Asus Xonar Essence One or Why Actually Listening to Gear is Important

Asus Xonar Essence One ($599, $899 Muses Edition)
I have been living for a while with the Asus Xonar Essence One with upgraded MUSES op-amps. This unit differs slightly from a full-blown "Muses Edition" in that it lacks the gain jumper present in the Muses edition. "MUSES" refers to what Asus claims are top of the line op-amps, and as such they are standard in their TOTL rig. It's worth noting that the Xonar Essence of any flavor is an op-amp roller's delight, with many such combinations documented throughout the internets. However, for the purposes of this review, I stuck with the MUSES op-amps that came installed in the unit.

In many ways, the Essence One confounded my sonic expectations. It was disappointing with the phones with which I thought it would mate perfectly and soared with the phones I thought would break its back. This, folks, is why we actually need to listen to this stuff.

Basics first. The Xonar Essence One is made by Asus. You know, the Taiwanese company that makes computers and all sorts of other computerish stuff. Well, they make audio components, too. And these are not el-cheapo devices. They range from $599 – $899 and boast performance to match. We'll see about that.

As some of you know, I have a soft spot in my heart for "Swiss Army Knife" audio gear. The all-in-one, small footprint, amp/DAC with a bunch of features is appealing to me in many ways. As an apartment-dweller, space is always at a premium, and if I can find a piece of kit that will replace several larger components, I am always interested. If not as a main rig, then at least in the bedroom or a secondary location. Further, for those looking to get into the hobby with a quality piece of gear that is quick and easy to buy, Swiss Army Knife audio gear is a good way to go. I often think of the original Benchmark DAC-1 as a bit of a pioneer in this category, which is now quite crowded.

The Xonar Essence is a headphone amp/DAC with 1/4" jack that also has analog outputs (both balanced and unbalanced) to drive an amp or active speakers. Or you can use those outputs to use it as a standalone DAC. The unit accepts USB, TOSLink, and Coax inputs, which choices I welcome. On the front panel, running left to right, we have the power button, upsampling button, input selector, mute (love it), speaker volume, headphone volume, headphone jack. All indicator lights are the ubiquitous bright blue LEDs. (Note to manufacturers: enough with that already.) The Xonar Essence can handle your high-resolution audio files no problem, with bright-ass indicator lights to show you sample rates. The form factor of the Essence One is reminiscent of Headroom's designs. It is a rectangular shape, wider than it is deep, with a bit of a curvature to it, meaning that stacking on top of it probably won't work. Unless it's a true work of art, I'm not a fan of this type of design and this gets minus 5 pretty points.


Regardless, the unit is well built for its price, and easy to open for those of you who want to take advantage of the op-amp rolling that is a feature of the Xonar Essence. As noted, I didn't roll op-amps for this review, opting to stay with the Muses op-amps. However, I did open up the box and switching op-amps appeared to be a rather painless process. Personally, I prefer it when audio manufacturers make the decision for me based on their R&D and expertise. I don't want to have to fine tune an amp/DAC by swapping op-amps and trying all sorts of different combinations. If I'm going to do that, I might as well build my own. DIY is awfully rewarding, you know? Regardless, op-amp rolling is a feature I know will appeal to a significant segment of headphiles, and that's fine, too. Have at it!

So how does it sound? Well, this is where it gets interesting and a bit confusing...

sue4's picture

..such as output impedance, etc? Could you please add any measurement the way Till do?

Tyll Hertsens's picture

I'll have Dinny ship me the unit for furter tests.  It'll be a while, but will do.

xander01's picture

Hi, Tyll.  I'm sure you've got your hands full prepping for RMAF, but I was just wondering if this Essence One headphone output question ever got resolved, either here or somewhere else?  I read the article and didn't see it. I noticed you've mentioned using the unit in a good number of 2013 amp/HP reviews (at least the DAC), so I'm assuming that at least at some point you got a little curious.

One blog review said a rough test put it at "~4 ohms @ 1kHz", but based on the context and measurement issues noted throughout the article, it doesn't seem confident enough to be the last piece of the puzzle in my upgrade dilemma:


stv014's picture

Someone at Head-Fi  measured about 10 Ω output impedance, which is similar to the Xonar Essence ST/STX sound cards, and is not really impressive for an LME49600 based amplifier at this price. Perhaps the resistors were added to make sure that the amplifier remains stable with op amp "rolling", but in my opinion lower impedance with fixed chips would have been better.

Dinny FitzPatrick's picture

In the meantime, some specs can be found here.


Theogenes's picture

Nice review, Dinny. Thanks for taking the time ;) Wouldn't mind an update later with more impressions with more cans, given how picky the Xonar seems to be with cans. 

Thanks again!!

Jazz Casual's picture

I like the way you go about it Dinny. The absence of needless intellectualisation and poetic metaphors is most welcome. I can always overdose on that at Head-Fi.

John Grandberg's picture

Dinny's writing is a crisp white canvas bursting forth with word-pictures, while the rest of us scrape crudely on the walls of our respective caves. 

Tyll Hertsens's picture

Indeed. Dinny's posts are a guarenteed good read.

Dinny FitzPatrick's picture

Thanks for the kind words everyone. We all have our own styles and you guys are the ones who influence me so backatcha.  

n_maher's picture

Great review, Dinny.  I agree about the unecessary form-factor of the curved case.  I'm sure they were going for something when they did that and the odd touches to the bottom of the chassis.  But whatever it was it's lost on me.  I'm also 100% with you on the overly-bright blue LED phenomemon, enough already.  I don't need a flashlight to walk around my house at night.

ultrabike's picture

The form factor and the lights don't bother me that much. But a dimmer might be welcomed.

I definitively agree that it's hard to see what pairs well with what just by looking at the isolated characteristics of our gear. Some dark phones might not get along with some bright DAC/Amps. It's probably a complicated relationship involving impedances getting along, DAC reconstruction filter, distortion of the integrated system, and stuff. Sometimes it may be more than just that.

Very nice to hear that this DAC/Amp pairs well with the Senns! Also, I'm always for a well implemented Jack-of-all-Trades. Thanks Dinny!

Leonarfd's picture

Just wanted to chip in here, had both the Muses and standard edition for 21 days. And delivered the muses edition back. I did find the stock version more accepting to cans like HD600/650 while also being good for q701 and dt880 and 990. Another great combination has been the Mad Dog with Alpha Pad on the stock and the muses edition. The stock tended to give more bottom end so I liked it more, to feel the drum kicks or the bass instruments in the orcestra.


But still with both q701 and dt990 i prefered the MUSES edition but I could not accept the price difference, right now I have some MUSES op-amps on the way so I can change it when I want instead.

As for it being rounded on top I don't mind as Iike to see it as it is quite stylish with the gold marking ontop.

Dinny FitzPatrick's picture

It's helpful to have this kind of dialog, eapecially with so many editions floating around.  Interesting about your experience with the Mad Dog.  Sounds slightly similar to my experience with the LCD-2, is that a fair statement?

Leonarfd's picture

It is abit hard to say, for me I liked the stock with the Mad Dog better than MUSES. The MUSES did make it not so clean sounding to my ears. Might be something with orthos. Still im not the most experienced user and have not tested many headphones. Started my journey 5 years ago with hd600.


One thing that I love is that on my desktop rig this device can power my active studio speakers, my gaming speakers, headphones from both my pc and ps3 at the same time(my wife steals the tv to often so got a nice hdmi switch and now the sound is sorted aswell). 

PanzerIV's picture

What you mean exactly by the stock being "more accepting" and why did you prefer though the Muses for the Q701 headphone while you seem to say the stock was better with the HD600/650???

Is it also possible to order seperately the muses opamps as right now I can find online in Canada the stock version for 525$CAD + 5% Taxes but the Muses edition is at a ridiculous 900$ everywhere and at my work, employes price only lower this to 880$ + 15% Taxes and I hiiiighly doubt that the Muses sounds 2x better.

Actualy, does it only sound DIFFERENT or is it really much better as Asus marketing tend to let us believe? I'll be using AKG K702 headphone but mostly playing music through my KEF Q900 speakers.

Cami's picture

Could it be that the 10Ohm output impedance made a poor match with the 32Ohm Grados, the 50Ohm Audezes, but not so with the 300Ohm HD-800/HD-580s?

I mean versus concluding that because bright Amps have previosly "proven" to match well with bright headphones, they will most probably do it again.

Dinny FitzPatrick's picture

I'll let the more technically proficient try to answer.  However, you have misstated (inadvertently I'm sure) that I have concluded that bright amps will match well with bright cans.  I simply had a previous experience that informed this one. 

Dinny FitzPatrick's picture

I have updated the article to reflect that the unit I reviewed was actually the Asus Essence One (standard edition) but with Muses op-amps installed, rather than the actual Muses edition.  According to Asus, the only difference between the two, other than the op amps, is that the Muses edition has a gain jumper. 

PanzerIV's picture

I've read that too that the only difference was the "Gain Jumper" but what is it exactly and what does it do??? If it's nothing important at all then I'd guess that I'm better buying the stock edition at 525$ than the Muses at 900$ as nobody in Canada got it for a reasonable price unlike the stock version which you can find under the regular 600$ price tag.

sgrossklass's picture

From reading the article, it sounds like the Essence One may have some sort of issues with low-impedance cans. My bets would be on undersized output coupling caps or the amp struggling with the load. The effect of either should be readily visible when measuring loaded performance.

Still, I would find it odd to find a TPA6120 based output giving problems like that. I mean, that buffer isn't exactly ideal for loads of less than 64 ohms, but it still shouldn't break into sweat driving Grados. Orthos may be pushing it though.

John Grandberg's picture

The Essence One actually doesn't use the TPA6120a2. That's the Essence ST and STX. The One uses a pair of LME49600 opamps (not socketed) for the headphone stage. I can't find the output impedance listed anywhere - I'd think it would be single digits though. We should know at some point when Tyll runs it through his battery of tests. 

thenewyorker's picture

From Asus' Xonar/Muses Web page:


  • Dedicated 600ohm headphone amplifier for clearest detail
myownlegend's picture

I have the Nuforce HDP, Just wondering how the Asus Xonar compare to mine. Should i consider the upgrade. They cost only 35000yen in which I can simply use forwarding service.