Audio Note UK 4300E output tube

Introduction – Audio Note U.K. re-thinks the venerable Western Electric 300B

Many of you will be familiar with Audio Note (U.K.) and their plethora of tubed products. While these products, at least for me, represent the pinnacle of what can be achieved through thoughtful design and scrupulous choice of parts for their sonics when cost is not a concern, I have always had a concern when it comes to sourcing tubes. This is particularly the case with respect to the tubes utilized in my Audio Note Balanced Kegon amplifiers: a 5U4G rectifier, a VT-25 input, and two 300B output tubes. In each case, I have tried a variety of current production tubes, only to be dissatisfied with the end result. Consequently, I have found myself turning to NOS tubes, typically produced during WWII or the closely thereafter, much preferring their sound.  These tubes have become increasingly rare and increasingly expensive. This is particularly true for what has come to be my preferred 300B, which was produced by Western Electric prior to 1980, with older examples sounding even better but often selling for thousands of dollars.

Peter Qvortrup of Audio Note (U.K.) has made it a high priority to source new what was previously only possible with new old stock tubes and out of production parts, such as Black Gate capacitors, whenever possible improving upon the original. Working with tube manufacturer Psvane, he has researched and resurrected the best technology from the past, including but not limited to a Molybdenum anode 300B, which he has designated the 4300E. There is also a 211 version (4242E), but as I do not currently own an amp that utilizes a 211, I cannot really comment on that. Both the 4300E and the 4242E retail for $1,000 per pair.

Molybdenum is an extremely hard and difficult metal to work with. It has a melting point of over 3500 degrees centigrade, so very specialized tooling is needed to fabricate it. The cost of starting production is expensive and presents a significant barrier to entry. Concomitantly, the thickness of the plates can vary, making some examples glow red because the plate is slightly thinner than others. This is not a defect and should not affect reliability or sonics.

Audio Federation, the company’s Northern California retailer in Palo Alto near Stanford University, provided me two carefully matched pairs of the 4300E for review. These are currently available through any Audio Note authorized dealer. While these tubes sounded remarkably good straight out of the box, all listening tests were done after the tubes had been broken in for a minimum of 100 hours. My comments are organized by music selection with a conclusion at the end of the article.

Listening

In reading my remarks, please keep in mind that some of them clearly pertain to the subtleties of a specific recording and/or pressing; others to the specific sound of the 4300E’s. In the main, the 4300E’s are merely accurately reproducing what is in the groove.

Chris Connor (Bethlehem)

This is a mono jazz LP from Bethlehem’s better days. It is, effectively, a compilation of tracks Connor recorded in the early 50s. This was an early copy, with excellent sound, albeit subject to some limitations in the source material. Connor’s voice sounded superbly “present” in the way that some early deep groove pressings can. We had previously listened to the record using Western Electric tubes. With the new 4300E the sound of the voice seemed about the same as with the Western Electrics — terrific. The backing band sounded oddly “fresher” than previously. How does one describe an impression of the voice being better integrated with the band? What could the system be doing to bring that about? It seemed that the detail, including the ambience, was somewhat stronger than with the WE’s, which allowed Connor to sound more as if she were in the same room as the band. Most importantly, the record came across as very musical and a pleasure to listen to. Perhaps the WEs have a more seductive mid-range. I am not, however, pining away for it . . . so far.

Ansermet Crespin Ravel Scheherazade

This record seemed very musical in most respects except that it may have told us more than we really wanted to know about the recording technique and venue. Crespin did not sound like she was in the same room as the orchestra as there was more reverb around her voice than around the orchestral instruments. The orchestra sounded terrific — warm and natural. The voice, with the apparent additional reverb, sounded a little colder than I recollected from this recording.

Fennell Mercury Schoenberg Stravinsky

We were most interested in the Stravinsky on this late-50s issue of the LP. Aside from somewhat typical Mercury sound — slightly forward with some edge in the brass — the sound was excellent. Spatial presentation was everything one could want as one could easily point to the location of individual instruments. The instruments were well-rounded and they sounded about as authentic as recordings can present. I will be curious how this sounds with the WE tubes as a little additional warmth could be welcome. But this was a good listen.

Mel Torme, Lulu’s Back in Town, Bethlehem

Mid 1950’s Bethlehems present the most curious mono — you would almost think that it was some kind of early stereo because of the depth and the full middle of the sound stage as if the ensemble were spread out before you. The effect is fully present with the Audio Note tubes, as is the detail of Torme’s voice. The presence was at times remarkable . . . the breath, the articulation, even the distance from the mike. It was all right there.

I think that it is possible that the depth is not quite what it would be with the Western Electric 300B’s, but the Western Electrics might be less crisp. In any event, the sound drew me in and I found myself just listening and enjoying rather than worrying about those possibilities.

Debussy, Images (Paray) Mercury (FR2)

This is a very early Mercury stereo (90010) but is still a good listen. Instrument placement was very good, though the depth could have been better. The middle of the soundstage, as sometimes happens, seemed as if it could have been more realistically full; however, I do not think that was the tubes. The strings had good warmth without edge, but were more a mass of undifferentiated instruments than a section of individual instruments when the playing got loud. During softer, more chamberlike segments of the piece, detail and separation were quite convincing and very lovely. It is these more intimate segments that make the record an excellent listen. I do not believe that the imperfection I noted is an artifact of the AN tubes.

Mahler Symphony No. 4, Kubelik, DGG (large tulips)

This is an early DGG, a vaunted “Large Tulips,” that happened to be in superb shape with excellent sound. The AN 4300E tubes presented well, but not with the warmth that I would have liked.  Yet the sound was neither hard, shrill nor overly bright. In fact, the AN tubes deserve real praise for their detail and placement in the many chamberlike moments during the symphony. In those moments, it felt as if I were “right there.”  But, I have heard this record presented with a more luxuriant warmth that belies its age and provenance; DGG is not particularly known for these characteristics, although their recordings can surprise you.

Stravinsky Violin Concerto, Oistrahk (Phillips Plum)

This is another superb early stereo issue and it largely shined with the AN tubes. As seemed to be usual with these tubes the detail was first rate. Oistrahk is right in the room. Having heard the concerto just a few nights earlier played by the Houston Symphony, I was particularly curious to hear this recording. In concert, the solo violin had an unusual tendency to blend with the orchestra in such a way that I lost the thread too many times. The piece makes more sense to me through this recording (and the AN tubes). Of course, in the studio many imbalances can be righted, but with Oistrahk, I am thinking that was not a problem in the base case.

I have mentioned my nagging desire for more luxuriant warmth. The 4300E tubes do many — probably most — things really well. On this particular record, I was totally and completely absorbed by the performance. I was not thinking of whether or even if there could be more warmth.  Isn’t this where we all want to be when we listen?

Conclusions

The Audio Note UK 4300E tubes are somewhat more extended, particularly at the top, than the Western Electric NOS tubes, hence somewhat more revealing; however, this does not come across as aggressive or bright, grainy, or fatiguing. Indeed, the sound is very musical, if lacking the last bit of warmth one might find in a really good set of vintage WEs. With other contemporary versions of 300Bs I’ve heard, orchestral sound has tended to suffer; strings can be hard, or grainy, and generally fatiguing; brass instruments can sound edgy, winds can sound bodiless. That is not the case here. Surface noise issues are not particularly annoying with the AN tubes, which do a very good job of separating out the pops and tics from the music. In my Audio Note (U.K.) Balanced Kegon amps, the AN 4300E’s are sonically superior to the Takatsuki 300B and for that matter the wide range of other new production 300B’s that I have tried over the years (note that I have not auditioned the Elrog tubes). The 4300’s are somewhat more extended at the frequency extremes and somewhat more revealing, but with slightly less of the warmth and depth of the very best NOS WE300B’s, which have become almost impossible to find and command crazy prices.

For Dagogo readers who own Audio Note amplifiers that use 300B tubes, I strongly suggest that you replace whatever tubes you are currently using with the 4300E.  I do not think that you will be disappointed.

Copy editor: Dan Rubin