While reviewing the Audio Note UK Cobra integrated amplifier and DAC, I kept thinking of an industry friend who once joked about how easy it was to design an EL-34-based amplifier that offered good sound. “Let’s go out to the garage and make one right now,” he said with a chuckle.
It’s true, I do have an affinity for EL-34 based amps, especially integrated amplifiers. When I was a importer and distributor, the EL-34 integrated amps were my best sellers. They were usually affordable, they had a decent amount of power and they sounded really, really nice to my ears. (Added bonus: EL34 tubes were always affordable and plentiful.) I’ve also reviewed quite a number of them in the last few years from brands such as Margules and LSA and even Lab12–the Integre4 was supplied with KT150s, but EL34s also worked.
Words and Photos by Marc Phillips
It is easy to produce a good-sounding and reliable EL-34 amp–just look at the LSA VT-70 I reviewed a couple of years ago which retails for just $1,199 and still has that winning EL-34 sound, a combination of linearity and relative quickness compared to something like a KT-88. But a great EL-34 amp is the result of what you can add to the basic circuit to bring out a unique personality that goes beyond the inherent charm of the output tube. For instance, the Margules integrated was influenced by Julian Margules’ research into neural-acoustics and paying attention to the fundamentals, which is why his amps always sound so warm and engaging. You’d imagine Audio Note UK could apply that same out-of-the-box thinking for a simple, affordable EL34 integrated amp, and they’ve come up with a doozy of a perspective.
As I delve into the world of Audio Note UK this year, I’m reminded of my one good AN story. When I first started writing the Vinyl Anachronist columns for Perfect Sound Forever back in 1998, one of my first articles concerned an old friend of mine named Dr. Cameron. You can read the whole story here, but basically Dr. Cameron was one of the first fellow audiophiles I met during my journey in this hobby. When his wife passed away, he bought a killer audio system so he wouldn’t forget her daily piano recitals for him on her prized grand piano. He bought, among other components, an Audio Note Ongaku integrated amplifier.
The Ongaku has always been an example of ultra hi-fi with unbelievably dear prices–when I first heard about this integrated amplifier it was well over $40,000. By the time I’d written my first high-end audio review the price was, if I recall correctly, up to $89,200. Just 26 watts per channel, too, which seemed strange in those days. But the Ongaku also had 21 pounds of pure silver wire in it, and it was made carefully by hand. For many years, Dr. Cameron’s system was the finest I’d experienced.
Almost 25 years later, I’m reviewing the Audio Note UK Cobra integrated amplifier with built-in DAC. I’m duly impressed with it, too. But you won’t believe how much this thing costs: just $5,458. That’s with a built-in DAC. I know, right? I suppose I’ve always thought of Audio Note UK components as beyond my means, but the Cobra certainly isn’t a pipe dream. In fact, many of the Audio Note UK products I’m currently reviewing offer considerable value, and that makes me view this British company in a whole new light.
Inside the Audio Note UK Cobra
Audio Note UK can be reticent about the specifics of their products–you may have noticed that even the MSRPs of most of their products aren’t easy to find. I don’t think they’re being secretive about what goes inside, since it’s not hard to look inside an Audio Note UK Cobra and figure out what’s going on. According to Audio Note UK, the Cobra can be summarized thusly:
“Our latest integrated amplifier, producing 28 watts per channel from a pair of EL34 valves operating in Class A push-pull. It is capable of driving a wide variety of ‘speakers thanks to its exceptional double C-core output transformers, which are custom designed and manufactured by Audio Note (UK).
“Cobra is equipped with three analogue stereo inputs, and an additional three digital inputs, via the onboard DAC. The digital coax inputs can accept signals up to 24-bit/176.4kHz (native bit-depth for the Philips TDA1543 D/A converter chip is 16bit, so anything above this is truncated down). The Optical SPDIF input can accept signals up to 24-bit/96kHz (see above). The USB input can accept up to 16-bit/48kHz.”
Not to be flippant, but that could be the description of a number of EL-34 integrated amplifiers on the market. It doesn’t hint at the AN mystique at all, but there has to be something more to this design. The tube complement of the Audio Note UK Cobra integrated amp isn’t exotic–we’re talking four EL-34 for the output stage, and two 6AU6s and two 5670s for the input stage. The circuitry is push-pull and pure Class A.
As you dig deeper, however, you start to see where the Cobra asserts its unique personality. First of all, Audio Note UK is very proud of their C-core output transformers, custom made for the Cobra, which they have designed and manufactured themselves. (I learned that from my importing days, that a perfectly matched output transformer yields better overall amplifier performance.) The multi-element power supply employs choke-smoothing, and a separate DC supply is used for the tube filaments. If you’re one of the Audio Note UK faithful, the Cobra is designated as meeting all of the criteria for the company’s Level One products. The Cobra is far from a stripped-down Audio Note for the masses.
The back panel of the Audio Note UK Cobra is clean and logical in its layout. The speaker jacks take bananas, spades and bare wire. (It didn’t really matter to me since I used all Audio Note cabling with the Cobra, and those speaker cables have banana plugs.) This will make more sense as I get toward the end of the review of the entire system; these individual components, while extremely competent and musical on their own, tend to bloom dramatically when you use them with other AN products. If you’re one of those audiophiles who balks at the idea of one company making every single part of the system, you should understand that Audio Note has specialized in this strategy for decades. They practically invented the idea of voicing all the components together in a system to accomplish a signature sound.
The Audio Note UK Cobra integrated amplifier wasn’t sequestered in its own little world with the other AN components for the entire review period. Since it was the first Audio Note UK component that I actually installed in my review system, it got to play with some other kids in the sandbox. But once I connected the Cobra to the Audio Note UK AN-J/D Hemp loudspeakers, I had this sense that both components “woke up” and started asserting their strengths in a more confident manner. That led to the installation of the Audio Note UK CDT One/II digital transport, and suddenly I had a compact and relatively affordable system that started wowing me almost immediately.
A significant amount of time was spent listening to this small system–it got even smaller when I started using the built-in DAC for streaming and left the CDT out of the chain. After a few weeks, I finally received the analog part of the system chain: the Audio Note TT-Two Deluxe turntable with the Arm Three/II and the IQ III moving-magnet cartridge and the R Zero/II moving-magnet phono preamplifier.
But that first, simple configuration was illuminating.
The Audio Note UK Cobra DAC
First of all, my five-minute rule for DACs was upheld by the Audio Note UK Cobra DAC. But this DAC went the extra mile by initializing itself, so by the time I plugged in the USB into my laptop and fired up Qobuz, it was already playing music. Nothing needed to be initialized. I didn’t even have to click on a drop-down menu in order to choose the Audio Note option. It just took over and started playing Thurston Moore’s Into the Fire, the last album that was cued up on Qobuz.
The sound of the DAC in the Audio Note UK Cobra was surprisingly smooth and full. I’ve noticed that so many DAC manufacturers claim that their digital products offer the most analog-like sound ever, but I think the Cobra’s DAC actually fulfills that promise. Each component in the Audio Note UK system maintained that same consistent tonality, and for some reason I was surprised that the DAC in the Cobra took no sonic short cuts.
Shoot, I could see spending $5,458 on just a DAC that sounds this good and operates this easily.
As I just mentioned, the DAC performance set the tone for everything that came afterward once the Audio Note UK Cobra was placed in the system. This was the first time I noticed that all of the Audio Note UK components, from the amps to the sources to the cables to the speakers, all shared that common goal when it came to tonality. That’s right–there was a unity to the sound, a central vision that remained constant whether I was listening to vinyl, CDs or streaming Qobuz.
There is an Audio Note UK sound, and it does veer from the norm. While that sounds troubling to audiophiles who are loyal to mainstream high-end audio brands, it’s quite different to hear this tonality in real time while listening to your favorite music. I’m an audiophile who doesn’t believe in “one true sound,” and that means I encounter and embrace the Audio Note UK individualism in the same way I cottoned to the sound of low-powered SET amplifiers and single-driver speakers, or the way I was flabbergasted by the lowered noise floor of quality class D amplification from Aavik and others. In fact, we can paint a broader picture of these differences by mentioning preferences between analog and digital, or tubes and solid-state. We’re talking about stuff not sounding the same as each other in a hobby obsessed with fidelity and perfection. That makes some audiophiles nervous. Not me.
So it comes down to this: how does the Audio Note UK Cobra sound different, and are you going to like it?
Let’s tackle the first part. The signature sound of Audio Note UK revolves a around the company’s idea of a tonality that sounds like real musical instruments with less emphasis on all the bells and whistles that the high-end audio industry insists is the path to truth. We’re talking imaging and soundstaging and a wide frequency response and coherence. That’s all important stuff, and the Audio Note UK Cobra does all of it well. But as I spent week after week, month after month with this system, I noticed that I experienced the music more as part of a natural whole than of independent strengths that competed for my attention.
This tonality wasn’t at the cost of inner detail, either. But when I listened to the Audio Note UK Cobra guiding and commanding this system, I felt more of that energy you feel when you are listening to live music, the way it hits you all at once, the way you hear how the physical space around the music is impacted by it. It’s all connected. It pulls you into the music in a sly, seductive way that detaches you from all your audiophile expectations.
This reminds me of the time I visited the Audio Note UK room last year and was given a private performance by cellist Vincent Belanger, who played along with a recording of himself over another Audio Note UK system. While I would never say I couldn’t tell the difference between live Belanger and reproduced Belanger, it was far more subtle than I expected. That’s the Audio Note UK objective in a nutshell–first and foremost, make it sound like real music.
When I say that the Audio Note UK Cobra integrated amplifier and the rest of the AN system sounds like “real musical instruments,” I’m probably thinking first and foremost of the piano. There are so many individual sounds happening within those big wooden boxes, and that means capturing the essence of what it’s like sitting at the bench, next to the performer, and watching those fingers levitate and then descend to make a corresponding sound.
I had the perfect recording to judge the Audio Note UK Cobra and its ability to preserve all that sound and motion, and that’s Lorenzo De Finti’s new CD Lullabies from an Unknown Time from Losen Records in Norway. This is a stark, even naked recording of a grand piano, accompanied by Fabrizio Bosso’s trumpet, and it’s spellbinding because it’s so stripped down and real. These are pure tones, so deeply embedded in what we experience while hearing live music. We hear the individual notes, we deduce the timbres, we say to ourselves that the music is what we should expect and because of that it sounds live.
At the same time, the Audio Note UK Cobra system connect so many of the peripheral dots between the notes–the positioning of the two performers, how they faced each other, and how the room reflected those positions. I could clearly detect all the effort and intention in the performances, but at the same time I could hear all that energy released into the room, both the recording venue and my listening space, and I could easily close my eyes and pretend that De Finti and Bosso were pulling a Vincent Belanger by sneaking into the room.
On Hilary Hahn’s latest album, Eclipse, she tackles Dvorak’s Violin Concerto in A Minor and releases such high and perfect tones from the upper registers of her violin, fusing strength with an airiness and delicacy that’s Hahn’s trademark. As I mentioned in the review of the Audio Note UK AN-J/D Hemp loudspeakers, an AN system stretches and expands noticeably once you place the speakers in the proper positioning along the side walls and not quite all the way to the back corners of the room. I’ve heard Eclipse a number of times before–Hahn playing Pablo De Sarasate’s Carmen Fantasy is every bit as magical as it sounds–but the Audio Note UK Cobra and the AN-Js spread out the Frankfurt Radio Orchestra into a thrilling panorama of sound that seemed both realistically proportioned and yet bigger than I thought possible in my listening room.
The Audio Note UK Cobra didn’t scrimp on musical weight, which can be an issue with a relatively low-powered tube amplifier. Bass was always natural and full, with plenty of tangible edges around the notes. On 2L Recordings’ new Trio Mediaeval performance, An Old Hall Ladymass, I heard that weight even though we are talking mostly about a women’s choir backed by an organetto. When those voices are merged together, there should be an increase in the visceral impact of the music–we’re talking “strength in numbers” in its purest apparition.
That’s where the Audio Note UK Cobra made its personality clear–those pieces of music that represent two opposing performances, and how beauty can be found right at the intersection when they collide. That’s a result of the AN system capturing the energy of a performance and saving it for you to hear any time that you desire. This is a truly musical system–one that constantly celebrates the emotions behind the notes.
Audio Note UK Cobra Conclusions
At this stage in my Audio Note UK exploration–I’m about halfway through at this point, I believe–I’m totally focused on the fact that the Audio Note UK Cobra, the Audio Note UK CDT-One/II digital transport and the Audio Note UK AN-J/D Hemp speakers comprise an awesome system for around $15K. I’m not saying it’s merely a good system, but one I could see owning. You can ever forego the transport if you’re dedicated to streaming–now you’re down to just $10K.
I would have never suspected that I’d be talking about Audio Note UK as a value proposition, but that’s what the Cobra is–an amazing tube amplifier with a built-in DAC that meets and even surpasses my expectations for the kind of hi-fi I need to be happy.
After just a few weeks with the Audio Note UK Cobra integrated amplifier in my system, I started thinking about how special it was, in an entirely non-flashy way. Sometimes when you’re running tube amplifiers vs. solid state, you have to pay a little more attention. You might have to swap a bad tube once in a while. You might need to turn your components off in a particular order, and sometimes you might forget. But the Cobra, for some reason or another, is incredibly easy to live with as tube amps go.
It worked flawlessly, and it always sounded great to my ears. The operation is smooth and logical and ergonomic. It doesn’t cost crazy money. That’s when I started thinking, you know, that the year’s only half over but I’m thinking the Cobra is something that might be talked about at the end of the year. Like the Lab12 Integre4 tube integrated amplifier that won out Best Value Award for 2022, the Audio Note UK Cobra hits all the same marks. It’s a little more expensive than the Integre4, but it has that DAC. In fact, the real value here is the Cobra and the CDT and the AN-Js as that complete system for $15K–if that’s the amount of money I have to spend on a system, this is what I want.
But if you have just $5,458 to spend, grab this. Add the rest later. Be happy now.