Like the Hugo, the Mojo is designed with the thought that its sophisticated digital functions should be implemented through circuitry and firmware that consumes as little power as possible, while creating as little noise as possible. This approach leaves the lion’s share of the unit’s battery power available to drive Mojo’s very efficient, low noise, discrete analogue audio section. Chord specifies the Mojo’s maximum power output as 720mW @ 8 Ohms with THD of 0.00017%, which is more than adequate to drive today’s more demanding full-size headphones. The result is a tiny little portable amp/DAC that in every way sounds like a truly sophisticated, full-size desktop unit (or perhaps even better than that). Chord claims the Mojo provides, “state of the are 3μV output noise with 5V output voltage, (yielding) 125dB dynamic range.”
Unlike some competing portable headphone amp/DACs, neither the Hugo nor the Mojo provides (or requires) master gain adjustment switches so as to accommodate sensitivity differences between power-hungry full size headphones and ultra easy-to-drive CIEMs. Chord’s staunch position is that, when DAC and analogue circuitry are appropriately low in noise, gain switches not only are not necessary, but also are potentially detrimental to sound quality. To put that claim to the test, I listened to the Mojo through my HiFiMAN HE 1000 and Edition X full-size headphones and through my Noble Audio 4S and Westone ES60 custom-fit in-ear monitors. I also did regular comparisons between the Mojo and the Chord Hugo that I use as my portable amp/DAC reference. In every instance, the Mojo had more than ample power for the full-size headphones, yet was so quiet that it proved absolutely enchanting when used with my CIEMs.
Now we’ve come to the point where we can focus on the aspect of the Mojo we care about most: namely, its sound. If I had to summarise the Mojo’s sound with just three descriptors, the three I would choose are these: natural, organic, and authoritative. Let’s talk about each in turn.
When I say the Mojo sounds natural, I mean that it renders musical timbres, textures, and transient sounds in a wonderfully believable and unforced way. As you listen, there is less a sense of being in the presence of bowls-you-over grade ‘great hi-fi’ and more a sense of effortless connection with the real-world sounds of human and instrumental voices. In short, the Mojo invites listeners to focus less on the constituent elements of sounds and more on the overarching whole. Note that this does not imply any sort of lack of transient or harmonic information, since the Mojo does a terrific job on both counts. Rather, it is more a matter of proportion and balance; instruments and voices simply sound like themselves, without any artificial spotlighting or underscoring of their sounds merely for ‘dramatic effect’. It’s the sort of quality you might not notice in the first 30 seconds of listening, but after enjoying a track (or album) or two one gradually becomes aware that virtually every piece of musical material the Mojo touches seems to come out sounding spot on.
This quality became most apparent to me in listening to pianist Alfred Brendel’s performance of Mozart’s Fantasia in C minor [Mozart: Favourite Works for Piano, Philips]. One of Brendel’s great gifts—especially for this music—is that his performances typically are less about pianistic flash and pyrotechnics, and more about subtlety, fluidity, and masterful touch. The Mojo played right into this schema as it, too, is capable of revealing (but never overplaying) almost infinitesimal shifts in phrasing, dynamics, and—here’s that word again—touch. When you listen through a Mojo, you can’t help but sense that you and your music are in good hands.
The Mojo’s organic quality focuses specifically on the timbres and distinctive attack and decay characteristics that are the defining ‘signatures’ of the instruments we enjoy hearing. To borrow a term from contemporary architectural discussions, I found the Mojo handily reveals the ‘materiality’ of the instruments in play. Thus, acoustic basses sound realistically large and ‘woody’, trumpets sound incisively articulate and ‘brassy’, tubular bells sound, well, believably tubular and ‘metallic’, and so forth. These might seem like perfectly ordinary things that all DACs and amps should do, but in my experience they are not as simple or ordinary as you might think. The difference I mean to point out involves the quality of authenticity; many DAC/amps can give you a fair simulacrum of the real thing, but the Mojo (like the Hugo before it) steps things up several notches in terms of realism, believability, and timbral accuracy.
One track that brought this organic quality home for me was the title song “Gaucho” from Steely Dan’s album of the same name [Gaucho, Geffen 24/192]. The track at one point features a stunningly beautiful sax solo, and through the Mojo I found I could fairly sense the shimmer of the horn, the touch of the performer’s fingers on its pads, and the distinctive and expressive rasp of its reed. I wasn’t hearing a simulation of a horn, but rather something much more like a real horn in play.
Finally, the Mojo sounds authoritative, by which I mean that it figuratively grasps music (any kind of music) by the scruff of the neck, gives it a good shake, and then breathes life into the performances at hand. This holds true even on powerful and at times raucous rock material played at considerable volume. A perfect example would be the track “We Are Finding Who We Are” from King’s X’s Faith Hope Love [Metal Blade]. Bassist/vocalist Doug Pinnick’s thunderous yet articulate bass lines and penetrating lyrics have been known to overwhelm lesser portable amp/DACs but the Mojo took them in stride with casual, confident ease. That last quality—the ability to handle potentially difficult passages with palpable ease—is what the Mojo’s authoritative sound is all about.