At an AES conference in 1973, Dr. Matti Otala presented a paper describing a distortion that he termed Transient Intermodulation (TIM). Attending this conference was Svein Erik Børja, a Norwegian record and broadcasting producer and a great audio enthusiast.
The seminar held by Dr. Otala on TIM provided Svein Erik with an explanation of the audible imperfections he had experienced from audio amplifiers. Svein Erik Børja brought the AES papers to Electrocompaniet, and asked if they could make an amplifier based on Dr. Otala’s and Dr. Jan Lohstroh’s theory. A few prototype amplifiers were made and the sound, compared to other transistor amplifiers, was encouraging.
But Svein Erik Børja, being the perfectionist he was, felt that this amplifier design approach had a greater potential. At that time they did not know too much about high-end audio designs. This gave an element of neutrality to their research, which they believe contributed to the amplifier’s success. They consider their audio designers from that time to have been the first in what may be called the new “TIM-free” school.
The next 3 years went to further research and design improvement. During this time they had to develop a new “language” to translate what they were hearing, into practical design parameters distortion, frequency response etc. A new mathematical equation was developed to better describe the AC (music) characteristics of the transistor, rather than the normal DC characteristics.
The result of this work culminated in the launch of their first 2 x 25W unit, “The 2 Channel Audio Power Amplifier”. The final approval came in 1976 when the American “bible”, The Audio Critic magazine, tested the amplifier and wrote:
Audio freaks – eat your hearts out. This is the world’s best sounding amplifier.