Not sure if this would be of interest to anyone - it is a board to allow use of Industrial Sensors that output 0-30V signals with 5V or 3.3V microcontrollers: https://www.crowdsupply.com/newsteder/pl1-0-universal-sensor-interface
I am not associated with this project - I just noticed it in a newsletter I get and thought I'd pass it along. Also, I am not sure if the RF-based isolation (instead of opto-isolators) would be an issue for audio applications or not, so if someone more knowledgeable wanted to weigh in...
Regards,
John