Small and Mighty: The Resonessence Labs Concero HP Page 2


Before we get to the sound, I want to make sure we keep in mind the compact size of this device. And remember, it's an all in one DAC and headphone amp, running from USB power. Is this a disclaimer to help soften the blow when I describe the sound quality as merely adequate? Absolutely not! On the contrary, I bring this up as it becomes that much more impressive that this little thing can sound so phenomenal. Seriously, this is one of the best all-in-one devices I've ever encountered—and I've had many of them. Power, dynamics, clarity, low end grunt, expansive soundstage, precision imaging...the Concero HP pretty much does it all, with nary a downfall to speak of when operating within the scope of its capabilities. No, it doesn't have a ton of connectivity. And no, it isn't a good choice for driving the HiFiMAN HE-6 or other extremely difficult loads. In addition to those two potential shortcomings.... nope, I've got nothing else to complain about. Sorry. This thing is good.

The first headphone I tasked Concero HP with driving was the V-Moda M100 (with XL pads of course). I figured a simple, efficient, low impedance headphone should be a good starting point. Let's not force the little thing to break a sweat right off the bat. The result was...stunning. I'd not heard the M100 sound so good this side of $5,000 worth of gear. The M100 is an inductee into the Wall of Fame and I can absolutely see why. Does it challenge the HD800 or LCD-3? Of course not. But for what it is, I love it. The Concero HP makes sure the midbass bloat keeps to a minimum, and presents the midrange in a fairly engaging way—which is a good thing considering the V-shaped signature. This is a very satisfying combo.

Next I switched to the more demanding Sennheiser HD800. Is this a likely combo? Maybe, maybe not. There is definitely something behind the idea of spending the bulk of your budget on the headphone rather than the associated gear, so I can see this happening in some instances. The HP did a very good job with the flagship Sennheisers. There was a distinct lack of harshness which I really appreciated. Or let me rephrase...there was some harshness or brightness at times, but not more than the HD800 should have. I've heard plenty of more aggressive amps that paired rather poorly with the HD800 but thankfully this isn't one of them. I got a healthy dose of that massive presentation HD800 is known for while playing Wilco's Sky Blue Sky, as well as some solid response down low with tracks like Lovetown by Peter Gabriel (from the soundtrack to the movie Philadelphia, an album I highly recommend). Was the Concero HP the best I've ever heard? Not really. My reference system sounds even more open, spacious, and accurate, with even better bass texture. But it'll cost you a considerable sum to achieve that.

I then moved on to a bunch of other headphones, to see how Concero HP handled a wider variety of loads. I tried AKG K550, ADL H118, Focal Spirit Pro, and Grado PS-500. Each one was handled very well, with no shortcomings to speak of. I thought the HP had superb voicing—thickness of note without becoming muddy, very good top end air without splashy cymbals, and—still surprising for a tiny USB powered thing—impressive, weighty bass reproduction. Not sure how they pulled this off but it's probably my favorite part of this device.

I finally found a minor limitation when trying out some planar magnetic headphones. The HiFiMAN HE-500 paired well enough with the Concero HP, but I thought there was maybe a bit too much energy in the top octaves. It wasn't necessarily harsh but I found it a little fatiguing in the long term. It also seemed like dynamics suffered compared to some of the more potent stand-alone amps in my collection. I then switched to the Audeze LCD-2 which has never been described as overly energetic up top. That's one problem solved, but the dynamics were still a bit dull. Not terrible mind you, but nothing to write home about either. Interestingly, the more efficient HiFiMAN HE-400 sounded excellent. Was the Concero HP running out of steam with the more difficult loads? Maybe. Volume was certainly not an issue, but it seemed like dynamic peaks had less gusto than they should have. Keep in mind that I'm nitpicking here—I could still very much enjoy the Concero HP driving the LCD-2 for general listening. I had to put on my critical (uppity?) audio reviewer cap and play some exceptional recordings to spot the deficiency.

Things got a whole lot better when I switched to some ultra-sensitive IEMs. As a lover of IEMs and especially custom IEMs, I can't stress this enough—they almost qualify as a different category than full sized headphones. Big cans need more juice, more gain, and aren't so concerned with minor background noise. IEMs on the other hand are ruthless and unforgiving of even the slightest hiss, static, hum, or channel imbalance at low volumes. I've got multiple amps here with four-figure price tags that drive big headphones amazingly well, yet aren't ideal with sensitive IEMs for one reason or another. It's almost an inherent counterpart to the power levels required for driving planar headphones (which most amps these days would like to do properly). So I'm happy to report the Concero HP is an ideal dance partner for my JH13 FreqPhase, Westone ES5, Heir Audio 8.A, and a whole bunch of other custom IEMs that I enjoy. I can hear just the tiniest hint of hiss with one or two of the most sensitive IEMs in my collection, but even then it is barely perceptible. All the rest are dead silent. Talk about a killer transportable system...a laptop, a Concero HP, and a set of CIEMs is a killer rig that can be taken on planes, trains, or automobiles with minimal hassle. Just a single USB cable ties the whole rig together. And remember that low 2.2 ohm output impedance? Low enough to avoid any trouble save for a few extreme examples—none of which are in my collection—that have ultra-low impedance dips. And even those interactions should be fairly minor.

There's really no way to separate the performance between DAC and amp sections. But I don't mind—the result indicates both stages work very well as individuals, making for a killer pairing. That bleeding edge Sabre chip really does sound incredibly transparent. And the amp stage seems up to the task of translating that performance into real world results. I simply can't recall anything else that sounds so refined, so accurate, and so downright realistic that isn't many times the size of this device. I recently reviewed (and quite enjoyed) the AMI Musik DDH-1 and wouldn't hesitate to recommend it. However, in comparison to the Concero HP, that device sounds a bit veiled and slow. It offers way more functionality but if all one needed was USB in and headphone out, the Concero HP takes the cake. Same story for the Parasound Zdac and the Izmo M1 and just about any other compact DAC/amp combo I can think of. All of those I just mentioned are very good indeed but Concero HP just takes it up a notch in the SQ department. Not to mention the DSD support, which was flawless in my experience. If you've been looking to get into that admittedly limited (but growing!) format, Concero HP is an affordable way to do it right.

It should be clear by now that I really enjoy this device. It seems ideal for headphone users who want great sound in a tiny package, without a lot of hassle. Users who need more typical DAC functionality should use the Concero HD instead, to get the same great sound out to a dedicated amp. Wanna know a little secret though? The Concero HP does a pretty good job as a preamp! How? Just use a 1/4" to RCA cable and connect directly to the headphone jack. You take a performance hit compared to the Concero HD but it's still great for occasional use—I'm guessing if you choose Concero HP you're still mainly focused on headphones. I tried this method for my desktop system with some Adam Audio F5 active monitors and it sounded just dandy. So just because one goes with the HP, it doesn't completely lock them in to exclusively using headphones.

The Concero HP is good. But maybe good doesn't cover it. Great? No, that seems too cliche. Amazing? Superb? Preposterously capable? Now we're getting closer. How about this: I'm confident enough in the HP to bestow upon it the Wall of Fame award. That means it's among the absolute best I've encountered for anywhere near the price. Does that get my point across? For the modern user who doesn't have a lot of space, and doesn't need a dozen inputs, it really doesn't get much better than this. Doubly so if IEMs are your weapons of choice. Can you get more if you spend more? Always. But a lot of people won't need more and that's the whole point of this device. As sound quality goes, there is very little compromise involved—maximum power is about the only thing to watch out for. Aside from that, a brilliant device that I really can't recommend strongly enough.

Editor's Note: I will shortly be putting up a few more categories on the "Wall of Fame." The Resonessence Concero HP will be on it when the headphone amp section posts.

Resonessence Labs

tomscy2000's picture

It's here! Congrats! Glad you like the HP with IEMs as much as I do! yes

John Grandberg's picture

For anyone who has not yet done so, please see this excellent review of the Concero HP at Cymbacavum. Dude knows what he's talking about. 

longbowbbs's picture

Another great review, John!

It is going to be interesting to see how the new Light Harmonic Geek does alongside this and the Herus....Portable audio is getting better all the time.

poleepkwa's picture

How would this compare to the Xonar Essence One and ODAC/O2 stack?

John Grandberg's picture

I prefer the Concero HP to the Essence One Muses Edition. The Xonar is by far the more feature-laden option, but for pure listening quality with headphones I'd take the Concero HP by a decent margin.

Unfortunately I haven't spent enough time with the O2/ODAC stack to compare those models. 

poleepkwa's picture

Double post

cansman's picture

Hi John,

Thanks for your review of the Concero HP. Enjoyed it!

Q: Are you planning a Herus review anytime soon?



John Grandberg's picture

I've got one here and am very impressed with it. Such a tiny thing, but packs big sound in there somehow. 

Mitsios's picture

I have Hifiman HE-500 and Meridian Explorer. Is there a better portable dac/amp for HE-500??

John Grandberg's picture

I wouldn't consider the HE-500 portable in the least. For me, portable is something I'd use on a bus or train or while out for a walk. Maybe I'm being too picky about the language, but if we use the term "transportable" then it makes more sense to me. 

In any case, I'd choose the Concero HP over the Explorer any day. They belong to different size and price classes though, so it's not really a fair fight. 

Mitsios's picture

Thanks for your answer John smiley

Didn't consider HE-500 as portable. My setup is as this: 1.Kids going to sleep. 2. Me opening drawer, getting HE-500 and Explorer out. 3. Listening music for about an hour, until i cannot keep my eyes open... 4. Packing everything to drawer again till tomorrow. That's why i am asking for the best portable and small DAC/amp to play good with HE-500.

John Grandberg's picture

Concero HP will do well in that scenario. It's a little on the brighter side compared to my bigger/more expensive amps, but certainly not unmanagable. 

webkiwi's picture

It should be interesting to compare this with others using the same chip.  The Geek Pulse comes to mind. Their MSRPs should be in the same range... though through Indiegogo you can back it and save some money Indiegogo Geek Pulse

I believe that they are also using the same ESS9019mk2 chip (two of them in their dual mono balanced version), I'm pleased to hear that others like the sound it produces.

John Grandberg's picture

I have mixed feelings about the Geek stuff. Take away the crowd funding aspect and what's left is hopefully a competent little device, with good specs for a reasonable price. On the other hand I do see a bit too much hype surrounding them. Just because Light Harmonic makes expensive DACs doesn't automatically make their budget line spectacular. Just look at Musical Fidelity. 

Mitsios's picture

Is Concero HP thin sounding? Does it have body? I don't want a thin sounding dac/amp which costs an arm and a leg... My headphones are Senn HD 650, Denon AH-7000 and HIFIMAN HE-500.

John Grandberg's picture

It's not thin at all imho. I know it's hard to reconcile a small device having a big sound, or USB power having plenty of low-end grunt.... Resonessence Labs really pulls it off though. 

Mitsios's picture

Thanks John. Your answers are valuable for my decision. Last question. If you had my headphones with the exception of Senn 650 which i am going to sell, what would you choose? Concero HP or Vioelectric V200 ? I know they are different - sized animals  but if sound was the only factor what would you choose ?

John Grandberg's picture

Are we talking a V200 with the DAC option? If so, I'd wait until Violectric finishes the new 192khz USB option which should be ready very soon. Even then, V200 will have superior amplification, and Concero HP will have a clear advantage in the DAC portion. I'd probably choose the HP for the Denon and V200 for the HE-500. HD650 is split down the middle, both have merit. 

DoctorX's picture

The Concero HP ticks a lot of boxes for me, how does the unit pair (esp. the amp part) with HD650 compared to let's say the Bottlehead Crack?

John Grandberg's picture

The HP does a very credible job with the HD650. It will of course be more "matter of fact" than the creamy richness of the Crack (which I love when paired with most Sennheisers). So it depends on what you gravitate towards - clean, accurate, detailed, or smooth, warm, "fun". 

TheStonedMonk's picture

This amp sounds amazing, it was rewarded the Wall of Fame tag, but it isn't included in the Wall Of Fame post for headphone amp

Beast's picture

I was thinking of getting a pair of CE6P to pair with my Concero HP, but was worried that, with an impedance of 16, it might be a bit low for the HP. Do you think it will be an issue? Thanks for the great review.