Hi Everyone,
I bought a linear power supply with R-core transformer and did some soldering. I compared the sound quality for different powering source and location. It's just for reference on my own, don't ask me what the difference is. I can only say I can feel. I'm not that sensitive in sound quality like others. I score it from 5 (best) to 1 (worst) for sound quality as follows
GPIO on Rpi by linear power supply(5)>P3 on hifiberry digi+ by linear power(4)>mini USB port on Rpi by mobile battery (3)>mini USB port on Rpi by wall-wart charger(1).
PS: How to attach images? Thanks for teaching.
