I have never formally reviewed an Audionote product despite 75% of my system being Audionote. I was, therefore, determined to persuade Audionote to let me loose on one of their products. And my chance came at the Bristol audio show last year. This show is an event for me as I normally meet up with a good audio friend and we go to Bristol and make a weekend of it. So, before the 2020 Bristol Show, I thought what product should I ask for? A nice Ongaku, a Gaku-On or a Tomei?

During the Saturday evening at the Show we went off for a great evening meal and I got a chance to meet Chris Frankland and we had a great discussion on his conversion from Linn/Naim to Single Ended Triodes. Chris was one of the original Linn/Naim supporters and went as far as getting a top active Linn/Naim system, but now he sings the praises of Audionote products. Not only that but he was singing the praises of their less expensive products. He asked whether I had heard their new Cobra amplifier. I had paid a quick visit to the Audionote room but not a serious listen so I made a bee-line for the Audionote room the next day. And there it was.

I needed to persuade Audionote’s leader, the affable Peter Qvortrup, of my wish to review the Cobra. His son Daniel was doing an excellent job of being the MC in the Audionote room and he said his father would be joining the exhibition at lunchtime. So, at lunchtime, we went off to the bar and sure enough there he was in the bar (where else?). And as always with Peter, the conversation drifted to many other subjects with only a few passing references to audio. However, I soon raised the subject of the new amplifier, which I said was a surprise product as it was not the usual SET amplifier. Peter smiled in his inimitable way. And yes, it should be possible to get a review product over to me as soon as they had one available. But it may take some time.

And then Covid struck.

Fast forward to 2021 and after an exchange of e-mails with Peter he said he had a Cobra available for review as the flow of necessary components had been restored. He suggested I should e-mail Micky Seaton who was looking after this part of the business (and 101 other duties). Micky recommended that the Cobra stayed at Audionote for another week so he could burn it in. And 10 days later there it was on its own wooden palette. I remember asking my long-suffering wife to help carry the amplifier on its palette indoors but it was not the expected 50Kg, but a mere 13.6Kg. This was not an amplifier behemoth. I soon had the Cobra out of its protective overcoat and on top of my DBase rack. And I have to admit it looks cute. A sort of mini-Jinro shape with all its valves on display and not hidden away in a black box.

cobra naked.jpg

And yes, this is a surprise amplifier aimed at a different market to most previous Audionote aficionados. It uses 4xEL34 valves. I mentioned to Peter that I thought Audionote had not used EL34s before but he said that they had used them in Audio Innovations amplifiers. The EL34s are operated in a Class A push-pull configuration. In this configuration, they produce about 28w/channel. Excluding the big 211 amplifiers from Audionote, these amplifiers are one of the most powerful amplifiers Audionote make. Interesting. The ‘front end’ of the circuit consisted of a pair of phase splitters for the push-pull circuit and a pair of drivers for the EL34s (6AU6 and 5670s). All the valves are easy to obtain and do not cost the earth. Apart from replacing the valves they do not require adjustment or fiddling with. More interesting.

Now as everyone and their pets know, the sound quality of a valve amplifier is very strongly influenced by the quality of the output transformers. Peter Q mentioned that they tried a large number of bought-in transformers as they could not get the sound quality they demanded, so they made their own. It is an advantage of having your own transformer-making capability but that would surely mean the price goes up? Especially as the transformers can be one of the most expensive items in an amplifier. Peter agreed but he could not make that sacrifice. But the surprises did not end there. The integrated amplifier has its own DAC board. No stock chip put into a vanilla circuit. Audionote uses the TDA1543, R-2-R chip that is strictly 16/44.1 (well 16/48). It can accept resolutions up to 24/96 but will downsample to 16/44.1. An unusual choice in today’s sigma/delta world but not for Audionote. Why? Because Peter said it just sounds better than the more usual delta/sigma chips. Here it is on a separate board.


The integrated amplifier has 6 inputs A1-A3 and D1-3 for 3 analogue inputs and 3 digital inputs. For the first time (I think) for Audionote amplifiers, there is a remote control that changes the inputs as well and it also controls the volume (with a mute), all from the comfort of your armchair. Although a small addition, it was yet another surprise.

Despite all these surprises, it would come to nought if the sound quality was not of Audionote’s high standard. Have the compromises gone too far and seriously affected the sound quality?

Nothing for it but to connect it to the two systems I had lined up. My main system would really test its capabilities to the limit and a more balanced system would be typical of the systems people would use the Cobra in.

I started off with the Cobra in my second system. This has a CD Zero CD player, a Logitech Touch as a streamer, the Cobra and an old pair of Audionote Es. This is wired with standard mains cables and a standard coax cable with the one luxury, a pair of Audionote copper cables with the snazzy yellow outers. I let this warm up for a few hours and then got down to some serious listening. And here was the final surprise. The sound quality. The overall sound was relaxed and easy to listen to. There was no super-dramatic and ultimately wearing impressive sound here. It was just musical (cliché apology).

No, not a soft ill-timed EL34 amplifier from your dad’s era. The mid-range was excellent and very easy to listen to with voices being realistic. This is a known forte of EL34s but they can come with soft bass and rolled-off treble. And whilst some audiophiles like that warm, glowing and cuddly sound, I do not. However, the two do not always have to come with EL34s. When I first heard the Unison Research S6 the old image of EL34s was permanently changed. So much so I bought it. The transformers in that amp were large and heavy and controlled the bass better than many valve amplifiers I have listened to. The Cobra matched that bass and with lighter transformers. Why, better design?

And the treble? No serious roll-off here. Cymbals sounded like metallic instruments, not the sound of escaping steam as some amplifiers are prone to do. But all this taking the sound apart is to miss their great strength, their overall balance. All the instruments have equal prominence in the music if that is the way they are recorded. There did not appear to be any accentuation of any instrument or frequency. The sound was an integrated whole. It was easy to listen to the musical whole or focus on individual instruments. You could hear the power of an orchestra in full flow or the different instruments in the string section of an orchestra. What attracts me to this balanced approach to sound is that I can well imagine someone hearing this amplifier and saying that’s it for me, just what I want. Some less expensive systems will play some parts of the audio spectrum really well but fall short in one or two others areas and leave you wanting to upgrade. Great bass but the top end is too forward and bright. Or great mid-range but where is the bass?

Some people, including Peter Q, are not fans of streaming music. Well, the Logitech Touch is not the best streamer, but it worked really well in this system. Whilst it was not as good as CD, streamed local music or Qobuz, it is such a small step down it was easy to forget the small differences and enjoy the music. I enjoyed listening to my test and streamed music and it showed off what the Cobra could do. But anyone wanting a good £5K system could assemble this set-up and just relax and enjoy the music without any of the fuss no matter whether it was CD, local streamed or Qobuz.

But what could it do when put in a more ambitious system?

Off to the main system. Here I used a CD4T transport, DAC4.1x, Cobra and Audionote E Silver signature speakers with separate crossovers. The cables were mainly silver or silver ribbon cables. For streaming duty, I used a dCS Bridge.

Well, the CD4T really got things going. The hifi aspects of the sound and the music went up a few notches but the system started to sound slightly unbalanced. Add the DAC4.1x and again there were gains all round but that unbalanced feeling remained. Do not get me wrong the sound quality was far, far better but maybe it was just me seeing a system where the interconnects are more expensive than the Cobra and I could not help thinking that it was unbalanced. So, to even it all out I tried using a DAC2.1x instead of the internal Cobra DAC. And what was a surprise, the 2.1x was better, but not by an enormous margin. Despite that, I would say anyone wanting to upgrade the system should consider using a 2.1X DAC. However, I suspect the DAC1.1X may be an improvement, it would possibly not be enough to justify the extra cost.

Despite that, I really enjoyed using the Cobra in my system being fed by a CD4T and the dCS. It had more of the hifi aspects sorted with better dynamics and details without impacting the musical enjoyment. In fact, having played my usual test lists and CDs I just wandered around my music collection and really enjoyed what the Cobra was doing.

The Cobra really enjoyed playing my higher-quality music with the Mike Valentine recordings being very atmospheric and giving great clues to the church hall environments where the music was played and recorded. They were as evocative as when I attended those recordings. But when I played the US + Them Roger Waters recordings from his live shows it required all 28w/channel in my system to get across the power and drama but not at the expense of hearing the audience's appreciation of his music. Hearing ‘Being There’ is a strength of the Cobra.

Before concluding I would like to deal with the question of who should buy this amplifier. If you are interested in hearing real music and want a cute valve amplifier without all the fuss and bother of valves then the Cobra is ideal. If you like valve swapping and trying out new cables and fiddling and enjoying the equipment then a less integrated set-up may be more your cup of tea. I can imagine a ‘trendy’ liking vinyl and valves seeing this as ideal. It looks cool, requires just a CD or a turntable with phono and a set of speakers such as AX2s. Job done. It is really well balanced and plays great music without driving you to want to upgrade all the time. With a price of £3,500 it is aggressively priced and embarrasses a lot of other amplifiers. It was better than my Unison Research S6.

So, in conclusion, this is a well-built, rugged, integrated amplifier/DAC which has the audio magic of Audionote and a significant number of modern conveniences and represents an excellent place to start and then stop your audio journey for most people.

Audionote : https://www.audionote.co.uk/

Technical Specifications


28 Watts per channel


4 x EL34

2 x 6AU6

2 x 5670


340(w) x 199(h) x 451(d) mm incl. valves, knobs and connectors


Black Only


13.6 Kg