Product Review

Audio Note CD2.1x Tube Output Stage CD Player

August, 2003

Jason Serinus




Tube Compliment: One 6111WA Output Stage
Reference Output: 3.0V RMS (approx.)
Channel Separation: > 80 dB

Power Consumption: 15W
● Size: 116 (h) x 470 (w) x 350 (d) (mm)
Weight: 10 Kilograms
MSRP: $1,750 USA


Audio Note (UK) Limited


Toward the end of the last century, what is now known as Audio Note Japan became known as the manufacturer of extremely expensive single-ended triode equipment. Photos of $120,000/pair 27W Class A SE triode Ongaku monoblocks graced covers of major audiophile publications, accompanied by interviews with company founder Kondo San that treated him with a kid glove reverence usually reserved for the Dalai Lama and other spiritual leaders. While scores of readers shook their heads with disbelief as they read that the reason the equipment cost so much was that a small cadre of devotees spent days and days on end hand winding silver wire transformers, other audiophiles were tempted to take a listen.

I cannot resist describing my initial Audio Note Japan listening experiences. The first occurred perhaps 14 years ago at New York's Sound by Singer, where the then top-of-the-line Ongakus, manufactured by Kondo, were connected to Wilson Grand Slams. Since I lacked both reviewer credentials and the appearance of someone with a huge bank account, I literally had to be snuck in by a friendly salesperson who said to me, “Can you believe I've sold three of these already?”

While I was assured that the huge Wilsons were sensitive enough to be powered by 27W SE triodes, what I heard left me confused. On the one hand, the orchestra in Fritz Reiner's Chesky performance of Brahms' Symphony No. 4 took on monumental proportions to do justice to the scale of Brahms' monumental music. I had never before heard such a huge soundstage, let alone so much air around vocals and instruments. The sense of space, and the sense of actual hall reverberation were immensely exciting. The sound was nothing like that I'd heard in live concert situations, but it was most certainly amazing.

However, in the case of a much smaller-scaled recording, a Brahms lieder recital on Hyperion featuring soprano Elly Ameling and pianist Rudolf Jansen, the balance between voice and piano was so off, the normally bright voice so blanched out on top, and the soundstaging so artificial that I couldn't figure out what was going on. Ameling and the piano sounded miles apart, separated by a wind tunnel. I left the showroom dismayed that what I had been told was the best sound money could buy could create such a distorted listening experience. How much of what disturbed me had to do with a serious component mismatch, I cannot say. But I do know that what I had heard from equipment in an adjacent room that cost 1/10 the price proved far more satisfying.

My second listening experience was at a now-defunct Audio Note dealer showroom in Marin County. In a special afternoon session open only to members of the Bay Area Audiophile Society, I spent quite some time listening to $18,000 Audio Note amps (and other high quality Audio Note components) driving imposing Avantgarde Trio horn speakers. The dealer was very much into vinyl, and kept offering us one tempting analogue recording after another: Leonard Bernstein conducting Mahler's Das Lied von der Erde with James King and Fischer-Dieskau, so and so doing baroque music on period instruments, a rare RCA Living Stereo in mint condition, etc. He also played some of the best-sounding CDs available at the time. Frankly, it didn't matter what was played. Everything sounded the same. Glorious midrange, uniform coloring, no top, no bottom. Never did a harpsichord or violin sparkle; never did a timpani thunder. Once again, it sounded nothing like the real thing.

At one point, I left the room to join a growing contingent of BAAS members who had retreated to the sunny outdoors. I sat next to a local dealer, and asked in a low voice, “Can you believe what we're hearing?” His reply, which I quote verbatim: “It's all a scam, Jason, it's all a scam.”

While I would never pretend to be a final source of truth on such matters, especially given the plethora of pages devoted to praising Audio Note Japan products, I must admit that these experiences left me deeply skeptical of the company.

Since those two listening experiences, however, two very different Audio Note companies have emerged. Initial company founder Kondo, formerly a super engineer for Sony Corporation, originally designed and manufactured all Audio Note products in Japan. Peter Qvortrup from the UK was the company's worldwide marketing director, as well as one of the owners of UK's Audio Innovations.

At one point, Peter felt the world needed more affordable Audio Note equipment. With Kondo's permission, he began to build Audio Note's Level Ones to Three in England, while Kondo built the higher-level gear (Levels Four to Eight) in Japan.

Eventually, when Kondo expressed a desire to build push-pull designs, and Peter wished to stay with single-ended triodes, there was a falling out between the men. Peter turned out to hold marketing rights to the Audio Note name, and proceeded to build and distribute Audio Note UK products everywhere except in Japan, where Kondo's Audio Note Japan remained in control. Audio Note UK also began manufacturing Audio Note equipment up to Level 10. At this point in time, for example, both companies manufacture the Ongaku.

What's the difference between the sound of the two company's products? According to Audio Note UK's US distributor Ray Lombardi, Audio Note Japan equipment tends to have a more “romantic,” classic tube sound, while Audio Note UK's products tend to have far more treble and bass extension. In addition, Audio Note Japan is a very small operation, with a long lead-time on orders. Audio Note UK, on the other hand, now claims to be the largest audio company in Great Britain (excluding B&W), and produces on a much larger scale with faster turnover.

Sometime last year, I spent some time at Audio Note dealer Joe Cutrufelli's place in Martinez, California. Joe is in love with Audio Note UK products, finding them extremely musical and satisfying. I liked what I heard at JC Audio much better than the Audio Note heard on previous occasions. I also could not help noting that the equipment Joe was selling cost considerably less that the Audio Note Japan equipment I had found so disappointing.

Thanks to Joe, I contacted Ray Lombardi and received, many moons ago, the $1,750 Audio Note CD2.1x entry level CD player and, shortly after HE 2003, the $6,000 M3 Line Stage Preamp ($7,499 with phono stage). These creations have led me to view Audio Note-UK in a favorable light.

Technical Notes and Description

Audio Note's entry level CD player unites their CDT Zero transport and DAC One.1x in a single chassis for a price considerably lower than for the separate components. Since a one-box unit dispenses with the need for a digital cable and a second after market powercord (if one chooses to use after market powercords), the 2.1x certainly qualifies as a financial win-win proposition.

The player's online manual describes the unit:

“The CD2.1x uses the revolutionary and currently exclusive Audio Note™ digital technology dubbed the 1X oversampling™ direct from disc™ circuit topology. The ultimate version of this technology is found in the extremely expensive DAC5 Signature, and we have taken great to ensure that as much of the inherent advantages of the topology have been retained in the sound of the CD2.1x. The technology dispenses with all the correction measures inherent in all other D-A converters and presents the digital signal directly to the converter after reformatting. This allow you to hear what is actually recorded on each disc, rather than, as has been the case up to now, some technically and cosmetically altered version, as a result the reproduction is more reminiscent of a master tape in quality.

“Not surprisingly for an Audio Note™ product, the CD uses valve technology, implemented using traditional Audio Note techniques, of simple signal paths incorporating no correction or feedback operating the valves at their most linear operating points for best sound and longevity.”

The player contains an 18 Bit 44.1/48/96 kHz compatible multi-bit converter chip. Its 1X oversampling system truncates information at 20, 22 and 24 bits, which the company claims “is a very much milder form of information loss than that introduced by traditional oversampling and digital filtering, etc.” The unit can either be used as a one-piece CD player or, via its RCA digital output, as a transport.

Notes from Colin Miller: 1X oversampling is no oversampling, which means no digital reconstruction filter, i.e., a total reliance on an analog reconstruction filter, i.e., either the phase-incoherent and severely ringing analog 'brick wall' filter, or a whole bunch of RF 'imaging' artifacts. As for the deleterious effects of oversampling, the higher the rate, the better, and if it's done correctly, none of the original data are changed, but rather the points between the data are established via a low-pass filter, just as it would be with an analog one, but without the phase problems, and the following analog filter can be much more gentle, and transparent.

This front-loading unit has six buttons on the front: Open/Close, Play/Pause, Random, Skip forward, Skip back, and Clear. The lightweight, modestly sized remote control also offers Stop, Memory, Search, Time, Repeat, and Intro functions, plus track keys ranging from “0” to “9” and “+10.”

And the Sound . . .

To test how easily the remote control worked, I dispensed with reading the manual and instead took a guess at how to program the unit. Nothing could be simpler. On the first try, I succeeded in getting demagnetizing and break-in tracks 6 through 8 on the old Sheffield/XLO to repeat until, a few hundred hours later, I felt the unit was sufficiently broken in for auditioning.

After reading the manual, I variously auditioned the unit as a one-piece player and as a transport. When used as a one-piece unit, I powered the 2.1x with the same Elrod EPS-1 cord used on my far more costly Theta Gen Va DAC. When used as a transport, I powered it with the same Shunyata Python cord used on my more expensive Audio Alchemy DDS-Pro transport. I was also able to use the same Nordost Valhalla interconnects between preamp and Audio Note as between preamp and Theta. However, the Audio Note's lack of an XLR digital output meant I could not audition it as a stand alone transport employing my usual XLR-terminated Nordost Valhalla digital interconnect. I instead called upon an almost-as-good Nordost Silver Shadow digital interconnect configured with an RCA input and BNC output. This worked perfectly between the CD player and the Theta DAC.

As a CD Player . . .

The Audio Note boasts an impressively large soundstage, certainly equal to my far more costly standard setup. Thanks to its tube output stage, it is also quite musical, barking out none of the harsh digital sound associated with lower price digital equipment.

While it is many moons since the $499 NAD CD player I reviewed for Secrets resided chez Serinus, my sonic memory suggests that, on non-HDCD recordings, the sound of the Audio Note certainly justifies its higher price. I received considerably greater musical information from this unit, delivered with greater clarity. For music lovers who cannot afford more than $1750 for a one-piece CD player, these pluses suggest that the Audio Note is a unit worth auditioning.

It is also true that my digital reference system (Audio Alchemy DDS-Pro transport, Perpetual Technologies P-1A, Theta Gen Va DAC) is far more costly than the Audio Note. Extended comparisons suggest that the extra expense is justified. The Audio Note 2.1x simply cannot deliver the degree of resolution and sense of space rendered by the Theta.

A case in point is Hilary Hahn's twice Golden Eared recording of the Brahms and Stravinsky Violin Concertos. This is a disc whose SACD version I lugged room-to-room at CES 2002 and HE 2003, affording me ample opportunity to hear what different equipment combinations can glean from its bits.

When I played the non-SACD pressing of the Hahn on my far more costly combo, I experienced a reasonable (if not ideal) sense of the sheer mass and weight of instruments in the orchestra. I could roughly guess at the size of the violin section from the glisten of individual strings. The percussion and double basses registered fairly clearly at one end, while the violins shone at the other. Other solo instruments and bodies of instruments also emerged from the basic fabric, making the experience quite involving.

When I played Hahn's Brahms on the Audio Note, everything sounded more congealed. The violins seemed more of one solid mass rather than an assemblage of individual instruments. The Theta's fabled fullness on lower midrange and bottom was also absent, and the timpani registered as weaker. Most important, there was a degree of grayness to the Audio Notes' sound. The Theta, with or without the P-1A in the chain, delivered sound more colorful, no doubt abetted by its “blacker black.” The absence of ultimate color and detail were what I missed the most when listening to the Audio Note. This was not due to a noise floor issue, as shown by the graph below. It is a very quiet machine.

Turning to a new addition to my CD collection, I next played M.A. Recordings' superb sounding Será una Noche: La Segunda. (My review of this disc should appear in the September edition of Secrets). Recorded at a 176.4 kHz sampling rate in Argentina's Monasterio Gandara, this disc offers wonderful musicianship enhanced by a magical three dimensional sense of space around instruments. M.A.'s sound leaves most other digital recordings in the dust.

Because this recording has many fewer instruments to reproduce, each of which is separated by distance from the other, the major difference between my reference combo and the Audio Note was on the leading edge of transients. The Audio Note tended to soften the edges, blurring detail. The slight hoarseness and edge to Rosa Passos' voice, for example, was more clearly heard through my reference. Similarly, the thumps of percussion and bass instruments were more clearly defined.

Over the long haul, these differences determine the difference between a system more suited to casual and background listening than one used primarily for extended listening with rapt attention. Just as I much prefer to hear a soloist in Berkeley's Hertz Hall than in San Francisco's drier Herbst Theater, so too do I find myself far more satisfied by my reference setup.

As a Transport . . .

Because I could not use the same digital cable for comparisons, I hesitate to pronounce judgment on the 2.1x used as a stand-alone transport. As far as I could tell, it seemed to do a really good job, coming close to if not equaling the older Audio Alchemy (which was always touted to work best with the I2S interface that I don't employ).


For an entry level (albeit hardly inexpensive) CD player with a tube output, the Audio Note does quite well. It may lack ultimate detail, clarity, slam, and color, but it is musical and satisfying in its own right, probably due to the tube in the output stage. If you're looking for a player in the $1,750 price range, this unit is definitely one to audition.

- Jason Serinus -

Associated Equipment

Theta Gen. 5A single-ended DAC
Perpetual Technologies P-1A with Modwright modified Monolithic Power Supply
Audio Alchemy DDS-Pro transport
Bruce Moore 100W dual mono tube power amp with Electro-Harmonix KT-88 and Siemens Cca tubes
Bruce Moore Companion III tube preamp
Talon Khorus X speakers (with final modifications)
Digital: Nordost Valhalla interconnects and digital interconnects
Analog: Tara Decade and Nirvana SL-1 to phono preamp
Nordost Valhalla bi-wired speaker cable
Powercables: Shunyata Python, Nordost, AudioPrism Super Natural S2, Elrod EPS-1, 2, and 3 plus EPS Signature-2.
PS Audio P600 Power Plant power synthesizer with MultiWave I
PS Audio Ultimate Outlet; PS Audio Power Ports
Michael Green Deluxe Ultrarack, Basic Racks, room treatment, and Audiopoints
Black Diamond Racing Cones
Inner tube, maple cutting boards, bags of sand
Shakti stone and Shakti On-Lines
Bedini Quadra Beam Ultraclarifier
Audioprism Stoplight and Blacklight, Marigo Disc
Gryphon Exorcist
Sheffield/XLO degmagnetiser and break-in disc
Analog Front End Dual 1219
Sumiko Blue Point cartridge
Classe 6 phono preamp with optional umbilical cord

Related to the article above, we recommend the following:

High Fidelity

Nature of Equipment Reviews

Accuracy, Distortion, and the Audiophile

What we Hear

© Copyright 2002 Secrets of Home Theater & High Fidelity
Return to Table of Contents for this
Go to Home Page


About Secrets


Terms and Conditions of Use

Our Vault pages may have some display quirks. Let us know if we need to take a look at this page or fix a bug.
Connect with us
  • Instagram
  • Google+
  • YouTube
  • LinkedIn
  • Pinterest
Secrets "Cave"