Audio Note DAC Kit 2.1 Level A and B
Digital-to-Analog Converter

Click here if you are unsure about what a DAC is or its role in your hi-fi system.

Welcome to the DAC 2.1 product page.

We are very excited to bring you the updated DAC kit 2.1. This product was first introduced in 2007 and has been one of our biggest selling products. Incorporating the updated M2 Power Supply PCB with mounted heat sinks - our DAC2.1 Digital Board, IV transformers and 6922/6DJ8 output stage designed by Andy Grove. We bring you the latest version we are shipping in 2011.

Here are some of the things that make this DAC kit a clear cut above the rest:

* The Digital Board can be upgraded with an Audio Note Digital Interface Transformer (with toroidal core made from very thin laminate spun 80% nickel strip)

A USB interface is also available for all configurations of the DAC Kit 2.1 and 3.1 .

The M2 power supply is an enhanced PCB version of the original M2 power supply taken from the Audio Note finished products line. This uses a Mains transformer/Choke combination with 6X5 for tube rectification and the ECL82 for regulation. This powers a high quality, 6922 analog output stage.

Also, as with all the very latest Audio Note DAC's, the DAC Kit 2.1 comes without an analog filter in all its available versions.

Anatomy of the DAC Kit 2.1 - Level B version

Signature Digital Board and USB Input Options

The signature Digital Board includes high quality Nichicon capacitors without any digital or analog filtering - giving it it's highly praised Audio Note sound.


The USB Interface Option allows you to connect a P.C. to your DAC - a highly requested option that gives you the ability to experiment in that direction (software is not included but the interface is Plug-and-Play compatible).


General Specification

Available Inputs Switchable between any two inputs from the following three choices:
  • Standard 75-ohm RCA (S/PDIF)
  • 110-ohm AES/EBU balanced (XLR)
  • USB (requires additional USB add-on board option)
Available Outputs Single-ended stereo outputs via Left/Right RCA sockets
Output Impedance 1.3 K
Output Level 2.5V RMS both channels
Chassis Dimensions 15" wide, 16" back to front, 5.75" height including height from floor

Inputs and Outputs

There is one RCA input, one XLR input, and one USB input (RCA + USB Options shown above). Any two can be made active and switched between using the switch located below the RCA input.

Two RCA, line level outputs (left and right) are shown on top of each other.

Level B's I/V Transformers

The picture on the left shows how the I/V transformers are clamped and mounted on the chassis.

The I/V transformers were specially designed by AudioNote engineering to provide an affordable yet highly effective transformer for the DAC2.1 Kit.

I/V Transformers are used to maximize the energy transfer during the Current-to-Voltage phase of the conversion; resulting in increased dynamics.

An extract from the article 'Why is Audio Note's 1x oversampling unique?' by Andy Grove describes the use and advantages of the I/V transformer:

The output of most resistor ladder DAC chips is in the form of a current rather than a voltage. There are many ways to convert the current into a voltage but the most commonly used system is that of an op-amp connected as an I to V converter. This system requires the use of a high degree of feedback, and as a result there are problems associated with it. One of those is internal slew rate limiting of the op-amp itself. The rate of change of current at the output of even an audio DAC is very fast indeed. Even modern fast op-amps will slew limit internally and that affects sound quality. Some engineers have found that using extremely fast op-amps improves the sound quality, but we have completely sidestepped the issue by using a transformer I/V system. The transformer not only provides an I to V function but the way it is used in our latest DACs transfers maximum energy from the DAC chip itself. This in itself reduces overshoot and ringing and because the system is slightly overdamped the rise time is reduced to an acceptable rate as well.

The full article can be seen in the Related Links section below.

Pricing and Configuration

DAC Kit 2.1 Level A $1,250(USD)

The Level A version of the new DAC Kit 2.1 is the same as the Level B but without I/V transformers which can be added later as an upgrade. It includes the following:

DAC 2.1 Digital Board
M2 Power Supply
6922 Output Stage
PTFE wire (silver plated copper)
AN-A Cable

DAC Kit 2.1 Level B $1,550(USD)

The Level B version is the same as Level A but adds Audio Note I/V transformers:

DAC 2.1 Digital Board
M2 Power Supply
6922 Output Stage
PTFE wire (silver plated copper)
AN-A Cable
Audio Note I/V transformers

USB Input Option $129(USD)

The USB Interface board allows you to use your computer as a transport and is simple to install.
General Support

We have included a 1KHz test tone WAV file here that may be useful when you are building your DAC Kit. It allows you to feed the signal into your DAC so that test voltages can be measured.

Click here to play the file.

To download the file to your computer, right-click on the link and select 'Save Target As...' (Internet Explorer) or 'Save Link As...' (Firefox) from the pop-up menu.

What customers are saying about the DAC Kit 2.1 Level A and B

The end result is astonishing and a massive step up from my modified Beresford 7520. It's very similar in sound quality to how I remember the various demos of the factory built DAC 2.1x. Highly involving, dramatic, sonorous and bringing all the performers into the room with human presence. Gosh this is really where it's at."

Andrew Randle


Just a quick email to say that the 2.1 Sig is now fully built (with 75 Ohmspdif connector) and...

...it is absolutely brilliant! :) Worked first time. Replacing my modified Beresford DAC, the AN DAC has really made a difference and now shows what my home designed amps and newly acquired AZ-Three (hempconed) loudspeakers can do. From what I can recall, it certainly sounds like the factory built 2.1 DAC:

Many thanks and will update you with photos later.

Andrew Randle


I am writing to share with you my continuing happiness with the DAC. I have recently purchased a tuner with coax digital output. In FM mode operating through the DAC kit 2-1 it sounds awesome!

Best wishes
Misha


I just want to tell you that I’m very satisfied of my DAC2.1 w/ USB. I let it run for about 80 hours and now it is playing so perfectly.

The sound is smooth and natural with a lot of details. I am re-discovering my old albums.

Thanks!
Guy


Ah yes, the DAC is mellowing, more accurately, the sound is becoming more spacious as well as detailed. I love it and am enjoying playing many old CD's!

Anyway, it has been fun and a challenge to build this excellent DAC. The proof of the pudding is in the eating, and it tastes really good.

Misha Norland


Hi Brian,

I completed the DAC 2.1B today, used around 10 hours to complete! Now enjoy the music! One word to say, wonderful! Very musical and dynamic, powerful high and low frequency! I can't heard from my DIY TDA1543 DAC that I built before, also the low level dynamic is excellent! World class DAC! Highly recommend for everyone!
Thanks!

Regards
Kenneth Lau


Amazing, when I first turned on the DAC I was really dissapointed, it was like looking through a tube in the audio sense. 5 hours later and I am blown away, it's like hearing my music collection for the first time.

What an awesome kit, thanks!

Mike Engledew


DAC2.1 Level B is sounding fantastically well! The best source i've heared yet.

Pierre Murray


"My kit is sounding just incredible right now."

Pierre Murray


..."Using the USB connection causes no fatigue at all, you can listen for hours and hours. The sound quality of fine recorded Jazz and classical music is truly wonderful and organic sounding."...

Paul Lederberg


"Now that I've had some time living with the DAC 2.1B, I can say it is a terrific performer. It has the ability to get out of the way of the music and is very transparent in the sense that it conveys only what the source is feeding to it and doesn't seem to infer any of it's own personality to what is heard. This has become clear from using several different sources with it.

I'm really impressed with the 6922 output stage as well. It is really clean and clear, and homongenous as well , i.e. with no single attribute of the music being emphasized. Those EH 6922's are really well-balanced also, or is it just the character of the output stage that the brand of tube isn't critical?"

Frank Egan


...ideally suited to the acoustic blues that I spend most of my listening time with...

...Of interest to the kit builder is the quality of components and support; Both are absolutely first rate and I would have no hesitation in recommending this kit to anyone else...

...Overall though, it's good fun to build and is very easy on the ears... Isn't that what it's all about? Ten out of Ten.

Jim Watson


My DAC is working wonderfully; I had noticed on my first 100 hours burn a big stretch on frequency levels. After 200 hours burn I experienced many of details coming true, The final tests revealed a fine tune on tonal balance.

Marcello Lasalvia


"The DAC 2.1 is ready! Worked with no problems from the beginning absolutly quite! Then I took him 1 day without interruption in electricity supply. The first aural impression has exceeded my expectations.

After 200h I will make an audio report.

The Manual is very good and easy to use."

Many hours later...

"Unbelievably (from) a CD so much music. I understand the world no longer. I know many brands Conrad Johnson, Audio Research and many other expensive audio equipment. I have never heard music so natural, not from CDs!"

Heinz Gabriel


Hope everything is well with you and the kit business. I just got a used transport, a PS Audio Lambda, for my DAC 2.1 instead of my DVD player and it makes a world of difference. I just love this DAC, it has that analogue just-want-to-hear-more quality that is so hard to get in digital, even more than my old Sonic Frontiers cd player.

Peter Guarino


I've been 'burning in' the DAC all week, guess 170 hrs now, it sure is sweet. I REALLY like it , a lot, and am so glad I bought it and built it. Definitely worth the money, CD never sounded so smooth and lifelike. Have to admit I was a little skeptical, but I greatly prefer listening with the DAC

Randy Morgan, Atlanta


Firstly I am totally blown away by the Dac 2.1 kit, it has easily surpassed my expectations...

Adam Stanhope


The kit is brilliant - I finished it today and it all works extremely well.

It is early days but it does sound very good - extremely refined and detailed.

Kind regards and thank you for such a truly excellent product.

Adam Stanhope


I took delivery of the DAC 2.1 kit yesterday and got around to unpacking it. I must say that this is the most well organized kit I have encountered. I was shocked to see all the wire actually cut and twisted. Visual inspection of everything reveals it is of the highest quality. Thank you.

Charles Southwick


Brilliant! Just stunning. Fired up and working with all instruments naturally present and detailed and smooth.

Thanks so much for your help.

Richard Carter, UK


The DAC went together very well. The manual is well though out, easy to read, and the pictures are a great tool for the beginner. The component and build quality are equally excellent. All in all a superb kit.

Michael B. Haener


I swear that I can hear passages of music that I have never heard before on some of my cd's, it's uncanny!

Brian Pyplacz


...As for the sound, it's noticeably different from my Arcam CD player, which I am now using as a transport. I am struck by how much the bass has developed and tightened, and how the sound-stage has grown - resulting in my classical recordings sounding more balanced and realistic...

Mark Leece


...Since I am not a techno head, I started off slowly and read the manual 5 times before I actually put the first screw through the chassis. The manual is an excellent document with colour photos and detailed explanations. I guess I had been a pain to Brian as I kept emailing him about all kinds of questions and uncertainties and he kept his promise by answering every single one of those “stupid questions”. Within 2 weeks, I had the kit completed and I can still remember the joy when it was first switched on. It worked the first time and the sound was just astonishing - so much more information coming out from the DAC and the sound stage now is much much open. I can say it's even 200% better than my friend's DAC 1.1 (in my opinion). It's probably one of the best investments I’ve made in my continual search for sonic improvements in the last tens years...

Jackson Hui, Australia


...The result is really unbelievable. The sound is extremely homogeneous on the entire spectrum. The basses are deep enough and all the details which give live to music are present. The instruments are sounding as they are near you. You will be surprised by the realism without any exaggeration, the transparency, the dynamism and the perfect special localisation of the instruments. The natural sound of the DAC is very close to vinyl sound. I am convinced that this level of sound quality is very difficult or impossible to obtain with classical over sampling methods which introduce jitter and loose of information’s with their complicated filtering methods. You had to spend at least 3-4 times more to reach an equivalent result. I am now in the phase of discovering of all my old CDs and I have really the impression as they were new ones...

Rifat Gürsel, France


...The soundstage is plenty wide and deep enough but what really comes through for me is the added space between instruments and vocalists. This allows the true details and nuances to be heard. What had always seemed to be unintelligable vocal passages now came clearly into focus. This also applies to the instrumentalists. One can hear more of the details and energy that they put into the performance. The dynamics are also surprising as one listens to oft heard recordings and gets stunned by how much dynamic range there really is. Part of this is due to the very low noise floor and "black" background that the music has as it's base.

This DAC allowed me to hear more layering in older jazz recordings which were sometimes recorded with bass and drums in one channel making it difficult to follow individual players. Try Bill Evans' "Live at the Village Vanguard" to get a sense of this. You should be able to hear the players at different depths of the stage instead of on top of one another...

...The overall sense that listening to this unit gives me is that the performers are not just performing, they are performing for you. I cannot count how many times I have been listening and have had an involuntary reaction in my gut to passages I have heard a hundred times before. There are some discs that have languished in my collection that have found new life with this unit. If you haven't found yourself listening to a CD from start to finish for a while, skipping all but your favorite cuts, give this DAC a try. It is not the music you are tired of, it may be the presentation of it. Just be sure that you don't have to get up early the next morning, it may be morning before you finally stop listening...

Tony Landry


...After completing the kit, it worked the first time I plugged it in. That alone was amazing to me. But the sound was astounding. The single biggest improvement in sound I have ever experienced from a single component. My Spendor SP 100s have the imaging I always expected. Detail was far greater, tonality richer without being muddy.

There was an aspect beyond the specific description of the sound. It had a natural quality, harmonic. The dimensionality was unlike I have experienced before. Quite amazing – maybe I could have heard this much sooner if I had tripled my investment years before… I am a hopeless tinker but I have had no interest in modifying the DAC 2.1 (I purchased all the extras)...

Richard Rose - Glendale, CA


...The Audio Note DAC Kit 2.1 is a world beater - even before it has fully broken in. It is, by far, the best digital that I have ever heard in my system and manages to pull out a huge amount of detail from those CD's as well as creating an extra sense of space and involvement within the music...

Paul Brookes - UK


...I am very happy that I decided to get DAC 2.1. It is an excellent value as I feel it outperforms many other much more expensive "high -end" digital front-end products that I auditioned in the past couple of years. It is the product that I feel I can use and enjoy for a long time to come not only because of its performance but also because the kit offers many opportunities for DIY upgrade. When I feel that the sound can be improved, I can just upgrade to the next level with a minimal cost for the parts...

Isaku Higa


Related Links