I am having problems with powering of external USB devices.
1. My externally powered USB hub tries to feed power back to the RPi when normal power is removed from the RPI power connector but not the hub. This does not seem to be a good idea. Do all brands of hub do this?
2. My audio device does not like working through a hub but does work when directly connected to the RPi but draws too much current and has no external power connector.
I thought of getting around these problems by constructing a male to female USB adapter with the 5V wire disconnected at the RPi end. In this way no power could be taken from or fed to the RPi. To enable powering the external device the +5V wire from the external device USB connector could then be fed direct from my 5V power supply. RF engineers might call this a bias tee. Is this a technically acceptable move?