Virtue Audio's Dodd Modified Sensation M451 Integrated Amplifier
Hearing Is Believing
Review By Ron Nagle
Audio story should not be told outside the framework of one other company, and
that is Tripath Technology Inc. located in San Jose California. Founded in 1995
by Adya S. Tripathi, Tripath Technology is a semiconductor company that develops
designs and markets integrated circuit devices. Tripath markets their IC chips,
or chipsets for use in products made by other companies. The Tripath chip is
referred to as a "Class T" amplifier; it is a variant implementation of a "Class
D" Digital Amplifier. The Tripath Company redesigned the IC digital control
functions to increase efficiency and improve the quality of audio amplification.
One of their amplifiers, the TA 2020 was named one of the twenty five chips that
shook the world by the IEEE Spectrum Magazine. "Class T" is a registered
trademark of Tripath Technology Inc.
Virtue Audio was founded in 2005 by Seth Krinsky.
Mr. Krinsky knew that Tripath the digital chipmaker was in the process of filing
for reorganization under chapter 11. The Bankruptcy filing became a reality on
February 8, 2007. The visionary Mr. Krinsky subsequently purchased a large
inventory of Tripath Chips even though at that time he did not have an amplifier
that could use them. As of now Mr. Krinsky owns approximately 50,000 Tripath
chipsets. Finally, as reported by Bloomberg Business Week, on April 22, 2008
Etelos Inc. an IP provider acquired Tripath Technology in a reverse merger
transaction. Subsequently Cirrus logic purchased the Tripath intellectual
Property from Etelos in an auction for about $3 Million Dollars but did not
produce a high power chipset.
Virtue Audio made their first public appearance at the
Rocky Mountain Audio Fest in
Denver, which was October 10, 2008. I remember seeing their colorful
amplifier the Virtue 1, base price $249 in room 2032 at the Marriott Tech
Center. The Virtue 1 used the Tripath TC2000 and TP2051 chipsets in a dual mono
configuration. The following year, January 2009 they exhibited the Virtue 1 and
the up scaled Virtue 2 at The Home Entertainment Show in Las Vegas. I visited
them that year in Las Vegas; they were at the Alexis Park Hotel in two rooms,
1703 and 1510. It was in room 1510 that I heard these diminutive amplifiers
driving the $21,000 Clairaudient line source speakers.
On a personal note, about two and a half years ago I
attended a Rave Meeting
of the AudioCircles.com, the New York City audiophile group. At this meeting,
they conducted a "digital shoot out" of equipment that members owned and brought
to the meeting. That day the Rave
audiophile attendees auditioned and quickly dismissed a new and popular ICE
powered line amplifier that I had brought with me to the meeting. What was most
noteworthy at this meeting was the apparent differences between the Class D ICE
implemented digital technology developed by Bang and Olufsen and some of the
Tripath based components. Most of the Tripath based amplifiers brought to that
meeting sounded far more natural at the treble frequencies and exhibited fewer
My position regarding digital amplifiers is that
there should be made a broader classification of amplified sound. It would not
just include classic tube or solid state sound qualities but a third very
characteristic digital depiction of music.
The New Sensation
This article is the first formal Web Magazine review
of the modified Virtue Audio Sensation M451 amplifier equipped with the new Dodd
Audio Tube Buffer. The original Sensation amplifier has been around since early
2010. Engineer Micheal Mardis did the initial design work. Virtue Audio along
with the talented Gary Dodd has never stopped working to improve their
amplifiers. What really grabs my attention is the esthetic choices of wood grain
covers (the review sample has a zebra wood veneer top) and the room matching mix
of red, blue, yellow and green side panels and button colors. The basic
Sensation amplifier has a $799 list price.
The Virtue Audio web site is a testament to the
meaning of the word innovation. I will not even attempt to detail all of the
possible circuit upgrade options and interactive design it your self color
combinations available on this website. You really should visit this audio
freaks fantasy fun Web site and see it for yourself. Additionally the Dodd Audio
tube buffer may be purchased separately as a kit upgrade. It is possible to
purchase the basic no frills Sensation amplifier and latter on add improvements
when you can afford them.
M 451 Nomenclature
My review sample is finished in basic black anodized
aluminum. This is also true for the large motor driven Alps volume control knob,
positioned dead center of the front panel. To the right of that is a cool input
push button, each actuation of this button steps/selects one of the three
line level input's. The selected input is shown by one of three front panel blue
LED's. The left side panel has another intuitive multifunction power switch.
This push button power switch is labeled, Protect, Standby and On/Off, again one
of three blue LEDs will tell you which function is active. This amplifier comes
equipped with a remote control. The rear panel has a small on/off rocker switch;
this will switch power into the control amplifier from a separate outboard power
supply. The power supply connects to the amplifier with an umbilical cord and a
four pin DIN style plug. There is a selection of power supplies you could use
with the M451 amplifier. The basic switching power supply that comes with the
amplifier is rated at 24 volts and 65 watts. At additional cost, there is the 30
Volts at 90 watts power supply. And the next largest separate linear power
supply is specified at 30 volts and 130 watts and costs $149.
My test sample
came with the JT 130 watt transformer power supply capable of delivering 100
amperes. The JT 130 power supply option will add $249 Dollars to the price. The
last optional power supply is pure DC and sourced from a rechargeable battery.
This battery supply is made by Dodd Audio and the price is $149, you can find it
on the Virtue web site. The stock Sensation M 451 power amplifier is rated at 87
watts per channel and can deliver a maximum of 7 Amperes under load. Respectable
specs even so it will not adequately drive a few of the more inefficient
speakers made for the high-end market.
The back of the amplifier has nine RCA female
jacks. Three pairs of jacks are inputs for the three line level sources. Two are
left and right Pre-out and the last RCA connection is for a center channel mono
subwoofer. I did not use the subwoofer out for this two channel review. A very
nice feature is the Propeller style speaker binding posts. These Propeller
binding posts make it very easy to secure your speaker cables.
The Best Is Last
My sample M 451 came supplied with the Dodd Audio tube
buffer and a JJ branded ECC 803S/12AX7 tube. There is much more audiophile fun
and madness in store when you start tube rolling the Buffer circuit. The tube
filament / heater supply is 12 Volts so you may substitute most any dual triode
9 pin tube that uses a 12 Volt heater. The top of the amplifier can slide open
giving you access to a switch that will remove the Buffer from the amplifier
circuits. And because of this It is possible to do a quick A/B comparison with
the tube switched in or out. If you do swap tubes, the amplifiers sound will
change and take on the characteristics of the tube you substitute into the
Buffer circuit. This feature is a tube tweakers dream. Additionally the Tube
Buffer circuit may be added post purchase to the M 451 as a $300 upgrade. The
Owner's Manual contains a long list of substitutable tube types.
Hearing Is Believing
Like most amplifiers (albeit very quickly) when first
turned on it takes an interval of playing time for a burned in M 451 to properly
hum a tune. The manufacturer advises running the amplifier for a hundred hours
to fully burn it in. Under normal operating conditions the Sensation runs
unusually warm for a digital amplifier. Having said that, I'll have to describe
the amplifiers sound two ways: tube in
and tube out. The easiest thing to do is tell you that with the
tube buffer switched out it is one
of the best digital amplifiers I have ever heard. It is fast, clean, and free of
the cold grainy treble and the characteristically elevated bass response of
other digital amplifiers.
With The Tube Switched Out
Listening to the Clarity Cable CD track 14, Take The
Long Way Home by Supertramp. This is a multi track cut with a ton of
studio reverb that is fast punchy and full of rock and roll excitement. This
style of Rock and Roll is a good match for the Sensations digital sound. With
long term listening you will find there is vanishing digital grain riding on the
musical fundamentals. Bottom line, if you know what a classic transistor-based
Class A/B amplifier sounds like, than you know ninety five percent of the
Sensation M451 Triamp sound.
With The Tube Switched In
The first half second of listening your brain shouts,
something is missing! But rapidly the reasoning hemisphere of your noodle
cuts in and you realize you can better relate to what you are hearing. When you
switch in the tube buffer with the JJ ECC 803S, the sound you hear is a
softening of transient attack. This is most noticeable at higher frequencies but
in actuality, it affects all frequencies. However, the trade off, if you can
call it that, is a richer harmonic envelope encapsulating all the individual
components of the music. This effectively paints everything into a more
realistic and dimensional sound space. The next ear test is the Clarity Cable
CD, track 2, Peggy Lee singing "Fever". Wonderful song wonderful
artist wonderful way too listen to the sound of my primary reference, a human
The gestalt is this, when Peggy pauses to take a
breath, so do you, when Peggy's phrasing sounds suggestive, she is really coming
on to you. That's the Audiophile way it should be, she's speaking directly to
you and drawing you deeper into the performance. The Tube Buffer brings out the
human warmth in her voice and now any possible digital graininess is banished.
Curiosity compelled me to roll yet another tube; it was a new Sovtek 12AX7WA.
Bottom line, a bit different sound but not a
better sound. The Sovtek opened up the top/treble with more extension and speed
but at the other end of the spectrum the bass frequencies dried up what reviewer
geeks like to call, sustain. With a borrowed supply of tubes from my audiophile
friend, Paul Mah, I launched into a tube swapping frenzy. The differing
qualities of the tubes are too numerous to include in this report. Suffice it to
say most of the differences in the tubes sound are subtle. But still this
difference is important to an audiophile seeking the very last ounce of
believability. Seven tubes later, I found my favorite dynamic "Class A"
KT88 tube amplifier sound was contained within a vintage British Mullard 12AU7.
The Dodd Audio, Virtue Audio Sensation M 451 is an
advance in digital design that finally bridges the gap that existed between
digital and tube and solid-state amplifiers. It seems evident to me that no
matter what type of music you enjoy be it classical, jazz, or rock you now have
options at your fingertips.
However Audiopals be aware that not all Tripath
based amplifiers are the same, as there can be vast differences. The Tripath IC
is only a building block, a starting point for a circuit design. Therefore, the
Sensations M451 performance can only be attributable to Seth Krinsky and his
team collaboration with talented designers. A musical component such as this is
hardly ever seen with so many options and so many features. Indeed, there is so
much going on that it will take time before this perfectionist writer runs out
of fun things to try. I'm going to get me a Sensation M 451 even though I
already have three amplifiers. All factors in place, the reasonable start up
price, the performance the impressively solid construction and a thirty day no
fault trial period means the Sensation M451 garners my rare recommendation to
"The true world of the Audiophile is not static it is a constant quest for all the things that reach inside of you and touch your emotions."
As always, Semper Hi-Fi
Source Components: Marantz DV8400 Universal CD player,
Cambridge Audio Discmagic-1 CD transport, Cambridge S-700 Isomagic HDCD D/A
Converter, ART DI/O Up sampling D/A and A/D processor, Magnum Dynalab FT 101a
tuner and Dynalab Signal Sleuth.
Speakers: Aurum Cantus SES 2, Fritz Audio Carbon 7 monitors.
Power Conditioning: Richard Gray
20 ampere Substation, Islatrol Industrial 20amp ac line conditioner, Alpha Core
Balanced Transformer Power Supply, Audio Power PE-1 power enhancer, Triad
2-ampere isolation transformer
Accessories: VPI Magic bricks, Argent
Room Lens system, Room Tunes Panels, a comfortable chair