01-17-2021, 11:33 AM
I'm no expert when it comes to the various types of the headphones socket, but, based on my earlier limited research on the subject, I can confirm that many types exist, including a strange variant (example C in the linked image) that has a pair of built-in isolated switches, intended for powering up a device upon plugging in the headphones. Thus, selecting and sourcing a perfectly suitable, "shared-nothing" headphones socket for the PineBook Pro should be rather easy.
Quite frankly, before diving into the PineBook Pro schematics and the whole ALSA thing, I expected the PineBook Pro's heaphones socket to do the switching itself, with no additional software support. (Despite being a Linux user for over two decades, I've never had interest to research the way Linux sound subsystem actually works.) Now, I can confidently say that ALSA is well architected, and that having the headphones socket doing the actual switching would be against the general level of post-2000 audio hardware and against the support for the advanced audio features made available by ALSA.
Things inevitably change, and the improvements should be embraced while remembering the origins. However, improvements are sometimes not actually improvements, but luckily, audio hardware actually got better over time.
Quite frankly, before diving into the PineBook Pro schematics and the whole ALSA thing, I expected the PineBook Pro's heaphones socket to do the switching itself, with no additional software support. (Despite being a Linux user for over two decades, I've never had interest to research the way Linux sound subsystem actually works.) Now, I can confidently say that ALSA is well architected, and that having the headphones socket doing the actual switching would be against the general level of post-2000 audio hardware and against the support for the advanced audio features made available by ALSA.
Things inevitably change, and the improvements should be embraced while remembering the origins. However, improvements are sometimes not actually improvements, but luckily, audio hardware actually got better over time.