November 2005

Art Audio Carissa Stereo Amplifier
Good for the soul.
Review By Todd Warnke

  Former Supreme Court Justice Potter Stewart would have long ago faded off into whatever sunset non-activist judges find themselves except for his immortal, "I shall not further define it... but I know it when I see it" remark about pornography.  This is a remark that puts pornography in the same class as hip, cool and soul; each being an indefinable but readily identifiable essence.  Now, of these last three things I know nothing about hip except what I read, am so far from cool that a picture of me sits in the dictionary as its antonym, but soul I feel a mile away.  Which is why certain pieces of gear never get a rise out of me in spite of near-perfect specs while other gear, even with the odd flaw, can excite me like a teenager the first time he sees Deep Thro... uh... let's just say I enjoy it immensely.

Anyway, Joe Fratus' stuff from Art Audio has almost always excited me with its particularly canny mix of specifications and deep soul.  Or rather, of soul that measures pretty damn well.  At the Rocky Mountain Audio Fest in 2004 I had the opportunity to listen closely to his Carissa amplifier and I was thoroughly impressed by its amazing power, harmonic detail and deep bass extension.  But mostly I was moved by the way it communicated the human element, the soul of music.  On track after track of my demo material – ranging from Dizzy Gillespie and Gil Evans to Bach and on to Curtis Mayfield, Muddy Waters and Joni Mitchell – I was shocked at how present and moving each different style of music seemed.  No, at least in show conditions the Carissa was not one of those amplifiers that locks in with one or two types of music and disappoints on the rest.  So, after hearing so many soulful sounds I asked Joe for a review sample, a request he (obviously) agreed to.

The Carissa, regardless of her sonics, looks exceptional.  At 14 inches wide by 19 inches deep and 9 inches tall she has the over-square, deep dimensions of a classically styled amplifier.  The chrome-like, hand-polished stainless steel chassis only adds to that classic profile.  And with the two 845 power tubes - one per channel - placed right up front, there is no doubt this is a visual throwback.  It is a look that it pulls off so well that looking at the rear apron you expect to see a screw strip or at least multiple taps for the speakers.  However, the apron is straight forward and modern with a pair of RCA input jacks, two pair of heavy-duty gold binding posts, the power switch and an IEC jack.  Lastly, on the front panel the version of the Carissa I had in for review had an old-timey looking wooden rotary knob to control the add-on, minimalist volume attenuator (a $200 option).

While retro rules the outside, inside the Carissa is all state of the art... well, as state of the art as a tubed, single-ended power amplifier can be.  And how state-of-the-art can a retro tube unit be?  Rather than to rely on the old charts describing the characteristics of the 845, a tube whose original purpose was as a transmitter, Mr Fratus spent – literally – hundreds of hours modeling the power response and impedance of current issue 845 tubes at a large east coast technical university.  Armed with more exacting and more recent data, Mr. Fratus then designed a circuit to extend the linearity of the 845 without losing the powerful and magic mid-bass through mid-range sound that the tube has become known for in audio circles.  The result of this research is 16 watts per channel, single-ended, pure ‘Class A,' zero-feedback, transformer-coupled design.  Yes, I hear you muttering to your computer screen, "16 watts, but aren't 845s power monsters?"  To which Mr. Fratus says (or at least he said to me) that they are, when dropped into circuits based on the old, out of date specs - but when using those specs they are not a particularly linear device either.  Good point, Joe.

So, after all that lab work Mr. Fratus, quite rightly, is not willing to spill all his circuit secrets willy-nilly, especially to a weak-headed reviewer, but the rest of the tube set is out in the open so I know I can describe it correctly  – a pair of NOS 12BH7As and a single NOS 6DJ8.  I also know that voltage regulation is handled via MOSFETs, because this is on his website as is the fact that the tubes are self-biased.  As for the rest of the specs, the one that stands out is the rated frequency range of +/-1dB from 20Hz to 20kHz.  Clearly, with the Carissa Mr. Fratus has not set out to deliver the stereotypical, purposely-skewed single-ended amplifier.  But, as always, it is the sound and not the intent or specs that matter.  So, let's adjourn to the listening room and, well, listen.

The Sound Of Soul?
Over the course of my listening sessions with the Carissa she was paired with loudspeakers from Mobile Fidelity (both the OML-1 and OML-2), Silverline Audio (Panatella III), Triangle (Antal ES) Cabasse (Bahia) and, of course, my reference Merlin VSM-Ms.  Pre-amplification was via my First Sound Presence Statement, though the built-in attenuator saw quite a bit of use.  Sources were the Cary CD 303-200, Berendsen CDP 1, and the Blue Circle BC-501 DAC.  Cabling was by Cardas, Acoustic Zen, Audio Magic, Stereovox and Shunyata Research.  Lastly, a great many listening sessions happened while under the influence of children, who can be remarkably keen listeners.  Sure, no four year old has the vocabulary to describe the differences between a Bosendorfer and the Fischer-Price piano up in his bedroom, but they sure know if what they are listening to makes ‘em dance, sing and laugh, which is what it's all about anyway, at any age.

Getting back to the point, I suppose that if you are going to determine the soulfulness of an audio component you should begin by listening to the Genius of Soul, and so I spent a lot of time spinning the absolutely essential three disk box set, The Birth of Soul [Atlantic 7 82310] by Ray Charles.  Covering the years 1952 to 1959, the set follows the amazing evolution of Charles from a Nat King Cole and Charles Brown influenced pop/R&B crooner into the full-blown Brother Ray.  On early tracks, such as Roll With My Baby, the Carissa impressed with its ability to extract every bit of musical detail from a middling recording.  Take, for example, the soft snare that sits at the back of the stage.  Through lesser gear it sounds like tissue paper – lacking body, punch and drive, but through the Carissa is had tonal texture, natural body and a real presence.

Jumping forward three years to when Charles records the Doc Pomus song, Lonely Avenue, the musical style has evolved and is gutsier, with both more gospel and more of the profane, in short, more soul – and the recording is far better as well.  On this track, with less noise and higher fidelity, the Carissa is able to bite deeply into the inner harmonics of the sax solo, lay bare the anguished growl of Charles' voice and the echoing reply of the Raylettes with a visceral punch.  The drums and Charles left hand bass have perfect propulsion, and the mono stage is deep and layered.  In short, a nuanced, harmonically rich and startling real performance.

Moving on to a different type of soul music, I spun my favorite version of the Arvo Part composition, Fratres.  The title, Latin for "Brothers," is meant to evoke the image of medieval monks marching to prayers, and the I Fiamminghi recording of the work (conducted by Rudolf Werthen [Telarc CD-80387] ) has six different settings of this piece using various combinations of strings, percussion and piano.  The state of the art recording took place in a small Basilica in Belgium and faithfully records the location as well as the instruments.  The first version opens with percussion playing softly and set way back in the stage, marking the monks approach from afar.  A string section gives voice to their Gregorian chant while deep basses mark time.  As the monks approach, the volume rises until the monks pass in the night.  Through the Carissa the percussion on this track had both explosive attack and long delay which allowed me to locate the walls of the Basilica even as I jumped at the impact of implied foot on stone.  The string section had exquisite tonal clarity and depth of tone and stayed absolutely spot on as the volume rose and fell.  As wonderful as this sounds, in many ways this recording is custom made for the Carissa as it highlights everything it does well – great attack coupled with an accurate and dense harmonic envelope, the ability to follow sounds deep into the noise floor, and the difficult to articulate but easy to feel magical skill of making musical tones sound as if humans are intimately involved in their creation.

So, after giving the Carissa, what for it amounts to a gimme layup, I tried to trip her up and so turned to my new favorite version of Mahler's 9^th Symphony, the SACD recording by the San Francisco Symphony and Michael Tilson Thomas [San Francisco Symphony 821936-0007-2].  The 1^st movement is, perhaps, the finest, most integrated piece of writing by Mahler, and the San Franciscans pull it off to perfection.  Though the scoring is at times dense, the Carissa has the skill to lay out each line with harmonic equality, favoring neither instrument nor frequency range, with the exception of the very slightest emphasis on the upper bass.  This allowed me to transparently follow melody and accompaniment as it is tossed from horn to violins to harp and to clarinet.  The third movement is a more violent piece of work, and here the power and dynamic kick of the Carissa drove home the music all the way through to the crashing end.  Staging, with a piece this massive can only add to the enjoyment and here, again, the Carissa stepped out of the way and allowed the ambiance of the live recording at Davies Hall to settle gently over the recording while precisely laying out the players on a three D platform.  And though the stage was not the widest I've ever heard, it was deep and held together regardless of dynamic contrasts.

No review up at the Warnke Music and Mountaineering Lodge is complete until we listen to some Joni Mitchell, and so the Carissa had to prove herself with one of Mitchell's overlooked masterpieces The Hissing of Summer Lawns [Asylum 1051-2].  The studio follow-up to Mitchell's best selling Court and Spark (a live album separated the two), Hissing takes that album's pop-jazz as a departure point and opens up into her finest openly experimental album.  So where Court ended with Mitchell taking a straight but joyful turn on the Annie Ross tune, Twisted, Hissing has her dropping in an ethereal and swinging version of the Johnny Mandel/Jon Hendricks song, Centerpiece, into the middle of Harry's House, a bitter tale of a disintegrating marriage which twists the meaning of the older tune while honoring it as well.  Even more experimental, on The Jungle Line Mitchell uses warrior drummers from Burundi to anchor the song, pre-dating the World Music movement of the late ‘80s by a decade or more.  And on the closing cut, Shadows and Light, Mitchell sings backed by a studio made choir of Joni's in a meditation on duality.  But my favorite track on the album is Edith and the Kingpin.  With backing by Joe Sample, Larry Carlton, Chuck Findley, Bud Shank, Wilton Felder and John Guerin, the playing is pop-jazz perfection while Mitchell, staying in her upper register, delivers perhaps her most impressive vocal.  Through the Carissa her voice was rendered with a seamless accuracy and presence that I have previously only heard through amplifiers costing multiples of the Art Audio product, all while the layers of horns, guitars and piano were likewise rich, harmonically full and easily distinguished.  Again, the Carissa proved that she had the ability to lay out individual lines while weaving them into a cohesive and vibrant whole.

Soul-Less?
So, where does the Carissa fail?  Baldly stated, in very few places.  First and as mentioned a few paragraphs up the page, she does have a slight mid and upper bass bump.  On a loudspeaker such as the Triangle Antal ES, which already has a strong presence in this area, the emphasis doesn't create a muddy bass as both components have a very clean presentation, but it does create a prominent bass.  Meanwhile, over on the more linear Sliverlines or the slightly bass shy Mobile Fidelity OML-1; this was either less of an issue or an actual blessing.

Second, and again as noted above, the stage of the Carissa is not as wide as I've heard through other comparable amplifiers, though it is deep and layered.  More important, it is an extremely stable stage with volume changes seldom resulting in stage changes.  This is a presentation that I can quite comfortably live with as depth and stability are more important to me than instruments poking outside of the loudspeakers, but I point it out because it's there.

Third, even though the Carissa has tremendous power for 16 watts, she still has only 16 watts.  When placed behind the Mobile Fidelity OML-2 – a fairly easy to drive but also inefficient 84dB loudspeaker – and when played to fairly loud levels, the Carissa began to round off peaks and lost a bit of dynamic explosiveness though she never failed to sound musical.

Fourth, least significant and last, right where the midrange meets the treble the Carissa has a touch of extra bite.  Coupled with the emphasis in the bass, this gives the amplifier a slightly more real than real presentation, which is not necessarily a bad thing even if it is not quite an accurate thing.

Soul-Full!
If you haven't figured it out yet, I had a completely enjoyable experience with the Carissa.  She has real dynamic growl, and sounds far more powerful than her rated power output.  On an efficient loudspeaker she sounds more like 60 than 16 watts.  Frequency wise, for a single-ended amplifier she reaches waayyy down there – I'd guess to at least 30 hertz – completely flat and with plenty of power for most any normal load, while having a clear and extended treble.  Yes, the upper bass and lower treble regions have very slight bumps (the treble to a lesser degree than the bass), but these deviations are shallow and fairly flat making them easy to deal with.  Harmonically, she offers gobs of detail and nuance as I could easily hear deep into both stage and noise floor.

Another point in her favor – the add-on attenuator is superb and using it avoids an additional source of audio failings.  Considering that it costs but $200, which has got to be less than you would spend on just the power cord for the pre-amplifier it replaces, getting it is a no-brainer.  If I were building a system around the Carissa I certainly would get it and then take the three to six thousand dollars I had budgeted for a pre and cables and drop them into a better source and loudspeakers.  Even more, I can see myself doing just that – building a system around the Carissa as she joyfully and with near completeness delivers not just a balanced, nuanced and detailed window into recordings, she also gets to the soul of every piece of music that passes though her.  And while I have tried over the years to describe exactly what soul is, I know this, in the Carissa I hear it and I think you will too.  Most highly recommended.

Specifications
Type: Vacuum tube stereo amplifier

Frequency Response: 20Hz to 20kHz

Tubes: Valve Art 845 output tubes (KR Audio 845 optional)

Output: 16 wpc single-ended, two channels

Design: transformer-coupled operating in 'Class A'

Feedback: zero

Bias: self-biasing circuitry

Chassis: optional hand-polished, non-magnetic, stainless steel chassis available

Input Sensitivity: 600mV

Input Impedance: 180k Ohms

Output Impedance: 4 or 8 Ohms

Warranty:  3-year parts & labor warranty, 90 days for tubes (KR Audio 845 output tubes 1 year)

Optional: volume control available for $200

Price: $5,500 for hand polished surgical stainless steel

Options: Passive Volume control adds $200
Goldpoint series stepped attenuator adds $400
Remote control version adds $500

Company Information
Art Audio
34 Briarwood Road
Cranston, Rhode Island 02920

Voice: (401) 826-8286
E-mail: vze572mh@verizon.net 
Website: www.artaudio.com