T+A’s HV-series first appeared in 2013, and was based on thirty years of experience in the development and construction of first-class transistor amplifiers and valve devices. The series incorporates a revolutionary concept combining the sonic and technical advantages of both technologies, at the same time avoiding the inherent disadvantages of present-day tubes. The HV = High Voltage technology is employed in the amplifier stages of all the machines in this series, and is the secret behind their outstanding performance and sound quality. The source devices of the same series are just as uncompromising and superb as the amplifiers. They represent absolutely the highest level in the processing and reproduction of all digital sources.

Design Philosophy

The HV-series is the true embodiment of the original meaning of the term ‘high-end’: innovative technologies, uncompromising construction and absolutely peak performance.

For the HV-series T+A developed a whole raft of unique and superior technologies which are available exclusively to T+A: amplifier stages work at very high voltages, and are therefore inherently more linear in character than conventional circuits; the players feature separate high-performance converters for PCM and DSD, digital and analogue signal processing are kept consistently separate from each other, and specific subassemblies are galvanically isolated. All devices are fully channel-separate and designed on the double-mono principle. They are of entirely discrete construction, without operational amplifiers (op-amps). Amplifier output is more than 500 Watt per channel. The mechanical construction of all cases is extremely sophisticated, based on an internal framework of 10 mm thick machined aluminum plates. All case components are manufactured from pure aluminum, some of them machined from the solid. Absolutely no ferro-magnetic components are used.

The Power Amplifier

The A 3000 HV is the ideal power amplifier and complement to the P 3000 HV pre-amplifier. It is designed as a stereo power amplifier, but can also be configured to work in mono mode, in which guise it is capable of delivering twice the current and in which it doubles the pure Class-A mode. Thanks to HV technology, this powerhouse offers superb sound characteristics as well as incredible power and performance: a standard which is unsurpassed even by much more expensive amplifiers. The principle of splitting a High-End system into separate pre-amplifier and power amplifier gave our development team the opportunity to implement the finest possible circuit designs and technologies without having to take into account space considerations and case restrictions. This applies both to the electronic components and the mechanical design of the case, since – if the aim is to attain the best possible sound – a preamplifier’s requirements are fundamentally different from those of an power amplifier: preamplifiers process relatively small signals, and the crucial aspect of their design is the avoidance of induced and other interference; power amplifier, on the other hand, have to cope with relatively large signals, and the stability of the power supply, its current delivery capacity and performance independent of load are much more important.

The Case Compartment

The entire electronic power circuit with output stages and mains power supply is housed in its own shielded compartment in the underside of the machine. The dividing wall between top and bottom sections is 10 mm thick and – of course – is also made of aluminium. Voltage amplification and current amplification circuitry is housed on separate circuit boards in separate case sections, in order to prevent mutual interaction. The sophistication of the design does not stop there, as we have even provided galvanic separation between the two. Thanks to this uncompromising design philosophy there is absolutely no feedback of the loudspeaker currents into the voltage amplifier stages, and complete freedom from loudspeaker loading effects.

Amplifier Section

The voltage amplifier is an extremely linear, broad-band, cross-coupled differential cascode amplifier, followed by a single-ended Class A large signal stage which provides superb sound quality.

The fully symmetrical current amplifier stage (output stage) is fitted with MOSFET drivers and the latest “thermal tracking” bi-polar output transistors; this combination delivers a very harmonious audiophile sound image combined with tremendous current delivery capacity. The output stage transistors feature integral temperature monitor diodes which we use to maintain the power transistors at an absolutely constant operating point, regardless of temperature, allowing us to control the circuit’s distortion behaviour perfectly, regardless of the momentary load. By maintaining full symmetry in the arrangement of all conductors in the output stages, speaker cables and mains power supply we have succeeded in providing complete compensation for all signal currents. The net result is a complete lack of magnetic stray fields, and no electromagnetic
feedback into the input stages.

The Speaker Terminals

The enormous power of the power amplifier calls for particularly high-quality, stable loudspeaker terminals; they are machined from solid pure brass and rhodium-plated on every surface. Rhodium is the perfect contact material: as conductive as silver, as durable as platinum, as corrosion-resistant as gold (and unfortunately as expensive as all three put together).
For the most exacting requirements a further option exists for improving the quality of the voltage and current supply: this is the PS 3000 HV supplementary mains unit.

Specifications

All measurements at 120 / 240 V mains voltage

Power bandwith1 Hz – 150 kHz