the art audio carissa 845 set amplifier - Audio Note Singapore

THE ART AUDIO CARISSA 845 SET AMPLIFIER
Art Audio's new Carissa is a 16wpc, 845-based, no negative feedback, single-ended
triode amplifier that operates in pure Class A. Retailing at $3,995 with black chassis
and chrome accents - or $4,495 with hand-polished stainless steel case - it is neither
cheap nor bank-breaking. Further specs include input sensitivity of 600mV; input impedance
of 180kohms; output impedance of 1.2 ohms; and frequency response of
20Hz-20kHz +/-1dB to full rated power. The Carissa's binding posts can be internally
connected to the output transformers' 8- or 4-ohm taps. My sample was connected at 8
ohms. A 3-year warranty covers parts & labor, an optional passive volume control is
available for $200. Standard power tubes are by Valve Art, but KR Audio equivalents
may be substituted for an additional $500 - these upgrade tubes retail separately for
$600.
My sample didn't come with the optional $500 active-convection glass chimneys and polished stainless collars
[upper right] but did have a working heat sink - visible below at the rear of the amp - which is connected to the input
transformer. Originally, this heat sink was implemented on all of Art Audio's higher-voltage models but isn't strictly
necessary for lower-power domestic models built for 117V/60Hz line voltages. Nevertheless, it is available for $25 -
about Art Audio's cost.
The Carissa measures 12½ inches wide by 19 inches deep by 10½ inches high when measured at the top of the
output tubes. It weighs around 60 pounds and represents a real hunk of amplifier. In its polished stainless livery, it
represents a beautiful hunk too, one that strikes me as a no-brainer even at its premium price. Construction and
finish quality are robust and superb. Hardware used is first rate, two pairs of sturdy gold-plated brass 5-way binding
posts - just one pair per channel - and two gold-plated, chassis-mounted RCAs. Of course the IEC power inlet is
standard fare these days and invites experimentation with after-market power cords. Lastly, at the right rear of the
amp is the power switch. There are no provisions for biasing - the amp is completely self-biased.
In his sneak peek, Srajan wrote "Considering its size, heft, power and detail
work versus the other entrants of the line, the Carissa nearly screams loss
leader." And it's true - it screams that loud and clear, something Art Audio's
Joe Fratus verified as fact. Fratus told me that the Carissa has been introduced
at a price that reduces their normal profit margin, in order to bring it
within reach of those not previously able to consider this marquee. My advice
is to not underestimate this amplifier based on its retail price positioning. This
is nobody's entry-level amp.
What, a watt is a watt? Not!
Automotive enthusiasts know how there's more to engine performance than can be gleaned from its noted horsepower.
Horsepower only tells so much of the story. There's also low-end torque to consider, and its ability to get a
car off the mark. Then there's midrange performance, determined by the engine's power band which in turn is determined
by where the torque peaks and falls off proportionally to where horsepower takes the baton and (hopefully)
surges to redline.
But there's even more to a car's performance than can be gathered from the above. After all, the engine doesn't
perform in a vacuum, isn't directly connected to the wheels but intermediated by a transmission. The transmission's
gear ratios will determine how engine torque is best utilized. It's why a little four-banger can get off the mark almost
as quickly as a much larger engine. After reaching cruising speed, the smaller power plant might even be able to
keep up with its larger counterpart - as long as the terrain is flat. But a steep incline will have the little engine fall
behind unless the driver gears way down. It just doesn't have the horsepower to keep up with the bigger motor.

Amplifiers are a lot like engines. They are the driving force in audio and mostly
judged by their horsepower delivery (watts) but with little concern expended
over torque (current). Neither do they operate in a vacuum. They require careful
matching to a transmission (speakers) before there is music. You wouldn't pair
a low-powered amplifier with a speaker that only came to life at high revs. Surprisingly,
pairing a big amp with a high-efficiency speaker not requiring those
high revs is no guarantee for performance either - unless it delivered high
torque at low RPMs. A high-efficiency speaker may be far better off paired with
a very small amplifier that maximizes its power delivery band within, not outside
the speaker's usable range. In this case, current is at least as important as
watts. Which brings me to the Art Audio Carissa, just one such amplifier. Judge
its fortitude and brawn based on its relatively meager specs at your own peril.
As they say, "it's not the size of the sword but the fury of its onslaught"
[especially when the puny pen is said to be mightier - Ed.].
Where the rubber meets the road
When I read in Srajan's preview that I was expected to try the Carissa on my pair of Magnapan MG 1.6QRs, I
thought he'd probably been out too long in the New Mexican sun. Everybody knows that the 1.6QRs require a big
solid-state amplifier. Right? Well, not necessarily - but still, what affront to common sense.
Long story short, once I installed the higher-current KR Audio 845 tubes, I
was shocked at how well the Carissa handled the Maggies. Sure, 16 watts of
revving power limited ultimate loudness but the amp had the unexpected current
delivery and torque to take the Maggies firmly in hand. Bass was surprisingly
robust -- solid and tuneful -- and where the stock Valve Art tubes produced
an upper midrange a bit too laid-back, the KRs snapped the Maggies
back in line to sound splendidly neutral.
Naturally, nobody in their right mind is going to recommend the long-term
mating of the Art Audio Carissa and the Maggies. I won't either. But the exercise
-- as apparently intended -- aptly demonstrated that this is not your
stereotypical prissy SET amplifier. It was but the first glimpse of what is so
special about this plucky amplifier.
Art Audio claims that the Carissa is "a different twist on other 845 based amplifiers. Of course, the hand-wound
split-core output transformers - not usually seen in SET designs - and power supply (designed by Art Audio's
UK founder Tom Willis) are the secret ingredients." I'm told that a rethinking of what has been standard procedure in
845 amplifier design netted some noteworthy innovations. First, Art Audio lowered the input impedance at the output
transformer to boost dynamics, clarity, and high frequency extension. Next, they eschewed tubed voltage regulation
in favor of Mosfets. Last but not least, they significantly lowered plate voltage to 800 volts, doubling available
current over traditional designs at the expense of fewer available output watts. Then there was the choice of 845
power triodes.
The optional KR Audio 845, said to be one of Dr. Riccardo Kron's last designs before his recent death, is, among
other things, responsible for some difficulty organizing this review. I could easily have written an entirely separate
review on the Carissa with the KR 845 installed - the difference between the Valve Art and KR tubes is that significant.
But in the end, what makes the KR tube significant is that it shares the basic theme of the Carissa while taking
it to another level. Though the Carissa with the Valve Art tubes installed sounds very different from the Carissa with
the KR tubes, both share the same traits, just to different degrees. Everything about the Carissa is intensified
through the use of the KR tube. If you like what the Valve Art-equipped Carissa is all about, you may be ecstatic
about what the KR does. Or, you may not. The intensified bass of the KR could be too much for your room or your
tastes. I can't imagine why, but you may not enjoy the added saturation of tonal colors and harmonics that the KR
brings to the table, nor its added drive. But you do owe yourself an audition of the Carissa equipped both ways.
For the duration of the review, be mindful that I'm talking about the Carissa with the stock Art Valve tubes - but feel
free to read between the lines, to infer that all positive observations were intensified with the insertion of the KR
845. I started off by talking about fortitude - completely unexpected in an 845 amplifier. But that's only the beginning
of the Carissa's charms. This is one seriously charismatic amplifier, with all the fine attributes that tubes have to
offer. Those who favor the 845 beam triode will instantly find much to love. Those not familiar will be instantly impressed
by an expansive, light and airy soundstage. Loyalists won't be bothered at all by slightly soft image outlines
- as compared to what 300B or even EL-34 fans may expect - though they still exceed what live music offers. While
depth is very good, the Carissa isn't exactly the last word in front-to-back layering.

A soft and romantic treble is another common expectation. Here the Carissa comes closer to conforming to expectations
-- if only to a degree -- but still surprises. Like a Champagne Sabayon, the Carissa produces a treble that is
crisp yet sweet and gentle, with a velvety smoothness that never bites. Not dark or closed-in, it's nevertheless not
quite the ultimate statement in hyper extension. But, it's eminently satisfying and always forgivingly musical.
Through the midrange, the Art Audio Carissa has all the transparency and intimacy
aficionados will expect of just about any SET amplifier, in this price range
and beyond. It doesn't quite measure up to the standards set by some 300B
amplifiers but far surpasses any EL34 or 6550 tube I've ever heard - and it
comes with a combination of price and raw moxy that seems almost too good
to be true. From what I gather, an important priority at Art Audio is an amp's
ability to drive real world speakers. I reckon that from reading their website, but
mostly from living with the Carissa. This 16-watt amplifier drives like no other
tube amplifier I've heard. Through the bass region, it reminds me of the push/
pull Audio Research VS-55, a 50wpc amplifier utilizing the 6550 tube, well
known for its bass prowess though less so for musical finesse and transparency.
Not only does the Carissa do bass like the ARC but it sounds every bit
as powerful. I never ran short of power. This shiny amplifier maintained a previously
unheard-of control over my Silverline Sonata IIs’ twin woofers - and
through some very spirited listening sessions to boot.
The Carissa has, at least temporarily, changed my listening habits. It's got me pulling out Rock recordings
that I either haven't listened to in a while, or that were sonically too disappointing to use as
part of the review process. Two such CDs suffer from a multitude of careless mastering sins: Bowling
For Soup's Drunk Enough To Dance [Silverstone/Jive 01241-41819-2] and Avril Lavigne's Let
Go [Arista 07822-14740-2]. Both exhibit no more than the usual amount of Pop CD midrange veiling
- but the tremendously transparent Carissa does a superb job of minimizing that annoyance. The
amplifier further produces a meaty and harmonically dense presentation that lends superb body to
both CDs to help propel the music. Not only do vocals project as they never did before, but they
emerge from a huge wall of highly saturated sound that perfectly serves the music.
Of course these CDs are also well served by the Carissa's aforementioned bass prowess, so much
so that I've enjoyed listening to this amplifier with hard-driving Rock more than any amplifier I've ever
had here, my Herron M150s excepted - possibly. Remember all that talk about car engines and
amp/speaker matching? The Carissa, by leaps and bounds, sounds more powerful into my Silverlines
than my 500-watt Bryston 7B STs. It's not even close. The Brystons sound hollow and anemic
by comparison. But before I give the impression that the Carissa is a bass-heavy monster superimposing
its personality on every CD and system it comes in contact with, let me set that record
straight.
One day I gave a spin to a Telarc copy of Hector Berlioz' Symphonie Fantastique, Op.14 [Telarc CD
80076] and sat back for some bombastic fun. I expected the Carissa's usual way and looked forward
to some plucked double basses energizing my room as maybe I'd never heard them do before, even
if sounding a bit larger than life in turn. Didn't happen. It wasn't until the 5th movement when the
fireworks commence [think of the repetitive segment throughout Julia Roberts' Sleeping With The
Enemy if you don't know it] that the Carissa even started to show its metal. It was basically the same
when I fired up Rostropovich, Return To Russia [Sony Classical SK 45836]. I started to realize that
the Carissa doesn't add bass; it just makes the absolute most of whatever it finds. If the CD contains
gentle shadings, that's what the Carissa delivers. But when the bass gets loud, powerful and demanding
of amplifier current, the Carissa, more so than any tube amplifier I've ever used, steps up to
give you what you paid for.
Through the midrange, or more specifically, through the upper midrange, the Carissa isn't exactly
the last word in neutrality. Like a good Sauvignon Blanc, it has a crispness that is stimulating, refreshing
and bold, making it the perfect complement to the Carissa's overall forthright and full-bodied
character. It features a gentle upward-tilt through the upper mids that adds life, excitement and
charged musical emotion. This deviation from linearity is minor in amplitude and no greater than
found with highly regarded amplifiers of varying persuasions. While this aberration isn't nearly large
enough to be characterized as bright, it does result in some added vibrancy to strings, brass, guitar
and female vocals. It also brings the soundstage just a touch closer. In my room, the music just
comes alive. The infusion of energy through this region can be absolutely addicting. It not only increases
tonal saturation, it balances the bass for a really kinetic rush. Instruments through this range
are more expressive and emotionally communicative and never detrimental to musical cohesion.

Every Breath You Take: The Classics, the Police compilation SACD [A&M06949 36072], made for an
interesting experience. The first three tracks don't indicate much in the way of remastering and are
sonic disappointments. Still, the transparency of the Carissa well illuminates the changes in recording
techniques and venues used from track to track, imposing no personality in the process - the
first three cuts indeed have very little in common. But by the time "Walking On The Moon" cues up,
things change radically. There's that bass authority and power I was talking about earlier. Sting's
bass line is as intense as Stuart Copeland's drum beat. And it's tight, resonant and articulate, with
lots of air around instruments in a very expansive sense of space, Sting's voice incredibly present.
David Johansen And The Harry Smith's SACD [Chesky SACD 225] is an album that held few if any
surprises since the Carissa wasn't called upon to create anything supernatural. But boy did it sound
good. It's a very well recorded SACD (sounding good in multichannel as well) with transparency in
spades. Not only did the Carissa get me up close and personal with Johansen's vocals, the bass
lines, while not unduly heavy, just oozed authenticity with rich woody resonance and all the attendant
string/neck buzz. The bluesy riffs from the acoustic guitar hung in the air like cigarette smoke in a
bar.
While I was going though my lesser listened-to SACDs, I came upon Stevie Ray Vaughn's Couldn't
Stand The Weather [Epic/Legacy ES 65871]. I'm a huge SRV fan. In my book, he's one of the best
there ever was. But his is not the kind of music that you sit, eyes closed, in front of the speakers with.
Half the time, I have to pick up my own guitar to play along, only to put it down in frustration five minutes
later - but that's another story. Imagine my surprise when I sat at the conclusion of "Stang's
Swang" to suddenly hear Stevie talking! It was then that I learned of five bonus tracks I'd never noticed
before. In more than a year of owning the disc, I'd never sat still long enough to hear it all the
way through. On this day, I apparently couldn't get enough. That's the extent of the Carissa's mesmerizing
power.
Point/Counterpoint
At the conclusion of the Audiopax Stereo 88 review, I promised to compare
the two amps in today's evaluation. Drawing distinctions between these two
very excellent performers is easy to do. Choosing which one to take home?
That'd be a whole 'nuther matter.
Both amplifiers are superbly transparent. The slight up-tilt in the Carissa's
upper mids causes differentiation from the Stereo 88 in several ways. First,
the Carissa's soundstage presentation is more up- front and intimate while
the Audiopax moves it significantly behind my speakers. The Audiopax also
throws more highly delineated images with more obvious degrees of depth,
though both go nice and deep. Soundstage focus too is a touch better with
the Brazilian. Perhaps it's the frequency response contouring, perhaps not -
but the Carissa sounds just slightly more raw and raucous through the upper
vocal range where the Audiopax merely exudes smooth refinement. Another
listener may describe the Carissa as the more aggressive of the two, the
Stereo 88 the more polite. Depending on the music being played, the scales
could tip either way for me.
I don't detect a whole lot of difference between the treble performance in
either amp. Both are first rate and I'd take their music-friendly nature and run
with it any day of the week. Down low is where the two completely diverge. I
characterized the Audiopax as being somewhat intellectual overall. The
Carissa is excitable and exciting though always in control, emotionally
charged and expressively satisfying, subjectively the more powerful and
driven of the two. I likened the bass of the Audiopax to a subtly seasoned cut
of fine Filet Mignon. By contrast, the Carissa is a thick juicy cut of Delmonico,
Pittsburgh Rare with Red-Chile Béarnaise and crispy onions on the side -
rich, flavorful and highly satisfying in a sinfully gluttonous sort of way. Yeah!

Conclusion
Readers who partook of Srajan's preview will no doubt have noticed that we seem somewhat at odds over the
Carissa's sound. Having talked with our Editor who's owned both the Art Audio Jota and PX-25, we both agree on
the likelihood that the amp's mighty 845 bottles will come into their own at a point higher into their power band than
high-efficiency speakers would ever see. In other words, the meatier, slower, thicker presentation Srajan noted -
with probably half a watt of average output level into his 103dB DUOs - caused his preference for the Jota and PX-
25. With my 95dB Sonata IIs, the Carissa put out higher power to enter a more optimal zone of current/torque delivery.
It thus rewarded me with the kind of sonics its designer intended and which I described above. This riveting
performance must have eluded Srajan on his horn speakers which never allowed the amp to get out of first gear - if
it ever even got into it.
I found the Art Audio Carissa to be one exceedingly fine amplifier. Her combination of muscular intensity and musical
finesse puts her among the very best of amplifiers I've yet used in my system. Carissa has the transparency and
intimacy I've come to expect from a good SET design and combines it with a spirited personality that's just plain fun
to be around. She may not be the most neutral amplifier in the Art Audio line but seems so deliberately voiced and
articulated that I have to think that she was not intended to be. And that works extraordinarily well for me.
PS: Dreading the day when I had to
sent the Carissa onward ho back to
its maker, I treated myself for my
birthday. If you can only have one
tube amp, the Carissa is it…
John Potis
6moons.com
The S-Word Recos: End-of-Year Syszygy or
Favorite Discoveries of 2003 by 6moons’ Merry Knaves
The Art Audio Carissa 845 SET tube amplifier received a 6moons Blue Moon Award for
''Refinement, Fun & Raw Drive" in the SET amplifier category. It's an important amplifier
that forever banishes the notion that SET amplifiers are refined but wimpy, tasty but for
sophisticated connoisseurs only. Not. SET amplifiers no longer are only for those who
value midrange transparency and liquidity at the expense of the opposing ends of the
spectrum.
Even more importantly, the Carissa has the power and drive to make it appropriate with
speakers previously not considered optimum matches with a relatively low-power SET
amplifier. With the Carissa, you can have it all.
John Potis
6moons.com
32 Briarwood Rd.
Cranston, RI 02920
USA
401.826.8286
www.artaudio.com
Reprinted by permission of publisher, of John Potis’ original September 2003 review on 6moons.com