With the end of World War II, design solutions and technologies began to be put into common use, the result of which was the dynamic development of audio technology. Then, within a dozen or so years, the stage of developing and adopting standards for high-fidelity stereo equipment was completed. The largest consumer market in the second half of the twentieth century was the United States, and this is where devices known as HiFi (from the words high fidelity - high fidelity) began to be mass-produced and sold. Standards defined by this concept were included in the German study / standard DIN45500 in 1973 (they were also used in other countries). In the 1960s, these standards were unknown, but a significant portion of tube equipment from the receiver segment complied with these standards with a significant excess. However, in order to start listening to music with high fidelity, a few new technologies had to appear - inventions:

• the technique of recording on a tape with the use of high-frequency background current - a technology developed before WWII in Germany by AEG - made it possible to first make high-quality recordings, then be introduced to radio studios and finally reach individual users,

• broadcasting with FM modulation in the ultra-short wave band (FM) - the technology developed before WWII in the USA allowed for the propagation of broadcasts with a wide bandwidth, and thus better dynamics and greater resistance to interference than on AM waves,

• introduction at the end of the 1950s of the micro-groove recording standard on LP and single vinyl records.

    In addition to the above-mentioned, other innovations also played an important role, such as the development in the 1930s for the needs of film technology and cinema design of amplifiers with a wide frequency range, and the development of loudspeakers and loudspeakers with a corresponding band.

    However, there would be no HiFi without stereo which was, basically, transmitting the audio signal through two channels. Its history dates back to the 1920s, but it was not until the mid-1950s and early 1960s that commonly used technologies appeared, such as:

• stereo recording / recording in studios,

• development of a stereo pressing system for vinyl records,

• development of a stereo transmission system on ultra-short waves (FM), named Zenith-General-Electric - the current name is MPX

    The terms "hiend, topend", etc., used today, do not have any scientific basis (like the term HiFi itself). Their use is only a manifestation of marketing activity. It can be assumed that the production from the 1960s could be covered with stickers with the word "hajend" today and it would be justified by their parameters.