House in London.
Chord’s products are known to have a distinctive and quirky design, paired with outstanding build quality. The Mojo is no exception. Out of the box, the Mojo is surprisingly small, solid-feeling and heavy. Imagine a deck of cards made out of black aluminum and you are getting in the right ballpark. The iconic multi-colored roller-ball buttons are just as retro-cool as the pictures indicate.
I love the look and feel.
I remember there was a time (not so long ago) when I thought the Mojo looked a bit odd. The entire Chord esthetic was lost on me. Times change and I’ve grown to (very much) appreciate their unusual design. Now let’s see if I love how it works as well.
- Delightful design.
- Impeccable build.
- Luscious sound.
- It can get hot with use, and…
- Excessive heat reduces battery life, and…
- Chord’s battery replacement service is silly expensive!
- Charging Input: 1x 1amp Micro USB Charging Port
- Usb Input: 1x Micro USB 768kHz/32-bit Capable Input Port
- Coaxial Input: 1x 3.5mm Jack Coaxial 768kHz/32-bit Capable Input Port
- Optical Input: 1x Optical TOSLINK 96kHz/24-bit Capable Input Port
- Output Jacks: 2x 3.5mm Headphone Jacks
- Output Impedance: 75mOhms
- Dynamic Range: 125dB
- THD @ 3v: 0.00017%
- Output Power @ 1kHz – 600Ω: 35mW
- Output Power @ 1kHz – 8Ω: 720mW
- Weight: 180g (0.4lbs)
- Dimensions: 82mm (l) x 60mm (w) x 22mm (h)
Simplicity is the name of the game here. The Mojo comes nestled in a small black cardboard box. Slide off the top and you will find the Mojo ensconced in white foam and wrapped in a protective plastic bag. Under the Mojo is a 10cm micro USB cable that can be used for charging or for connection to a source (phone, computer, transport, etc.).
The sample rate frequency guide is printed on both sides of the slip-in box. This is a 10-step color chart ranging from 44 to 768 and DSD. Since the power button, volume buttons and the battery state indicator LED all cycle through colors to indicate level, it would have been nice to include these visual graphics on the other side, rather than repeating the same frequency guide information on both sides.
No manual is included, so Chord must expect users to have some experience in hooking up such devices or to read the online manual.
DSD files are decoded without decimation to PCM. The Mojo incorporates trickle-down DAC technology from Chord’s own higher-end Hugo series and Dave products.
Chord uses a unique DAC implementation based on FPGA technology. An FPGA (field-programmable gate array) is an integrated circuit (IC) that can be programmed after manufacture. But more on this later.
Designed and built in England, the Mojo features a solid CNC milled aluminum shell with distinctive frosted marble-style LED indicator buttons. It features USB, coaxial and optical digital inputs and two 3.5mm headphone jack outputs.
The Mojo won the ‘What Hi-Fi 2018 Awards’ for ‘Best DAC 300-500 pounds’. It also won the ‘EISA Award Best Product 2016-2017’ for ‘USB DAC/Headphone Amplifier’
Round Glowing Balls
Undoubtedly the most distinctive design element of the Mojo is the three round glowing buttons. These function as multipurpose indicators of volume level and bit rate, while also being volume and power controls.
Depress the power button (the slightly further away marble) for 3 seconds or so and the Mojo powers on. The power button cycles through a rainbow of colors and with an audible click, it’s ready to go. The brightness of the LEDs can be toggled from (LOOK AT ME!) bright to (a much subtler) dim by pressing the volume up and volume down buttons simultaneously.
The power button will not illuminate if the Mojo doesn’t pair successfully with the source. Low-quality USB cables or those over 1.5m long are not recommended.
I did experience audible digital artifacts when using the Onkyo Music app on my old Alcatel Android phone. I improved things using the USB Audio Player Pro app and after playing around in the settings, but I never got it to sound as clean as with the iPhone. I ordered a Fiio OTG cable to see if this resolves the issue, but it has not arrived in time for this review.
At the lowest and highest volume levels, one LED will stay a static color while the other cycles through the rainbow of colors for very fine volume control. This can be useful for dialing in a comfortable volume with extremely sensitive IEMs.
The Mojo can support line-level output for use with an external amplifier or speaker system. When powering on the Mojo, hold down both volume buttons to set the volume to a standard output level (3V) for typical line-out usage. Both volume balls will illuminate light blue.
The Mojo does not have a separate amplifier section, as the output comes directly from the DAC circuit (albeit with the addition of analog circuitry). This means that any volume level can be used as a line-level output without degradation of signal, nor is any need to “bypass” the amplifier circuitry for the highest quality signal.
Although the Mojo has a pair of 3.5 mm outputs, it is single-ended only and does not support a balanced headphone connection. It was designed to output up to 5V, which should be sufficient to generate 120 dB of sound cleanly into most headphones. Chord claims support for up to 800 Ohm headphones, and I can attest that the Mojo will power the 600 Ohm Beyerdynamic T1 with aplomb.
Sticking with single-ended architecture also means the Mojo doesn’t need to double its internal circuitry and thus it maintains its small size. This avoids some of the potential issues with balanced headphone connections, while maintaining an impressively high-power output for a portable device.
The Mojo features 3 different digital inputs: coaxial, optical and USB. Input selection is automatic and by default, the Mojo will always select the USB input if this is plugged in. Input priority is in the order: USB – Coaxial – Optical.
Battery and Charging
Battery life is approximately 8 hours and it takes about 4 hours to charge the Mojo using a 2A 5V charger. There is a small LED indicator located below the micro USB charging port that changes color to indicate the battery level.
It is possible to listen to the Mojo while charging, but the charge will take longer than if the Mojo is powered off. This will also make the Mojo quite warm. There have been reports of unwanted audible noise and hum being introduced by certain chargers, so it may take some trial and error to find a charger that works for you.
Mojo Magic. What Makes It Different?
An FPGA (field-programmable gate array) is not a dedicated DAC but is a multi-purpose chip that can be programmed to make virtually any digital device. It has much more processing power than typical audio chips. Rob says the “…Mojo has 500 times more processing power than conventional high performance DACs.”
Rob believes that extremely high precision digital filtering is the key to extracting the highest quality sound from the digital to analog conversion process. In his words, the “filter’s job in a DAC is to re-create the missing parts of the original analogue signal – the signal in between one sample and the next.” The sampled signal data is stored and then “tapped” in order to access it.
“…when I was at university, I studied electronics. But I was passionate about audio, and was interested in the physiology of hearing…what I did learn was that transients were a very important perceptual cue, and that the timing of transients was crucial. From transients the ear brain locates sounds in space, it is also used to compute pitch (particularly for bass) and it’s used for getting the timbre of an instrument…
…it is a fact that if you had an infinite tap length FIR filter you would perfectly reconstruct the original bandwidth limited analogue signal… it was very clear to me that having a limited tap length would create timing errors.” – Rob Watts
Critics of Rob’s work cite that his listening experiments are sighted and unscientific, but Rob passionately maintains that sound quality is directly related to the precision of the filters. He claims that this results in decreased jitter, noise and distortion.
The Mojo came out about 2 years after the Hugo was initially developed. In that time, chip technology had radically changed. The chip inside the Mojo is approximately four times larger and much more powerful than the Hugo FPGA chip which supports about 27,000 taps.
Upsampling and More Filtering
All of Rob’s DAC designs upsample to 2048 times (about 16 times more than is typical). Often it is recommended that the source does any upsampling before the signal is fed to a DAC. This is not the case with the Mojo, as additional filtering is done when the Mojo upsamples the signal.
Hot Topic Concerns
What makes the Mojo special is also the cause of some concerns. All that processing power in the FPGA chipset has an unwanted side effect: heat. And we all know that heat is the enemy of electronics and batteries.
You should expect the Mojo to get noticeably warm when playing music and when charging (especially when doing both simultaneously). The Mojo uses 1.7W of power when in use, and charging will add approximately another watt, but it does have three independent thermal cut-outs to prevent any internal overheating damage. The Mojo can never get hot enough to cause any burns or damage.
The Mojo uses its beefy aluminum case to dissipate heat (the battery and electronics are thermally connected to the case), so the surrounding temperature has much to do with how warm the device will feel. If the Mojo is wrapped or insulated, this will tend to cause it to heat up to a much greater degree.
All that being said, there are a number of online user reports of greatly reduced battery life after a few years of use (whether it be attributable to charging habits or to heat is debatable). Regardless, the battery is located directly above the hot chip. What is very disappointing is the reported $200 replacement cost for a new battery from Chord.
The Mojo is somewhat susceptible to EMI/RFI interference when tethered to a phone and I did experience occasional telltale electronic buzzing and clicking noises. It was not especially prone and really no worse than any other portable DAC/Amp that I’ve used. Of course, engaging airplane mode on your phone eliminates this.
The final concern that I want to mention is one of design. I don’t mean the quirky esthetic shape and size, but the decision to streamline all controls and indicators into 3 pushbuttons. This interface will not appeal to everyone.
The iFi xDSD uses similar, but very tiny, multi-color LED indicators to inform the user of bit rate and volume level, but in practice, I found the xDSD a bit unfathomable.
The difference compared to the Mojo is one of complexity. Where the xDSD is overflowing with features and a multitude of tiny LEDs (for 3D+, XBass, kHz, and INPUT), the Mojo is much more refined. The round buttons on the Mojo are sufficiently large and simple enough to comfortably see and interact with.
Where I found the Mojo user interface to be intuitive and elegant, I can see some folks struggling with the integrated controls, or preferring a standard twistable volume pot, or wishing for something other than an arbitrary color as an indicator. If nothing else, iFi and Chord could (at the very least!) include a chart on the case listing LED color with the associated description or value.
The performance of the Mojo has been measured by several reputable sources including Stereophile, Ohmimage, and AudioScienceReview. Stereophile summarized their results with “…the Chord Mojo offers measured performance that is superb for a portable device, and would not be out of place in a high-priced conventional D/A processor.”
Ohmimage was just as enthusiastic, stating “…Mojo blows by most if not all hi-end DAPs. It blows by many, if not most bleeding-edge desktop DACs and headphone amps. Sure, they may supply more voltage into high-Ω loads, but no all-rounder I’ve tested even comes close. Not even close.”
AudioScienceReview was much less excited in their conclusion regarding the Mojo’s measurements. It should be noted that the “…point of the review here is to check on technical superiority of the design because that is what Rob advertises.” Concerns seem mainly focused around the issue of price vs performance and if it lives up to the designer’s claims.
“There is really nothing broken in Chord Mojo. It performs well in a variety of tests. The issue with it is so much technical hype about its superiority that one is left empty after seeing performance that is well below state-of-the-art.
We have DACs at less than half the price easily outperforming it on many tests. I cannot see any technical benefit to its design approach. On the contrary, that approach brings with it much higher cost, and power consumption. Combine that with the poor user interface and the Chord Mojo is simply not my cup of tea.” – AudioScienceReview
It should be noted that the AudioScienceReview measurements were done solely with the USB input. However, depending on the source, each digital input may sound different. Rob explains why the different inputs may sound better or worse:
Mojo is primarily designed as a portable device. Yes, it can be used as a stationary desktop DAC, but let’s face it, internal battery plus compact size equals portability. This means the bulk of my listening was completed using my Apple iPhone X. However, the comments in this section are my generalizations for all sources unless noted.
Ironically for a tiny portable device, I found the Mojo to shine the most with full-size headphones. Not to say it doesn’t work great with IEMs, but the diminutive size belays the power and ease that it can drive difficult-to-power large cans. Got the 600-Ohm Beyerdynamic T1? No problem here.
It isn’t just the power that impressed me when listening to the Mojo powered T1. I’ve paired the T1 with a number of amps, both tube, and solid-state, in an effort to tame their clinically unforgiving high-end. Somehow the diminutive Mojo combines shockingly well with the notoriously upper-frequency focused T1.
I think this speaks directly to the overall sound signature of the Mojo. It’s a warm, detailed and musical sounding little device. If anything, while the high end Is smooth and without grain, it may roll-off the highest-frequencies a touch. The treble comes across on the relaxed side and is just the ticket for taming an upper frequency dominant can like the T1 without losing clarity or a feeling of transparency.
The overall impression is of listening to a much larger amp, one that is on the warmer side of neutral, powerful but tightly controlled. The bass response is very full and oh-so-smooth-sounding up into the mid-range. Resolution and detail reproduction are terrific. Vocals and instruments have a natural but weighty quality.
I tried a variety of full-sized headphones from the challenging-to-drive MrSpeakers Alpha Dogs, to the Sennheiser HD58X and the Meze 99 Classics. Regardless of design, sensitivity or impedance, the mighty little Mojo drove them all effortlessly.
Did I mention you can plug in two headphones at once? Other than dramatic volume differences between headphones of different requirements, two folks can simultaneously listen to high-quality headphones with superior sound.
The Mojo brings out the best qualities of the headphones that are connected. The bright T1 feels warmer and fuller. The occasionally loose lower end on the 99 Classics tightens up. The mid-bass becomes a visceral presence in the music that demands head-bobbing and toe-tapping (yet without becoming overbearing).
But didn’t you say this thing is all about portability? Who cares about full-sized headphones, what about sensitive IEMs?
Plug in your favorite IEMs and you are greeted with blessed, wonderful silence. No background noise or hiss and yet gobs of power on demand. Just what you (and I) hoped for.
Keep in mind, this is not a sterile sounding device. Perhaps due to the power reserves, the presentation feels immediate and up-front, rather than laid back. Regardless of what IEM or full-sized headphones I tried, the character of the Mojo engaged me with the music.
I genuinely love the tonality of the Mojo. This is what music listening is all about. Pop on your favorite cans, queue up that new album and get lost in sonic bliss. Or dare I say “joy” in a “mobile” form?
I happen to have a couple of similar battery-powered DAC/AMPs that have made the journey through headphone audio with me. I really like both the JDS Labs C5D and the iFi Nano iDSD and they have honestly done yeoman’s duty over the last few years. Neither the C5D nor the Nano iDSD are still in production.
iFi Nano iDSD is smooth and a smidge warm sounding. It cost about $200 and was released a bit before the Mojo. It supports up to 384KHz PCM and 12.4MHz DSD. It served as my primary desktop DAC until being recently ousted by the Khadas Toneboard (review within my NhHybrid article).
The JDSLabs C5D costs about $250 and only supports up to 24/96 playback. It sounds quite clean and clear but suffers a bit from being a little thin sounding for my evolving tastes. I find I often use the first level of bass boost on the C5D to add a bit of punch and warmth to the sound (depending of course on the music being listened to).
The Mojo does not have a bass boost circuit, nor gain controls and frankly, those additions would be entirely unnecessary. The Mojo low end is tight and punchy, controlled but very present in the sound.
The iFi and the C5D, while both being fine devices in their own right, are simply outclassed by the Mojo. Power, clarity, presence, and warmth are all on a higher level.
A worthier competitor may be the iFi xDSD. Although with its wireless capabilities, it is closer to a Mojo+Poly combo. I didn’t fall in love with the xDSD, but compared to the price of the Mojo+Poly, the xDSD does come across as an attractive and affordable alternative. Sound quality (even via Bluetooth) was transparent and top-notch.
Yet, the Mojo just has an ineffable quality about it. The sum of the design and performance seems to add up to more than just the parts.
Well. What is there left to say?
The Mojo is a beautiful little doodad. It has more than earned its reputation as a portable device that others must be measured against. It has superb build quality, an iconic design, a simple interface, and outstanding format support.
That all wouldn’t be worth much if it didn’t sound so darn good.
Fortunately, the Mojo embodies all the standard audiophile descriptions for worthy sound. It’s oh-so pleasing and engaging. It’s warm and musical, balanced but energetic, clean, clear and transparent. Detailed and natural. Powerful but controlled.
Oh yes. I like the Mojo.
Is it absolutely perfect? Not quite. A switch to disengage the battery for dedicated plugged-in desktop use would be great. A $200 battery replacement is frankly ridiculous. And hey companies, if you are going to use a multitude of colors as indicators, engrave the values on the case!
Does mojo mean confidence, energy or enthusiasm? Is it success? How about sex appeal? Perhaps bewitchment or enchantment? In the case of Chord’s Mojo, the answer is yes.