Hi,
I was wondering if it would be possible to “hijack” the main volume control (maybe define a new mixer control) to send volume up / down signals to the amp using GPIO pins on the Pi. I’m pretty sure the software volume control minimally impacts sound quality, but I’d like to try this for the hack value 
Also would it be possible to send a signal to the amp to turn it on automatically when Volumio web gui is started?
I guess I could start by creating a plug in that displays a button to turn on the amp, and it’s own volume control, but it would be nicer if I could handle the power on and volume up / down without creating additional UI elements.
I found some python code on github that controls my amp (Cambridge CXA80) via GPIO and RCA cable input to the amp’s control port, so I have that side covered.
Thanks!