The Tigris™

Headphone Amplifier from the makers of the world- famous MESA/Boogies® and the highly acclaimed MESA® BARON™.

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 and choosing an integrated design.

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 

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 BARON's 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 biasof 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. 

Download the User Manual for complete details on this product.