The Aurender Flow’s ability to scale while retaining detail, body and control is simply wonderful. Here is a convergence device, amp and DAC that not only stays firmly within the boundaries of having a very musical after taste but lacks any perceived or overriding coloration that sacrifices detail and clarity. It is by no means a cold tonality, it is a precise presentation but it has a hint of warmth and smoothness right across the range that keeps everything ticking along without a hitch. It is a tremendously difficult challenge to offer up this level of clarity without sounding overly dry or monitor like or simply being a bit boring. That is not the case with the Aurender Flow.
I have a tendency to be distracted heavily by peakiness or tizzy treble responses on cans or any sort of amplification or decoding flavors. Even if the rest of the reproduction is either exciting or tonally correct that overworked cymbal or sibilant vocal performance is going to kill it for me. The Flow displays not of that treble peakiness and instead drives smoothly as far north as you can imagine without a single duff or sizzling note. It is very clear indeed but more importantly there is space and separation for the top end to sparkle and remain very much a coherent part of the overall presentation. The Flow is not a treble dominant device but the treble is present and very much a performer and gives that extra added dimension with headphones or IEM’s that really need that type of performance to shine.
Scaling on the Treble
Remember I said scale also? Yes the Flow can scale. The treble on the VE6 Xcontrol custom monitor was detailed, articulate and perfectly balanced without a hint of harshness. Sensitivity was handled pretty well by the Flow with a very noise free and black background. Swapping over to the 300ohm HD800 brought a surprisingly smooth and extended treble performance and oddly the peakiness sometimes prevalent on other sources dissipated slightly with the Flow. The jump in volume demands was noticeable from -50db to -15db to get the HD800 singing but it was again just on the right side of smooth and musical. It is an awful meme to use but it really did “flow’ (there I said it, it was on the tip of my fingers for about 30 minutes now). Queen’s “A Kind of Magic” (SCAD/DSD64) sounded full and engaging without being colored, that slight peak from the Senn was still there but minimal and Freddie’s vocals where sibilant free right out of the jack. The Alpha Primes were a little bit harder to drive at -20db but still sounded confident and full. Though I wouldn’t put at EF6 levels of power the Primes in no way sounded shrill or lacking for treble performance. Something I know Dan worked a lot to perfect and improve upon over the Dogs.
Aurender have been quite restrained also in the midrange tuning keeping it relatively neutral but ensuring it remains uncongested and clean much like the treble performance. That is a dual edged sword because while it its accurate and remarkably realistic it tends to be more standoff in its presentation than intimate or euphoric to my ears. Perhaps it is more of a question of preference but I like my vocals to be a bit thicker and richer with plenty of detail and emotion. Yes the Flow is wonderfully smooth and there is not a hair out of place in the mids, vocals are blissfully sibilant free but it just lacks a little bit of character to handle raw or hard hitting vocals with conviction.
It really is a question of matching for me. Vocals such as the operatic female vocal and string interplay on Saint Preux’s “Concerto Pour Une Voix & Le Piano Sous La Mer” sounds so deliciously clean and insanely accurate. Katherine Jenkins 2008’s “Panis Angelicus” is both absorbing and controlled with excellent separation not once getting lost behind the plethora of supporting choir vocals in the background. Quite the match really especially with sound stage kings such as the UM Merlins, the HD800 and the VE6 Xcontrol custom monitors. However Adema’s 2005 ‘Shoot The Arrows” sounded a bit lacking in body, aggression and character. This is a grungy raw male vocal that needs to soar and drip with angst and I didn’t get the feeling the Flow wanted to go in that direction. Perhaps I like my rock vocal presence a bit more forward with more body, perhaps dare I say it a bit more colored?
The Flow’s bass is detailed, smooth and fast without ever sounding too lean or shallow. It can extend with the right matchup but never really humps or blooms on its way down. It is tuned to behave but with an ever so slight midrange elevation just to keep things musical and weighted rather than analytical and sterile. I actually found the bass to possess a slightly warm edge to it which keeps lower frequencies smooth and engaging. Using the Flow the bass on the Primes, the HD800 and the VE6x customs felt really coherent and detailed without ever sounding over emphasized or lacking in dynamics.
The Flow is just about the “matchiest” DAC/AMP I have reviewed to date for head gear. Not only does it scale well from sensitive earphones to 600ohm cans without missing a beat and has enough power for demanding planars such as the Alpha Prime but it also possesses a very addictive tonality that is both clean and detailed as well as smooth and musical. That is a tough thing to achieve indeed given how other combinations often display a fatal characteristic somewhere in such a broad range of headphones or earphones.
The Smooth K501
A wonderful example of the Flow’s ability is my old warhorse the AKG K501 which is a 94db efficiency rates 120ohm can. On paper, it is on par with say the new HE400i but power wise I always need a bit more, maybe a lot more for it to really shine. A slightly underpowered or poorly matched K501 is shallow and anemic with a complete lack of punch. The mid section of the K501 is where it shines but without that punch its a frustrating headphone. Delightfully the K501 sounds full with solid extension and depth and match extremely well tonally with the Flow. It is rare I found a match as good as outside of desktop systems. Pink Floyd’s ‘Talkin Hawkin’ from their new Endless River on DSD128 is a track that really needs a huge sound stage to shine and on the K501/Flow combo it gets all the room it needs yet at the same time individual instruments such as the Floyd’s signature guitar solos sound full, accurate and very present.
David Elias very kindly allowed me to review his new “Acoustic Trio DVD Sessions” album a while back and this is a real wow moment with the K501. The detail and clarity on “Vision of Her’ is excellent. There is not a hint of coldness in the presentation with excellent depth and a midrange that plays to the strength of the Flow. The flow offers a really delicate but pleasurable treatment of David’s sometimes soft yet emotionally driven ‘Simon & Garfunkel’ like vocal. Whilst the K501 hits its stride around -15db on the Flow it never sounds like it is about to max out and it was rare I needed to go further than about -10db.
Taming the K550
The more accessible and modern K550 had no issues around -30db and whilst it sounded a bit more clinical than the more natural sounding K501 its inherent tendency to sound tizzy and peaky at 5-7k was felt less prominent using the Flow matchup. No issues on bass extension and imaging also with the K550 sounding full, agile and pleasingly dynamic without the usual K550 abundance of hot treble interfering.
Better than expected with the IE800
The Sennheiser IE800 is another one that I have a love hate relationship with. Many times I am equally enthralled and frustrated with its sometimes uneven treble that can at times sound brittle and tizzy with some matches. The Creative E5 and IE800 was just such a match that didn’t gel at all for me in treble performance. The Flow on the other hand kept the excellent and deep bass that the IE800 is known for, laid down a noiseless black background and smoothed out that treble range almost perfectly. That sibilant nature I sometimes found in the upper midrange was also very well behaved, more so than I expected. Buika’s husky vocals on “La Falsa Monedo” were tight and sibilant free with the IE800/Flow match. This is a vocal range that very prone to dropping an “s” or two when poorly matched and this pairing didn’t drop the ball once.
I am still not a fan of the Flow with heavier rock or emotionally driven rock vocals and the IE800’s more neutral midrange vocal presence can feel a bit lost as a result. Gavin Rossdale’s vocal performance on “Comedown” from 1994’s Sixteen Stone just felt a bit too distant and lacking in grit to really convince with the IE800 and the Flow. Chris Cornell’s soaring vocals on “You Know My Name” are pitch perfect and clear but with the IE800/Flow it lacks a bit of soul and character. Again this is a preference in some ways but the Flow for me it not a complete ‘rock out’ source for hard hitting vocal performances.
The noise free UE900
Again a noise free experience matched with the UE900. I have yet to find a sensitive IEM in my collection that did have any noise with the Flow thankfully. The UE900, a more mature offering in my mind over the older TF10, surprisingly needs a lot more oomph on the Flow than other earphones with a sweet spot more in the headphone range at around -33db but the smoothness and clarity where off the chart for this pairing. It has been a while since I came across a source that drives the UE900 so well without it sounding uneven in the treble range. I had noted before that the UE900 maybe lacked a bit of bite in the treble and whilst the Flow doesn’t change that overall perception it does add a better sense of space and clarity in the UE900’s top end. Mid are beautiful with the UE900 and the Flow especially with acoustics sets such as Delta Goodram’s “Hypnotized” acoustic version Diana Krall’s “Exactly Like You” which was clear, controlled and played to the strengths of both the UE900 and the Flow’s treatment of mids and vocals.
I thoroughly enjoyed my time with the Aurender Flow and despite some design quirks and worries on the total cost of ownership to get at some of those USP’s I would heartily recommend it for those thinking of buying a well behaved transportable DAC and Amp solution. The codec resolution capability of the Flow is right in keeping with modern DAC trends with both PCM, DSD up to 128 as well as the usual plethora of lossy and lossless codecs from Mp3 to Flac and ALAC and Wav.
The whole “cable for this, cable for that” I could have done without and would have preferred to see some more dedicated ports such as coaxial and a dedicated line out rather than use a single port and fiddle with menu options. I am also not totally sold on the mSATA feature other than a small storage for bringing out to meets your favorite reference tracks for quick access from a laptop but otherwise this feature just raises the total cost of ownership unnecessarily and thankfully Aurender have made that an optional feature.
It is certainly a unique and well designed device though. The Flow waves might not be the most stackable but it looks a stylish companion to the digital desktop and possesses a more than capable LCD display and a very smooth pot. I would have preferred the pot to have skipped a few steps up to around -db as its starting point though but power wise there is no question the Flow can handle just about anything you connect it to and still sound pretty good. I wouldn’t call it completely portable though, more transportable than anything else. That battery life won’t get you as far as you might think especially if you hit that DSD option every 5 seconds and work the menu equally but as an office or stationary quiet moment device away from your main desk that Flow has it covered pretty well.
Sadly I don’t have a Hugo from Chord, not sure if I ever will but given the fact the Flow comes in a good bit cheaper might encourage high end rollers to pause and do an AB between both because by all accounts so far the Flow maybe a real and viable competitor.
Aurender Flow Technical Specifications
|Input||USB 3.0 ( Audio Class 2.0)|
|Output||1/4 inch/6.35mm Headphone Jack|
|Volume Control||-110dB ~ 0dB, Velocity Sensitive Operation|
|mSATA Slot||Optional mSATA storage up to 1TB|
|Output Impedance||0.06 Ohm Max|
|SPDIF Mode(Optic)||up to 24bit/192kHz|
|PCM Mode(USB)||up to 32bit/384kHz|
|DSD Mode(USB)||DSD64, DSD128 / Dop Mode|
|Play Time||7+ Hours|
|Battery||SAMSUNG SDI 4450 mAh|
|Output Power THD+N 0.0002%|
|43 mW/600 ohms, 87 mW/300 ohms,|
320 mW/60 ohms,
380 mW/32 ohms,
|THD+N (1kHz 5.1V rms output)||0.0002%|
|Dynamic Rage||Max 122dB|
|Dimensions||80 x 137 x 28 (mm)|
3.1 x 5.4 x 1.1 (inches)