What is it about single-ended amplification that causes such disagreement among audiophiles? It’s even a bigger chasm than that separating those who like valve amps from those prefer sand amps. I know to some degree it has to do with the absolute disbelief by some that any speaker really needs only single digit power. Every so often I read an article where someone gets really excited about how wonderful high-efficient speakers sound with high power amps. There some truth in this, but all of these articles I have read were written by someone who already like the sound of powerful amps, so I do not find it a surprise they like these amps better with high-efficient speakers.
A friend of mine had a system with the Audio Note Es, SEC Signature version speakers that he played with huge Goldmund amps. I would be the first to admit that the sound was incredible: deep powerful bass, huge soundstage, and extended highs. The problem is he loves the sound of Goldmund amps and I love the sound of SETs so while we both could agree on how great the speakers sounded with the Goldmund and Audio Note amps, we didn’t agree on which one we would own. As will come as no surprise to my regular readers, I fall into the camp of those who love SET amps. That’s not to say I like all SET amps. To be specific I like most SETs, but would only own the ones that are fast, quick, and have that special alive sound. I should also admit that I am also of the Western Electric 300B tube camp. I have heard other tubes that I could live with, but so far my favorite is the Western Electric that sadly, is not available new at this time.
Having shared the above it should come as no surprise that when last year I got a call from Tom Hills of Hudson Audio saying if I would be interested in reviewing a 300B amp that had been designed from the ground up to use Western Electric 300B, I jumped at the chance. Of course the problem is they now have to sell the amp with other 300B since as mentioned above, the Western Electrics are not currently available. The real surprise for me was when he told me the name and brand of the amp. It was the Art Audio Diavolo TW Ref Signature series amplifier.
The surprise here was on several levels. First, I had no idea that Art Audio was an English audio company; I had thought that it was Joe Fratus’ company when in fact, Joe was actually the U.S. importer at one time. Second, I was unaware that the company had been around for over twenty years.
The other surprise was that there was a version of the Diavolo designed around Western Electric type 300B tubes instead of the higher current Czech versions of the tube. About ten or eleven years ago I had spent some time with an Art Audio Diavolo, but it was not a 300B amp. It had been designed around the KR VV32B triode because of its unusually high amperage. I also had a chance to spend some time with both the Art Audio Jota and the wonderful little PX-25. At the time I had found all these Art Audio amps to have a family sound, albeit a very good one. They all had an unmistakable “you are there” immediacy, yet with a touch more warmth than many SETs. Their amps satisfied those who desire a beautiful blend of harmonics, tonal colors and detail. The Diavolo TW Ref Signature I have in for review does not stray from this house sound much.
Let me start by saying the Diavolo is not the most neutral amp in the world. It comes across slightly more beautiful and romantic compared to absolute neutrality. Don’t misunderstand: The Diavolo is not overly colored in a lush, overly warm way that would rob it of detail. Neither is it rolled off in the frequency extremes. Still this amp, like most SETs is more about midrange beauty than flat frequency response.
I used the Diavolo WE with my Teresonic Ingeniums that use Lowthers DX4 silver drivers. The Diavolo did an exemplary job of driving these speakers. It played them with good transient speed, nice control of the bass, very good treble extension, and a midrange sound that can only be called lush, relaxed, and natural.
Another point in the Diavolo TW Ref Signature’s favor is its presentation of spatial information. On my system it played a truly believable, coherent, and dimensional soundstage. The depth and width perspectives were especially good without distracting the listener from the music. Individual images were palpably resolved while occupying a believable space. It was easy to delineate individual instruments and voices from each other.
The Diavolo sounds excellent with different types of music, and I think that important factor helps it rise above the performance of many SETs, especially those priced below $20,000. The exception to that would be the Shindo Cortese F2A amplifier, though these two amps have a slightly different presentation of music. The Shindo Cortese uses the F2 tube instead of 300Bs, though both put out around 10 watts of single ended beauty. The Cortese has the quickest, most accurate bass I have heard from any amp under $20,000; it also sounds far more powerful than its 10-watt output. What it lacks ever so slightly is the midrange aliveness of the 300B tube. The Diavolo comes very close to the bass and power of the Cortese, yet provides the glory of 300Bs. Neither amp is as quick, nimble, or as alive as the Wavac EC 300B amp, but that amp does cost three times as much.
Let’s Play Some Tunes
Let’s start with the Mercury Living Presence recording of Janos Starker playing Schumann and Lalo. This is one of the most beautiful cello recordings I have ever heard. With the Diavolo, Starker’s performance comes through as beautiful and full of emotion. The cello sounded slightly warm but very quick with a great sense of air, space, and decay around and within it. As the bow is slowly pulled across the strings you can hear layers and textures of the tones of the strings in such a realistic way.
Next let’s talk about one of my favorite albums, Verve’s incredible recording of Ella and Louis. On cut 2, “Isn’t This a Lovely Day,” it was so easy to hear the sheer beauty and lushness of Ella’s voice, and at the same time the gravely power of Satchmo’s voice. The voices are very prominent, and the horn seems just right. By the way I ended up listening to the whole side before I realized I hadn’t made any notes. I would say on this LP, the Diavolo came as close as any amp has in my system to sounding as alive as the Wavac EC 300B.
In 1986, North Star Record release a recording of Arturo Delmoni playing the violin called, Songs My Mother Taught Me. I remember vividly the first time I heard this album. It was at a Dr. Norton’s house in Auburn, Alabama. On his Futterman amps driving a pair of Quad 63, I was simply blown away by the beauty of the violin and piano. Twenty-seven years later I acquired that very LP thanks to a friend in Auburn, and I couldn’t wait to hear it on my system. So often memories make things sound better than they actually were, but I was delighted to find that it sounded even more beautiful than I remembered. I was very impressed with how the Diavolo and Teresonic let the beauty and tone of this recording come through. It is without a doubt as realistic as I have heard recorded violin sound.
Another recording that I often listen to for reviewing purposes, and just for fun, is Elvis is Back, which contains Elvis’ version of “Fever.” This cut will tell me in a heartbeat if a system is all about slam and tightness or if it’s about feeling the emotions of the music. The Diavolo did a very admirable job of balancing those two. It was fast and powerful, but not to the point of not sounding like a real performance.
Rereading the review, I notice I have failed to mention that the Art Audio Diavolo TW Ref Signature is built like the preferable tank and looks like a million bucks. It joins the ranks of Audio Note, Shindo, and Wavac of making 300B amps that sound very much like real music.
Comment from Hudson Audio, U.S. importer:
I would like to thank Jack for taking the time to review the Art Audio Diavolo TW Ref Signature series amplifier. I am glad you enjoyed your time with this fine reference 300B-based amplifier. Here are some of the key design features of the family of Art Audio products:
Automatic Biasing – This holds the current valve draw at its present level and helps keep the valve performing at its optimal level at all times thus achieving longer valve life and reliabilty.
Sentry Circuit – Monitors thermal runaway and over current conditions and shuts down the High Voltage supply. Simply replace the valve and switch the amp back on. This then resets the circuit.
Valve Condition Monitor Circuit – Indicating when the valve is drawing insufficient current to work properly (used at this time in the conductor series amps only, but will be outfitted to other designs soon).
- (Page 1 of 1)