Transistor Stuff (yech!)
In the history of audio, there are many interesting little "eddie currents" that make up the whole. The first is the megaphone. But even before that there is the invention of music itself. In order to keep things simple here, I will not delve into that and reserve that as a subject for the music page. However, the desire to make the music available to a vast audience likely caused the need for writing the music down, and for manufacturing musical instruments and the teaching of them etc.
But many individuals were incapable of learning how to play an instrument, or did not desire to do so. So they were compelled to make times for the enjoyment of music at concerts. It was likely started by the joining of family members, who would either for religious reason (likely the first and foremost reason for music) or family gatherings (usually a tribe consisted of purely family members), after a meal would sit around and exchange pleasantries, which likely included music. I know my family does to this day.
It wasn't until the 19th century that the possiibility of storing the actual sounds became the topic for scientific discussion and invention. Men such as Maxwell, and Hertz and Gauss and Faraday and Fourier were talking of the magnetic and acoustic fluctuations as waves, and that sound was made up of many waves. It took men like Tesla and Marconi and others to actually make use of the electromagnetic fluctuations for the transmission of information. Tesla had pictured and theorized that it would be possible to transmit not only sound but image through thin air. The early patents and implementation of the FAX proved that images can be sent through wires. However, it took Edison to make the phonograph to show that information can be stored, and played back later.
Thus was the beginning of high fidelity audio. It is interesting and amusing to see the ads for the "improved" versions of Edison's original phonograph cylinder. Ads touting the "realism of reproduction" of recorded music. This from a bakelite disc of undulating grooves, where a literal needle would ride in as the disk rotated by a tensioned spring at a rate of 78 RPM, the vibrations being amplified by the throat of a horn, like the megaphone.
As an interesting side note, the phonograph seems to have gone out the same way as it came: by direct to disc recording. There were no recording studios or tape recording instruments at the time, so master disks had to be recorded live. In the early to mid eighties, direct-metal mastering became the last ditch effort of recording companies to save the LP from doom as CD's became more popular. I have a couple of those direct-metal mastering LP's. They sound incredible. If it weren't for those darned pops, clicks that eventually came up and other imperfections due to non-linear groove tracking (except for the in-line groove tracking turntables) the direct-metal mastering would have been the saviour of the LP. In fact, there was a test done in the late eighties where a symphony was recorded both digitally and analoguely with direct metal mastering. Many golden ears subjects could not hear a difference in the sound quality. They both sounded equally good.
In any event, when the triode was invented by DeForest, many new devices were made to amplify small signals. First for radio, then for the voice. The first microphones were made out of carbon. So if memory serves, I believe that the first cartridges were merely carbon microphones placed in lieu of the meechanical diaphragms to pick up the audible vibrations of the needle, and then passed through a two or thee tube amplifier, only to go into another carbon element connected to a horn. Hence the first "hi-fi" system was created.
Eventually dynamic elements were invented for both the microphone and speakers, higher quality and power tubes were made and circuits and linearity techniques (NFB et al) invented. High fidelity audio was made. It did not become a hobby until the early fifties. Likely it was due to the mass production of home entertainment equipment. Prices of tubes came down from the outragious $5 (about 1/5th the salary for a week back then) to about 25 cents apiece (my father was a technician in the fifties while going to school. He told me that they were that cheap!). So most people could afford to get into building their own hi-fi.
The hobby did not really reach its peak until the sixties. But by then transistor amplifiers began to replace the "bulky, unreliable, inefficient" tube amplifiers. Anybody who really appreciated music did not like it. Many reasons for this were the claims that they just weren't used to the high frequency content that was missing from tube audio, transistors were noisy and lacked bass, tubes manufactured bass, and many other things which eventually proved to be a matter for psychoacoustics and harmonic content. But this will be discussed in the paper The Nature of Sound. One could also see what an earlier researcher compiled, Russel O. Hamm.