Head-Fi Buying Guide (Portable Amps, DACs, & DAPs)
- Author joe
- Publish date
- Article read time 44 min read
Chord's original Hugo was something of an unusual revelation for me. I was quite used to thinking that high-end DACs had to be big, power-hungry beasts in heavy aluminium cases, and indeed top-of-the-line models generally are. As digital conversion with any serious degree of accuracy requires a very high degree of precision in the components, all that weight goes into both eliminating noise from the digital circuits, generated both from power supplies and by the digital conversion chips themselves.
To have my current DAC at the time knocked off its crown by a small, battery-powered box was crazy to say the very least. In the conclusion to my Hugo review, I wrote: Warren [Chi] commented: 'Someone send this to Chord as my non-impression impressions: "Hey you guys, I've come to a decision... I've been thinking about it for a while now, and I want y'all to be the first to know. I do NOT want to listen to the Hugo. I don't want to try it out, I don't want to be in any reviews of it, nothing. It's like a couple grand, and EVERY M****F**** WHO HEARS IT BUYS ONE."'
Since Chord had released the Mojo, which was only a bit behind the Hugo in sound quality, for a quarter of the price, it remained to be seen how Chord would improve on their design.
The community had not been lacking in their criticisms of the ergonomics of the original and the Hugo 2, while much the same size, has changed quite a bit.
To start with, like the Mojo, the Hugo 2 has separate micro-USB port for charging and input. However at least a 2.1A charger is required for continuous use, or the Hugo 2 will only show that it is charging at half the rate it is capable and the battery will eventually run out if left on all day.
With the included or similar powered charger, if the Hugo 2 is left connected to power, fully-charged, for 24 hours, it will switch into "desktop mode", indicated by a change in the colour of the power button, and bypass the batteries entirely, preventing their deterioration. To aid that, a fully-functional remote control is now included.
Most interesting are the two screw holes on that side, with word that there will be a future "2go" for the Hugo as there is the Poly for the Mojo.
The Hugo 2 maintains it’s plethora of inputs, but adds a second coaxial digital input allowing connection of an M-Scaler. While no portable version currently exists, it does suggest that in the future some serious portable digital hardware might be available to connect to it.
The 6.3mm and 3.5mm outputs are now flush with the body, good for those people who have cables that use the big Canare or similar plugs that wouldn't work with the original Hugo. However the RCA sockets of the Hugo 2 are still recessed, so users of cables with very large RCA plugs are going to have issues.
Most importantly is that the Hugo 2 is a significant step up over the original when it comes to performance. With around double the number of taps, courtesy of more serious FPGA power and Rob Watts’ code. The $2000+ DAC market is very fiercely contested, primarily by Schiit Audio’s Yggdrasil, which has just had upgrades, and Audio-gd’s new R2R 7, as well as the emergence of other R2R DACs in the last year.
When I reviewed the Chord Dave, I wrote:
Within a minute of plugging my HD800s into the DAVE and beginning to listen I knew immediately I wanted one. I also knew that any language I'd used to describe DACs before was useless. Normal questions about the sound, such as those relating to tone, texture, detail and distortion, do not exist, as what I felt I was experiencing was something else entirely from what I'd experienced before.
The Hugo 2, with top headphones, has some of that magic, seemingly able to tap into the very atmosphere in which a recording was made, going beyond realistic instrument reproduction, into expressing the very feeling of an entire recording.
It wasn't too long ago that I used to say that one couldn't have a good enough DAC to go with a Stax rig, such was their resolving ability. Now I can say the same about Focal's Utopias and HiFiMan's Susvara, as they revealed things about my system I didn't know it was capable of. However now I can say, almost in reverse, that you cannot have a good enough system for the Chord Hugo 2, such is its ability to bring out the actual music, and what is more, you can take the experience with you when you travel too.
The Chord Hugo caused a huge stir in the headphone audio community when it was released back in 2014 at CES. It was the first serious attempt at penetrating the portable audio market for venerable British Hif-Fi manufacturer, Chord Electronics. And it was a runaway success. The subsequent release of the even more portable (and affordable) Mojo enabled the Chord sound to reach many additional consumers for whom otherwise the stretch to a Chord DAC product might have been too far.
The Hugo ("you-go") concept was to create an all-in-one portable device, meaning a DAC, preamp, and headphone amp, along with DSD and high-res PCM capability, aptX Bluetooth, and a useful crossfeed function. But perhaps the real highlight of the original Hugo was the FPGA (field-programmable gate array) design of the DAC that Chord’s Lead Designer, Rob Watts, used as opposed to using an off-the-shelf commercial chip. I remember my first listen to the Hugo and being wowed at the time with the sense of realism and engagement.
Fast forward to 2017 and the highly anticipated Hugo 2 was announced in January, again at CES. After several showings at CanJam in NYC, Singapore, Los Angeles, and London, the Hugo 2 finally became more readily available to the consumer market this past summer. Was the wait worth it? You bet it was.
The Hugo 2 builds on the success of the original Hugo while making significant upgrades both in terms of performance and ergonomics. From the revised casework to the glowing and color-shifting spherical control buttons that give users visual cues as to the current settings on the unit, to the enlarged RCA output jacks, to the more solid micro USB connection points, the Hugo 2 has been completely overhauled. The included remote control is one of my favorite new features as this adds so much flexibility when using in full-size and desktop systems, as I do.
Under the hood, the Hugo 2 utilizes the next generation FPGA Xilinx Artix 7 chipset which upgrades the 45nm Spartan 6 used in the original Hugo. This translates into an increased tap-length capability from 26,368 to 49,152 using a 10 element Pulse Array design. More taps means a more finely tuned conversion response and combined with a newly revised output stage will provide, according to Chord, lower measurable harmonic distortion than the original Hugo.
The Hugo 2 is an all-in-one unit as its predecessor and combines a plethora of of inputs and outputs including micro-USB, digital optical, digital coaxial inputs, and RCA, mini (3.5mm) and ¼ (6.3mm) headphone outputs. Charging is done via a separate micro-USB connection and the unit can remain plugged in continuously whether in actual use or turned off. After 24 hours on a constant charge, the Hugo 2 will enter into Intelligent Desktop Mode where the battery is neither charged or discharged.
One of the key features of the Hugo 2 is the ability to tailor the sound using the built-in sound filtering options as well as the crossfeed function. The filters range from white (neutral incisive), green (high frequency roll-off), orange (warm), red (even warmer). These filter options in combination with the 3 settings of X-PHD crossfeed (min, med, max) can come into handy when faced with different music genres, levels of recording and/or file quality, and mood. My reference is the white filter but I also use green and red on occasion.
The sound quality of the Hugo 2 is for me, a significant step up from the original Hugo. It’s increased resolution, dynamics, and sense of timing enable me to get closer to my music and the fact that I can also use this a transportable device is icing on the cake. Although most of my listening is done using the Hugo 2 as DAC only feeding an external tube headphone amplifier, using the Hugo 2 on its own injects an increased level of immediacy and engagement. The Hugo 2 can pretty much drive any full size headphone (with the exception of the some of the harder to drive Hifiman headphones such as Susvara and HE-6). The headphones and in-ears I mostly use directly out of the Hugo 2 are the Focal Utopia, 64 Audio Tia Fourte, and Campfire Andromeda, all of which sound fantastic directly driven from the Hugo 2.
The Chord Hugo 2 retails for $2379 (USA). For anyone in the market for a DAC upgrade in this price category or for those looking to make the jump into their first high-end headphone audio rig, the Hugo 2 is a fantastic solution. With the added benefit of being able to go wherever "you-go". Enthusiastically recommended.
At the 2014 CanJam @ RMAF, an audio industry friend and I were chatting about gear we've been enjoying, and I mentioned the Chord Hugo. "Have you checked out Aurender's Hugo competitor?" he asked? When I answered I hadn't, he insisted I should. As chance would have it, I later ran into ComputerAudiophile.com founder Chris Connaker, and he also asked if I'd heard the new Aurender portable DAC/amp. That was two people I knew and respected asking me about the same product, so I asked Chris if he could introduce me to Aurender. Ten minutes later, I was meeting with Harry Lee and other Aurender team members, listening to the Aurender Flow for the very first time.
Okay, to be clear, the Aurender Flow was already in development before the Hugo was even announced, so it wasn't created in response to Chord's mega-successful portable DAC/amp combo. Once you put them both on a table, though, there's no avoiding the comparison. The Aurender Flow is a high-end, high-res portable DAC/amp combo; it is clad in a robust silver aluminum chassis, and it's more or less similar in size to the Hugo.
In terms of styling, though, they are certainly very different. The Flow is sharp corners and smooth flowing lines, with a beautiful (and huge) volume knob dominating its topside, and a digital display smack dab in the middle of that volume knob (which I'll get to shortly). The Hugo sounds absolutely amazing, but it is a strange creature to behold, with its domed hey-check-out-my-FPGA viewing window to the PCB, unusual recessed volume control ball thingie (that glows different colors to indicate volume levels), recessed jacks galore, a host of LED's of varying colors that a colorblind guy like me has a hard time making heads or tails of, and strange little chassis design flourishes that seem almost random. The Flow looks decidedly more straightforward and business-like in comparison.
In terms of specs, the comparisons certainly have more in common than their chassis styling. Both are 32/384-capable via USB. Both are 24/192-capable via optical. Both will play DSD files up to DSD128. (The Hugo also has a coaxial digital input, which the Flow does not.) Rated output power comparisons show the Hugo a bit more powerful into 32 ohms (600mW for the Hugo versus 570mW for the Flow); and the Flow is a bit more powerful into 300 ohms (87mW for the Flow versus 70mW for the Hugo). Both have vanishingly low output impedance specs, with the Hugo at 0.075Ω and the Flow at 0.06Ω. Battery life for the Hugo is rated at around 12 hours (which might be a bit optimistic) and the Flow at 7+ hours (which is probably mildly conservative). The Hugo's DAC is based on a custom-coded FPGA DAC, and the Flow's DAC section uses the Sabre ES9018K2M.
Due to the display in the middle of its wide volume knob, and the media control buttons on the side, the Flow is regularly mistaken for a standalone media player, which it is not. The display shows a visual volume indicator, various functional modes, battery status, current sample rate, and other bits and bobs. The buttons are for playback control (of your computer), and can control iTunes and some other media player software (play, pause, track backward, track forward).
Another reason people seem to assume the Aurender Flow is a portable media player is because it has an mSATA slot into which can be installed an SSD drive up to 1TB. Again, to be clear, the Aurender Flow is not a portable media player like an Astell&Kern players. It is a DAC/amp combo, and installing an SSD drive turns it into a USB 3.0 media storage device. I've installed a Samsung 1TB SSD in mine, and the read/write times are fast. If you're still unclear why one would want an SSD drive in his DAC/amp, here's my personal answer: My laptops of choice is a MacBook Air that has only two USB slots. With the Aurender Flow, both my media storage and DAC/amp functionality are served with a single USB slot. It's less to carry, and it keeps my other USB slot free for other things (like my photo storage drive or other peripherals).
As for how its performance compares to the Chord Hugo, I'd say the Aurender Flow is so far the strongest competitor to the Chord Hugo I've listened to. If your primary headphone is a sensitive IEM, you might actually prefer the Aurender Flow, as, in terms of self-noise with an ultra-sensitive in-ear, it is dead quiet, whereas my most sensitive IEMs can touch and reveal the Hugo's noise floor. When it comes to sensitive IEMs, I also like how the Aurender Flow always jumps back to -90dB volume level (-110dB is its lowest setting) when you unplug the headphone from it, which is nice for added hearing safety.
The Aurender Flow is a very resolving DAC, to my ears approaching (but not quite reaching) the Hugo in terms of inner detail and accurately conveying imaging and soundstaging (using albums I was present for the recordings of as my references). With most of my over-ear headphones, and with my loudspeaker setups, I still have to give the edge to the Hugo, though, for its ability to present a sense of solidity--a corporeality--that I typically associate with good tube gear. The Flow is good in this regard, but that edge is the Hugo's. This is not faint praise--the Hugo is far more expensive, and is one of my favorite DACs ever, regardless of form factor. With two portable products like these at the top of their games, there'll be some who prefer one over the other, and I think the Aurender Flow will win the battle with some of you.
This has been a very heavy travel year for me, and the Aurender Flow has edged out the Hugo as my carryon-only travel companion, due to its ability to be both my DAC/amp and my media drive all-in-one. When I travel extra-light, my best in-ears always win the role of primary headphones, and the Flow's advantage with my most sensitive in-ears also contributes to its status as my current #1 travel DAC/amp combo.
If you don't need the SSD drive, the Aurender Flow comes in at just over half the price of the Chord Hugo. Even with a 1TB drive, it's priced at just under $1800, which is still $700 less than Chord's portable marvel.