ASUS Xonar Essence One
The ASUS Xonar Essence One is a jack of all trades with endless competition albeit at much higher prices. Asynchronous USB input? Check. High power headphone output? Check. Hardware volume control? Check. The point should be clear. The features found on the Essence One are now ubiquitous in high end audio but totally new for the majority of mainstream products. ASUS is one of the biggest manufacturers of computer components in the world and supplies millions of people across the globe with mainstream products. I can only imagine how large ASUS' chip orders are, think C-Media not Cheetos, and how far this huge volume drives down the price compared to traditional high end manufacturers. Whether the high end has had an impact on mainstream products like the Essence One or ASUS views the high end market as another opportunity or both is anyone's guess. Either way the fact that ASUS has produced a featured filled mainstream yet high end product is a great thing for everyone.
Overall the Essence One is a good product with good features and good sound quality. Under certain circumstances the usefulness of the features and the sound quality ebb and flow. Using the Essence One as a headphone amp with Sennheiser HD600s is a really nice combination. On the other hand running the Essence One's balanced outputs into a Spectral Audio DMA260 amplifier delivers less than good results.
The Essence One features an asynchronous USB input using the C-Media CMI6631 USB audio processor. This is completely different from the common XMOS, M2Tech, and Tenor chips. Nearly all DACs using the common audiophile USB chips receive power over the USB bus from a computer or music server. The Essence One's C-Media chip is powered from the main power supply. This enables the USB interface to function with or without power from a computer. In addition the Essence One works with Generation 1-3 iPads and a camera kit because the USB chip doesn't require more power than the iPad can deliver.
A dedicated internal power supply consumes a fair amount of space inside the Essence One. Using the DAC on a desktop I much prefer this PSU configuration as I can simply plug a regular power cord into the unit. I'm not a fan of external wall wart supplies or external supplies that look like an anaconda with a rat in its stomach (think thick cable with brick in the middle). This internal supply made it easy for me to use my favorite power cords the ALO Audio AC6. These cords are very light and flexible making them perfect for desktop use. Unfortunately ALO Audio no longer offers the AC6.
Other features of the Essence One include balanced analog outputs (4 Vrms), easy op-amp switching, powerful headphone output, bit perfect indicator, sample rate display, 8x symmetrical upsampling, separate volume controls for line and headphone output, and for the most part great build quality. Under the right conditions these features shine but under the wrong conditions these features are an Achilles heel. The powerful headphone output works great with Sennheiser HD600 headphone but I'd never recommend using the Essence One with Ultimate Ears ue11 Pro in ear monitors. The 8x symmetrical upsampling sounds like a great idea and maybe the best thing since async USB but to my ears it produced an artificial sound similar to DSP attempting to make surround sound from two channel recordings. 8x symmetrical upsampling upsamples 44.1/88.2 /176.4kHz input to 352.8kHz and 48/96/192kHz input to 384kHz in a symmetrical manner. I'm a big fan of using multiples of 44.1 and 48 when doing anything to the sample rate, but it doesn't equate to better sound compared to playing music at its native rate in my experience.
The Bit perfect / sample rate indicator according to the user manual offers the following, (1) The relevant LED will light up to indicate the sample rate of your audio source (44.1kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, and 192 kHz), and (2) Bit perfect: light on under ASIO model. Unfortunately the bit perfect feature is misleading and capable of supplying the user with incorrect information. In fact I think the feature does more harm than good. The bit perfect indicator illuminates whenever the playback application uses ASIO output mode. That's it. Audio can be run through an EQ, one or two software volume controls, or even resampled yet the bit perfect indicator will still illuminate as long as ASIO output mode is in use. During the review period I sent equalized and attenuated audio to the Essence One but still lit the bit perfect light when using ASIO. In addition the bit perfect indicator will not illuminate when using any other output mode such as WASAPI or WASAPI - Event Style even though the audio output is bit perfect. I recommend ASUS either remove this "feature" or rename it to an ASIO indicator.
For the most part the Essence One's build quality is much better than most mass produced products and equal to many high end audio products. The case is very solid second only to products milled from a solid block of metal. My one issue with the build quality is the volume dials on the front panel. These dials are made from cheap feeling plastic that can make a user question the quality of the entire product. Essence One users have the most contact with the unit through its volume dials. Thus, better quality dials would give users a much better everyday experience. A minor item that bugs me with the Essence One's case is the convex top cover. I'm sure this rounded top is by design to prevent me from doing exactly what I want to do, place items on top of the DAC. I like desktop audio component that I can integrate with my messy desk-style. I like to place my phone, remote, or other items on top of the components when I run out of room on my desk. Again, the Essence One's design is perfect for eliminating heat through the top and eliminating the chance that a user will place items on top blocking the escaping heat.
One feature that ASUS doesn't advertise is the Essence One works just fine on Mac OS X Mountain Lion. There are no drivers to install. I connected the DAC via USB to my MacBook Pro Retina. The Essence One appeared as "Speaker" in Audio Midi Setup and was identified as the Essence One in OS X USB Prober. All sample rate from 44.1 through 192 kHz with 2 channel 16/24 bit audio are supported. Using Audirvana Plus version 126.96.36.199 I was able to use Exclusive Access Mode, Direct Mode, and Integer Mode with the Essence One on OS X.
Listening Through The ASUS Xonar Essence One
Listening through the ASUS Xonar Essence One on both OS X and Windows can be pleasurable or pathetic depending on one's configuration. First and foremost when using Windows the ASIO driver must be manually set to 24/32 bits if the user has content over 16 bits. All high resolution 24 bit content will be truncated to 16 bits if this ASIO setting isn't changed from the default. Strangely enough to change this setting the user must go into the JRiver audio settings to bring up the ASUS ASIO configuration. I would much prefer this setting default to 24 bits or even better let the playback application completely control the bit depth.
I'll start with the pathetic. OK maybe pathetic is a bit strong and an overreaction. The sound quality in this configuration was unenjoyable to say the least. I connected the Essence One directly to my Spectral Audio DMA260 amplifier via balanced cables. I used only the Essence One's main volume control. Playing Passacaglia from the Kansas City Symphony was very revealing of this configuration's shortcomings. As the track progresses the energy grows with more instruments and more dynamic range. With this progression I could hear the sound stage getting squashed more and more on both left/right and top/bottom. The final straw was about five minutes into the track when the sound figuratively fell apart and the music sounded like a single synthetic symphony.
Moving to the don't try this at home category, I used the problematic Ultimate Ears ue11 Pro in ear monitors connected to the headphone output of the Essence One. I don't really blame ASUS for what I heard as the ue11 monitors are ridiculous to drive and not the everyday headphone for which this DAC was designed. I expected loud, but didn't expect this loud. With the volume dial on step three I heard enough sound in the left channel but little to no sound in the right. Stepping up another notch provided enough volume for comfortable but near the maximum comfortable listening level. Setting the dial to step 5 was closer to the mythical 11 as the level jumped more than I could comfortably listen for any length of time. Readers should understand this volume dial has 40 steps and I was stuck at step 3 as the only comfortable listening level.
* Shortly after publishing the review I heard the following from ASUS, "The sound presentation can be changed quite drastically by changing out the op-amps. And also, the just to be released MUSES Edition features an internal jumper that will lower the gain of the headphone output, making it possible to use some of the sensitive IEMs that some audiophiles use. The MUSES Edition has an SRP of $899, and has six MUSES op-amps installed by default in I/V and LPF locations. Of all the op-amps we tried in the Essence One, they have the best texture and immediacy."
Enough negativity let's talk about the good stuff. The Essence One paired with the Sennheiser HD600 headphones was the best combination I used during the review. The sound quality was good with very controlled bass being the best quality. The bass heavy baritone of Leonard Cohen was controlled very well similar to listening through an amplifier with endless power. This tight control of the low frequencies made listening to my favorite bass busting tracks a blast. Suzanne Vega's Headshots, my favorite track of late, provides perfect baselines for the Essence One to really show its stuff and it certainly did just that. The HD600 / Essence One combination has a little trouble reproducing vocal texture like some of the high end integrateds. Keb Mo's guitar on Every Morning sounded good but the vocal was missing texture as was the case with Ray LaMontagne's Are We Really Through. Good guitar but lack of vocal texture. It's this texture that can really draw me into the music and forget about the equipment reproducing it in my listening room. This level of performance just wasn't there with the Essence One. Wrapping up my listening experience on a good note was Issac Hayes' extended version of Walk On By at 24/96 and Where Will I Be from Emmylou Harris's Wrecking Ball album. Issac's deep vocal sounded good as did Emmylou's rich but much higher pitched vocal. The trippy electric guitar throughout Walk On By was really fun to hear as was the powerful drum opening on Where Will I Be. This drum opening was tight and Emmylou's vocal was right up front when listening through the HD600 headphones. This forward presentation is rare when using the HD600s. I liked what I heard with the up front vocal.
The ASUS Xonar Essence One, ranging in price from $530-$742 depending on the store, is a good all-in-one unit that covers many bases. Most users will find the Essence One covers all the bases and then some. The picky audiophiles may take issue with some features or the sound quality under certain conditions, but that's to be expected with every product. Readers with the Essence One still on their holiday lists of must audition components should heed their own advice as well as mine and audition this DAC. Sound quality with every headphone and every component is different. Some of us like upsampling while others run from it as fast as they can. On this Cyber Monday make a point trying the ASUS Xonar Essence One with your own headphones or own system. It's a good quality component that will fit nicely under a tree or on a desktop.
- Product - ASUS Xonar Essence One USB DAC / Headphone Amplifier
- Price - $530-$742 depending on the store
- Product Page - Link
- Product Manual - Link (1.5MB PDF)
- Source: 15" MacBook Pro w/ Retina Display, C.A.P.S. v2.0 Server
- DAC: EMM Labs DAC2X
- Preamp: Spectral Audio DMC-30SS Series 2
- Amplifier: Spectral Audio DMA-260
- Loudspeakers: TAD Labs CR1 Compact Reference
- Remote Control Software: JRemote, Apple Remote
- Remote Control Hardware: iPhone 4, iPad (3rd Generation)
- Playback Software Windows 7: J River Media Center 18
- Playback Software Mac OS X 10.8.2 : Audirvana Plus
- Cables: MIT Matrix HD 60 Bi-Wire Loudspeaker Cable, MIT Oracle Matrix 50 Analog Interconnects (RCA), AudioQuest Niagara (XLR), 1.5 meter Mogami W3173 Heavy Duty AES 110, ALO Audio AC6 Power Cables, Wire World Silver Starlight USB Cable, AudioQuest Diamond USB Cable
- Network: Cisco SG200-26 Switch, Baaske MI-1005 Ethernet Isolator, Micro Connectors Augmented Cat6A Ethernet Cable, Apple AirPort Extreme, Cisco RVS4000 Router, Cisco DPC3000 Docsis 3.0 cable modem, Comcast Extreme 105 Mbps Internet Service