Ever since we first tested the ASUS Xonar STX soundcard, which passed our tests with flying colours, it was clear to us that ASUS has stepped firmly into audiophile waters. A number of soundcards and headphones have been presented in the series in the meantime, and the device we’re testing today is the latest addition to the fold in the high-end segment, namely Xonar Essence One. The device has a set of digital inputs, USB, coaxial and TOSLINK. These inputs accept digital signals in sampling rates of up to 192 KHz. The outputs consist of a pair of standard RCA (CINCH) connectors, and surprisingly enough, a pair of professional XLR-out connectors. The analogue signal is then conducted from the converter output to the integrated headphone amplifier input or the said RCA or XLR outputs, and then via appropriate cables to preamp, integrated amp, mixer or active speakers. The front panel contains all controls and commands, as well as analogue headphone output with the standard jack (6.3 mm) or a mini-jack adapter (3.5 mm). In a word, it’s a very versatile and compact gadget.
Xonar Essence One 1 cover

ASUS has definitely invested a lot of effort into the design, giving Xonar Essence One a likeable look rather than making it just another black box. The curved lines, tangible weight and modest dimensions all give the device a sense of inertness, i.e. resistance to vibration, which is commendable. The on/off switch may confuse less experienced users, so here’s a brief explanation of the concept. Since the entire device is very compact, in its robust metal (not tin) casing, all other fittings and components have to be of an equally high quality. This is why it may appear that the quality of the power switch isn’t up to par with the rest of the device. Although it may be a bit rough and noisier than one would expect, it still feels trustworthy. Being as it may, the body of the switch itself is located on the PCB directly, connected to the button on the outside via a tiny lever. The connection between the button and lever is relatively weak, but this was done in order to protect the switch itself and provide a large number of on/off cycles without the need for replacement. The step of the button/switch is relatively deep, as is the case with all devices with strong power sections. Rather than show disregard, it’s likely that ASUS’ engineers have in fact tried to show that they’ve thought every single thing through when designing this soundcard.

Xonar Essence One 1 sThe next notable thing is the pair of professional XLR connectors for balanced line with a preamp or active speakers, but not PC ones. The advantage of balanced line is mostly noticeable with large cable lengths (from a few meters to a few dozen meters) and is reflected in a much better protection of the signal in the cables against RF distortion, especially if they’re situated closely to or even intertwined with other power cables, or even worse, lighting cables. Balanced cables have two lines for signal and one for mass. XLR connection has to be established between all devices in the chain in order for balanced line to have any effect. Technically, you could have an XLR connector at the end of one cable and an RCA one on another, but you’d have to bridge balanced to unbalanced at the RCA end by connecting the minus line and mass into a single point. Therefore, you can always turn a balanced cable into a non-balanced one, but not vice versa, as it depends solely on the configuration of a particular device.

If you have a standard 2.0 system, i.e. a standard dual-channel Hi-Fi home stereo, balanced line has no advantage over unbalanced unless your preamp and amp have XLR inputs and outputs. For professional applications, such as studios and similar, balanced line is not only advantageous, but irreplaceable.

ASUS states that the signal-to-noise ratio of this soundcard is 120 dB. This is an impressive number, but doesn’t mean that much in practice and shouldn’t be regarded as highly as some would have you believe. The same performance could be achieved with a far lower SNR of, say, 90 dB. For comparison’s sake, an analogue gramophone record has an SNR of 60 dB in ideal conditions. The front panel contains an “upsampling” switch right next to the power button. We don’t have enough time or space to delve into the technical explanations of the terms “oversampling” and “upsampling”, but in short, make sure that “upsampling” is turned off, as it degrades sound quality quite obviously.

Listening test

We were lucky to obtain a test sample that had already been “played”, so we could get down to some serious listening at once. The audio material used is as follows:

1)    Anouar Brahem, John Shurman, Dave Holland – “Thimar”

Xonar Essence One Front sIn “Badhra”, the double-bass is just as dominant as supposed to (i.e. a bit overexposed), regardless of whether Holland uses a fiddlestick or fingers to make strings vibrate. Details are very clearly positioned and microdynamics are on a high level. Shurman’s bass clarinet is pleasant, warm, with a large and excellently balanced tone. Unlike the double-bass, clarinet has a bit of reverb added to it, in order to give a livelier feel to the recording. The lute’s sound is nothing short of impressive and fits perfectly into the darker tonal colour that characterises this CD.

2)    Biljana Krstic – “Zapisi”

Xonar reveals the lacklustre nature of the recording studio at once, with the entire CD simply too loud and a volume level higher by some 6 dB than one would expect on a CD of this nature. Biljana’s vocals are sufficiently articulated and the beauty of her voice is faithfully reproduced. The sound is hard and backing vocals a bit foggy, but this has more to do with the recording process than the quality of our device.

3)    Renzo Arbore – “E Maggio”

This recording has the drummer touching the cymbals very faintly from the very beginning of the recording, behind the piano. The male and female vocals are both more than convincing, while all acoustic instruments possess extraordinary colour and dynamics. The recording has more of a club atmosphere than a studio one.

4)    Maria Pradera Dolores – “Toda Una Vida”

The two male backing vocals are very clearly differentiated, while Pradera’s vocals are partially overshadowed by a pronounced artificial reverb. It’s good that Xonar is able to easily discern all this finesse, regardless of whether one appreciates them or not.

5)    Richard Strauss – “Also Sprach Zarathustra” (Staccato 2, nr. 12, op. 30)

This recording is a very large bite even for many expensive systems. Listening to it makes you regret that you were unable to attend the cathedral in which it was recorded. It’s clear that headphones have no place here, as you simply can’t capture the entire sound span of an organ without a top-notch pair of speakers. The pedal tones are deep enough to amaze you. The hiss of air escaping through the huge tubes and the vibrations it causes can’t be compared to anything else. Xonar Essence One is up to par. The old rule of thumb for speaker systems states that if a church organ sounds precise, any other material will.

6)    Sergei Prokofiev – “Romeo and Juliet”, Suite No. 2

Xonar Essence One R sThe entire orchestra was recorded with a single stereo microphone, live, without compression or reverb. It’s a scholarly example of a perfect recording. Xonar confirms the absence of colouration and any nasal nuance yet again. The resolution is wondrous, everything sounds great, the strings, blowers and percussionists are all well-balanced in the mix, with the latter having an amazing attack, while the sound of the large drum dominates the space, despite coming from the depth of the orchestra.

7)    Stanley Clarke 1st – “Life Suite, Spanish Phases…”

The rhythm section is phenomenal and the sound astonishingly firm and focused. Although we’re dealing with jazz-rock, everything’s potable and well-balanced. The sound of bass guitar and bass drum is strong and well-defined, without even a hint of any fuzziness. Having in mind the fierce execution, you’d expect a dose of aggressiveness in the recording, but it’s nowhere to be found.

8)    Richard Galliano – “Viaggio”

This is a jazz ensemble with the accordion player at the front. Phenomenally played, it requires loud reproduction to come to life. It feels as if there is no Xonar in between, with a neutral sound, rich in details, firm and tight. Just like on all other recordings, the bass drum sounds relatively dry, which is a compliment to Xonar. The accordion played by the virtuoso Galliano remains non-aggressive even in the highest register.

9)    Lalo Schifrin with WDR big band – “Gillespiana” (Africana, Bachianas Brasilieras no. 5)

This is a live recording from a concert, with all players in their proper places. The dynamics and microdynamics are fantastic, while the richness of details make every instrument sound as if it was recorded on its own.
Xonar EssenceOne internal s

10)    Chavela Vargas – “Piensa en mi”

11)    Jacinta – “Lush Life” (Boulevard of Broken Dreams)

12)    Howard Levy, Miroslav Tadic, Mark Nauseef - „The Old Country“ (Hucano oro)

13)    Lalo Schifrin – “Kaleidoscope“ (Peanut Vendor)

14)    Lalo Schifrin – “Latin Jazz Suite“ (Ritual)

15)    Lalo Schifrin – “Metamorphosis“ (La Nevada)

16)    Astor Piazzolla – “Libertango“

17)    Aziza Mustafa Zadeh 1st – “Oriental fantasy“

18)    Cheryl Bentyne – “Killing me softly“

19)    Antonin Dvorak – “Symphony no. 9“ (E minor From The New World)

20)    Ella Fitzgerald – “Caravan“ (1957)

Headphone sound

ASUS Xonar Essence One is very neutral when playing on headphones, with the impression that sound reaches you without any intermediate party. It’s bound to have a character to it, but the headphone test doesn’t show that. The sound is exceptionally precise, ultimate, firm and very well-defined. It makes no difference whether you’re listening to one, two or more instruments, or even complex player structures. There’s no murkiness, lack of clarity or false colour. Listening to massive orchestras doesn’t impact the feeling of everything being in its place, with realistic relations between instruments, which emphasises Xonar’s dynamic capabilities. The rendering of space is limited by the headphones, which can be heard. Longer listening sessions aren’t tiring at all. Both male and female vocals have the necessary largesse and weight. The power section is excellent and the amp has more than enough power for high-resistance headphones (from 240 to 600 Ohms). Comparing Essence One to another in-house soundcard, Essence XT, makes the difference very clear and puts Xonar Essence One up in front in all fields.
Xonar Essence One 2

Speaker sound

Unlike headphone sound, speaker sound brings it the much-needed spatial dimension. All features showcased by Essence One over the headphones have been confirmed over the speakers, with the enrichment of the feeling of space and air around the vocals and instruments. Everything remains precise, rich, fast, detailed and transparent. The tonal balance is perfect, and the same goes for dynamics and attack. Instrument colour is natural, while space is somewhat reduced in depth.

The general impression by playing any material is that the entire sound image is a bit withdrawn (from the listening position) back to the listener, making it shallower across the depth. We’ve already mentioned that it’s bound to have its own tonal character, and that’s finally come out as a slightly brighter sound. The bass area is not as clearly defined as other ones, while vocals are large, but lack fullness, i.e. hearing (feeling?) the thorax. Every hit of the baton across the piano string is perfectly clear, but the sound created could benefit from more voluminosity.

ASUS Xonar Essence One 
Signal/Noise ratio 120 dB
Audio processor C-Media CM6631 High-Definition Sound Processor
Playback Sample rate and resolution 4.1K/48K/88.2K/96K/176.4K/192KHz @ 16bit/24bit
S/PDIF Coax and optical in / USB 44.1K/48K/96K/192KHz @ 16bit/24bit
Analogue out 2x 3.5 mm, 1x6.3mm, 2xBalanced Output (XLR)
Dimension 261.3x230x60.65 mm
Price $580

Is it worth anything?

In order to gain a more realistic image of the test results, it’s important to stress that parts of the listening test were done as an A-B test between Xonar Essence One and a local constructor’s custom converter. ASUS has definitely stepped it up with Xonar Essence One and now stands as the prime USB converter in the 450€ price range, neck-to-neck with USB converters of specialised audio manufacturers, but bettering most of them in audio and production quality, while even containing an excellent headphone amp. Add to this the capability to change operational amps as desired (which is important to technically advanced users), and it’s even clearer that Xonar Essence One has no match in this or the next price category.