I use amp+ with my pi and I have a 12v 6a power supply connected to the amp+.
The pi - as written there https://www.hifiberry.com/build/documentation/connecting-power-supply-and-speakers-to-the-hifiberry-amp/ has no own power supply.
The pi still has some usb ports that can be used. Are there any limitations for additional appliances / decives connected via usb as screens, hard discs, ... that also needs electricity?
Thanks in advance