Simple mod for RaspberryPi and HifiBerry DAC / Digi - plus various others ;-)
Some people may have seen this mod elsewhere but it is something I only spotted this morning.
It involves feeding 5 volts into the HifiBerry DAC or Digi which then powers the RPi - so DO NOT CONNECT USING THE MINI USB SOCKET.
The reason for doing this is to bypass the switching circuits on the RPi, this means that the 5 volts should come from a linear power supply not another switcher.
The mod is completely reversable, which is nice!
I have done this on RPi 2B and a HifiBerry DIGI+ (and I will try it on the DAC+ Pro), I am not sure about earlier models having this facility.
On the HifiBerry DAC+ and DIGI+ there is a connector marked P3 which sometimes is also marked [- 5V +]. The first thing to do is to solder into this position a two pronged connector (vertical or horizontal) with 2.5mm spacing. Now a means of connecting an external 5 volt supply is needed.
I decided to use a connector cut into the side of the case which I soldered to the pins, needless to say if you get the connections round the wrong IT IS GOODBYE TO THE DAC/DIGI AND THE RPI - so please be careful. I then connected my John Swenson design 5volt psu, the result - impressed, very impressed.
I will take some photos of the RPi and DIGI boards tomorrow and post them. It is Saturday evening and it is time to relax, read a book and listen to some music.