The era of transistor amplifiers began at the end of the 1960s, when only a handful of small manufacturers, such as Dipl.-Ing. Th. Reussenzehn about the advantages and the future of tube technology in the audio sector, but the old tube technology still had its gaps and weak points. So I got down to work in 1968 and, in years of detailed work, got the most out of the circuit and mechanical principles. It turned out that only an effective, very compact circuit principle with a high proportion of free point-to-point wiring and oversized high-quality components could be superior to transistor technology. Old weak points, such as the linearity of the output transformer, especially in the transparency and in the bass range, had to be further developed. Modern tube amplifiers, such as the Reussenzehn devices, slowly but surely led into a completely new class of audio technology. Despite the quantitative superiority of transistor amplifiers that were much cheaper to produce, there were more and more tube lovers, including musicians like me, who were convinced and enthusiastic about the sound advantage of the Reussenzehn devices. In the beginning, the audio specialist press could not escape the fashionable trend towards increasingly cheaper mass transistor devices. Until the 1990s, it largely ignored the outstanding sound properties of tube technology. But the call of a demanding audience for quality could no longer be ignored. A real revival of tube technology began, also in the press. It smelled of easy business and easy money: new, unknown manufacturers, labels and ephemera sprang up like mushrooms. Laboriously acquired knowledge about sound, circuit technology and safety were thrown overboard. Some amateur concepts were even life-threatening for the user. Others operated according to the motto "the more expensive the better (... for the manufacturer)" and hid cheap Far East output transformers and other junk goods behind shiny chrome facades. The tube standard is only fundamentally mastered by a few. In the absence of well-founded specialist knowledge, problems in circuit design are often concealed with absurd auxiliary circuits. This creates mishmash devices made of tube, transistor and microprocessor technology, in which the tube is only used as a sales argument and light bulb. Many of these so-called tube amplifiers, knitted with a hot needle, are even inferior to a transistor amp of reasonable quality, not to mention the durability and stability. There are many reasons to beware of rascals, smugglers and farmer catchers. Conclusion: Only an ingeniously simple concept with high-quality components that get the most out of it will meet customer expectations. My experience from 35 years teaches: The tube technology requires neither auxiliary nor special circuits; unnecessarily many phase rotations would only reduce the quality. The breathing tube circuit, which is not attenuated in its high resistance, has been inspiring since 1968. With sensible concepts and strict principles, the Reussenzehn company guarantees great robustness and durability of its devices, as well as extreme value retention.