Hi-fi philosophy from a European point of view

The paper deals with popularizing hi-fi listening facilities in Europe which, due to a difference in broadcasting practice is easier over there than in the United States. These differences are analyzed and the conclusion of the writer is that a large contingent of hi-fi listeners in Europe could be created by improving the reproduction quality of fm radio sets without increasing the cost too much. As a distortion limit for this purpose a figure of 1 per cent is chosen, while the output power should be near the 10-watt figure. To realize these properties a special circuit has been designed viz., a single-ended push-pull output stage with combined positive and negative feedback. A loudspeaker with a voice coil impedance of 800 ohms is being used, making an output transformer superfluous. This direct coupling is one of the necessities to get a cheap but very good setup. Further, the so-called 3D system and means for getting rid of the keyhole effect are discussed.