Erno Borbely arrived in Norway in 1957 after fleeing his native Hungary due to Cold War events in that part of Europe. He earned his masters at the Institute of Technology, University of Trondheim, in 1960; his thesis was the design of an arithmetic unit for a CPU, with discrete Philips germanium transistors clocked at a phenomenal 250kHz! After designing studio equipment for the Norwegian Broadcasting Corporation, David Hafler persuaded him to come to the USA and design amplifiers for Dynaco. He designed the Dynaco FM5 tuner and received a patent for one of its circuits. After completing the Dynaco 400 power amp, Erno left Dynaco and started to work for Motorola in Switzerland. Being an Applications Engineer he had access to the latest jFET devices and I started to use them in most of his designs. In 1978 David Hafler started the David Hafler Company and once again brought Erno to the USA at his Director of Engineering. Erno designed the DH101 preamp and the DH200 power amp, the first power amp with MOSFET output stage in the US. In 1984, back in Europe, Erno and his wife Irene started Borbely Audio selling high-performance audio kits and writing numerous articles for The Audio Amateur (the precursor to the current audio Xpress). Having retired some years ago, Erno enjoys his life in southern Germany but still occasionally designs audio equipment. (see also Erno’s interview by the editor at http://www.linearaudio.nl ).
Although Erno Borbely must have designed a dozen or more phono preamps, he never tires of trying new avenues of circuit design to find that elusive holy grail. In this article he teamed up with...