I've seen some questions similar to this, but none exactly like mine.
I use Volumio, RPi3, Hifiberry AMP+ and a battery eliminator (12V DC 5A).
Is it a recommendation to power off the Hifiberry AMP+ system when not using it, or is it advisable to never turn it off, letting it stay idle? Would the electricity cost be significant?
(As a side note, I use Kodi on a RPi2 and that consumes about $3 of electricity each year, always turned on.)