by J. Dan Daniell
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Unbelievable. That is how I felt the day the new Esoteric K-01X arrived at my home. After nearly a year of research and procrastination followed by anxious anticipation, here was the K-01X in a big box sitting on the floor in my studio. Yes, my heart was pounding, mostly from wrestling the three box shipping container holding 68 lbs. of Esoteric engineering excellence. Getting to the K-01X was like opening a present that had been hidden in nested boxes. One box led to another box that led to a third box. Finally there it was, surrounded by foam in yet another ingeniously designed cardboard lift with handles that allow the K-01X to be safely lifted free of the shipping cartons. It takes some muscle and a relatively strong back to lift 68 lbs. from the center of these large boxes. I probably should have sought help but reckless euphoria overcame me.
Once out of the box, its cloth covered protection removed, I found the K-01X to be ice cold. Touching the beautiful aluminum enclosure with my warm hands immediately left moisture condensing in an outline of my fingers on the surface. I decided to leave it sit right there for a few hours to warm up. The K-01X traveled from Esoteric in California to my home in Florida by overland freight, passing through the Midwest along its journey. It had plenty of time to absorb winter’s chill in a cold semi-trailer. After a few hours the K-01X had warmed so I installed it in the same location of the studio two channel rack where the K-03 had resided the past four years. All the cables were in place so making the connections was quick work. Getting the Aurender N10 music server in place on top of the K-01X was equally simple and quick. It was time to press the power button.
I was told in advance to expect a considerably higher performance level from the Esoteric K-01X than I had become familiar with from my K-03. I have been so satisfied with the K-03’s performance I had doubts any differences would rise to the high level of praise. I also know the break-in period is an extended event, so I was not going to let initial impressions cloud my judgement before considerable break-in time had transpired. Despite that determination I will admit it took less than 10 minutes to identify several aspects of the K-01X performance I liked better than the K-03. I will reserve those comments at the moment since there were many hours of break-in ahead and at that particular moment I had no idea where the chips would ultimately land.
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The break-in process began with the transport. I spent several hours with the K-01X during the first evening listening to CD’s and SACD’s, Ray Charles – Genius Loves Company, Diana Krall – The Girl In The Other Room, Anne Akiko Meyers – The Four Seasons, Yellowjackets – A Rise In The Road, and more, switching through the various upconversion and digital filter settings. With less than five hours on the K-01X transport I was already in awe of its poise. After my lengthy first day audition I set the transport playback to repeat, placed Tommy Castro – Exception To The Rule in the transport, set the upconversion to 2Fs and the digital filter to FIR2. The remaining equipment was turned off leaving the K-01X to tend to itself for the next 16 hours or so. The next afternoon I switched the source from the transport to asynchronous USB playback from the Aurender N10 music server, spent a few hours listening to assorted music from Anthony Wilson Trio – Jack of Hearts, Beth Rowley – Little Dreamer, George Benson & Al Jarreau – Givin’ It Up, then set the N10 to repeat a playlist. The K-01X was beginning to reveal its secrets. Resolution and soundstage were stunning. Once again I left the K-01X to continue logging hours. This same process continued day after day as I switched to the N10 coaxial output feeding the K-01X SPDIF coaxial input. I selected different upconversion and digital filter settings during the ensuing time to continue logging hours on the various playback options. There is no fast-tracking the K-01X break-in. It takes time with signals passing through all the various circuits. For this review there would be no way to log 300 hours of break-in on each upconversion setting, each digital filter setting, 300 hours on the DSD upconversion setting, plus 300 hours on the transport. That would total 3000 hours. I did accumulate 350 hours on the K-01X making use of every setting. I am comfortable that the analog output stages gained enough hours to consider them broke in as I began a more critical analysis of the K-01X sound. The upconversion and digital filter circuits have each had plenty of hours. Playing both CD’s and SACD’s, the transport has approximately 150 hours on it. I have been assured that additional break-in up to 500 hours will continue to yield even greater clarity and dimension to the K-01X performance. I am confident those gold nuggets will arrive in their own good time.
Briefly, the K-01X is an engineering masterpiece, a technical marvel in design and execution. The thick aluminum casework, graciously sculpted face, and close tolerance assembly personify a true work of art. The K-01X inherited the Esoteric VRDS-NEO VMK-3.5-20S transport from the Grandioso P1, as well as two independent monaural DAC units derived from the Grandioso D1 design. Each left and right channel monaural DAC uses the Asahi Kasei Microdevices 32-bit AKM4495s DAC IC. This exceptional DAC takes full advantage of 8 parallel/differential circuits with 16 outputs driving each channel. Each channel’s monaural DAC is independently powered by separate toroidal transformers and independent power supplies. There are two additional toroidal transformers in the K-01X, one powering the VS-DD spindle driver, and the other powering the audio circuitry. Rather than take up space in this review outlining the K-01X specifications and technical excellence, the information is available on the Esoteric website.
http://www.esoteric.jp/products/esot...1x/indexe.html If the K-01X piques your interest, the features and specifications are informative and worth reading.
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The Esoteric K-01X has acquired just over 14 and a half days of 24 hours a day break-in. At this time the sound is nothing short of sensational. My initial apprehension with respect to the K-01X substantially outperforming my Esoteric K-03 vanished immediately during the first few hours and never returned. As I mentioned earlier, it did not take me 10 minutes to find several performance aspects that exceeded my expectations. On day one, from a player/DAC with less than one hour on it, I was astonished at the harmonic richness. By this I mean the authentic weight and tonal character of instruments and voices creating an emotional connection, very much like a live performance. There is no sensation of listening to digital. The sound is fully matured, dare I say analog, and this from a player/DAC right out of the box. Not a single sound hinted at being edgy, exaggerated, or grainy. Music reproduced on the K-01X is engaging, deliciously ripe with vibrancy, harmonic texture, accurate timbre and weight in a comparative relationship that feels and sounds perfect. No aspect of the sound seemed over emphasized at any frequency or dynamic extreme including the all-important midrange. Listening to Stacey Kent - Let Yourself Go, the title track placed her presence and unique voice directly in the middle of the room. The separation of her voice from the instruments across the sound stage was almost dreamlike. All of Stacy Kent’s recordings are excellent. The K-01X reproduces this premium level of recording without reservation.
One thing I sensed on day one and remains evident after 350 hours is the K-01X bass authority, the manner and dimension in which bass frequencies are presented. There is a proportional strength to bass notes that render them faithful and felt without encroaching on other sounds. Massed instruments and voices do not crowd or cloud each other in the slightest, nor diminish the lowest octave’s energy and presence. A plucked acoustic bass string carries its initial impact, resonating harmonically rich wood tones and decay in its own space. This remains true even while coexisting with the impact of a bass drum being struck by a foot pedal. The sound of a bass drum strike and resulting low frequency vibration is reproduced completely separate with its own strength, dynamics, and purity. At the same time, the acoustic bass strings present themselves equally defined yet fully independent. This is easily heard on the track “Punta Del Soul”, Lee Ritenour – Rhythm Sessions. Bass is deep, powerful, and tuneful while at the same time the bass drum pedal strikes retain precise dynamics and decay in an individual space. Neither instrument shadows, mars, or conceals the other. The K-01X reproduces this type of sound combination without compromising the full robustness of each instrument, all the while delivering precise proportions and space for the remaining instruments in the performance. The uninhibited airy presentation of the K-01X, with its seemingly endless potential to establish a wide and deep three dimensional sound stage, sets it apart from all other player/DAC’s I have had in my sound system. The Esoteric K-01X is an authentic chameleon, becoming the color of the recording, not the other way around.
I have played so many familiar recordings during the break-in I lost track, but in each case I sensed hearing a recording not fully experienced before. The K-01X made recordings sound fresh and new again. One evening during the break-in I was listening to a Chuck Loeb CD if memory serves me correctly, when out of nowhere a distant synthesizer warble sound drifted from the back of stage center to beyond the left channel speaker in a matter of two seconds. It was a very faint yet distinct sound. It immediately caught my attention because I had never heard it before. I wasn’t positive I had not imagined it so I backed the recording up and played through that section again. Sure enough, there was the distant and fleeting synthesized warble sound. It was as if it appeared out of nowhere from a point in the recording I had never experienced. This incident demonstrated the K-01X’s uncanny ability to flesh out and clearly reproduce even the faintest of audible information without it becoming homogenized, smeared, or otherwise lost in the mix. This is one aspect of the K-01X performance that continues to impress me recording after recording. Intimacy coupled with immediacy never seems to be compromised.
Another facet of the K-01X performance that impresses me is the complete lack of grain or glare reproducing a piano’s upper register. I enjoy solo piano and easily find myself emotionally connected when a talented pianist brings life to the keys of a well recorded performance. Piano is a difficult instrument to record due in part to its physical size and shape, wide frequency range, complex harmonics, and extraordinary dynamic range. When high quality microphones are correctly located and the recording is captured in a good room using premium equipment in the hands of skilled engineers the sound of piano can be mesmerizing. Listening to Liz Story with Joel Di Bartolo – “The Very Thought Of You” was sheer delight. The grand piano and acoustic double bass each revealed perfect tonal weight. I have enjoyed this compact disc over 100 times through the years. The K-01X reproduced this recording with the utmost clarity and sonic integrity I have ever experienced from this CD. It was absolutely enchanting.
The downside to recording piano can often end in infuriatingly abrasive results, especially in the upper octaves. This is often the repercussion of improper microphone placements, low quality microphones, poor engineering techniques, less than ideal room acoustics, and over use of compression. I am grateful to find the K-01X flows through this difficult piano range with aplomb providing a recording has been captured with special care by pros from the likes of Windham Hill, Narada, GRP, and others. The K-01X reproduces fresh and vibrant upper octaves without the bite that often has us reaching for the volume control. I will say this though, the K-01X will not produce a silk purse from a sows ear. If a recording is raw, compressed, mixed hot, or poorly mastered it will sound exactly that way. The K-01X does not sugarcoat bitter recordings. It can bring out the best or the worst a recording has to offer. On the other hand, it reproduces well recorded CDs, SACD’s, and high-resolution performances as show stopping, jaw dropping events every time. There is a soul touching wholeness and transparency in the K-01X sound that enlists an emotional connection. The sound is undeniably satisfying.
The K-01X manages to build a remarkably holographic sound stage. I did much of my auditioning for this review with the lights turned off in my studio. I even turned off the meter lighting so all that remained was a faint orange tube glow from the power amps and soft lighting from the illuminated nomenclature on the components. In this serene state it became effortless to fabricate tangible three dimensional images in my mind without visual distractions that diminish the experience. The K-01X places musicians so accurately and stable in the sound stage that I felt present rather than being a passively detached listener. During many recordings the sound stage exceeded the dimensions of my studio, occasionally eliminating the physical boundaries entirely. One example of this came while listening to Doug MacLeod – Brand New Eyes. The title song features Doug singing, playing his Dobro guitar while tapping his foot and guitar for rhythm, nothing else. The recording is so clean you can hear the ambience of the room as his voice and guitar reflect off the room’s walls and floor. The K-01X turned my room into his room. It was just me and Doug. I nearly felt obliged to shake his hand when the performance finished. It was that real. While listening to Janis Siegel – I Wish You Love, “Don’t Go To Strangers” I found myself spellbound by her beautiful voice, the piano and acoustic bass. The performance from the K-01X transported me to a small jazz lounge where Janis, her pianist and bass player effortlessly held my undivided attention. The K-01X has the extraordinary ability to remove the hardware from the equation. It becomes just the music, sincere and astoundingly lifelike.
After many hours auditioning the multiple upconversion and digital filter settings available on the K-01X I settled on two particular combinations that induced the most holistic sound to my ears, at least at this time. One is 2Fs upconversion with the FIR2 filter. The second is 4Fs upconversion and the SDLY2 filter. Don’t take my word for it, though. With Original, 2FS, 4FS, 8FS, and DSD upconversion, plus OFF, FIR1, FIR2, SDLY1, and SDLY2 digital filter settings there are a plethora of choices for all listeners. I was also impressed with upconversion set to Original and the digital filter set to OFF. I am fascinated with all the K-01X options so I am not married to any upconversion or digital filter setting. That’s the beauty of the Esoteric K-01X. It allows the listener to determine a choice with the ability to change your mind at any point.
It goes without saying the Esoteric K-01X is a substantial investment. It took me quite some time to convince myself to write that check. It was an exhilarating moment to finally make the purchase decision. My expectations were high and made even higher by those who already owned the K-01X and reported their experiences. The good thing is this purchase did not disappoint me. In fact, the Esoteric K-01X sound and performance exceeds what I hoped for by a wide margin.
I have a few comments about the remote control. While it is more streamlined and much easier to handle than the K-03 remote, there are still buttons that do not function with the K-01X. Of particular disappointment is the loss of being able to select digital inputs from the remote like the K-03 remote allows. I am required to approach the K-01X and press one of its buttons to select a different input. Since I use all three digital inputs on the K-01X, this is inconvenient. There is no way to select upconversion or filter settings from the remote control. In my humble opinion, this is a regrettable design omission, especially for an audio component that tips the scale at $20K. This player/DAC should arrive with a full function dedicated remote control. It also seems the infrared emitter is not very powerful. I find myself on occasion pressing a remote control button more than once before the command is accepted. Those are my only nit picks about an otherwise overwhelmingly positive impression of the Esoteric K-01X.
Concluding this review I must say the Esoteric K-01X is stunning in every respect. It effortlessly yields amazing full bodied sound and I am overjoyed to own this incredible CD/SACD/DAC. I am also delighted that the K-01X clearly demonstrated the high caliber resolution of my studio sound system which presented no difficulty faithfully reproducing the performance differences between the K-03 and the K-01X. The combined synergy of the studio sound system and the K-01X is intensely exhilarating. The final verdict is I would not hesitate to recommend the Esoteric K-01X to anyone. It is the most analog sounding digital playback I have ever experienced.
Equipment used for review:
McIntosh C1000C/P, McIntosh MC2301 (2), Aurender N10, Esoteric K-01X, PurePower 2000, Furutech Flux 50, Sonus Faber Amati Anniversario speakers, Stillpoints Ultra Mini's, Wireword Silver Eclipse IC's, Silver Electra PC's, Supernova Toslink, Platnum Starlight coaxial and USB cables, Silver Eclipse speaker cables.
