ASV Tube Amplifier TA-80

It is the fact that the design of audio components has been going back to the tradition, to what was once discarded as obsolete, of course in a more developed in modernized forms. The question is why? Why should old and maybe obsolete designs be revitalized and redesigned? Why should long forgotten vacuum tubes be used again in high quality audio components?
It should be admitted too, that interest for audio components with tubes has never really died. During the period of absolute reign of transistors, ICs, hybrids, mass robotized production of audio components, a significant number of audio fans remained devoted to the old-fashioned and unique and perhaps exotic atmosphere created by the glow of tubes.
Several manufacturers have never discontinued this tradition, and many new ones are entering the market.
A special acknowledgment for the revival of tubes is to be paid to Japanese designer Hiraga who earned international recognition and acclaim. He has designed unique tubeamps noted for their

simplicity and minimum number of components employed.
It should also be noted that the quality of all audio components has improved significantly. There is a great supply and choice of high quality and good value audio components, e.g.: CD players, record players, tuners, loudspeakers, etc.
The availability of naturally recorded CDs and analog records is increasing too. All these components have brought about a significant development and improvements in the audio field.
It is the fact that tube amps differ from the semiconductor ones considerably as far as sound handling is concerned. They provide a particular, warmer sound which is so highly appreciated by audiophiles all over the world.
There is no uniform answer to the question "Why" asked at the beginning. It shall have to be answered by each audiophile individually. We have spent years looking for the answer to this rather rhetorical question. And the answer is here in front of you. We shall be most pleased to share it with audiophiles - prospective buyers of our tube amp.

The concept

The integrated tube amp ASV TA-80 is at your disposal. It is the result of years of careful and persistent development and design. There have been no compromises in achieving ultimate quality. The ASV TA-80 has been designed as a dual mono block fitted in the same housing containing two power stages, two power supplies and a passive pre-amplifier stage with inputs for CD, Tuner and Tape, and a REC output, a high-quality input switcher and a stereo potentiometer. Thanking to a relatively high level of input sensitivity no separate pre-amplifier is needed, except for MM or MC heads.
The housing is made of a quality varnished steel sheet. Label plates have a champagne gold finish. Large brass feet and circular array of tubes on top panel all together contribute to an overall elegant outlook of the tubeamp. Optionally the label plates can be gold plated, while the two output transformers housings can be chrome plated.
Rear panel is fitted with terminals and measuring points. On the right side panel there are the stand-by and power switches.

The circuit

All components built in the ASV TA-80 have been carefully selected: polypropylene capacitors, metal film resistors, ceramic tube sockets, toroid power transformers, high quality electrolytics. In the basic design the principles of Williamson topology have been followed. As active components in the input and the driver phase-splitter stage dual triodes ECC 81 (12AT7) are used. In the power stage the EL 34 pentodes (6CA7) are used. They work in the push-pull AB1 configuration with a high quality double C cores output transformer. The output tubes (pentodes) work under fixed but adjustable bias for each tube separately. The bias for AB1 class is adjustable through trimmer pots located near tube sockets on the top panel and measuring points on the rear panel. It takes only a cheap AVO meter to do it.

The output transformer

A high-quality output transformer is the heart of the tube amplifier. A poor output transformer fitted in a well designed amplifier will spoil its performance.
Needless to say that the design and optimization of an output transformer takes high skill and know-how because performance requirements are complex and high. The transformer must deliver adequate and constant power without core-saturation. It should provide wide frequency bandwidth at a minimum distortion. Moreover, it should provide a constant outstanding performance to retain the open, spacious qualities of recorded music. The sound quality of ASV transformers is exceptional: low distortion and an extremely wide frequency and dynamic range.
The present ASV AOT-40 transformer has a double C core and has been carefully wound, has no internal solder joints, is impregnated and encapsulated in a metal housing.

Performances

The final results are excellent and also confirmed by measurements. In the basic model of the ASV TA-80 the output pentodes EL 34 work in the so-called ultralinear push-pull configuration without negative overall feedback. This provides a clean, airy performance and is capable of delivering truly classic and warm tube sound. It re-creates a glory of tube sound, it focuses well, has very good depth and transparency with fine image width. The amplifier can also be supplied in push-pull triode configuration. Of course the output power in this case is lower, but the sound is richer and sweeter.
The ASV TA-80 tube amp has been manufactured in the classical manner of manual soldering of all components and joints. All elements and connections are entirely hard-wired on the circuit assembly. No printed circuits are used in this amplifier.
We believe that only such a manner of manufacture can together with a great degree of skill, know-how and enthusiasm provide the result: warm natural sound without disturbing, sharp transients. An outstanding quality of reproduction from such an amplifier can be enjoyed for hours and hours.