I’d like to see a 5V pio trigger for the PI to turn off and on the Power Amp.
The relays are commonly available. The Volumio software needs to be aware
no audio output for the last X-minutes (user selectable) at which point, it
triggers the 0VDC on the a PIO pin to turn off the amp. If Volumio start playing audio,
the trigger should put 5VDC on the PIO pin to turn on the amp.