There was a time before digital audio came onto the field where we had magnetic symmetry.
Our sources—both vinyl and tape—were magnetically coupled, while our playback too was driven by the power of magnetic motors in our speakers.
Magnets in and magnets out.
No physical connections between ins and outs.
All coupled through magnetism.
Today, of course, we've managed to eliminate the magnetic isolation (many would call distortion) of our sources.
All that is left is our magnetically coupled motors that move the air so we can hear sound (and even electrostats eliminated that).
On the source side, one could have argued that bits are magnetically stored first on floppy discs and later on hard drives but, alas, it's almost all solid-state now.
I am pretty certain none of this actually matters. Not at the level of technical excellence most of us have arrived at.
I did find the idea of how everything we listened to was magnetically coupled intriguing (if not totally nerdy).
