Linear power supply for Pi3 and Hifiberry Digi+

[tboooe]

I wasn't sure where to post this so I hope this is the appropriate forum.

I want to run both my Pi3 and Hifiberry Digi+ off a linear supply to see if it makes any difference in sound. My intention is to try powering both the Pi3 and Digi+ off a single power supply and then try powering the Pi3 and Digi+ with separate power supplies. I just want to doublecheck with this forum before fry something.

Powering both Pi3 and Digi+ from same linear power supply:
All I need to do is supply 5V to P3 on the Digi+ board from power supply #1? This would supply power to both the Pi3 and Digi+. As I understand it, the Digi+ also needs 3.3V so it will still be able to get this from the Pi3 converting the 5V I am feeding it through the Digi+?

Powering Pi3 and Digi+ from separate power supplies:
I understand that the Digi+ needs both 5V and 3.3V. I need to still supply 5V to P3 on the Digi+ board. Do I then supply 3.3V to pins 1 and 17 of the GPIO on the Digi+? What ground pin should I use? I also read that the Digi+ only needs 5V if I am using Toslink. If I am using the coaxial output I only need to supply 3.3v?

I then need to cut pins 1, 2, 4, and 17 from the GPIO header on the Pi3 so that I am not providing any power to the Digi+ board from the Pi3. To power the Pi3, I just need to plug my power supply #2 into the micro usb port.

Thank you in advance for the help.

[pksato]

Hi,
Digi+ is a S/PDIF audio output "hat".
And have option with full galvanic isolation of the electrical coax output.
And a optical output.

Since it is a pure digital output, noise from power supply or other noise source not affect audio quality.