Listening
Tests And Performance
With three 2X150VT units
on hand, I dedicated one to the stereo front pair, another to the surround
pair, and the third for powering the center and back surround channels.
Listening source material consisted of various music CDs, DTS CDs, and DVD
movie soundtracks. The CAL CL-2500 DVD-Video player served as the
playback unit, operating through the EAD TheaterMaster Ovation surround
processor. The 2X150VTs fed the James Loudspeaker system. I also performed a
comparison, using the front channels, to the Proceed HPA3 power amplifier which
I normally use as a reference.
During tests with two-channel
music, it wasn't difficult to notice one of the standout signatures of the
sound produced by this amplifier. There was a definite sense of three-dimensionality,
a palpable, compelling perception of "air," or atmosphere, from the
sound I was hearing. I like to describe the audio images imparted by this
amplifier as instruments, voices, etc., floating in air, sometime even seeming
to breathe. Such an attribute particularly brought out the ambiance of certain
symphonic recordings. For example, a solo violin session of a concerto
performance had a distinct spatial character, for which its presence and the
concert hall reverberation imaged into the room convincingly.
Sovtek 6922 Dual Triode Tube
The 2X150VT therefore
certainly imparted a sense of warmth, owing to its spatial, lively sonic
character. It also produced a sound that could be characterized as smooth, for
which human voices and instruments seemed tonally rich, with also a slight
sense of softness in the upper-midrange. Low level detail was absolutely
noteworthy, as well as their spatial placement within the three-dimensional
listening space. Also, the performance of the 2X150VT during transient moments
was remarkable, reproducing with particular poignancy. Much of these sonic
attributes seem to be comparable to what would be expected from a tube-based
amplifier.
In the low-end, the
amplifier registered low frequencies with a notable sense of harmonic depth and
detail. Bass response also seemed a bit liberal in nature, giving on one hand,
for example, the lowest notes of the string ensemble of an orchestra a distinct
sense of gusto and authority. At other times, the low-end sounded a
little loose, and with a bit more mid-bass rendering than what I was
accustomed to.
With surround sound
music, the 2X150VTs performed admirably, again delivering that palatable sense
of three-dimensionality, this time all around you. This was especially
the case for certain DTS music CDs, particularly those of light jazz
performances with an abundance of atmospheric surround envelopment. And for
movie soundtracks, I found very little, if anything, to fault the performance
of these amplifiers for such a purpose.
Reproduction of dynamic range was excellent, and
the aforementioned slight softness in the upper midrange can be a beneficial
factor in helping to offset the occasionally strident nature of movie
soundtracks. The 2X150VT also produced peak sound pressure
levels authoritatively, and the low-end with gutsy slam and impact, such
as during the avalanche sequences in Vertical Limit.
But again, the
characteristic sense of air" created by these amplifiers proved their
worthiness with movie soundtracks, such as those for Unbreakable and Thirteen
Days. For both of these movies,
there's a remarkable sense of spatial depth and envelopment that the complement
of 2X150VT’s seemed to bring out with uncanniness. Unbreakable's textured details with
atmospheric sound effects, and the spacious, layered music score for Thirteen Days were both rendered into
the listening space with articulation and a somewhat unique, but certainly
convincing holosonic perception.
When compared to the
Proceed HPA3, the 2X150VT performed notably well, though there
were some subtle, albeit discernable, distinctions to be noted. The Proceed's
ability to render longitudinal depth with sonic imaging wasn't quite as
compelling as the SMART amplifier. However, I felt that lateral imaging was
slightly more focused with the Proceed. The HPAS’s upper-midrange rendering
also sounded a bit more open to me. Additionally, the low end response seemed a
little tighter, and I slightly preferred the Proceed's capability to control
the mid-bass region. It should be noted that such observed differences
are likely to at least partially result from the fact that the HPA3 uses
bipolar transistors for its output stage, as opposed to MOSFET’s for the SMART
unit. Bipolars are known to have different sonic characteristics than MOSFETS,
and the number of MOSFET devices used can be an important factor in an
amplifier's ability to control the low-end.
Conclusion
For its price, the SMART 2X150VT faces some
considerable competition from the likes of Theta Digital, California Audio
Labs, and others. Nonetheless, this is an amplifier that seems to distinguish
itself from the rest of the pack, for offering sound that is warm and smooth, with pleasing, engaging three
dimensional depth. It also offers excellent home theatre performance, with
dynamic range and transient performance that should certainly impress. This is
a unit that I believe will particularly appeal to fans of tube-based
components, who are looking for a suitable complement of amplification for
their home theatre systems, to deliver the sound they know and cherish. From
that perspective, considering the high price of tube-based amplifiers,
these SMART amplifiers could be a very attractive bargain.
SMART Theatre Systems 2X150VT
Tube/MOSFET Hybrid Power Amplifier
Inputs: Two Line-Level,
Gold-Plated RCA
Outputs: Two
Speaker-Level, Five-Way, GoldPlated Binding
Posts
Rated Power Output: 150 Watts Into 8 Ohms, 240 Watts Into 4 Ohms, 500 Watts Into 8 Ohm (Bridged)
Distortion: Less
than 0.25% THD+N At 1 kHz,
(Measured At 150
Watts Into 8 Ohms)
Frequency Response:
10 Hz-20 kHz (+/0.15dB), -0.5dB
At 60 kHz, -1.2dB At 100 kHz
Signal-To-Noise Ratio: Greater Than 100dB At Full Output
Channel Separation: Greater Than 60dB From 10 Hz-20 kHz
Dimensions (WHD
Inches): 15.75 x 5.75 x 10.
Weight: 23 Pounds
Price: $2,250
Manufactured In The
U.S.A. By:
SMART Devices, Inc.
5945 Peachtree Corners
East
Norcross, Georgia 30071
Tel: 770 449 6698 / Fax:
770 449 6728
www.smart-cinema.com
Reference System For Reviews
Enlightened Audio Designs TheaterMaster Ovation Surround
Processor
Parasound", CSE 6.1 Circle Surround* Back Surround Decoder
James Loudspeaker Grand Symphonic 10 (Front Left And Right),
Symphonic 8.2 C (Center)
Symphonic 8.2 SIR (Left, Right, And Back Surround), 10 S
Subwoofer
Proceed' HPA3 Power Amplifier (Front Left, Center, And Right)
Adcom GFA-7000 Power Amplifier (Left, Right, And Back Surround)
California Audio
Labs CL-2500 DVD-Video Player
Sony' KV36XBR400
Trinitron WEGA Monitor
AudioQuest
Gibraltar And CV-4 Speaker Cables
AudioQuest Viper
And Diamondback Interconnects
SMR Cable Max 1
Digital Interconnect
Power Wedge 11 And
1118 Line Conditioners
