While the asphalt was glowing outside due to the summer heat, electron tubes were glowing in mid-July on the premises of the Schlierbach elementary school. The retired teacher Josef Haindorfer and other fans of glow bulbs presented their tube amplifiers to a wide audience.
Schlierbach. In 1969, Jimi Hendrix made his fenders yelp with Marshall tube amps at the legendary Woodstock Festival, and the hippies took buses to Kabul. At Josef Haindorfer’s, vinyls with music by the Beatles, Pink Floyd, Doors and Led Zeppelin turned on his mono portable turntable. “It wasn’t really booming on my speakers, but the music was cool,” remembers the man from Schlierbach. The music lover found an old tube radio in the attic at home and removed the loudspeaker with the green paper cone, a real Greencone. “I was fascinated by the sound of this horn”, says Haindorfer, “I was mocked by my roommate at the HTL Vöcklabruck, but I didn’t care”. He had been infected with tube fever since those days.
tube fever
Is it the mysterious glow of the cathodes or is it nostalgia for the good old days? Tubes have an irresistible retro charm, like vintage cars, while others radiate a science fiction atmosphere. “The whole procedure makes you feverish”, describes the tube lover the symptoms, “the tinkering and the peculiarities of this technology make the fascination”. Most of the time it doesn’t fit right away when building amplifiers, something hisses and hums. Then, in the middle of the night, he often has an inspiration as to how it might work.
Long live the tube amp!
He has been collecting old electron tubes for twenty years, “the oldest dates back to 1928”. At the beginning of the 20th century, it was possible to put glass flasks under a vacuum for the first time. “Otherwise the wire inside would burn up,” says Josef Haindorfer, explaining this revolution, which made technologies such as telephony or cinema screenings possible in the first place. “Then they were supplanted by transistors,” says the tube lover, “however, many top-class high-end amplifiers are still built using tube technology.” And since he had the necessary tubes, in his search for the perfect sound he decided to build his own tube amplifier. “Since I was initially not very experienced in electronics, I asked a friend to help me with the necessary construction and soldering work”. Building the mechanical components such as the chassis and reading circuit diagrams gave the electronics hobbyist a lot of thought. After numerous calls to the hi-fi freak friend and training in soldering, wire selection and socket assignment, the time had finally come: the amplifier ran. He has now built ten, which he is constantly improving. “A certain know-how and, above all, manual skills should be available. But once you’ve made it, you can look forward to the finest music,” enthuses the electronics hobbyist.
Look deeper into the tube
Haindorfer gives a glimpse into the inner workings of a “hand-wired” tube amplifier: glass bulbs of all kinds, colorful cables, resistors and powerful capacitors. “The input transformer provides the heating voltage of the tubes,” the hi-fi enthusiast demonstrates his knowledge of tubes. The rectifier tube, which converts the AC voltage from the power grid into DC voltage, is located in the middle in front of the transformer. “Every tube sounds different,” says Josef Haindorfer, describing the secret of the different sounds. Combined with boxes, turntables or CD players, these music systems ensure a very special sound experience. Digital enthusiasts have no idea how much sound and warmth they are losing. “In my listening sessions, some found that they heard details that they had never heard before.”
Haindorfer moderates the program “Röhrenfieber” every Monday on Radio B138 and in order to better network all those who pursue this fascinating hobby, the Schlierbacher set up the website roehrenfieber.com.
