>>128339446
yeah its all super tiny but you can think of a mono groove as a physical representation of the waveform. the stylus tracks it making the armature waggle side to side, coils and magnets at the other end of the armature turn that movement into a tiny electrical current, amplitude and frequency being dictated by the shape of the groove, then its just a matter of doing a bit of EQ and amplifying it. but yeah it is super cool that you can get good fidelity out of a purely electro-mechanical system.
stereo though involves flipping everything over 45 degrees and having the stylus go up and down as well as left to right, having 2 separate sets of coils and magnets and pulling 2 separate channels of information out of that