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A short history of the "Tube-T Amp" hybrid Tube / Class T integrated amplifier

The Tube-T is a complex product that actually took almost one year to develop. It's the result of the original dream to merge the quality and sound of tubes with a Class T output stage.

Class T power amplifiers are clearly a breakthrough innovation in the audio world. After decades of alternative choices ranging from high quality with low efficiency (Class A) to high efficiency with low quality (Class D), Tripath's "Class T" brings us the best of both worlds: a simple power efficient power stage that exhibits the refined behaviour of "high end" amplifier systems.

Is it the ultimate amplifier ever?

Obviously not, but it's clearly unbeatable for the price. Initially only a few people recognized that, now thousands of audiophiles are convinced that a "Class T" amp is the best way to get "hi-end sound" with a budget compatible with your pocket. The original "T-Amp" is clearly only a starting point. Developed for mass markets, it compromises on everything (case, parts, heatsink ...) in the name of low price. We can go a long way from it, and our "Class T" amps are here to state that. Higher quality parts, starting from the condensers to the output inductors, really bring a giant step further. Our "air core" inductors really change completely the sound, already giving you a "tube-like" audio reproduction that is simply wonderful.

Is it possible to do even better?

Well of course. Records only exist to be surpassed one day.
In our case we were convinced since the beginning that to further improve the "Class T" sound the only way to go was to merge the best from both old and new audio technologies: joining a tube preamp with a Class T output stage. The Class T amplifiers have a very good sound, yet a tube preamp allows a vast improvement of it: the "warmth" of the tubes is easy to recognize, it adds a bit of three-dimensionality to voices and instruments and really involve completely the listener in the sound.

The development of the "Tube-T"

Marrying the tube preamp with the Class T power amp was no easy task. We wanted also to create a very stable product, so completely stabilized power supplies were included for both the tube and the output chip. A headphone out was requested by some people who saw the first images of the prototypes ... and as a final touch we desired to fit all of that inside a small package (power efficiency allows for that). After much experimentation, prototypes and exchanging of tubes and parts (see the picture on the right, an early version), the "Tube-T" line of amplifiers was born.

The "Tube-T" PCB board is quite complex with respect to plain "Class T" amplifiers. We have the tube and all the associated power supply circuitry, plus an oversized supply for the power chip and further add-ons like a "Class A" headphone driver.

The "Tube-T" incorporates our "dual tube socket" technology, which allows to assemble an Octal or Noval socket on the PCB, to configure the supply for the filament as 6.3 or 12.6 Vdc (stabilized, of course ...) and to route it to the appropriate pins of the tube just by configuring a few jumpers. We actually offer two major versions (with an Octal 6SL7 tube, or with a noval Ecc82 tube, the one in the picture. Actually almost any "signal" tube can be used and configured by simply setting up a few jumpers.

Tube T 2020: some technical details

Tube preamplifier based on ECC82 or 6SL7 tube
Completely stabilized "virtual battery" anode supply, with soft start
DC power supply for filaments: no hum at all
High quality ALPS RK27 volume control
Mosfet buffer stage between the tube and the power amp chip
Power amp based on the Tripath TA2020 chip (the one used in the "Class T" amp kit and Class T 2020 amplifier)
Fully stabilized 5A power supply for the power stages
Air core inductors in the output stage
Class A Mosfet based Headphone output
Very small footprint: only 16 x 10 cm. Low height, can be assembled to fit in one rack unit (with the tube coming out on top).

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