The concept of magnetic recording to a moving tape was invented by the German-Austrian engineer Fritz Pfleumer and received a patent back in 1928. The basic idea was to translate the voltage from the audio signal straight into magnetic energy, which then induces magnetic particles on a tape (moving along the inductor at constant speed). These particles manage to store the audio information. The whole process goes the other way around for recall.
Although this was a revolution for both broadcast and recording industry, there were many technical challenges to be addressed before its success during the middle of the last century. Some physical limitations can’t be ignored even today. While electromechanical problems, such as wow and flutter or noise and crosstalk have been improved over the years, the electromagnetic phenomena, such as magnetic permeability, hysteresis or the Barkhausen effect still must be addressed.
Additionally, since a tape can’t store unlimited amounts of energy, a natural saturation occurs when signal levels are driven too hot. Normally this has to be avoided, as it can lead to heavy distortion. Nonetheless, this type of saturation was (and still is) frequently used as an artistic audio effect.
The new digital recording technologies that emerged towards the end of the 20th century overcame these shortcomings of analog recording and made tape obsolete – if regarded from a purely technical and workflow-related point of view. Yet some of the positive effects of high quality tape and recorders are still highly appreciated in today’s audio production, and there is quite a lot of myth and buzz going on about it’s “magical” qualities.
In fact, what makes a good tape and recorder still attractive in the digital age is its overall ability to balance audio dynamics while adding harmonic content and gently limiting the peaks. If properly applied, this can result in a very pleasant sonic experience. However, it still comes at the expense of some of the mentioned artifacts and side effects, not to mention the time and cost of operation and maintenance.