Audio Note (UK) DAC 4.1x Balanced Signature by Terry London


TerryLondon.jpgLater in the review, I will share the particularities of how the Audio Note (UK) DAC 4.1x Balanced Signature, which retails for $37,700, rendered the most exquisite musical experience I have ever achieved in my reference system. However, I first want to make some general remarks about the Audio Note (UK) Company and its creator Peter Qvortrup and his design group that has led me to believe that Audio Note (UK) and its products have a very special status in the high-end audio world. 

Audio Note (UK) is one of the few companies that designs and builds (in-house) every component, including sources (analog or digital), all wiring for power cables/IC connectors/speaker cables, preamps, integrated amps, single-chassis or monoblock amplifiers, and speakers in their product line. All their components are tube-based. You can start with an all-Audio Note (UK) system that retails for around $10,000 and work your way up to the ultimate reference level for over two million dollars! In the last few years, I have talked to numerous listeners who explain the Audio Note (UK) presentation of music as “natural, the anti-thesis of an analytical Hi-Fi sound.” “Engaging, it brings you closer to the heart of the music.” “Makes other systems sound like a mechanical reproduction of the music.” “Voices just sound more real to me.” “I replaced my system, which cost over $70K with an Audio Note system that cost under $20,000. I’m so happy that I did because now I listen to the music, not the system.” “It’s hard to put into words, but I just enjoy the music at a higher level through the Audio Note gear.” Recently, there was a YouTube video of three hardcore audiophiles who each had spent time with the Audio Note (UK) Cobra integrated amp with a built-in DAC and a pair of Audio Note (UK) speakers. All three loved what they heard, but you could see them struggling because their gear was much more expensive and, based on specs, measured better. Still, this relatively inexpensive Audio Note (UK) system was charming them to a higher musical level of enjoyment.

psaudiobox.jpgAs I stated in my StereoTimes review on the Audio Note (UK) DAC 3.1 Balanced MKII (here), Peter Qvortrup is an iconoclastic designer who, along with his design teammates of Darko Greguras & Andy Grove, use their collective abilities to hear what music sounds like in a natural context and then take straight forward design topographies and over the years, like a group of Zen Masters, hone these designs to higher levels of musicality. This is often done by replacing critical internal components (manufactured in-house) while keeping the circuitry the same. An example would be their hand-wound transformers which can use either unique copper or silver wiring to affect the overall sound of that piece of equipment.

One of my favorite philosophers of understanding the structure and development of human knowledge is Ken Wilber. In his overall model of constructs, called Holarchy, Wilber explains how we go from a more primitive/concrete viewpoint to a more accurate/abstract understanding by the process of “all-inclusive and then transcends.” My listening experience with Audio Note’s (UK) different levels of gear, with a total of seven levels, follows this path to higher and higher levels of musical complexity and purity. Let me give you a concrete illustration of this special and qualitative shift found in the different levels of Audio Note (UK), compared to the quantitative shift produced by other companies.

I consider Nelson Pass a genius of solid-state gear, and historically his Threshold, Pass Labs, and First Watt enterprises have always brought great equipment to the market. I have owned and reviewed over a dozen high-end audio components from the abovementioned companies. Here’s the illustration to make clear the difference between how Audio Note’s (UK) different levels add on “then transcends” compared to Pass Labs’ “quantitative” addition when you go up their line of amplifiers. Unless you need more current/watts because of a problematic speaker load to drive, a Pass Labs XA-30.8 amplifier’s overall sound presentation, it’s a great amplifier, will be approximately the same as a pair of XA-60.8 or XA-100.8 monoblocks. All great amplifiers, you get more power, if needed, as you move to the next level. However, they all have a very similar sound signature. How do I know that this is a valid statement? Because I have owned these amplifiers and compared them in my reference system. The one exception in the current Pass Labs XA-.8 series is the XA-25 which is single-ended, not a balanced design, and uses very different output transistors. It happens to be my favorite in the current generation of Pass Labs amplifiers. This observation is not a criticism of Nelson Pass’s amplifiers’ great designs and sound quality. It’s my way of clarifying that as you go up the seven levels in Audio Note’s (UK) stable of gear, you get all of the musical magic of the less expensive levels, plus qualitative additions across the sonic spectrum.









Since I have had the Audio Note (UK) DAC 3.1 Balanced MKII as my source, I have experienced thousands of hours of musical bliss and pleasure listening to my system. I found everything in its performance and was satisfied that I was not even thinking of auditioning another DAC for my reference system. Then, I received an Email from Peter Qvortrup, owner/designer of Audio Note (UK), asking if I would be interested in reviewing the next DAC up in the different gear levels, which would be the DAC 4.1x Balanced Signature. Of course, I was and wondered how much different/better could the 4.1x Signature be compared to my 3.1 Balanced MKII. The 4.1x Signature uses the same AD1865 18-Bit converter chipset. The significant changes revolve around: 1) upgraded M6 line preamplifier output stage, using NOS 5814a and 6463 double triode tubes. 2) This linestage in the analog conversion is coupled to an output transformer, wound with Audio Note (UK) copper on a high B core. 3) It incorporates a dual-channel power supply with double choke filtering and valve rectification. 4) The use of Audio Note (UK) capacitors and Tantalum film resistors. The DAC 4.1x Balanced Signature dimensions are 18” x 6” x 17”, and weighs 42 pounds. Around the back is where you’ll find the IEC receptacle, on/off switch, and RCA and XLR inputs and outputs. The 4.1x Signature sent to me had a grey silver faceplate with a single LED to indicate that it was powered on and a classy Audio Note badge. Because of the very robust power supply, this DAC had the size and weight of many amplifiers.

ethan.jpgMy first music listening selection was “Common Practice by the Ethan Iverson Quartet with Tom Harrell. This disc was recorded live at The Village Vanguard in New York City by ECM. It was apparent that the 4.1x Signature retained all the virtues of the 3.1 Balanced DAC and then added a higher level of purity regarding the brass tonality of Tom Harrell’s trumpet. The air around the different players and their spacing on the stage was astounding in how realistic these spatial qualities came across. The soundstage became even wider and deeper and more clearly defined. I could hear the room’s acoustics, with the music embedded in that space, which made it easier to feel that you were in the Village Vanguard listening to live music.

One of my favorite jazz pianists is Kenny Barron. He is a national treasure playing as great as he did fifty years ago. His album, “The Traveler,” features compositions that incorporate many Latin and World Beat rhythms in these musical selections. The DAC 4.1x Signature produced the powerful bass notes of the Steinway grand piano he was playing with grip, definition, and impact that I could feel viscerally in my listening space. Regardless if it was vocals or instruments such as acoustic guitar, soprano saxophone, or drums, the density of each player’s different timbres/tonality stood out beautifully and vividly.

cobbhargrove.jpgSince the album, “Jazz In the Key of Blue,” came out in 2005, we have lost both Jimmy Cobb and Roy Hargrove. This album is one of the finest mainstream jazz records that has come out in the last twenty years. It was also, thank goodness, beautifully recorded and produced by David Chesky. When I played this album through the Audio Note DAC 4.1x Balanced Signature, I was swept away by the emotions that the musicians were conveying in these ballads. The 4.1x Balanced Signature, to a degree that I had never experienced, allowed these emotions and moods to captivate me in a unique and wonderful way. Every nuance in Jimmy Cobb’s cymbal work had a delicacy and sweetness you hear in a live performance.

I have stated in many of my writings that there is no BEST piece of stereo equipment. There are many wonderful pieces of gear; of course, personal taste is always part of the equation. However, there is no doubt for my ears that the best DAC I have ever listened to is the Audio Note (UK) DAC 4.1x Balanced Signature. It lived up to my statement that as you go from one level to higher levels in the Audio Note (UK) gear, you not only get all-inclusive, all the sonic virtues of that level, but the next level transcends and qualitatively delivers even more than the level below it. Even though I heard it easily, I was still shocked that the 4.1x Balanced Signature, compared to my 3.1 Balanced MKII, offered more powerful dynamics, effortless liquidity that allowed the music to “flow” out of my speakers, a higher level of clarity which allowed the nuances of the music to pop in the mix, gorgeous timbres/tonality, deep taut room-filling bass notes, and finally, the most realistic, airy and layered soundstage I have ever heard in my listening space. Well, I’m biting the financial “bullet” and saving my pennies to purchase it because I don’t want the 4.1x Balanced Signature to leave my home because of the beauty and joy it brings to my musical experience.



  terry london    

Price: $37,700


Input: RCA 75 Ohms SPDif

XLR 110 Ohms AES/EBU

Output Impedance: 600 Ohms, Balanced or Single Ended

Reference Output: 1.5V RMS(Balanced) / 3.2V RMS (Balanced Sig.)

Channel Balance: Less than 0.2dB

Valve Compliment: 1 x ECC82 / 5814a

1 x 5687WB (Balanced version)

1 x 6463 (Balanced Signature version)

1 x ECL82

1 x 6X5

1 x 5651 (Balanced Signature version)

Unit Weight: 18 kg (Balanced version)

19 kg (Balanced Signature version)

Unit Dimensions: 145mm (h) x 450mm (w) x 425mm (d)

Digital System: 18Bit Analogue Devices AD1865N

44.1 / 48 / 96KHz input capability.


Note: Due to Audio Note (UK)’s ongoing research and development program, specifications are subject to change without notice.


Audio Note (UK) Ltd,

Viscount House,

Units C, D & E, Star Road,

Star Trading Estate,

Partridge Green,

West Sussex,

RH13 8RA

United Kingdom

Tel: +44 (0) 1273 830800

Website: Music’s Finest Conductor | Audio Note (UK) England

TJ’s Associated Equipment


Pass Labs DAC-1

Audio Note (UK) DAC 4.1x Balanced Signature 

Pro-Ject reference CD transport & Linear Tube Audio Power Supply

CEC-3 belt-driven transport


Coda FET 07x preamplifier

Coda 16.0 amplifier

SPL Elector preamplifier

SPL 1200 amplifier

Threshold 550e amplifier

AricAudio Super SET 300B amplifier

AricAudio Motherlode MKIII preamplifier


Tekton Design Ulfberth & Perfect Set

NSMT Model 100

NSMT band pass sub woofer x two


Black Cat Cables- digit 110 AES/EBU – 3202 XLR ICs

Kirmuss Audio Adrenaline speaker wire

Krolo Design reference rack & footers

Puritan Labs Audio conditioner & circuit grounding system 

Audio Archon AC cords

2 thoughts on "Audio Note (UK) DAC 4.1x Balanced Signature by Terry London"

  1. Rob says:

    I am wondering how much they pay you for those AN reviews. I was auditioning AN DAC 2.1 Signature and 3.1 Balanced. Both DACs sound far away from live experience. The sound is not even close in the signature. After couple of tracks i was already bored with the sound because everything sounded polished, softened and without engagement. That was really disappointing experience because i own AN CDT TWO/II and i was hoping to own also AN DAC.

    1. David Cope says:

      Really? A difference in opinion/perception and you declare the other party corrupt? You must be a lot of fun at parties.

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