Digital Processor Reviews

The midrange receded slightly with upsampling engaged, as Michael Lavorgna described in his review. The voices in the Bachian arrangement of Noël Coward's "I'll See You Again," from The King's Singers Sing Flanders & Swann and Noël Coward (24/192 ALAC file from 1977 LP, EMI EMC 3196), acquired a touch more palpability. However, the recording lost a little bit of "air" around the singers' images, and the inevitable ticks in this needle drop sounded slightly softer. Augustin Dumay's performance of Beethoven's Violin Sonata 3 in E-flat, from his complete set of the sonatas accompanied by pianist Maria João Pires (ALAC from CD, Deutsche Grammophon 471 495-2), sounded a little darker with upsampling, though again, the instruments within the soundstage gained a touch more palpability. Overall, I preferred the sound with upsampling engaged, though the Pretenders tracks sounded too polite with upsampling, losing a little drive.

Comparisons
The obvious comparison was with the Channel Islands Transient Mk.II USB DAC, which Jon Iverson felt to be "up there with the best" in its price range, in his review elsewhere in this issue. The Transient brackets the price of the Essence One: it costs $699 when purchased alone, or $1028 with its matching VDC•5 power supply. With its power supply, the Channel Islands DAC was tonally very similar to the Xonar Essence One, though with perhaps a little more drive to its low frequencies and a little more weight to the kick drum in the Pretenders' "Back on the Chain Gang."

The Transient didn't have the palpability I heard from the Xonar DAC with its upsampling in action, but the voices in "I'll See You Again" were a little more forward in the soundstage, and with slightly grainier high frequencies in Daniel Lanois's haunting, pulsating "O Marie," from his Acadie: Gold Top Edition (ALAC files ripped from CD, Opal/Warner Bros. 25969-2).

One comparison I didn't perform but would have liked to was with the non-Muses version of the Essence One, which costs $300 less.

Headphone Listening
When I used the Xonar as a headphone amplifier with, primarily, Audeze LCD-X and Sennheiser HD800 headphones, its smooth character was still evident, particularly in level-matched comparisons with the Benchmark DAC1 ($995), which has always had incisive highs. It thus proved a better match with the brighter-balanced Sennheisers than with the Audezes, with their softer top end.

But unlike the character from its line outputs, the headphone output slightly emphasized vocal sibilants. I mention, in my Audeze review in this issue, listening to Beth Orton's performance of "Go Down Easy," from Johnny Boy Would Love This . . . A Tribute to John Martyn (256kbps AAC file). Orton's close-miked voice is indeed breathy, but became more so through the Essence One's headphone output. Similarly, Daniel Lanois's "O Marie" lost a little of its midrange delicacy via headphones.

The Benchmark headphone amplifier's low frequencies have always been its strong suit. When I compared the Essence One's headphone output with that of the DAC1, feeding both data via TosLink with "Cyril Davies," Ginger Baker's tribute to the late English blues harp player on our June 1999 "Recording of the Month," Coward of the County (ALAC file ripped from CD, Atlantic 83168-2), the Xonar's bass was warmer, and a little less well defined in the kick-drum-and-double-bass figure that starts the track. The Benchmark reproduced the kick drum with more weight.

And as with the line outputs, whether or not upsampling produced a sound I preferred through headphones depended very much on the music played. I liked what it did for vocal recordings, where the extra palpability was welcome. I also liked its effect on the sound of Ginger Baker's drums—it moved the kit back a little in the soundstage. But it slightly detracted from the clarity of the image of the drum kit in my first mixes of the May 2013 concert by Bob Reina's jazz ensemble Attention Screen.

One thing that needs to be mentioned is that way too much gain is available from the Essence One's headphone output. With sensitive 'phones like the Audezes, I was using the volume control set to 9 o'clock or below to avoid blasting my ears with rock music. Even with the less-sensitive Sennheisers, the maximum volume I could cope with was with the control set to 11 o'clock.

Conclusion
I find it difficult to sum up my opinion of the ASUS Xonar Essence One Muses Edition. Taken on its own merits, the Essence One offers an appropriately high standard of sound quality for its price. It is also beautifully made, and beautiful in appearance. As a D/A processor, it has a signature that is "friendly" rather than, as the audiophile cliché has it, "ruthlessly revealing." Whether the upsampling was beneficial or not depended on the recording, but I must admit that I was puzzled by the measured results with upsampling. The Essence One's headphone output sounded slightly coarser overall, though otherwise similar in character to the line outputs.

If I were looking for a USB DAC and headphone amplifier, I would consider springing the extra $296 for Benchmark's DAC1 USB ($1195). Overall, I preferred the sound quality of my 2003 sample of the DAC1 to the Essence One—and when I compared the DAC1 USB to that same DAC1 in my January 2008 review, I felt the newer version had smoother, less grainy highs.

So, while I recommend the ASUS Xonar Essence One Muses Edition, particularly as a D/A processor, I feel purchasers should audition it for themselves to hear if what it offers fits their own needs and tastes.