Already did quite a few times, even if I don't have the data on hands (nor the WiiM Pro Plus itself, for what matters). The difference between the stock PSU, a powerbank/battery or whatever phone charger is completely negligeable and absolutely nothing to write home about, IMHO. How it has been visible? In my case, a bit of hum @50Hz (domestic), mainly, or @100Hz. Kept way below thresholds of hearing. At the end of the day, it only affected final SINAD number by 0.1 to 0.3dB (depending on runs).Someone should measure the stock power supply for the WiiM pro to se how much noise it puts out on the main grid ( If any ).
That will be all for me. Honestly, I'm done with this product.The WiiM Pro Plus is indeed an excellent streamer, regarding both features and objective performance, especially considering its price point. It sure wasn't textbook perfect, but WiiM did their homework correctly by fixing most issues @onlyoneme and I observed before the final commercialisation. Case closed, as far as I'm concerned.
Cheers.