⌈ ESOTERIC COMPANY is a relatively young brand, founded in 1987. It is a branch of the well-known Japanese brand company TAEC CORPORATION, which used to operate mainly in the field of professional equipment. Today TEAC offers devices also for audiophiles, from the entry-level and mid-price range, and Esoteric has focused on the high-end. ⌋

HERE ARE FEW AUDIO COMPANIES that have made a career - in terms of industry standards - like ESOTERIC. It is a company run by engineers, similar in terms of operation to Accuphase, but with a much stronger financial support - TEAC is a powerful company-institution. It is no coincidence that I mention engineers, because it is one of THOSE companies where precision, measurable changes and hi-tech are the order of the day and they set a direction of development.

Esoteric's lineup is focused around two types of products: digital sources, with an emphasis on SACD players, and amplifiers. The catalog of this manufacturer is transparent and is divided into several levels, which are "counted" from '07', through '05', '03', '02' to '01'; the tested K-01XD SACD player belongs to the latter. At the very top, there is a separate Grandioso series with its own website - there are two more levels in it.

As I said, the Super Audio CD players are the core products for Esoteric, as the company is one of the three currently operating manufacturers of SACD transports and - this is the common opinion - the best one. Their products are used in the top devices of this type from other brands, such as dCS, emm Labs, etc., and yet the best transports models can be found only in Esoteric products. In addition to SACD players, the company also offers file players, clocks, preamplifiers and power amplifiers, as well as integrated amplifiers.

| K-01XD

The K-01XD MODEL, along with the cheaper K-3XD, is the latest addition to their portfolio. This is a Super Audio CD player with three digital inputs, two outputs and the ability to use an external clock, such as the G01X.

Its mechanical design quality is above average and it is, next to the Accuphase, an example of how the high-end should be built. A huge, aluminum chassis, anti-vibration feet and a "loose" top cover on one side, and on the other side the latest version of the VRDS-Altas SACD transport (version 01), which no other brand has an access to, as well as a proprietary discreet Digital-toAnalog Converter called Master Sound - it all adds up to an extraordinary product.

The device offers playback of SACD and CD discs, although it does not play DVD-R discs with PCM hi-res or DSD (DSD Disc) files. I am talking about it because such discs, with files burned non-commercially, are played by players from Accuphase and McIntosh, using D&M transports - so they are also played by devices by Denon and Marantz.

| FEATURES

BUT IT IS ABSOLUTELY MINOR ISSUE. More importantly, the device allows for synchronous upsampling of the PCM signal from discs and digital inputs, or to a higher resolution PCM - in four steps up to 16 fs (705.6 kHz) - or to DSD64. We can also choose one of the three PCM conversion modes and three separate DSD ones. Users can adjust brightness of the display, activate or deactivate analog and digital outputs, and even determine whether the analog XLR output is "wired" in accordance with the DIN standard or the "American" one.

The device features four digital inputs, two outputs and a separate BNC input for an external clock clocking at 10 MHz. The USB input features the most modern chip available, allowing for the support for 16-32 bits, 44.1-384 kHz (including DXD) PCM signal, as well as DSD signal from DSD64 up to DSD512 (22.5 MHz). The other digital inputs - RCA and optical - are also very good, because in addition to the PCM 16-24 bit, 44.1-192 kHz signal, they can be used to send the DSD signal using the DoP protocol.

The output signal is available either on digital outputs - RCA (S/PDIF) and XLR (AES/EBU) and analog outputs - RCA and XLR. This is a fully balanced design so the latter is the preferred output. As I said, you can choose which XLR pin is "hot" in the menu, but it is not only the only choice. It has long been known that the transmission of a voltage signal - that is, between almost all home audio products - has its issues, the most important of which are quite high noise and susceptibility to external interference.

A current transmission is a standard in recording studios. Interestingly, in "our" world it is also used sometimes - at some point American companies Krell ("Krell Current Mode") and Playback Design, and now primarily the Swiss darTZeel ("50-ohm Zeel") were/are supporters of this solution. The Esoteric did it in its own way, because while those solutions require BNC cables with an impedance of 50 Ω, ordinary XLR cables will suffice here; its solution is called ES-Link.

| DESIGN

EVERY digital optical disc player consists of two main modules: transport (drive, mechanics) and digital-to-analog converter (DAC). And only around these two other functions/features are built. In the case of the Esoteric both of these modules are proprietary ones and have come a long way to arrive at the form featured in the K-01XD.

⸜ VRDS | The letter 'D' in the name informs us that this model features the latest version of the VRDS transport, the VRDS-Atlas. VRDS stands for Vibration-Free Rigid Disc-Clamping System. It speaks of a mechanically solid, heavy transport of Compact Discs (and now also SACDs), in which the CD is clamped from above with a heavy disc/clamp. This mechanism was used for the first time in the company's top CD transport, the 1997 P-0, which is still sought after by collectors.

⸤ Three versions of the VRDS transport (from the left): original VRDS, VRDS-NEO VMK-3.5, VRDS-ATLAS 01 - the latter both outside and its cross-section | photo by Esoteric

However, it is best known not from the Esoteric products, nor they made it famous, but rather Wadia players, models 860 and 861. This American manufacturer bought the transport and added its own electronics to it; importantly, it was exactly the same model used by Esoteric. In 2013, TEAC proposed a new version of its flagship solution, the VRDS-NEO, which was a SACD transport. From then on, the Japanese offered only mid-range mechanisms to external companies such as dCS, reserving the best ones for themselves.

In the 193 issue of the Japanese quarterly "Stereo Sound" (Summer) magazine, another VRDS iteration was presented, this time called VRDS-Atlas. It is still an SACD drive, but with an even more solid design than the VRDS-NEO, with a heavier clamp, a new brushless motor and improved electronics. It is used in the two models from the Grandioso series, as well as the two most expensive models of the "basic" series, the tested K-01XD and K-03XD (VRDS-Atlas 01 and VRDS-Atlas 03 respectively).

⸜ Master Sound Discrete | The second element constituting the Esoteric SACD players is the digital-to-analog converter. This is one of the companies that do not use of-the-shelf chips and that developed their own discrete DAC, that is, composed of separate, surface soldered resistors. Solutions of this type are known in audio, for example - one by the dCS ("Ring DAC"), they can be found also in MBS products ("The Discrete DAC") or totalDAC ("R2R DAC") converters.

⸤ One channel of the MASTER SOUND DISCRETE converter

They share some common features, not only design-wise, but also sonic-wise. Their design, apart from the necessary FPGA (Field-Programmable Gate Array) software that controls the switching of resistors, also differs in the basic issue - dCS prefers a 6-bit delta-sigma circuit, and the rest focus on multi-bit circuits. On the other hand, Esoteric's MSD DAC is a 64-bit circuit, but controlled by the ΔΣ modulator. It natively decodes PCM signal up to 32/768 and DSD up to DSD512.

The company materials emphasize that it is a simple system - consisting of only 32 elements - but controlled by a precise algorithm and made in an ultra-precise process. The company also points out that in its output one finds another proprietary solution, i.e. the high-current buffers, that the company calls HCLD ("High Current Line Drive") with a very fast rise time - the materials speak of the values of the order of 2000 V/μs. This buffer was used to the maximum, offering a current method of signal transmission to the brand’s amplifiers. The solution, as we said before, is called ES-Link.

We already know that Esoteric offers a whole range of external clocks, in which they remind me of the dCS, which also hails from the PRO world. An external clock can be connected to the K-01XD, but the player is well "equipped" in itself, so to speak. For the clocking of digital circuits, it uses brand’s own VXCO II clock with a precision of ± 0.5 ppm, originally developed for players from the Grandioso series.

⸜ All the rest | The K-01XD chassis is made of thick aluminum plates, and additionally a 5 mm steel plate is screwed in the center, which separates the audio circuits and the power supply section. It is located at 1/3 of the device’s height - the audio circuits and the transport are screwed from the top, and the power supply from the bottom.

The device rests on three anti-vibration feet - two at the front and one at the back - resembling Finite Elemente feet. This is another Esoteric's proprietary design, for which the company has appropriate patents (no. 4075477 and 3778108). In the accessories box you will find soft pads that can be stuck underneath so as not to scratch the surface on which the player is placed. I would like to add that the bottom plate has been cut in such a way as to transfer as little vibrations from one foot to the other as possible.

An interesting fact is that the top plate of the chassis is not rigidly fixed, and it can be slightly raised - by about 2 mm. I do not know if you have seen the photos from the Esoteric mastering studio, where remasters of the "Master Sound Works" albums are prepared - if not, then it's worth looking for them. And it's worth it, because you can see that the devices of this company used by sound engineers have the tops unscrewed and placed on separating elements. They still shield the circuits inside, but they are far enough not to disturb their operation (with eddy currents).

It turns out that it offers measurable benefits and improves the sound. This is why the top plate in the K-01XD is movable. For security reasons - and user safety is paramount! - it cannot be completely removed. However, you can slightly lift it and insert rubber, wood, Teflon washers, etc. into the gap between the chassis and the top plate - give it a try, it’s fun. :)

The player is very heavy, which results from the housing, the mechanism and the power supply. Inside there are as many as four large toroidal transformers, supplying the transport, left DAC channel, right DAC channel and digital circuits, including logic, each of them independently. The power supplies use low-feedback voltage regulators originally developed for the Grandioso series. As many as 71 capacitors with a total capacity of 1,850,000 μF work with them.

As we said before, external digital sources can be connected to the player. The signal from all of them, just like from CDs, can be upsampled to 32/768 or to DSD or left in its native form. The K-01XD also decodes the MQA signal - it is one of the few high-end disc players, next to the Luxman D-10X, which also decodes MQA-CDs, the latest hit on the Japanese market. I ordered some of them, but unfortunately I didn't have them yet at the time of the test.

⸜ Summary | The K-01XD is one of the best-built digital players I have seen in my life. This is the level of dCS and Accuphase, or maybe even a hair better. The VRDS-Altas transport is the best mechanics for reading optical discs in the world. The player offers a vide variety of features, because not only does it read SACDs, CDs and MQA-CDs, but we can send virtually any digital signal to it. It also features an extensive upsampling section, and its operation is extremely pleasant.

The RC-1333 remote control proves how well-thought-out the project is. It is convenient, and the buttons are placed on both sides - on one side are the more frequently used ones, and on the other - the less frequently used ones.

| SOUND

HOW WE TESTED The tested player was placed on the top shelf of the Finite Elemente Master Reference Pagode Edition rack. It was compared to the Ideon Audio ABSOLUTE and my Ayon Audio CD-35 HF EDITION SACD player.

This letter comparison consisted of two stages. In the first one, both devices were treated identically, i.e. they were powered by Acoustic Revive Absolute cables, and I used the Crystal Cable Ultimate Dream interconnects. In the second part, both players were listened to separately both benefited fully from all the upgrades and accessories that I use with my player:

• power cable and interconnect Siltech Triple Crown |ARTICLE ⸜ ARTICLE|,
• anti-vibration platform Acoustic Revive RAF-48H | REVIEW|,
• generator Nordost QPoint with power supply QSource | REVIEW|,
• Artificial ground Nordost QKore | REVIEW|,
• socket plugs Acoustic Revive REALITY ENCHANCER PLUGS
RES-RCA | RET-RCA i RES-XLR | RET-XLR | REVIEW|

The Esoteric player offers user digital filters to choose from as well as a choice of the type of upsampling. I listened to it for a long time with the PCM signal upsampled to DSD, but I gave it up. Converting PCM to DSD in this case results in a warmer, darker sound, which, however, does not have the dynamics of the original, nor its resolution. So in the end I listened to music with PCM max upsampling (16 fs). For PCM I chose M3 filter and for DSD the FLT2 one.

Recordings used for the test | a selection

→ Super Audio CD
⸤ AL JARREAU, All I Got, GRP ‎065 082-2 | SUDL 003630, Test Press SACD/CD (2002)
⸤ ART BLAKEY & THE JAZZ MESSENGERS, Just Coolin', Blue Note/Universal Music LLC (Japan) UCGQ-9027, SHM-SACD ([1959] 2020); ⸤ CHET BAKER, Baker’s Holiday, Verve Records B0003279-16/SUHD 009960, Test Press SACD (1965/2004)
⸤ THE POLICE, Reggatta De Blanc, A&M Records 493 705-2/SUSS 004390, Test Press SACD (1979/2003)
⸤ TSUYOSHI YAMAMOTO TRIO, Vol. 1: The Look of Love – Live At Jazz Is, Venus Records VHGD-355, SACD (2020);
→ Compact Disc
⸤ EMERSON, LIKE & PALMER, Pictures at an Exhibition, Island/Victor VICP-78003, „7-inch mini LP”, Platinum SHM-CD (1971/2014)
⸤ JOHN COLTRANE, Giant Steps, „Deluxe Edition 60 Years”, Atlantic/Warner Music Japan WPCR-18311/2, SD 1311, 2 x SHM-CD (1960/2008); ⸤ JOHN SCOFIELD, Swallow Tales, ECM Records /Universal Music LLC (Japan) UCCE-1183, CD (2020); ⸤ MARIO SUZUKI, Masterpiece II: Touching Folklore Music, Master Music XRCD24-NT021, XRCD24 (2018)
⸤ PIOTR WYLEŻOŁ, Human Things, Polskie Nagrania | Warner Music Polska 9029570037, „Polish Jazz vol. 79”, Master CD-R (2018)

Many years have passed since any audio device surprised me as much as the tested player. I have known Esoteric products for years, I have listened to them at countless exhibitions and shows, and I have been collecting their releases from the very beginning - it would seem, then, that I really know Esoteric sound, or at least I’m familiar with it. It turned out that I didn't know anything about the Esoteric.

The thing is that all the shows I am talking about presented the products of this brand in terms of precision, technical refinement and perfection. Although the SACDs released with the logo of this manufacturer were completely different, the impression I am talking about was so strong that I took them for granted, for truth. I assumed that the Esoteric is a "technical" company - excellent at what it does, but still with the primacy of measurements over listening sessions. There is nothing wrong with that. We know, however, that this is just the beginning of the high-end road, not the end.

So the bigger was my surprise, the longer my reflection on myself, that I found the Esoteric K-01XD sounding completely, completely different. This is one of the warmest sounding digital sources I know. But also - this is an extremely important reservation! - t offers everything one expects from an "engineering" company. And the most important thing is that it sounds in "its own" way, different from all the best one-piece CD/SACD players I have heard.

The warmth I am talking about comes from the outstanding resolution. This is what I was expecting, this is what I heard at all the shows I mentioned earlier. Listening to any disc on the K-01XD, we enter its sound deeper than usual, everything is precisely differentiated, there is a lot of colors, shades and emotions in this presentation. However, this differentiation does not result from exaggerated precision or unnatural selectivity. This is a “gut” resolution, if I may say so, flowing from INSIDE the music, not imposed from outside.

The warmth in question manifests itself, for example, in the perfect reproduction of the strings of a classical guitar. Probably only with the top dCS Vivaldi system I heard something similar. Mario Suzuki, Masao Okada and Miyuki Fujimoto, who played on the album Masterpiece II: Touching Folklore Music, released on the XRCD24 disc by Mr. Kazuo Kiuchi from Combak Corporation as part of the "Master Music" series sounded better than live - I'm not exaggerating! Even sitting in the best place in an acoustically good room, we won't hear it in such a tangible way as I heard it with the Esoteric.

I had a similar impression with the Coltrane’s saxophone from the re-issue of the Giant Steps ("Deluxe Edition 60 Years"), and the sound of The Police album Reggatta De Blanc, played from the test SACD release. I was prepared for the first one to sound like that, I knew that I would hear a dense, deep, very accurate sound, but The Police album was a surprise for me. It's a bit bright, a bit hard recording and production, it’s a rock album after all. The tested player showed me what it was all about, but it also "embraced" everything in such a way that I did not want to turn off this album, I did not even want to check how higher quality discs sound like.

And this is a very rare quality because it makes it easier to listen to music recorded in less than optimal quality. The Esoteric K-01XD shows the characteristics of the recordings, is - as I said - precise, but gives so much information that they make up a realistic presentation, something that may be defective, but defective in such a way that we believe it is real. It is not only about a perfect tonal differentiation, but also of dynamics, as well as the free construction of space with realistic, dense sound sources.

And it is in the latter that you can best perceive the "own" sound of the tested device. The thing is that it is a player that slightly rounds the texture of sounds. They are incredibly saturated, they are also precisely located in space, have a clear "body", and yet they are not as "raw" as the sound from the tape recorder and master tape, or from the reference player. In this respect, the K-01XD would be the closest to the dCS device, the Vivaldi One.

But also not entirely. On the other hand, the attack of the sound is quick and natural here, in which it resembles the GRYPHON ETHOS and ACCUPHASE DP950 / DC950. It is a similar approach, in the sense that the Esoteric does not "warm up" the sound - it is a warm sound, but not warmed up. Same as both of the aforementioned devices, the Esoteric does not round off the attack of the sound, but allows it to strike and reverberate in the richness of harmonics, delivering a rich, firm presentation.

But it is also internally smoothed. In a sense - similar to the one we get with players and D/A converters from EMM LABS, MSB or totalDAC. This is about a similar pursuit of "truth" by thickening the "playing field", that is by saturating the sound in such a way that we get a coherent, meaningful "wall of sound" in front of us. It's a three-dimensional representation, excellent 3D rendering, but showing bigger planes rather than small details. It is all there, without details and subtleties the presentation cannot be truly credible - but you cannot hear them as such, they build something, and they are not there for themselves.

| Our albums

⸤ W.A. MOZART Piano Concertos No.20 K.466 & No.27 K.595 dyr. BENJAMIN BRITTEN, wyk. CLIFFORD CURZON

Esoteric ESSD-90014 | SACD/CD (1982/2008)

THE CD WITH MOZART PIANO CONCERTOS in question was recorded over two days in 1970 by one of the best specialists in this field, Kenneth Wilkinson. This is a classic recording for him, made with the help of the so-called "Decca Tree", ie with three omnidirectional microphones, on an analog tape. However, this performance did not satisfy Benjamin Britten, the conductor of the English Chamber Orchestra, and therefore it could not have been released until after his death, in 1982.

The first digital release comes from 1986 and last year the album was released in Japan by Tower Records Japan, but the most important re-release is the one in question. It was remastered on August 26, 2008 by Esoteric at the JVC Mastering Center, under the supervision of Kazuie Sugimoto, and released on SACD/CD and LP (200 g) in the "Master Sound Works" series. This is one of the first albums in this series and today both its versions - SACD and LP - are very rare, especially the vinyl record. Both were pressed in a thousand copies and today the mint version of the SACD cost $ 300 and more, and the LP’s price starts from $ 600.


We wrote about the "Master Sound Works" series in January 2017, in the report from the 107th meeting of the KRAKOW SONIC SOCIETY. Since then, several dozen new titles were released, as well as several large boxes. However, it is not entirely clear how the sound is prepared for them. It is only known that the original "master" tapes are not sent to Japan, but their digital PCM copies ("flat transfer"). However, they are prepared especially for these re-issues, and are often even re-mixed - like recordings from the Decca label.

There is uncertainty about the remastering process. However, one can risk such a supposition: high resolution files are played from a DAW workstation and converted to an analog signal using top Esoteric D/A converters. The material is then converted to DSD and digitally mastered in DSD format. This is unusual, but the result is an exceptional sound - despite the signal being converted twice. Furthermore, all titles become collector items pretty quickly and their value increases. A box with the Wagner's Ring of the Nibelung originally priced at $ 600 can now be purchased for $ 1900! ♦

ONE OF THE FEATURES that connects the K-01XD with the reference player is building the presentation in such a way that we have the impression that everything “flows” in it, we do not pay attention to details, unless the producers emphasize them. By themselves they are "blended" into the whole, or actually create it - they are the whole, although composed of millions of small particles.

So the sound is warm, but not warmed up, incredibly dynamic, but without a hard attack of the sound, it is also dense, but detailed. Space is built in a different way than by my player, Gryphon or Accuphase. The presentation comes out to us, surrounds us, is tangible. There is no particular depth of the soundstage here, it's not that kind of sound. Contrary to the usual, however, it is not because the resolution is too low, but because the presentation "flows" to us in waves, that it is how the performers come to us. It's just a certain type of presentation, not a flaw.

| Summary

The sound of the Esoteric K-01XD player is exceptionally refined. It offers everything that we expect from a top sound source, regardless of whether it is analog or digital one - just a source. It is both warm and precise, and such a combination is extremely rare. It is more “rounded” than the sound of the Ayon Audio player with which it was compared, warmer than the sound of the dCS Vivaldi One player, and yet it delivers just as much information, there is nothing missing in its presentation.

Its character could be best compared to a high-class turntable, but with a better gradation of gray, with less "analogue" sound, in the sense that it is not as "made" as on vinyl records - and let me remind you that a vinyl record is only an approximation of what is on the "master" tapes. There is a very low bass and a precise high treble in this sound, but we will notice it only when we are looking for it. Without it, the sound seems simply complete and natural, there is no separate "treble" or "bass" in it.

This is literally one of the best-sounding and best-built digital players that I have heard in my life. It is also so different from the other devices mentioned above that it will be easy to decide if it is "your" sound - because it is a sound shaped in a specific way, different than that of all the aforementioned sound sources. And yet it is not the most expensive source of this manufacturer! A unique product from an exceptional company. ■

Technical specifications (according to the manufacturer)

Supported disc types: Super Audio CD, CD (CD-R/W)
Output impedance:
XLR: 114 Ω | RCA: 34 Ω
Max output signal (1 kHz, 10 kΩ):
XLR: 5 Vrms | 2.5 Vrms
Digital inputs:
→ RCA (S/PDIF), optical (Toslink): PCM 32-192 kHz, 16/24 bits, DSD 2,8 MHz (DoP)
→ USB B (USB2.0): PCM 44.1-384 kHz, 16/24/32 bits, DSD 2.8 MHz, 5.6 MHz, 11.2 MHz, 22.5 MHz
Wejście zegara: BNC, 50 Ω, 10 MHz (±10 ppm)
Power consumption: 26 W
Dimensions (W x H x D): 445 × 162 × 438 mm
Weight: 31 kg