Integrated
& Headphone Amplifier from the makers of the world- famous
Mesa/Boogies and the highly acclaimed Mesa BARON.
The TIGRIS
Integrated and Headphone Amplifier is our second foray into
the audiophile arena. With it, we have brought the benchmark
performance of our Mesa BARON to a wider audience -
by reducing available power output to realistic levels, choosing
an integrated design and setting final retail at US$ 2,495.00.
The TIGRIS offers four single-ended line level inputs, one
fixed output and one single-ended variable output with dedicated
attenuator. The master volume control is of the continuously
variable design. Massive gold-plated TIFF 4-way binding posts
allow proper tightening of spade connectors with a wrench.
Both 4- and 8-ohm taps are provided. The removable tube cover
is standard, not optional. The TIGRIS is available in two
colors, champagne gold and silver. All tubes are computer-tested
and matched and carry a six months warranty. Tube sockets
are ceramic, resistors are 1% metal film, and three ounce
copper traces on epoxy boards are used in conjunction with
hand-soldered point-to-point flying leads construction.
Unique
to integrated amplifiers is our patent-pending Tandem State
Imaging. What is Tandem State Imaging?
It is a foregone conclusion amongst audiophiles sensitive
to tube amplification that the choice of power tubes,
their type and origin, will significantly impact the
sound of the component. Direct-heated triodes, tetrodes,
pentodes all have unique  "sonic
signatures", and audiophiles have favorites based
on listening preferences and personal theories. A few
of the expensive tube amps allow the end user to switch
between pentode/triode or tetrode/triode operation.
But it's an either-or scenario. And that's where Tandem
State Imaging differs. Envision an animal- or plant
breeder who cross-breeds to combine desirable traits
of two or more species into a new hybrid: Tandem State
Imaging allows the end user to combine varying amounts
of pentode/triode operation simultaneously, effectively
creating a sonic hybrid. This hybrid blends the harmonic
rightness of triode operation with the dynamics and
frequency extension of pentode operation. The following
characteristics are of note:
- Midrange
lushness and bass slam.
- Transparency
plus soundstage depth & width.
- Control
with finesse.
-
"Solid state" tightness and "tube-like"
warmth...
Astute
audio critics have repeatedly stated in print that Tandem
State Imaging in the BARON achieves an uncommon performance
quality, seemingly neither solid-state nor traditional tube,
but rather... musical. This validates our design goal: to
build musical instrument quality amplifiers.
Pioneered
in the Mesa BARON, Tandem State Imaging has also been
implemented in the TIGRIS. The reason it works is the
pin configuration of the power tubes, 5881s in the BARON,
EL84s and 6V6s in the TIGRIS. These tubes can be wired
for pentode or triode operation. By arranging them in
pairs and assigning operational  modes
for individual pairs via a selector, the amplifier literally
assumes a different mode when the appropriate switches
are engaged, altering tonal and soundstagingcharacteristics.
Pentode operation demonstrably widens the soundstage
and creates a front row perspective, while increased
triode activity reduces stage width and assumes a 10th
row perception. Because these imaging characteristics
are the most obvious effects of this flexibility, we
call it Tandem State Imaging. But discerning listeners
will also notice an associated change of tonal character,
dynamics and the emphasis shift toward the midrange
which results from higher triode participation.
The
TIGRIS is a push-pull design, utilizing 6 power tubes per
channel, arranged in 2 rows of three, each row amplifying
one half of the wave form .
The tubes are wired in pairs into one each of the three positions
of the front-mounted triode/pentode toggle switch. The three
possible switch positions thus correspond to:
- All
three pairs wired in pentode (35 W/Ch),
- 2 x
EL84s & 2 x 6V6s in pentode / 2 x EL84s in triode (28
W/Ch)
- 2
x EL 84s & 2 x 6V6s in triode / 2 x EL 84s in pentode
(20W/Ch).
Tandem State Imaging also includes a four-position
adjustable negative feedback selector. Varying amounts
of feedback (including zero feedback) will affect the
amp-speaker interface and the amp's behaviour at the
frequency extremes. The zero-feedback provision shows
clearly that in the TIGRIS, very moderate feedback is
merely applied as a tuning option rather than as band-aid
to hide the shortcomings of a poor design. User-adjustable
feedback increases the ability to properly mate the
amplifier with the speakers and the listening environment.
Fine-tuning feedback and the Tandem State Imaging variables
- all of which is possible during the performance -
allows the listener to select what sounds best to him
or her. This choice might be affected by mood, time
of day, company, or the type of music.
A quick mathematical survey will count 12 possible combinations
between pentode/triode operation and negative feedback intensity.
This allows unprecedented control over the system's sonics,
and although comprehensive, is of ultimate simplicity in use.
A flick of a switch, the turning of a knob - it's literally
that easy to experiment with these tuning options, and may
be done without interrupting playback.
From the BARONīs warranty cards we have learned that most
owners settle on one very definite setting that sounds best
to them most of the time, and to a lesser extent use one secondary
setting for certain occasions or music. Interestingly, and
proving the value of such flexibility, one person's favorite
setting is another one's least used. We also have reports
on file where due to a move or redecoration, a system environment
changed, and with it the favorite setting. Tandem State Imaging
thus also becomes an insurance policy against obsolescence.
Returning
briefly to the power tubes of the TIGRIS, it becomes evident
that here, too, we have chosen a combination of tubes, marrying
characteristics of two different types of tubes in a predetermined
2:1 ratio, 4 x EL84s plus 2 x 6V6s per channel. The hybrid
principle of blending characteristics of two different "species"
- as with Tandem State Imaging - is again successfully employed.
(In the Baron, a further example of this principle resulted
in using standard copper hook-up wire with hyper-expensive
Yamamura litz wire in parallel on the input-to-board leads).
The 6V6 tube is known for its prodigious bass power and warmth,
whereas the EL84 excels with dynamics and a lively, airy presentation.
Combined, the performance now features the sum total of these
qualities - impossible with all EL84s or 6V6s.
This attention to detail expresses our main design objective
for the TIGRIS : performance. Performance available not only
within the special confines of the sophisticated retailer
who knows how to "trick out" a system to offer spectacular
results, but performance that can readily be dialed in by
the consumer, by ear, and does not require prior exposure
to High-End audio - only a willingness to listen for easily
discernible differences and deciding on a favorite setting.
Another novelty in the TIGRIS is its convertible nature:
it is both an Integrated amp and a dedicated headphone amplifier.
It links the headphone jack to the entire array of output
tubes. Conventionally, a designer will drive the headphones
from the preamp stage or an IC-based opamp. The TIGRIS connects
the speaker outputs to the headphone jack though a load-resistor.
This makes Class A output power and Tandem State Imaging an
integral part of the headphone listening experience. To implement
this dual application of the output stage required an extraordinarily
low-noise power supply and sophisticated earthing arrangements
to reduce background noise to levels utterly inaudible even
over electrostatic headphones.
Whenever
the headphone selector is engaged, the TIGRIS literally converts
into a headphone amplifier of absolute reference caliber!
The TIGRIS offers in-built expansion options via a "Preamp"
output with dedicated attenuator. Avoiding the customary
pre-out/main-in jumper port, this output allows bi-amping
without external crossover, using the level set attenuator
to balance output levels of the second amplifier. This output
also accomodates active subwoofers and surround sound processors.
The Preamp output retains Tandem State Imaging which
avoids secondary adjustments of the level set control in bi-amp
scenarios when the TIGRIS changes output levels due to pentode/triode
switching.
Auto-bias circuitry frees the end user from manually monitoring
the bias of the tubes and adjusting bias and balance via
trimpots and meters. Cathode-biasing continually self-adjusts
the circuitry to account for tube drift and aging. This appeals
to listeners who would be discouraged if asked to perform
screwdriver adjustments on their audio gear to insure optimal
operation.
To remove the effects of thermal stabilization (i.e.
an amplifier, tube or solid state, will sound better after
hours of use than started up cold), the TIGRIS offers standby
operation which is selected with the front-mounted warm/operate
switches. The separate AC on/off switch encourages permanent
on-status, verified up front by the dimly-lit LEDs. Upon switching
from "warm" to "operate", the LEDs light
up brightly, and the amp is operational instantly, eliminating
any warm-up period. The highly reduced Hv to the tubes in
the "warm" position also lengthens tube and component
life by eliminating turn-on voltage fluctuations.
For added convenience and low noise operation, the TIGRIS
is equipped with a grounding switch. While the chassis always
remains grounded to the AC mains, signal ground may either
be coupled to chassis ground or floated. Potential ground-loop
induced hum can thus easily be removed without the use of
three-to-two prong adaptors (cheater plugs).
Finally, there is True Class A operation. Countless
technical white papers have extolled the virtues of full Class
A operation in audiophile power amplifiers. Many high-profile
manufacturers are dedicated exclusively to this design approach.
It thus seems unnecessary here to go into a full discussion
of the merits of Class A design. Let's just say that it nearly
always amounts to a higher-priced endeavor, or is limited
to very low-powered, single-ended triode tube designs.
With the TIGRIS, we have brought the sonic benefits
of True Class A operation into the affordable realm, and combined
it with enough real drive capability to mate well with the
majority of available speakers. Even though single-ended triode
designs have many adherents, it limits the choice of speakers
and program material to super-efficient, often horn-loaded
designs or dynamically restricted music that favors the midrange.
The push-pull circuitry of the TIGRIS offers true bass extension
and realistic high frequencies, dynamic fortitude and the
harmonic lushness for which triode amplifiers are justly famous
for. It further includes our patent-pending Tandem State Imaging,
a world-class headphone output, a tube cover, two available
color schemes, a three year parts and labor warranty, a six
months guarantee on tubes, and allows the original owner access
to complete retube kits for less than US$100.
Look
for new review on the Tigris in SoundStage!
To arrange
for an audition, contact us for the name of your closest dealer.
Mesa
Engineering Vacuum Tube Audio
1317 Ross Street
Petaluma, CA 94954 USA
Phone 707-778-9505 Fax 707-765-1503
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